JP2007064731A - Device and method for measuring porous material characteristics - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for measuring characteristics for a porous material provided with constitution capable of obtaining easily various characteristics of the porous material. <P>SOLUTION: The device 1 includes a storage part 3 for storing the porous material 2, a pressure detecting part 4 for detecting internal pressure of the storage part 3, a gas storage part 5 for storing prescribed gas introduced into the storage part 3, and a gas exhaust part 6 for exhausting the gas from the storage part 3. In this characteristic measuring instrument 1, an introduction volume of the gas into the storage part 3 and a discharge volume of the gas from the storage part 3 are controlled based on detection pressure detected by the pressure detecting part 4 to maintain the internal pressure in the storage part 3 at a constant level. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a porous material property measuring apparatus and a porous material property measuring method.

  A large amount of minute space is formed inside a porous material such as zeolite or activated carbon. Since this minute space adsorbs various gases, gas storage, separation, and reaction using the minute space have attracted attention. In recent years, development of new porous materials for storing hydrogen, methane, etc., removing environmentally hazardous materials, and the like has been actively conducted.

  The amount of gas taken into the minute space, that is, the amount of gas adsorbed is one of the important characteristics of the porous material. Therefore, when a new porous material is synthesized, the amount of gas adsorption is always measured. As a method for measuring the amount of adsorption, a gravimetric method in which the amount of adsorption is directly measured by measuring the weight increase of the porous material from the amount of expansion of an elastic body such as a coil spring, or a gas sealed in a sealed container. A capacity method is known in which the amount of adsorption is indirectly measured using a gas equation of state by measuring a change in pressure of the gas (see, for example, Patent Documents 1 to 3).

  In the weight method and the volume method, the pressure dependency of the adsorption amount is measured in a state in which the internal temperature of the storage container storing the porous substance is maintained at a predetermined temperature. That is, the amount of adsorption of the porous material when the internal pressure of the storage container is changed at a constant temperature is measured. Based on the measurement result, the amount of adsorption of the porous material at a constant temperature and the internal pressure of the storage container An adsorption isotherm showing the relationship is created. The measurement of the pressure dependency of the adsorption amount is performed while changing the internal temperature of the storage container as required, and an adsorption isotherm corresponding to each temperature is created. And the amount of adsorption | suction and the analysis of the other characteristic of a porous substance are performed using the produced adsorption isotherm.

JP 2005-69848 A JP 2002-277369 A JP 2000-292246 A

  As a characteristic of the porous material, there is an important characteristic other than the above-described adsorption amount. For example, the heat of adsorption, which is an index of the binding force between the adsorbed gas and the porous material, is an important characteristic of the porous material. However, it is the adsorption isotherm that can be obtained directly from the measurement results by the gravimetric method or the volumetric method. And in order to obtain characteristics other than the adsorption amount, a complicated analysis using the created adsorption isotherm is required.

  Accordingly, an object of the present invention is to provide a porous substance characteristic measuring apparatus and a porous substance characteristic measuring method having a configuration capable of easily obtaining various characteristics of a porous substance.

  In order to solve the above-described problems, the device for measuring characteristics of a porous material according to the present invention includes a storage unit having a constant volume and storing a porous material, and a gas storage storing a predetermined gas introduced into the storage unit. And a gas exhaust unit that exhausts gas from the storage unit, and has a pressure detection unit that detects the internal pressure of the storage unit, based on the detected pressure detected by the pressure detection unit. A feedback control unit is provided that controls at least one of the amount of gas introduced and the amount of gas discharged from the storage unit to maintain the internal pressure of the storage unit constant.

  The device for measuring characteristics of a porous material according to the present invention controls the at least one of the gas introduction amount and the gas discharge amount based on the detected pressure detected by the pressure detection unit to keep the internal pressure of the storage unit constant. A feedback control unit for maintaining Therefore, it is possible to change the temperature, electric field, or magnetic field inside the storage unit while introducing gas into the storage unit while keeping the internal pressure of the storage unit in which the porous material is stored constant. Moreover, it is possible to irradiate the porous material with light while changing the strength while introducing the gas into the storage portion while keeping the internal pressure of the storage portion constant. Therefore, various characteristics of the porous material under a constant pressure can be easily measured. For example, it is possible to measure the relationship between the temperature and the amount of adsorption of a porous material under a constant pressure, and it is possible to directly create an adsorption isobaric line based on the measurement result.

  In the present invention, the feedback control unit is disposed between the storage unit and the gas storage unit, and between the storage unit and the gas exhaust unit, an introduction amount adjustment unit that adjusts the amount of gas introduced into the storage unit. A discharge amount adjusting unit that adjusts the discharge amount of gas from the storage unit, and maintains the internal pressure of the storage unit at a predetermined set value based on the detected pressure detected by the pressure detection unit. It is preferable to adjust the flow rate of at least one of the introduction amount adjustment unit and the discharge amount adjustment unit. If comprised in this way, the amount of introduction | transduction and discharge | emission amount of gas can be adjusted easily by the introduction amount adjustment part and the discharge amount adjustment part.

  In the present invention, it is preferable to introduce gas into the storage portion even after the internal pressure of the storage portion reaches an equilibrium state at a predetermined set value. If comprised in this way, the characteristic of the more stable porous substance can be measured.

  In the present invention, the characteristic measurement device for a porous substance includes an introduction amount detection unit that detects the amount of gas introduced into the storage unit, and a discharge amount detection unit that detects the discharge amount of gas from the storage unit. It is preferable to measure the amount of gas adsorbed to the porous material from the difference between the amount of gas introduced detected by the amount detection unit and the amount of gas discharge detected by the discharge amount detection unit. If comprised in this way, the adsorption amount of the gas to a porous substance can be directly measured by simple structure of detecting the introduction amount and discharge amount of gas.

  In the present invention, the characteristic measurement device for a porous material includes a set pressure output unit that outputs a set pressure signal corresponding to a set value of the internal pressure of the storage unit, and a detection pressure signal and a set pressure signal that are output from the pressure detection unit. And a differential amplifier circuit that amplifies and outputs the difference between the set pressure signal and the detected pressure signal. Based on the output from the differential amplifier circuit, the amount of gas introduced and discharged It is preferable to perform at least one of the adjustments. If comprised in this way, the internal pressure of a storage part can be changed with the resolution of the setting pressure signal output from a setting pressure output part. Therefore, for example, the amount of adsorption of the porous material can be measured while changing the internal pressure of the storage unit in multiple steps and in small increments while keeping the internal temperature of the storage unit constant. That is, the adsorption amount of the porous material when the internal pressure of the storage unit is changed under a constant temperature can be measured in a state close to continuous measurement, and a more accurate adsorption isotherm can be created. . As a result, the accuracy of the characteristics (for example, pore diameter distribution) of the porous material obtained using the slope (differential value) of the adsorption isotherm can be dramatically improved.

  In the present invention, it is preferable that the amount of gas introduced by the introduction amount adjusting unit is substantially constant, and the amount of gas discharged is adjusted based on the detected pressure detected by the pressure detecting unit. With this configuration, it is only necessary to adjust the discharge amount, so that the gas flow rate can be easily adjusted. Moreover, liquefaction of the gas introduced into the storage unit can be prevented. That is, when adjusting the introduction amount, for example, it is necessary to apply a certain high pressure to the inlet side of the introduction amount adjustment unit so that the flow rate can be adjusted. Therefore, depending on the type of gas and the ambient temperature, the gas introduced into the storage unit may be liquefied. On the other hand, for adjusting the discharge amount, for example, it is sufficient to apply a negative pressure to the outlet side of the discharge amount adjustment unit, so that liquefaction of the gas introduced into the storage unit can be prevented.

  In order to solve the above-described problems, the device for measuring characteristics of a porous material according to the present invention stores a storage portion in which a porous material is stored with a constant volume, and a predetermined gas introduced into the storage portion. A gas storage unit and a gas exhaust unit that exhausts gas from the storage unit, a weight detection unit that detects the weight of the porous material, and a storage unit based on the detected weight detected by the weight detection unit A feedback control unit that controls at least one of the amount of gas introduced into the gas and the amount of gas discharged from the storage unit to maintain a constant amount of gas adsorbed to the porous material. .

ここで、ｑ_ｓｔは等量吸着熱、Ｐは内部圧力、Ｔは内部温度、Ｒはガス定数である。このように、本発明では等量吸着熱を求めるため、式（１）右辺に含まれる内部圧力と内部温度との関係を直接に測定することができる。 The device for measuring characteristics of a porous material according to the present invention controls the amount of gas introduced into a porous material by controlling at least one of the amount of gas introduced and discharged based on the detected weight detected by the weight detector. A feedback control unit that maintains the adsorption amount constant is provided. Therefore, changing the internal pressure and temperature of the storage unit, or the internal electric field and magnetic field while introducing the gas into the storage unit while keeping the adsorption amount of the gas adsorbed by the porous substance constant. Can do. Therefore, various characteristics of the porous material when the adsorption amount is constant can be easily measured. For example, it is possible to measure the relationship between the internal pressure and the internal temperature of the storage unit when the adsorption amount is constant, and it is possible to directly create an adsorption equivalence line based on the measurement result. Further, by using this adsorption isotherm, for example, the equivalent heat of adsorption that is a characteristic of the porous material can be easily obtained from the following Clapeyron-Clauus equation (Equation (1)).
[Formula 1]

Here, q _st is the equivalent heat of adsorption, P is the internal pressure, T is the internal temperature, and R is the gas constant. As described above, in the present invention, since the equivalent heat of adsorption is obtained, the relationship between the internal pressure and the internal temperature included in the right side of the equation (1) can be directly measured.

  In the present invention, the feedback control unit is disposed between the storage unit and the gas storage unit, and between the storage unit and the gas exhaust unit, an introduction amount adjustment unit that adjusts the amount of gas introduced into the storage unit. A discharge amount adjusting unit that adjusts the amount of gas discharged from the storage unit, and sets the gas adsorption amount to the porous material to a predetermined set value based on the detected weight detected by the weight detection unit. It is preferable to adjust the flow rate of at least one of the introduction amount adjustment unit and the discharge amount adjustment unit so as to maintain. If comprised in this way, the amount of introduction | transduction and discharge | emission amount of gas can be adjusted easily by the introduction amount adjustment part and the discharge amount adjustment part.

  In the present invention, it is preferable that the gas is introduced into the storage portion even after the gas adsorption amount to the porous material reaches a predetermined set value and the inside of the storage portion is in an equilibrium state. If comprised in this way, the characteristic of the more stable porous substance can be measured.

  Furthermore, in order to solve the above-mentioned problems, the method for measuring the characteristics of the porous material according to the present invention includes a step of equilibrating the inside of the storage part in which the volume is constant and the porous material is stored, A step of applying a stimulus, and at least one of an introduction amount of gas into the storage portion and a discharge amount of gas from the storage portion based on a detection pressure detected by a pressure detection portion that detects an internal pressure of the storage portion A step of controlling and maintaining the internal pressure of the storage unit, and detecting the amount of adsorption of the porous substance gas by external stimulation based on the difference between the amount of gas introduced and the amount of gas discharged To do.

  In the method for measuring characteristics of a porous material according to the present invention, the amount of gas introduced into the storage unit and the amount of gas discharged from the storage unit are controlled based on the detected pressure detected by the pressure detection unit. The pressure is maintained, and the gas adsorption amount of the porous substance by the external stimulus is detected based on the difference between the gas introduction amount and the gas discharge amount. Therefore, the external pressure such as temperature, electric field or magnetic field inside the storage unit was changed while introducing gas into the storage unit while keeping the internal pressure of the storage unit storing the porous material constant. In this state, the adsorption amount of the porous substance gas can be detected. In addition, while keeping the internal pressure of the storage unit constant, while introducing gas into the storage unit, the porous material is irradiated with light as an external stimulus while changing the strength, and the porous material gas after irradiation is irradiated. The amount of adsorption can be detected. Therefore, various characteristics of the porous material under a constant pressure can be easily measured.

  Furthermore, in order to solve the above problems, the method for measuring the characteristics of a porous material according to the present invention includes a step of equilibrating the inside of a storage unit in which the volume is constant and the porous material is stored; At least one of the step of applying an external stimulus and the amount of gas introduced into the storage unit and the amount of gas discharged from the storage unit based on the detected weight detected by the weight detection unit that detects the weight of the porous substance And maintaining the amount of gas adsorbed to the porous material, and measuring the characteristics of the porous material that changes in response to an external stimulus.

  In the method for measuring characteristics of a porous material according to the present invention, the amount of gas introduced into the storage unit and the amount of gas discharged from the storage unit are controlled on the basis of the detected weight detected by the weight detection unit. The characteristics of porous materials that change in response to external stimuli are measured while maintaining the gas adsorption amount. For this reason, while maintaining the amount of gas adsorbed by the porous material constant, while introducing gas into the storage section, external stimuli such as the internal pressure and temperature of the storage section, or the internal electric and magnetic fields are applied. Can be changed. Therefore, various characteristics of the porous material when the adsorption amount is constant can be easily measured.

  As described above, according to the porous material property measuring apparatus and the porous material property measuring method of the present invention, various properties of the porous material can be easily obtained.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

[Embodiment 1]
(Configuration of device for measuring characteristics of porous materials)
FIG. 1 is a schematic diagram showing a schematic configuration of a porous material property measuring apparatus 1 according to a first embodiment of the present invention.

  The porous substance characteristic measuring apparatus 1 (hereinafter referred to as “characteristic measuring apparatus 1”) of this embodiment measures various characteristics (for example, gas adsorption characteristics) of the porous substance 2 such as zeolite and activated carbon. It is a device for doing. As shown in FIG. 1, the characteristic measuring apparatus 1 includes a storage unit 3 in which a porous material 2 having a constant volume is stored, a pressure detection unit 4 that detects an internal pressure of the storage unit 3, and a storage unit 3. The gas storage unit 5 in which a predetermined gas to be introduced is stored, the gas exhaust unit 6 that discharges gas from the storage unit 3, and the storage unit 3 and the gas storage unit 5 are disposed between the storage unit 3 and the storage unit 3. An introduction amount adjusting valve 7 serving as an introduction amount adjusting unit for adjusting the amount of gas introduced into the storage unit 3 is disposed between the storage unit 3 and the gas exhaust unit 6, and adjusts the gas discharge amount from the storage unit 3. A discharge amount adjusting valve 8 as a discharge amount adjusting unit is provided. Note that the pressure detection unit 4 and the discharge amount adjustment valve 8 constitute a part of a feedback control unit that maintains the internal pressure of the storage unit 3 constant based on the detected pressure detected by the pressure detection unit 4. Yes.

  Further, as shown in FIG. 1, the characteristic measuring device 1 has an introduction-side flow meter 9 as an introduction amount detection unit that detects the amount of gas introduced into the storage unit 3, and the amount of gas discharged from the storage unit 3. A discharge-side flow meter 10 as a discharge amount detection unit to be detected is provided. In this embodiment, the introduction-side flow meter 9 is disposed between the introduction amount adjusting valve 7 and the gas storage unit 5, and the discharge-side flow meter 10 is disposed between the discharge amount adjusting valve 8 and the gas exhaust unit 6. It is arranged. The introduction-side flow meter 9 may be disposed between the storage unit 3 and the introduction amount adjustment valve 7, and the discharge-side flow meter 10 is provided between the storage unit 3 and the discharge amount adjustment valve 8. It may be arranged.

  Further, as shown in FIG. 1, the characteristic measuring apparatus 1 includes a control unit 12 that controls the characteristic measuring apparatus 1 and a differential amplifier circuit 13 that outputs a control signal to the discharge amount adjusting valve 8. . The control unit 12 of this embodiment is a set pressure output unit that outputs a set pressure signal corresponding to the set value of the internal pressure of the storage unit 3. The control unit 12 and the differential amplifier circuit 13 constitute a feedback control unit together with the pressure detection unit 4 and the like.

  There are a wide variety of gases used in the characteristic measurement apparatus 1 of this embodiment, such as nitrogen, hydrogen, water vapor, carbon dioxide, methane, methanol, chloroform, or bromoform. In this characteristic measuring apparatus 1, using these gases, for example, various characteristics such as structural characteristics such as the pore size distribution of the porous substance 2, dehumidifying performance, impurity removing performance, or harmful substance removing performance are used. Is able to get.

  As shown in FIG. 1, the storage unit 3 includes a storage container 14 in which the porous substance 2 is stored, and an intermediate container disposed between the introduction amount adjustment valve 7, the discharge amount adjustment valve 8, and the storage container 14. 15, and a connection path 16 that connects the storage container 14 and the intermediate container 15.

  The storage container 14 is composed of a container that can take in and out the porous material 2 and can be sealed. The intermediate container 15 has a function as a buffer that prevents the internal pressure of the storage container 14 from rapidly changing due to the introduction or discharge of gas. The intermediate container 15 is a sealed container. The connection path 16 connects the storage container 14 and the intermediate container 15 so that gas can freely pass between the storage container 14 and the intermediate container 15. The connection path 16 is configured so that incoming and outgoing gas does not leak to the outside.

  The gas storage unit 5 is a sealed container in which the gas introduced into the storage unit 3 is stored. For example, the gas storage unit 5 is a gas cylinder. The gas storage unit 5 includes an on-off valve (not shown). In addition, a predetermined internal pressure is applied to the gas storage unit 5 as necessary.

The gas exhaust unit 6 includes a vacuum pump (not shown) that exhausts gas from the storage unit 3. This vacuum pump has a capability of making the internal pressure of the storage unit 3 vacuum (more specifically, for example, 10 ⁻⁶ Torr).

  Both the introduction amount adjusting valve 7 and the discharge amount adjusting valve 8 of this embodiment are piezo valves that adjust the flow rate of gas by using a piezo element. By using the piezo valve, the introduction amount adjusting valve 7 and the discharge amount adjusting valve 8 can finely adjust the gas flow rate, and can make this fine adjustment at high speed. The introduction amount adjustment valve 7 is connected to the intermediate container 15 and the introduction side flow meter 9 by a predetermined pipe, and the discharge amount adjustment valve 8 is connected to the intermediate container 15 and the discharge side flow meter 10 by a predetermined pipe. It is connected to the.

  In this embodiment, the introduction amount adjustment valve 7 is adjusted so as to introduce a constant flow rate of gas into the storage unit 3. The flow rate at the introduction amount adjusting valve 7 is set by the control unit 12, for example, and the flow rate adjustment at the introduction amount adjusting valve 7 is performed in response to a control signal from the control unit 12. The introduction amount adjusting valve 7 is not limited to a piezo valve, but may be any flow adjusting valve capable of deriving a constant flow rate of gas to the storage unit 3.

  Further, in this embodiment, the flow rate at the discharge amount adjusting valve 8 is adjusted based on the detected pressure inside the storage unit 3 detected by the pressure detection unit 4. More specifically, as described later, the differential amplifier circuit 13 includes a detection pressure signal corresponding to the detected pressure of the storage unit 3 detected by the pressure detection unit 4 and a set value of the internal pressure of the storage unit 3. And the differential amplifier circuit 13 is configured to amplify and output the difference between the set pressure signal and the detected pressure signal. The flow rate at the discharge amount adjusting valve 8 is adjusted based on the control signal output from the differential amplifier circuit 13 so that the internal pressure of the storage unit 3 approaches the set value. The discharge amount adjusting valve 8 is not limited to a piezo valve, and may be any flow rate adjusting valve that can automatically adjust the flow rate by an electric signal from the differential amplifier circuit 13.

  As described above, in this embodiment, the flow rate at the introduction amount adjustment valve 7 is adjusted to be constant, and the flow rate at the discharge amount adjustment valve 8 is adjusted based on the control signal output from the differential amplifier circuit 13. The gas flow rate is adjusted (controlled) so that the internal pressure of the storage unit 3 becomes a set value. That is, the introduction amount adjustment valve 7 and the discharge amount adjustment valve 8 are adjusted so that the internal pressure of the storage unit 3 is kept constant in the vicinity of the set value.

  Both the introduction-side flow meter 9 and the discharge-side flow meter 10 of this embodiment are flow rate counters that measure the flow velocity of the passing gas. As shown in FIG. 1, a signal corresponding to the gas flow velocity detected by the introduction-side flow meter 9 and the discharge-side flow meter 10 is input to the control unit 12. The amount of gas introduced into the storage unit 3 is calculated by the control unit 12 from the time history of the gas flow velocity detected by the introduction-side flow meter 9. Similarly, the amount of gas discharged from the storage unit 3 is calculated by the control unit 12 from the time history of the gas flow velocity detected by the discharge-side flow meter 10. Further, from the difference between the calculated gas introduction amount and the gas discharge amount, the control unit 12 calculates the gas adsorption amount to the porous material 2.

  As shown in FIG. 1, the introduction-side flow meter 9 is connected to the introduction amount adjusting valve 7 and the gas storage unit 5 by a predetermined pipe. The discharge-side flow meter 10 is connected to the discharge amount adjusting valve 8 and the gas exhaust unit 6 by a predetermined pipe.

  The pressure detector 4 is a high-precision pressure sensor, for example, and detects the internal pressure of the intermediate container 15. The pressure detection unit 4 outputs a detected pressure signal corresponding to the detected pressure of the storage unit 3 toward the differential amplifier circuit 13 as a digital signal.

  The control unit 12 is, for example, a personal computer. In the control unit 12, as described above, the flow rate at the introduction amount adjustment valve 7 is input, or the flow rate of the gas detected by the introduction side flow meter 9 or the discharge side flow meter 10 is transferred to the storage unit 3. The amount of gas introduced, the amount of gas discharged from the storage 3, the amount of gas adsorbed on the porous material 2, and the like are calculated. Further, a set value of the internal pressure of the storage unit 3 is input to the control unit 12, and the control unit 12 outputs a set pressure signal corresponding to this set value toward the differential amplifier circuit 13. It is supposed to be. More specifically, the control unit 12 outputs a set pressure signal converted into a digital signal by the AD converter. That is, the control unit 12 can output a set pressure signal that is changed in multiple steps and in small increments with the resolution (step value) of the AD converter.

  The differential amplifier circuit 13 is configured to receive the detected pressure signal output from the pressure detector 4 and the set pressure signal output from the controller 12. The differential amplifier circuit 13 is configured to output a signal obtained by amplifying the difference between the set pressure signal and the detected pressure signal toward the discharge amount adjusting valve 8 as a control signal.

(Method for measuring the characteristics of porous materials)
FIG. 2 is a graph showing an adsorption isotherm created based on the measurement result of the characteristic measurement apparatus 1 of FIG. FIG. 3 is a graph showing adsorption isobaric lines created based on the measurement results obtained by the characteristic measuring apparatus 1 of FIG.

  Various characteristics of the porous material 2 are measured using the characteristic measuring apparatus 1 configured as described above. Hereinafter, as a representative method for measuring the characteristics of the porous material 2, the gas of the porous material 2 when the internal pressure of the storage unit 3 is changed while the internal temperature of the storage unit 3 is kept constant. An example of a method for measuring the amount of adsorption of the porous material 2 and an example of a method for measuring the amount of adsorption of the gas of the porous material 2 when the internal temperature of the storage unit 3 is changed while the internal pressure of the storage unit 3 is kept constant Two characteristic measurement methods will be described.

  First, an example of a method for measuring the gas adsorption amount of the porous material 2 when the internal pressure of the storage unit 3 is changed while the internal temperature of the storage unit 3 is kept constant will be described.

  First, with the on-off valve (not shown) of the gas storage unit 5 closed, the internal temperature of the storage unit 3 (that is, the storage container 14, the intermediate container 15 and the connection path 16) is set to a constant temperature T1. More specifically, for example, the storage unit 3 is arranged in a thermostat not shown, and the internal temperature of the storage unit 3 is set to the temperature T1. Thereafter, the storage unit 3 is evacuated by a vacuum pump (not shown) provided in the gas exhaust unit 6.

  When the storage unit 3 is in a vacuum state, the on-off valve of the gas storage unit 5 is opened, and gas is introduced into the storage unit 3 until the inside of the storage unit 3 is in an equilibrium state at a pressure corresponding to the first set value. To do. At this time, the control unit 12 outputs a set pressure signal corresponding to the first set value of the internal pressure of the storage unit 3, and the pressure detection unit 4 corresponds to the detected detected pressure of the storage unit 3. The detected pressure signal is output. Further, a control signal obtained by amplifying the difference between the set pressure signal and the detected pressure signal is output from the differential amplifier circuit 13, and this control signal is input to the discharge amount adjusting valve 8. Then, based on the control signal, the internal pressure of the storage unit 3 is brought close to the first set value (that is, the internal pressure of the storage unit 3 is kept constant with the pressure corresponding to the first set value). As described above, the gas discharge amount at the discharge amount adjustment valve 8 is adjusted. At this time, the amount of gas introduced by the introduction amount adjusting valve 7 is constant. At this time, a vacuum pump provided in the gas exhaust unit 6 is driven as necessary.

  Eventually, the inside of the storage unit 3 becomes in an equilibrium state with the internal pressure corresponding to the first set value. From the time history of the flow velocity of the gas detected by the introduction-side flow meter 9 and the discharge-side flow meter 10 from the introduction of the gas into the storage unit 3 until the inside of the storage unit 3 reaches an equilibrium state, the control unit 12 Then, the amount of gas adsorbed on the porous material 2 is calculated. When the inside of the storage unit 3 is in an equilibrium state, the amount of gas introduced into the storage unit 3 and the amount of gas discharged from the storage unit 3 become equal.

  After the inside of the storage unit 3 is in an equilibrium state, the set value of the internal pressure of the storage unit 3 is changed from the first set value to the second set value. More specifically, the set pressure signal output from the control unit 12 is changed to one corresponding to the second set value. When the set value of the internal pressure of the storage unit 3 is changed, the discharge amount of the gas in the discharge amount adjustment valve 8 is adjusted so that the internal pressure of the storage unit 3 approaches the set value after the change. Eventually, the inside of the storage unit 3 becomes in an equilibrium state with an internal pressure corresponding to the second set value. From the time history of the flow velocity of the gas detected by the introduction-side flow meter 9 and the discharge-side flow meter 10 from when the set value of the internal pressure of the storage unit 3 is changed to when the inside of the storage unit 3 becomes an equilibrium state, The controller 12 calculates the amount of gas adsorbed on the porous material 2.

  By repeating the above measurement while changing the set value of the internal pressure of the storage unit 3, the internal pressure of the storage unit 3 and the gas of the porous material 2 when the internal temperature of the storage unit 3 is set to a constant temperature T1. It is possible to measure the relationship with the adsorption amount. Moreover, an adsorption isotherm can be created from this measurement result, and for example, an adsorption isotherm as shown by a curve L1 in FIG. 2 can be obtained. In FIG. 2, the horizontal axis represents the relative pressure Po inside the storage unit 3, and the vertical axis represents the adsorption amount m of the porous material 2. In addition, when the same measurement as described above is performed with the internal temperature of the storage unit 3 being a constant temperature T2 lower than the temperature T1, an adsorption isotherm as shown by a curve L2 in FIG. 2 can be obtained.

  Here, as described above, the set pressure signal can be changed step by step with the resolution of the AD converter, so that a very large number of measured values can be obtained. Specifically, in this embodiment, the adsorption amount of the porous material 2 can be measured while changing the set value of the internal pressure of the storage unit 3 by 0.01 Torr. However, from the measurement result of the characteristic measuring apparatus 1, it is not possible to obtain the curves L1 and L2 that are completely continuous directly. Therefore, when an adsorption isotherm is created from the measurement result of the characteristic measuring apparatus 1, the value between the measurement points is complemented by the interpolation method.

  Moreover, in this characteristic measuring apparatus 1, the measurement time for measuring the adsorption amount of the porous material 2 while changing the internal pressure of the storage unit 3 is to obtain an equivalent amount of information by the conventional weight method or the volume method. About 1/3 to 1/5 of the measurement time.

  Next, an example of a method for measuring the gas adsorption amount of the porous material 2 when the internal temperature of the storage unit 3 is changed while the internal pressure of the storage unit 3 is kept constant will be described.

  First, as in the measurement method described above, the internal temperature of the storage unit 3 is set to a constant temperature T3 with the on-off valve (not shown) of the gas storage unit 5 closed. Thereafter, the storage unit 3 is evacuated by a vacuum pump (not shown) provided in the gas exhaust unit 6. When the storage unit 3 is in a vacuum state, the on-off valve of the gas storage unit 5 is opened, and gas is introduced into the storage unit 3 until the inside of the storage unit 3 reaches an equilibrium state.

  At this time, the internal pressure of the storage unit 3 is set to, for example, the pressure P1. Based on the input control signal, the discharge amount adjusting valve 8 adjusts the gas so as to bring the internal pressure of the storage unit 3 closer to the pressure P1 (that is, to maintain the internal pressure of the storage unit 3 at a constant pressure P1). Adjust the discharge amount. At this time, the amount of gas introduced by the introduction amount adjusting valve 7 is constant. At this time, a vacuum pump provided in the gas exhaust unit 6 is driven as necessary.

  Eventually, the inside of the storage part 3 becomes an equilibrium state at the pressure P1. From the time history of the flow velocity of the gas detected by the introduction-side flow meter 9 and the discharge-side flow meter 10 from the introduction of the gas into the storage unit 3 until the inside of the storage unit 3 reaches an equilibrium state, the control unit 12 Then, the amount of gas adsorbed on the porous material 2 is calculated.

  Thereafter, the internal temperature of the storage unit 3 is changed without changing the set value of the internal pressure of the storage unit 3. More specifically, for example, the set temperature of the thermostatic chamber in which the storage unit 3 is arranged is changed. When the internal temperature of the storage unit 3 is changed, the equilibrium state inside the storage unit 3 is lost. Further, a new gas is adsorbed on the porous material 2 or a gas adsorbed on the porous material 2 is released. Here, since the set value of the internal pressure of the storage unit 3 is not changed, the discharge amount adjustment valve 8 causes the internal pressure of the storage unit 3 to approach the pressure P1 (that is, the internal pressure of the storage unit 3 is constant). The gas discharge is adjusted to maintain the pressure P1. Eventually, the inside of the storage unit 3 is brought into an equilibrium state again at the pressure P1. Control from the time history of the flow velocity of the gas detected by the introduction-side flow meter 9 and the discharge-side flow meter 10 from when the internal temperature of the storage unit 3 is changed to when the inside of the storage unit 3 becomes equilibrium again. The unit 12 calculates a new amount of gas adsorbed on the porous material 2 or the amount of gas released from the porous material 2. Even when the internal temperature of the storage unit 3 is changed, the amount of gas introduced by the introduction amount adjusting valve 7 is constant.

  After the inside of the storage unit 3 is in an equilibrium state, the internal temperature of the storage unit 3 is changed again without changing the set value of the internal pressure of the storage unit 3, and the adsorption of gas to the porous material 2 is performed. The amount of gas released from the porous material 2 is calculated. By repeating the above measurement while changing the internal temperature of the storage unit 3, the internal temperature of the storage unit 3 and the adsorption of the gas of the porous material 2 when the internal pressure of the storage unit 3 is set to a constant pressure P1. The relationship with the quantity can be measured. Moreover, an adsorption isobaric line can be created from this measurement result, and for example, an adsorption isobaric line as shown by a curve L3 in FIG. 3 can be obtained. In FIG. 3, the horizontal axis represents the internal temperature T of the storage unit 3, and the vertical axis represents the adsorption amount m of the porous material 2. Further, if the same measurement as described above is performed with the internal pressure of the storage unit 3 being a constant pressure P2 higher than the pressure P1, an adsorption isobaric line as shown by a curve L4 in FIG. 3 can be obtained.

  In addition, since the internal temperature of the storage part 3 can only be changed in steps, the continuous curves L3 and L4 cannot be obtained directly from the measurement result of the characteristic measuring apparatus 1. Therefore, when the adsorption isobaric line is created from the measurement result of the characteristic measuring apparatus 1, the value between the measurement points is complemented by the interpolation method.

(Main effects of the first embodiment)
As described above, in the characteristic measurement device 1 according to the first embodiment, the internal pressure of the storage unit 3 in which the porous substance 2 is stored is kept constant based on the detected pressure detected by the pressure detection unit 4. Thus, the flow rate of the discharge amount adjusting valve 8 is adjusted. That is, gas is introduced into the storage unit 3 and gas is discharged from the storage unit 3 so that the inside of the storage unit 3 maintains an equilibrium state at a predetermined set pressure. Therefore, even if the set value of the internal pressure of the storage unit 3 is changed or the internal temperature of the storage unit 3 is changed under a predetermined pressure, the inside of the storage unit 3 has a pressure corresponding to the changed set value. Or immediately at a given pressure, the equilibrium state is reached. Therefore, for example, it is possible to change the internal temperature of the storage unit 3 while introducing gas into the storage unit 3 while keeping the internal pressure of the storage unit 3 constant. As a result, it is possible to easily measure the relationship between the internal temperature of the storage unit 3 and the amount of adsorption of the porous material 2 under a constant pressure, and it is possible to create an adsorption isobaric line directly based on the measurement result. .

  In the first embodiment, the amount of gas introduced into the storage unit 3 is calculated from the gas flow velocity detected by the introduction-side flow meter 9, and the gas flow rate detected from the discharge-side flow meter 10 is calculated from the storage unit 3. Gas emissions are calculated. The amount of gas adsorbed on the porous material 2 is calculated from the difference between the calculated gas introduction amount and the gas discharge amount. That is, the amount of gas adsorbed on the porous material 2 can be measured from the difference between the gas flow rate detected by the introduction-side flow meter 9 and the gas flow rate detected by the discharge-side flow meter 10. Yes. Therefore, the gas adsorption amount to the porous material 2 can be directly measured with a simple configuration in which the gas flow rate is detected.

  In the first embodiment, the set pressure signal output as a digital signal from the control unit 12 and the detected pressure signal output as a digital signal from the pressure detection unit 4 are input to the differential amplifier circuit 13. Yes. Further, the differential amplifier circuit 13 outputs a signal obtained by amplifying the difference between the set pressure signal and the detected pressure signal as a control signal toward the discharge amount adjusting valve 8, and based on the control signal, the discharge side adjusting valve 8. Is configured to adjust the flow rate. Therefore, while keeping the internal temperature of the storage unit 3 constant, the internal pressure of the storage unit 3 is changed in multiple steps and in small increments with the resolution of the set pressure signal output from the control unit 12. The amount of adsorption can be measured. That is, the adsorption amount of the porous material 2 when the internal pressure of the storage unit 3 is changed at a constant temperature can be measured in a state close to continuous measurement. As a result, even when an adsorption isotherm is created from the measurement result of the characteristic measuring device 1, high accuracy complementation is possible by interpolation, and a highly accurate adsorption isotherm can be created. Therefore, the accuracy of the characteristics of the porous material 2 such as the pore size distribution obtained by using the slope (differential value) of the adsorption isotherm can be dramatically improved. Further, since the internal pressure of the storage unit 3 can be changed in multiple steps and in small increments with the resolution of the set pressure signal output from the control unit 12, the internal pressure of the storage unit 3 is changed. However, the inside of the storage part 3 can be returned to the equilibrium state in a shorter time.

  In the first embodiment, the amount of gas introduced by the introduction amount adjustment valve 7 is constant, and the flow rate adjustment of the discharge amount adjustment valve 8 is performed based on the detected pressure detected by the pressure detection unit 4. Therefore, liquefaction of the gas introduced into the storage unit 3 can be prevented. That is, when the flow rate is adjusted by the introduction amount adjusting valve 7, it is necessary to apply a certain high pressure to the inlet side of the introduction amount adjusting valve 7 so that the flow rate can be adjusted. Therefore, the gas may be liquefied depending on the type of gas and the ambient temperature. On the other hand, in Embodiment 1, since the flow rate is adjusted by the discharge amount adjusting valve 8, if a negative pressure is applied to the outlet side of the discharge amount adjusting valve 8 by the vacuum pump provided in the gas exhaust unit 6. good. As a result, it is not necessary to apply a high pressure to the inlet side of the introduction amount adjusting valve 7, and gas liquefaction can be prevented.

[Embodiment 2]
(Configuration of device for measuring characteristics of porous materials)
FIG. 4 is a schematic diagram showing a schematic configuration of a porous material characteristic measuring apparatus 51 according to the second embodiment of the present invention.

  The main difference between the porous material property measuring apparatus 51 of the second embodiment (hereinafter referred to as “characteristic measuring device 51”) and the characteristic measuring device 1 of the first embodiment is that Based on the point provided with the weight detection unit 61 for detecting the weight and the detected weight detected by the weight detection unit 61, the weight of the porous material 2 is maintained constant (that is, the amount of gas adsorption) The flow rate of the discharge amount adjusting valve 8 is adjusted so as to maintain a constant value. Below, centering on this difference, the structure of the characteristic measurement apparatus 51 of Embodiment 2 and the characteristic measurement method of the porous substance 2 using the characteristic measurement apparatus 51 are demonstrated. In the following description, components that are the same as those of the characteristic measuring apparatus 1 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

  As shown in FIG. 4, the characteristic measuring device 51 is introduced into the storage unit 53 in which the volume is constant and the porous material 2 is stored, the pressure detection unit 4 that detects the internal pressure of the storage unit 53, and the storage unit 53. The gas storage unit 5 in which a predetermined gas is stored, the gas exhaust unit 6 that discharges gas from the storage unit 3, and the storage unit 3 and the gas storage unit 5 are disposed between the storage unit 3 and the storage unit 3. An introduction amount adjustment valve 7 that adjusts the amount of gas introduced, a discharge amount adjustment valve 8 that is disposed between the storage portion 3 and the gas exhaust portion 6 and adjusts the discharge amount of gas from the storage portion 3; A weight detection unit 61 that detects the weight of the porous material 2. As shown in FIG. 4, the characteristic measuring device 51 includes a control unit 12 that controls the characteristic measuring device 51 and a differential amplifier circuit 13 that outputs a control signal to the discharge amount adjusting valve 8. . Note that the weight detection unit 61, the discharge amount adjustment valve 8, the control unit 12, and the differential amplifier circuit 13 calculate the gas adsorption amount to the porous material 2 based on the detected weight detected by the weight detection unit 61. It constitutes a feedback control unit that keeps constant.

  Similar to the characteristic measurement apparatus 1 of the first embodiment, there are various gases used in the characteristic measurement apparatus 51 of the second embodiment. For example, nitrogen, hydrogen, water vapor, carbon dioxide, methane, methanol, chloroform, Or, bromoform or the like.

  The accommodating part 53 is comprised with the container which can take in and out the porous substance 2, and can be sealed. In addition, since the position of the porous material 2 is detected by an optical position sensor 63 described later, the lower end side of the storage portion 53 is transparent so that light can be transmitted.

  The weight detection unit 61 includes a levitation unit 62 that levitates the porous material 2 inside the storage unit 53 and a position sensor 63 that detects the position of the porous material 2.

  The levitation means 62 includes a movable portion 64 on which the porous material 2 is placed and a permanent magnet (not shown) is fixed, and a fixed portion 65 having an electromagnet (not shown) that levitates the movable portion 64. Yes. As shown in FIG. 4, the movable portion 64 is movably disposed inside the storage portion 53 with the porous material 2 placed thereon. As shown in FIG. 4, the fixing portion 65 is disposed in a state of being fixed to the lower side of the storage portion 53. When the electromagnet of the fixed portion 65 is energized, the movable portion 64 floats inside the storage portion 53 by the repulsive force between the electromagnet and the permanent magnet of the movable portion 64.

  The position sensor 63 is an optical sensor including a light emitting unit 66 having a light emitting element (not shown) and a light receiving unit 67 having a light receiving element (not shown) that receives light from the light emitting element. As shown in FIG. 4, the position sensor 63 is disposed on the side of the lower end side of the storage portion 53. More specifically, the position sensor 63 is disposed on the side of the lower end side of the storage portion 53 and at a position where the porous substance 2 in a state of floating with the movable portion 64 can be detected.

  In the weight detection unit 61, an electric current is supplied to the electromagnet of the fixed unit 65 so that the porous substance 2 placed on the movable unit 64 floats within the detection range of the position sensor 63. Yes. That is, in the weight detection unit 61, the current supplied to the electromagnet of the fixed unit 65 is measured or adjusted based on the detection signal from the position sensor 63 (specifically, the light receiving unit 67). Yes. Then, the weight of the porous material 2 is detected from the current value supplied to the electromagnet of the fixed portion 65. More specifically, as shown in FIG. 4, a detection signal corresponding to the internal pressure of the storage unit 53 detected by the pressure detection unit 4 is input to the fixing unit 65. In 65, the weight of the porous material 2 excluding the influence of the change in the internal pressure of the storage portion 53 is detected. The fixing unit 65 outputs a detected weight signal corresponding to the detected weight of the porous substance 2 as a digital signal toward the differential amplifier circuit 13.

  Similar to the first embodiment, both the introduction amount adjusting valve 7 and the discharge amount adjusting valve 8 of the second embodiment are piezo valves. The introduction amount adjustment valve 7 is connected to the storage unit 3 and the gas storage unit 5 by a predetermined pipe, and the discharge amount adjustment valve 8 is connected to the storage unit 3 and the gas exhaust unit 6 by a predetermined pipe. Yes.

  Similarly to the first embodiment, in the second embodiment, the introduction amount adjusting valve 7 is adjusted so as to lead a gas having a constant flow rate to the storage portion 53. Further, the flow rate at the discharge amount adjusting valve 8 is adjusted based on the detected weight of the porous substance 2 detected by the weight detection unit 61. More specifically, the differential amplifier circuit 13 has a detection weight signal corresponding to the detection weight of the porous substance 2 detected by the weight detection unit 61 and a setting corresponding to the set value of the weight of the porous substance 2. The weight signal is input, and the differential amplifier circuit 13 is configured to amplify and output the difference between the set weight signal and the detected weight signal. The flow rate at the discharge amount adjusting valve 8 is adjusted (controlled) so that the weight of the porous material 2 approaches the set value based on the control signal output from the differential amplifier circuit 13.

  As described above, in the second embodiment, similarly to the first embodiment, the flow rate at the introduction amount adjustment valve 7 is adjusted to be constant, and the flow rate at the discharge amount adjustment valve 8 is output from the differential amplifier circuit 13. By adjusting based on the signal, the gas flow rate is adjusted so that the weight of the porous material 2 approaches the set value. That is, the introduction amount adjustment valve 7 and the discharge amount adjustment valve 8 are adjusted so that the weight of the porous material 2 is kept constant in the vicinity of the set value.

  As shown in FIG. 4, a detection signal corresponding to the internal pressure of the storage unit 53 detected by the pressure detection unit 4 is input to the control unit 12. Further, a set value of the weight of the porous material 2 is input to the control unit 12, and the control unit 12 outputs a set weight signal corresponding to the set value to the differential amplifier circuit 13. It is supposed to be. More specifically, the control unit 12 outputs a set weight signal converted into a digital signal by the AD converter. That is, the control unit 12 can output a set weight signal that is changed in multiple steps and in small increments with the resolution (step value) of the AD converter.

(Method for measuring the characteristics of porous materials)
FIG. 5 is a graph showing an adsorption equivalence line created based on the measurement result of the characteristic measuring device 51 of FIG.

  Various characteristics of the porous material 2 are measured using the characteristic measuring apparatus 51 configured as described above. Hereinafter, when the internal temperature of the storage portion 53 is changed while the weight of the porous material 2 is kept constant (that is, the amount of gas adsorbed on the porous material 2 is kept constant). An example of a method for measuring the internal pressure of the storage unit 53 will be described.

  First, with the on-off valve (not shown) of the gas storage unit 5 closed, the internal temperature of the storage unit 53 is set to a constant temperature T4. For example, the storage part 53 is arrange | positioned in the thermostat which abbreviate | omits illustration, and the internal temperature of the storage part 53 is made into temperature T4. Thereafter, the storage unit 53 is evacuated by a vacuum pump (not shown) provided in the gas exhaust unit 6. When the storage unit 53 is in a vacuum state, the on-off valve of the gas storage unit 5 is opened, and gas is introduced into the storage unit 53 until the inside of the storage unit 53 reaches an equilibrium state.

  At this time, the weight of the porous material 2 excluding the influence of the change in the internal pressure of the storage portion 53 is set to, for example, the weight M1. In the discharge amount adjusting valve 8, based on the input control signal, the weight of the porous material 2 is brought close to the weight M 1 (that is, the weight of the porous material 2 is maintained at a constant weight M 1). Gas emissions are adjusted. At this time, the amount of gas introduced by the introduction amount adjusting valve 7 is constant. At this time, a vacuum pump provided in the gas exhaust unit 6 is driven as necessary.

  Eventually, the inside of the storage portion 53 becomes in an equilibrium state. The internal pressure of the storage part 53 at this time is measured. More specifically, for example, the control unit 12 calculates the internal pressure of the storage unit 53 based on a detection signal from the pressure detection unit 4.

  After the inside of the storage unit 53 reaches an equilibrium state, the internal temperature of the storage unit 53 is changed. For example, the set temperature of the thermostatic chamber in which the storage unit 53 is arranged is changed. After the internal temperature of the storage part 53 is changed and the inside of the storage part 53 is in an equilibrium state, the internal pressure of the storage part 53 is measured again. Here, when the internal temperature of the storage portion 53 is changed, a gas adsorption phenomenon to the porous material 2 or a gas release phenomenon adsorbed to the porous material 2 occurs. On the basis of the control signal, the gas discharge amount is adjusted so that the weight of the porous material 2 approaches the weight M1, so the weight of the porous material 2 excluding the influence of the change in the internal pressure of the storage portion 53 is A constant weight M1 is maintained.

  Thereafter, the internal temperature of the storage unit 53 is further changed, and after the inside of the storage unit 53 is in an equilibrium state, the internal pressure of the storage unit 53 is measured. By repeating the above measurement while changing the internal temperature of the storage unit 53, the relationship between the internal temperature of the storage unit 53 and the internal pressure when the weight of the porous material 2 is set to a constant weight M1 is measured. be able to. Further, from this measurement result, an adsorption equivalence line can be created. For example, an adsorption equivalence line as shown by a curve L5 in FIG. 5 can be obtained. In FIG. 3, the horizontal axis represents the internal temperature T of the storage unit 53, and the vertical axis represents the internal pressure P of the storage unit 53. Further, when the same measurement as described above is performed by setting the weight of the porous material 2 to a constant weight M2 heavier than the weight M1, an adsorption equivalence curve as shown by a curve L6 in FIG. 5 can be obtained.

  In addition, by using the adsorption equivalence line obtained from the measurement result of the characteristic measuring apparatus 1, the equivalent adsorption heat which is one of the characteristics of the porous material 2 is easily calculated from the above-described equation (1). be able to.

  In addition, since the internal temperature of the accommodating part 3 can only be changed in steps, the continuous curves L5 and L6 cannot be obtained directly from the measurement result of the characteristic measuring device 1. Therefore, when creating an adsorption equivalence line from the measurement result of the characteristic measuring apparatus 1, the value between the measurement points is complemented by the interpolation method.

(Main effects of the second embodiment)
As described above, in the characteristic measurement device 51 according to the second embodiment, the discharge amount so as to maintain the gas adsorption amount to the porous material 2 constant based on the detected weight detected by the weight detection unit 61. The flow rate of the regulating valve 8 is adjusted. Therefore, it is possible to change the internal temperature of the storage portion 53 while introducing the gas into the storage portion 53 in a state where the adsorption amount of the gas adsorbed on the porous material 2 is kept constant. Therefore, it is possible to easily measure the relationship between the internal pressure and the internal temperature of the storage portion 53 when the adsorption amount is constant, and it is possible to directly create an adsorption equivalence line based on the measurement result. . In addition, by using this adsorption isotherm, for example, it is possible to easily obtain an equivalent adsorption heat which is a characteristic of a porous substance.

  In the second embodiment, the amount of gas introduced by the introduction amount adjustment valve 7 is constant, and the flow rate adjustment of the discharge amount adjustment valve 8 is performed based on the detected weight detected by the weight detection unit 61. Therefore, liquefaction of the gas introduced into the storage unit 53 can be prevented.

[Other embodiments]
Each form mentioned above is an example of a suitable form of the present invention, but is not limited to this, and various modifications can be made without departing from the scope of the present invention. For example, in the description of each embodiment described above, the volume of the storage units 3 and 53 is “constant”, and the internal pressure and internal temperature of the storage units 3 and 53 or the gas adsorption amount of the porous material 2 are determined. Various characteristics of the porous material 2 are measured when “constant” is set, but this “constant” does not mean exactly the same state, but a range of errors allowed in measurement and detection. Also included are those that vary within the allowable range from the accuracy of the required measurement values.

  In Embodiment 1 described above, the internal pressure of the storage unit 3 is gradually changed while gas is introduced into the storage unit 3 while the internal temperature of the storage unit 3 is kept constant. While the internal pressure is kept constant, the internal temperature of the storage unit 3 is changed while introducing gas into the storage unit 3. That is, the internal pressure and internal temperature of the storage unit 3 are applied to the porous material 2 as external stimuli. In addition, for example, the electric field or magnetic field inside the storage unit 3 may be changed while introducing gas into the storage unit 3 while keeping the internal pressure of the storage unit 3 constant. Alternatively, the porous material 2 may be irradiated with light while changing the intensity of light while introducing gas into the storage unit 3 while keeping the internal pressure of the storage unit 3 constant. In this way, various characteristics of the porous material 2 under a constant pressure can be easily measured. For example, the relationship between the amount of adsorption of the porous material 2 and the strength of the electric field can be easily measured. Similarly, in the second embodiment, an electric field, a magnetic field, and the like inside the storage unit 53 are introduced while introducing the gas into the storage unit 53 while keeping the adsorption amount of the gas adsorbed by the porous material 2 constant. May be changed. That is, external stimuli for the porous material 2 include not only the internal pressure and internal temperature of the storage units 3 and 53 but also the electric field and magnetic field inside the storage units 3 and 53, or the light irradiated to the porous material 2. It can be a variety of stimuli.

  Further, the external electric stimulus is an electric field or a magnetic field inside the storage units 3 and 53, or the light irradiated on the porous material 2 is formed inside the porous material 2 by these external stimuli, for example. It is possible to search for a switching function in which the shape of the minute space is deformed and the gas adsorption amount changes. As the search for the switching function proceeds, the gas can be easily stored in the porous material 2 and the gas can be easily taken out from the porous material 2. In addition, it has been pointed out that the possibility of the formation of an ordered structure of molecules in the minute space formed inside the porous material 2 by an external stimulus has been pointed out. It is also possible to search for the formation of an ordered structure of molecules.

  Furthermore, in each embodiment described above, the amount of gas introduced by the introduction amount adjustment valve 7 is constant, and the flow rate adjustment of the discharge amount adjustment valve 8 is performed based on the detection result of the pressure detection unit 4 (or the weight detection unit 61). It is carried out. In addition to this, for example, the amount of gas discharged from the discharge amount adjusting valve 8 is made constant, and the flow rate of the introduction amount adjusting valve 7 is adjusted based on the detection result of the pressure detecting unit 4 (or the weight detecting unit 61). You can go. That is, the control signal from the differential amplifier circuit 13 may be input to the introduction amount adjusting valve 7 and the flow rate of the introduction amount adjusting valve 7 may be adjusted based on the control signal. In this case, the introduction amount adjusting valve 7 constitutes a part of the feedback control unit. Further, both the introduction amount adjusting valve 7 and the discharge amount adjusting valve 8 are configured to receive a control signal from the differential amplifier circuit 13, and the flow rate adjustment of both the introduction amount adjusting valve 7 and the discharge amount adjusting valve 8 is achieved. May be performed. In this case, both the introduction amount adjustment valve 7 and the discharge amount adjustment valve 8 constitute a part of the feedback control unit.

  Furthermore, in each of the above-described embodiments, when measuring various characteristics of the porous material 2, various characteristics are measured while maintaining the introduction and discharge of the gas. Various characteristics may be measured. That is, when the insides of the storage units 3 and 53 are in an equilibrium state, the introduction amount adjustment valve 7 and the discharge amount adjustment valve 8 may be closed once, and then the characteristics may be measured.

  In the first embodiment described above, the amount of gas adsorbed on the porous material 2 is measured using the introduction-side flow meter 9 and the discharge-side flow meter 10. In addition to this, for example, instead of the introduction-side flow meter 9 and the discharge-side flow meter 10, the weight detection unit 61 described in the second embodiment is arranged in the characteristic measurement device 1 of the first embodiment to detect the weight. The amount of gas adsorbed on the porous material 2 may be measured using the unit 61. Even in this case, various relationships such as the relationship between the amount of gas adsorbed to the porous material 2 and the internal pressure of the storage unit 3 are measured while the internal pressure of the storage unit 3 is kept constant. Can do.

  Furthermore, in each form mentioned above, the introduction amount adjustment valve 7 and the introduction side flowmeter 9 are provided as a configuration different from the gas storage unit 5, and the discharge amount adjustment valve 8 as a configuration different from the gas exhaust unit 6 A discharge flow meter 10 is provided. In addition, for example, the gas storage unit 5 may be provided with a gas introduction amount adjustment function and a measurement function, or the gas exhaust unit 6 may be provided with a gas discharge amount adjustment function and a measurement function.

  Furthermore, in each form mentioned above, an introduction amount detection part is the introduction side flow meter 9 which consists of a flow rate counter, and a discharge amount detection part is the discharge side flow meter 10 which consists of a flow rate counter. In addition to this, for example, the introduction amount detection unit and the discharge amount detection unit may be a molecular weight counter capable of directly measuring the molecular weight of the passing gas.

  Moreover, in Embodiment 2 mentioned above, the change of the internal pressure of the accommodating part 53 when the internal temperature of the accommodating part 53 is changed in the state which kept the adsorption amount of the porous substance 2 constant is measured. . In addition to this, for example, a change in the internal temperature of the storage unit 53 when the internal pressure of the storage unit 53 is changed may be measured, and an adsorption equivalence curve may be created from the result.

  Furthermore, in Embodiment 1 mentioned above, when measuring the gas adsorption amount of the porous substance 2 when the internal pressure of the storage unit 3 is changed while the internal temperature of the storage unit 3 is kept constant. First, the storage unit 3 is in a vacuum state. In addition to this, for example, as an initial state, the internal pressure of the storage unit 3 is set to a predetermined pressure, and then the porosity at a constant temperature while the internal pressure is gradually increased and the internal pressure is gradually decreased. The gas adsorption amount of the substance 2 may be measured.

  The internal pressure of the storage units 3 and 53 can be variously set in accordance with the gas used, such as a range from vacuum to 1 atm or a range from 1 to 20 atm. The gas employed in the configuration of the present invention may be a special state gas such as a supercritical gas.

It is a schematic diagram which shows schematic structure of the characteristic measuring apparatus of the porous substance concerning Embodiment 1 of this invention. It is a graph which shows the adsorption isotherm created based on the measurement result in the characteristic measuring apparatus of FIG. It is a graph which shows the adsorption isobaric line produced based on the measurement result in the characteristic measuring apparatus of FIG. It is a schematic diagram which shows schematic structure of the characteristic measuring apparatus of the porous substance concerning Embodiment 2 of this invention. It is a graph which shows the adsorption | suction equivalent curve created based on the measurement result in the characteristic measuring apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,51 Characteristic measuring apparatus 2 Porous substance 3,53 Storage part 4 Pressure detection part (a part of feedback control part)
5 Gas storage part 6 Gas exhaust part 7 Introduction amount adjustment valve (part of introduction amount adjustment part and feedback control part)
8 Emission control valve (part of the emission control unit and feedback control unit)
9 Introduction-side flow meter (introduction amount detector)
10 Discharge flow meter (discharge amount detection unit)
12 Control unit (set pressure output unit, part of feedback control unit)
13 Differential amplifier circuit (part of feedback controller)
61 Weight detector (part of feedback controller)

Claims (11)

A storage unit having a constant volume and storing a porous material, a gas storage unit storing a predetermined gas introduced into the storage unit, and a gas exhaust unit for exhausting the gas from the storage unit With
A pressure detection unit that detects an internal pressure of the storage unit, and based on the detected pressure detected by the pressure detection unit, the amount of the gas introduced into the storage unit and the discharge of the gas from the storage unit; A device for measuring characteristics of a porous material, comprising a feedback control unit that controls at least one of the amount and maintains the internal pressure of the storage unit constant.   The feedback control unit is disposed between the storage unit and the gas storage unit, and adjusts an introduction amount of the gas into the storage unit, and includes the storage unit and the gas exhaust unit. A discharge amount adjusting unit that adjusts the discharge amount of the gas from the storage unit, and the internal pressure of the storage unit is set to a predetermined value based on the detected pressure detected by the pressure detection unit. 2. The porous material characteristic measuring apparatus according to claim 1, wherein flow rate adjustment of at least one of the introduction amount adjusting unit and the discharge amount adjusting unit is performed so as to maintain a set value.   The apparatus for measuring characteristics of a porous material according to claim 2, wherein the gas is introduced into the storage portion even after the internal pressure of the storage portion reaches an equilibrium state at a predetermined set value. An introduction amount detection unit that detects an introduction amount of the gas into the storage unit; and a discharge amount detection unit that detects a discharge amount of the gas from the storage unit,
Measuring the amount of the gas adsorbed to the porous material from the difference between the amount of the gas introduced detected by the introduction amount detector and the amount of the gas detected detected by the exhaust amount detector. The device for measuring characteristics of a porous material according to any one of claims 1 to 3. A set pressure output unit that outputs a set pressure signal corresponding to a set value of the internal pressure of the storage unit;
A differential amplifier circuit that receives the detected pressure signal output from the pressure detector and the set pressure signal, and amplifies and outputs the difference between the set pressure signal and the detected pressure signal;
The characteristic of the porous material according to any one of claims 1 to 4, wherein at least one of the introduction amount and the discharge amount of the gas is adjusted based on an output from the differential amplifier circuit. measuring device.   The porosity according to any one of claims 1 to 5, wherein the gas introduction amount is set to be substantially constant, and the discharge amount of the gas is adjusted based on the detected pressure detected by the pressure detection unit. Material property measuring device. A storage unit having a constant volume and storing a porous material, a gas storage unit storing a predetermined gas introduced into the storage unit, and a gas exhaust unit for exhausting the gas from the storage unit With
A weight detection unit for detecting the weight of the porous material, and based on the detected weight detected by the weight detection unit, the amount of the gas introduced into the storage unit and the discharge of the gas from the storage unit; A device for measuring characteristics of a porous material, comprising a feedback control unit that controls at least one of the amount and the amount of adsorption of the gas to the porous material to be constant.   The feedback control unit is disposed between the storage unit and the gas storage unit, and adjusts an introduction amount of the gas into the storage unit, and includes the storage unit and the gas exhaust unit. A discharge amount adjustment unit that adjusts the discharge amount of the gas from the storage unit, and based on the detected weight detected by the weight detection unit, the gas to the porous material 8. The characteristic of a porous material according to claim 7, wherein the flow rate of at least one of the introduction amount adjustment unit and the discharge amount adjustment unit is adjusted so that the adsorption amount is maintained at a predetermined set value. measuring device.   The gas is introduced into the storage portion even after the amount of adsorption of the gas to the porous material reaches a predetermined set value and the inside of the storage portion is in an equilibrium state. 8. A device for measuring characteristics of a porous material according to 8. Detected by a step of equilibrating the inside of the storage unit in which the volume is constant and the porous material is stored, a step of applying an external stimulus to the porous material, and a pressure detection unit that detects the internal pressure of the storage unit And maintaining the internal pressure of the storage unit by controlling at least one of the introduction amount of the gas into the storage unit and the discharge amount of the gas from the storage unit based on the detected pressure. ,
A method for measuring a characteristic of a porous material, wherein the gas adsorption amount of the porous material by the external stimulus is detected based on a difference between the gas introduction amount and the gas discharge amount. Detected by a step of bringing the inside of the storage unit having a constant volume and storing the porous material into an equilibrium state, a step of applying an external stimulus to the porous material, and a weight detection unit for detecting the weight of the porous material. Based on the detected weight, the amount of the gas introduced into the storage portion and the amount of the gas discharged from the storage portion are controlled to maintain the amount of the gas adsorbed onto the porous material. Comprising the steps of:
A method for measuring a property of a porous material, wherein the property of the porous material that changes in response to the external stimulus is measured.

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