JPH0548415B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a scientific device for measuring thermodynamic and structural properties of materials. More specifically, the present invention relates to a device for simultaneous calorimetry-X-ray diffraction analysis. In characterizing the physical and chemical behavior of a substance, it is customary to study both its thermodynamic (eg caloric) and structural (eg crystalline) properties separately. Thermodynamic properties are determined by differential scanning calorimetry (DSC)
and commonly determined by differential thermal analysis. Modern DSC and DTA equipment is very advanced;
In some cases, temperature-sensitive adjustment and measurement of fractions up to 1°C is possible. The sample is rapidly heated to a wide range of temperatures in a very short period of time, allowing accurate calorimetry measurements. Crystallinity is often studied by X-ray diffraction (XRD) spectroscopy. Diffraction data is collected with photographic film or with a scintillation counter for detailed resolution. Such operations are time consuming, requiring 30 minutes or more of data acquisition time for each pattern at each temperature. One test over a temperature range can take one or more days. As described above, since data acquisition time for X-ray diffraction examination is time-consuming, it has not been possible to correlate structural data and calorific value data by a rapid method. In industrial processes, heat treatments and/or chemical treatments occur within minutes or seconds (eg polymer extraction or catalytic oxidation). Additionally, sample heating equipment for X-ray diffraction analysis was relatively crude. Constant sample temperature control, for example within 5° C., could only rarely be achieved except near room temperature. For both of these reasons, a rapid scan or dynamic reading of a series of X-ray diffraction patterns that is accurately and simultaneously correlated to the heating temperature of the sample has not been possible to date. On the other hand, attempts have generally been made to first analyze a sample by one of the aforementioned methods and then by another method. The two measurements were then fully correlated in order to elucidate as much as possible the thermal structural behavior of the sample. However, when attempting to match observed structural changes to individual caloric phenomena, diffraction data and calorific data are
Differences in sample heating conditions and sample size, as well as differences in data acquisition time between DSC and conventional XRD, precluded proper correlation. When this method is used for multicomponent samples, the separate physicochemical phenomena that occur at short temperatures are often misinterpreted because they represent instantaneous and irreversible phase changes that occur within 1 to 2 minutes. , or be misunderstood. Only recently have some of these been improved. That is, a position-sensitive detector has been developed as an X-ray detector that greatly improves the detection speed of diffraction data. This can shorten the analysis time of X-ray diffraction to the extent that it corresponds to the time of differential thermal analysis and differential scanning calorimetry. The present invention improves upon these advantages and provides an operating device and method for simultaneously dynamically measuring thermodynamic and structural properties of a sample subjected to temperature and/or ambient changes. It is something. The instrument of the invention consists of a combination of both an X-ray diffraction analyzer and a calorimeter (differential scanning calorimeter or differential thermal analyzer) for the same processing and simultaneous detection of the same sample to be analyzed. Diffraction analyzers are also used for the measurement of thermodynamic properties and include an X-ray beam source impinging on the sample to be measured and a rapid position sensitive system for receiving the radiation diffracted from the sample for measuring structural properties. Includes sex detector. The calorimeter has a sample holder in which the sample is placed and held for collaborative analysis in a sample holder device. The sample holder device has an entrance or x-ray transparent window positioned to impinge the x-ray beam of the diffractometer on the sample in the holder and an exit slit window for passing the diffracted radiation to the x-ray detector. . Furthermore, the analyzer has a control device for varying the temperature of the sample in the holder and a device for measuring the thermodynamic behavior of the sample during the change. Preferably, the x-ray source provides a focused monochromatic beam. It is advantageous to have a source with a Guinier diffraction system and a curved focal monochromator. The source and sample holder (and enclosure) are geometrically arranged so that the sample in the holder is located along the focal circle of the diffractometer. The X-ray detector is preferably a position-sensitive proportional counter mounted to move the focal circle of the diffraction analyzer with sensitive elements placed along the circumference. The detector is connected to an electronic readout circuit. It has a multichannel spectrometer with a display terminal or recorder that numerically and graphically represents the position and intensity of the lines forming the X-ray diffraction pattern. Preferably, the calorimeter is a differential scanning calorimeter equipped with an electronic readout circuit that displays and records both the temperature of the sample being analyzed and the presence and extent of calorimetric events occurring in the sample. The circuit also includes a device for controlling the temperature of the sample in the holder. Advantageously, the device can be programmed to raise, lower or maintain the temperature. A sample holder device (sometimes referred to as a sample holder device or cell) consists of a protective enclosure, such as, but not limited to, a metal block having a cover that hermetically seals the interior. The block has two chambers (or one common chamber) for sample and control holders.
have. A wider variety of sample holder device designs than those described herein are known and can be used instead. For example, as illustrated in the cited literature and commercially available instruments for DSC and DTA. Similarly, sample holders can be used in numerous forms and modified for simultaneous sample analysis according to the invention. The sample holder device is fitted with an X-ray transparent inlet and exit slit window and covered with a thin sheet of X-ray transparent material to seal it. If the instrument is used to study the influence of a gaseous medium on analytical test samples, the sample holder device may also be equipped with inlets and outlets for controlling the gas that passes through in contact with the sample. can. In addition to providing a novel device, the present invention also provides
Furthermore, it relates to a method for simultaneously analyzing thermodynamic and structural properties of materials. In this method the sample material is subjected to a program of temperature and/or ambient changes. In the program, for example in the DSC method, the differential heat flow to and from the sample is measured, which indicates the calorific behavior. At the same time, the sample is exposed to a focused x-ray beam and diffraction data from the sample is also measured during that time. The calorific data and x-ray data are then compared as a function of temperature and ambient. This contrast provides great insight into the fundamental physicochemical behavior of the sample and, in the case of multicomponent samples, of its constituent substances and how these substances interact with each other. Give. This equipment and method can be used over a wide range of temperatures and under many atmospheres. These simultaneously scan and record calorimetric and X-ray diffraction data while the sample is heated to hundreds of degrees, all within minutes. X-ray data is dynamically reacquired as the calorimetric analysis progresses, providing a direct correlation between structural changes and short-term instantaneous calorific events. Then, the kinetics of structural changes induced by heat and atmosphere are studied precisely, allowing the elucidation of complex DSC curves. In the case of samples containing several components, the phases can be easily separated and the calorific events can be reliably distributed to individual components or to more than one component. This type of result has never been achieved before. The invention will be explained below with reference to the accompanying drawings. FIG. 1 is a top view of a combined X-ray diffraction analyzer and differential scanning calorimeter according to the present invention, with the electronic control and recording system omitted. The figure shows the equipment according to the arrangement of the Haber-Guinier system. FIG. 2 is a partial side view of the central portion of the device of FIG. 1, enlarged to show the sample container and its attachment; FIG. 3 is a perspective view showing the inside of the sample container of FIG. 2; FIG. 4 is a cross-sectional elevational view of the sample container taken along line 4--4 of FIG. 3, showing the sample holder with heating and temperature sensing elements. Additionally, the figure shows the gas inlet and outlet. FIG. 5 is a sectional view of the linear position-sensitive proportional counter used as the X-ray detector shown in FIG. 6a and 6b are cross-sectional views of a curved position sensitive proportional counter used as a replacement for the counter of FIG. Additionally, this figure shows the typical errors associated with these types of detectors. FIG. 7 is a block diagram illustrating the detector control and recording system of an X-ray diffractometer of an instrument according to the present invention. FIG. 8 is a schematic diagram of another X-ray diffractometer using the Bragg-Bentano system arrangement. FIG. 9 is a block diagram of a differential scanning calorimeter electronic sensitivity and control system forming another part of the instrument of the present invention. FIG. 10 is an elevational view of an alternative device configuration in which the x-ray beam is directed vertically upwards. FIG. 11 is a block diagram showing the relationship between the control and recording system of the entire apparatus according to the present invention, which includes supplying gas to the sample container,
It includes a system for analyzing the effluent gas from the vessel. Figures 12A and 12B show a typical X-ray diffraction pattern (Figure 12B) and its equivalent produced by the apparatus of the present invention during a heating cycle.
Recording with DSC scanning (Figure 12A). Figures 13A and 13B are the same as the records in Figures 12A and 12B, respectively, except that they were made during the cooling cycle. Figures 14A-C show polymorphic organic compounds.
These are the DSC scans before the DSC/XFD test, during the test, and after the test. FIG. 15 shows the interconversion of polymorphs from low to high melting points produced by the apparatus of the present invention.
The line diffraction pattern is shown. The basic elements of a preferred construction of the invention are shown in FIGS. 1 and 2. These are an X-ray diffraction analyzer and a differential scanning calorimeter, shown at 17, the sample holder device of which is shown at 18. These are tightly sectioned and mounted on a common base 19 as described below. A sample of the substance to be measured is placed in a small dish or container 22 made of aluminum foil, for example, and placed in a sample holder (96 in FIG. 3) in the sample holder device 18.
Typically, milligram quantities of the substance in powder or film form are desired. The sample holder device of the previously described block design is constructed with a protective enclosure block 24 of a commercially available device. However, it has been modified and arranged to also serve as a sample support for an X-ray diffractometer. In this case, the sample is shared by the diffractometer 17 and the calorimeter and analyzed simultaneously. In the diffractometer 17, an x-ray source 26 produces an x-ray beam 28 that impinges on a monochromator 30. The latter disperses and redirects the X-rays to provide a single energy beam 32 that is focused on the sample 20. X-radiation passes through the sample and is diffracted from the main beam at various fixed angles. 1st
Two are shown in the figure as 34 and 34'. The diffraction or "scan" angle, commonly referred to as 2-theta (2-theta), and the corresponding diffracted X-ray intensity characterize the crystalline structure of the sample. The diffracted X-rays are collected on a position sensitive detector 36. The detector 36 records the acceptance of diffracted radiation and also provides information about the length (1-dimensional detector) and area (2-dimensional detector) in which the radiation is absorbed. For these, see American
Report of the Crystallographic Association (18 volumes,
(1982, p. 9, R.C. Chamlin, Ed.). The detector is of known design and consists of a 25 micron diameter wire 38 that is sensitive to the angular position and frequency (i.e., counts/second) of the incident X-ray photons. The detector has an angular range of about 20 DEG 2-theta and is connected to a multichannel analyzer 40 (FIG. 7). The latter stores output data indicating the angular position and intensity of the diffraction data. Furthermore, the detector and analyzer will be described below. The test sample 20 and the detector are placed horizontally on the outer periphery of the focal circle 41 (impingement circle in FIG. 1) of the X-ray diffractometer. The X-rays are best concentrated at all points of the circle, making diffraction data analysis most accurate. Although the sample 20 is fixed, the detector is attached to a bracket 42 that rotates about a post 44. The strut is screwed to a block 46 which is attached to the base 19 by means of equipment not shown. Block 46 is positioned so that post 44 is in the center of focal circle 41. In this arrangement, the detector can be rotated to the next position of the focal circle if data is to be measured over a wider range of angles than if it were extended in one direction relative to the detector. The surrounding block 24, in which the sample is placed in the path of the x-ray beam 32, is covered by a cover 48. Holes are drilled in the walls of the block 24 and the cover 48 to allow the X-rays to pass through.
An inlet 50 for receiving the radiation and an exit slit 52 for the X-rays are made (FIGS. 2-4). The entrance section 50 directs the focused X-ray beam 32 towards the sample.
conically inclined to minimize strength loss,
It narrows inward. A small hole 51 is made in the side of the sample holder 96 near the sample pan 22 in order to cause the X-rays to directly impinge on the sample 20. Typically, a sample holder cover (not shown) on top of sample holder 96 will need to be reshaped or removed if diffracted x-rays are to be emitted from sample holder 96 and surrounding block 24. X-ray entrance section 51
and the top of the sample holder for optimal DSC
To obtain calorimetric sensitivity, it is necessary to cover with an X-ray transparent material that minimizes undesired radioactive and convective heat transfer from the sample. Furthermore, if the room in the block is to be gas-tight, the inside and outside of the inlet and outlet slits may be covered with films 54, 56 of an X-ray transparent material such as sheets of beryllium or Mylar (polyethylene terephthalate resin). . The Mylar window has the advantage of allowing visual inspection of the sample at any time during testing if the sample pan is uncovered. To position the sample 20 in the X-ray beam,
The sample holder device 18 is adjusted and mounted in all directions by fixing it to a mounting device 58 (FIG. 2) on the base 19.
The sample holder device block 24 is mounted on a plate 60 which is inclined so that the X-ray beam 32 impinges on the sample 20 at an angle. Additionally, the tilted block provides good thermal contact between the sample pan 22 and the sample holder 96. The plate is secured to the pedestal 62 by pins 72 to the perforated, threaded stanchions 64.
is fixed. The other end of the post 64 is attached to a mounting block 66. Natsuto 6
8 is adjusting the sample holder device vertically. For side adjustment, the mounting block 66 is slid sideways onto the base 19 which is fastened with screws. The sample holder is thus rotated to the desired position and fixed in place by the fixing screw 71. The X-ray detector 36 of the preferred embodiment of the present invention is a linear position sensitive proportional counter and is a commercially available unit. This is shown in FIG. The detector has an elongated, shallow, box-shaped housing 74. Terminal 76 is insulated from the housing and is a high resistance carbon coated quartz fiber.
It supports one straight anode counter wire 38. A high voltage is applied between this wire and one or more cathode elements 75 parallel to it. Diffraction X-ray photon 34
enters the counter through and begins gas ionization characterizing the inlet location along the counter wire. An external electrical circuit supplies the desired voltage and records the angular position and intensity of the diffracted X-rays. A gas mixture such as argon-methane or xenon-methane is introduced into the inlet 82 and outlet 82' (FIG. 7).
is passed under pressure through the housing to maintain the sensitivity and efficiency levels of the detector in a known manner. On the other hand, a curved detector shown in FIGS. 6A and 6B may be used instead of the linear detector described above. Housing 75a is arched and supports curved counter wire 38a. Such a curved counter is described in US Pat. No. 4,076,981. Many position sensitive detectors are optimized for either speed, detection area, or resolution.
Depending on the particular experiment, one type of detector may be preferable to another (see, for example, reference (1) below for a detailed discussion of common errors associated with these detector receivers). Good luck). The following references are
These detectors are described. (1) RA Newmann, TGFawcett, P.M.
Kirchhoff, Advance in X-ray Analysis,
Vol.27, 1984 (in press) (2) HEGo¨bel, Advances in X-ray
Analysis, Vol.22, 1979, p.255-265. (3) HEGo¨bel, Advances in X-ray
Analysis, Vol.25, 1982, p.315−324. (4) CORuud, Industrial Research and
Development, January, 1983, p.84-87. (5) Proceedings of the Symposium on New
Crystallo-graphic, Detectors,
Transactions of the American
Crystallographic Association, Vol.18,
1982, R.C. Chamlin, Ed. The control and display devices associated with detector 36 are shown in FIG. The gas atmosphere in the detector is supplied by a feeder 8 that regulates the flow and pressure.
Supplied from 4. The high voltage on sensitive wire 38 is delivered from source 86 . X from detector
The line output data is processed by the digital analyzer 40.
Approximately 1,500 separate channels are stored therein, each corresponding to the location of the wire 38.
The detector and analyzer thus detect incoming X-ray photons and record diffraction data as the angular position or address at which the diffracted photon enters the detector chamber and its number of incidences at each position. 20°
The analyzer records 1500 channels with a detector receiver having an angular range of (2 seaters), allowing the selection of an arc of approximately 0.8 minutes to identify the angle of incidence. The analyzer for immediate analysis has a video terminal 88 that illustrates the data stored in the analyzer.
connected to. Furthermore, the raw data is sent to a computer 90. The computer records and outputs parameters such as angular position, peak intensity magnitude, peak area and half-width, and other desired parameters, such as peak fitting and data reduction procedures,
Programmed with smoothing and background-suppression algorithms. The output of the computer is the video terminal 9.
2 and recorded on the plotter 94 or printed on the printer 95. Diffraction data in which the intensity of the X-ray diffraction lines is expressed as a function of diffraction angle as in FIG. 15 constitutes the final data output of the diffractometer of the apparatus of the present invention. The detector and control and reading device are
It is commercially available. The use of the detector and the analysis of the results are known. For information on detector-counter tubes and appropriate electrical circuit components, see N.Broll, M.
Henna, W. Krantz, Siemens Corporation
Application Note, 57, Sept. 1980, Cherry
Hill, N.J., and Analytical Applications
Notes No.271from Innovative Technology,
Inc., South Hamilton, MA. As shown in FIGS. 2-4, the sample 20 and pan 22 are placed in a sample holder 96 mounted within the enclosure block 24, which is preferably made of metal, such as aluminum. This block provides a protective chamber and temperature controlled environment for the calorimeter. Although not shown in the drawings, this block is also provided with ancillary equipment for circulating liquid for cooling or heating purposes. The interior of the room is made gas-tight by a cover 48. Sample pan 22 is placed on thermally conductive sample holder 96 (FIG. 4) of block 24.
The holder is supported by a center column attached to a holder support disk 99, and a resistance heating element 100 and a resistance temperature -
It has a sensitive element 102. These elements are connected by leads to electronic control and sensing circuitry shown in FIG. Also located within block 24 is a control or comparison holder device (generally designated 96') for supporting any calorimetric comparison sample (not shown) placed in control pan 22'. In the known operation of a common type of differential scanning calorimeter, the same "average" power is applied to both heating elements 100 and 100' to determine the temperature of the sample and the reference material and the thermal behavior of the sample is analyzed. Control gradually and continuously over a temperature range. 2 heat measuring elements 10
The temperature indicated by 2,102' is measured throughout all scans by a control system which acts to maintain equilibrium by providing the required amount of power to the heating elements. If the sample is endothermic, the control system provides large differential power to the sample to equilibrate the sample and reference temperatures. For exothermic reactions, apply a small differential power to the sample. The magnitude of this differential power is the magnitude of the physical or chemical process. The values indicated by the instrument operations described herein are one of the principal parameters or outputs of the apparatus of the present invention. The control system (FIG. 9) uses an internal electrical circuit (FIG. 9) to direct the programmer 104 (with attached temperature recorder 106) to whether the test temperature condition is heating, cooling, isothermal, or a combination of these operations. (not shown) must be adjusted in advance. A programmer with a computer 108 that manages the temperature averaging network controls an amplifier 110 that provides main (or average) power to the sample and control. Differential power is provided by a second amplifier 112 and measured by a recorder 114. As shown, the electrical circuit consists of control loops for average temperature and for differential power. Solid state digital control systems are commercially available. Its use and analysis of results are known. For further details, see E. S. Watson et al., Analytical Chemistyr, 36,
1233-8 (1964) and U.S. Pat. Nos. 3,263,484 and 3,732,722. Recorders 106 and 114 (FIG. 9) are
Connected at the terminals and plotted at 115 (FIG. 11), a chart showing the change in differential power as a function of temperature is displayed. Such a DSC curve (shown in FIG. 12a) is the final output data of the calorimeter section of the apparatus of the present invention. A major feature of the present invention is that these calorimeter data are accurately correlated with X-ray diffraction data simultaneously obtained by a diffractometer. Insight into both the structural and thermodynamic properties of the sample is therefore possible. The X-ray diffraction unit shown in Figure 1 above is
It uses a Guinier diffraction system arrangement,
It is equipped with a Huber curved focusing crystal monochromator. On the Guinier system, sample 20
is located at a certain point around the 41st focal circle of the refractometer,
The detectors 36 are located at different points on the circumference. The x-ray beam 32 is focused through the sample, but is not sharply focused onto the sample. The focus is on the third point 1 of the 41st circle
It is 16. The actual reason is that the main beam ends up being unfocused due to the cessation of the X-rays. The X-rays 34 diffracted by the sample reach the true focus at a point around the circle 41 of the detector 36. this
For information on the Guinier device and its significance, please see HE
Advances in X-Ray Analysis by Go¨bel,
25, p. 315-324 (1982) and TGFawcett et al., Ioc.cit., 26, p. 171-180 (1982). The Guniner configuration, although preferred, is not essential to the invention. FIG. 8 shows another system, the Bragg-Brentano system. In this system, the x-rays 28 have their own focal circle 4
It is generated by a source 26 at one point in one revolution. The sample is placed at its center 120 instead of being located at the circumference.
Located in The sample is either at the reflection 21 or through 23 position. X-rays diffracted from the sample are measured by a detector at points on the circumference of the focal circle 41. This system also
Advances in X-Ray by Go¨bell
Analysis, 22, p. 255-265 (1979). Yet another arrangement which is satisfactory in the present invention is the Debye-Scherrer arrangement described in U.S. Pat.
It's from camera. As the X-ray configuration, either a wide-angle or narrow-angle configuration, ie, a Shatton configuration, is suitable. Monochromatic focal sources are preferred. High resolution systems are useful. Another diffractometer and DSC arrangement is shown in FIG.
In this case the X-ray beam passes vertically towards the bottom of the sample holder. Such an arrangement provides improved DSC sensitivity due to improved thermal contact and improved X-ray sensitivity due to placing more samples directly in the x-ray beam. The arrangement of FIG. 10 provides simultaneous x-ray and calorimetry measurements using an enclosure block 24 placed horizontally on a desk. The x-ray beam 32 is vertical upwards, entering the entrance window at the bottom of the block and exiting through the exit window at the top of the block. Then diffraction X-ray 34
is emitted from the exit window to the detector 36. The sample holder and holder column have, for example, a hollow center section for X-ray transmission. The sample is placed in a dish made of X-ray transparent material (not shown)
can be placed in While many diffractometer configurations are possible with the present invention, there are also many different sample and sample enclosure arrangements for the x-ray beam. For example, the arrangement according to FIG. 10 utilizes a Bragg-Brento arrangement (FIG. 8) as the diffractometer arrangement instead of the Guinier transmission arrangement (see FIG. 1). Debye−Scherrer
The placement is also suitable. In general, all arrangements are available in which the sample can be impinged with an X-ray beam and the diffracted X-rays can be measured by a position-sensitive detector. The simultaneous measurement of X-ray patterns and calorimetric data according to the present invention is used to advantage in studying phase transitions during the combination reaction of solid or semi-solid samples with gases. Such studies are particularly valuable in investigating oxidative and reductive changes in complex metal oxide compositions used as heterogeneous catalysts. For this purpose, the 11th
The arrangement shown in the figure is used. The sample is placed in a sample block 24 with an inlet 144 for introducing gas and an outlet 146 for releasing gas. The sample block is equipped with a cover, and contact with the gas inside the enclosure takes place through these inlets and outlets. Surrounding block 24 is positioned so that x-rays 32 impinge on the sample. Diffraction lines 34, 34'
is accepted by detector 36 and its production
Line data is PSPC electronic module 39 (7th
The data is stored in the multi-channel analyzer (detailed in the Figure) and displayed on terminal 88 as previously described. The calorimetric signal from the enclosure obtained by scanning the temperature of the sample over the range to be studied is received by the DSC electronic control unit 113 (detailed in FIG. 9) and displayed on the recorder 115. For research purposes, a reactive gas such as hydrogen or compressed gas from cylinder 130 or cylinder 131 may be used.
and a carrier gas such as nitrogen from another cylinder 132 are used. Gas is flowed through purification and pressure regulation unit 134. The gases merge in the mixing chamber 142 and then enter the inlet section 1.
44 into the sample block 24 and comes into contact with the research sample. The gaseous reaction products are
Via the outlet 146, a switch valve 139 leads to a flow meter 138 or a gas analyzer. Structural and chemical changes that occur in the sample during the scan are further identified and quantified by the gas analyzer 141 display by comparing the x-ray diffraction pattern and the calorimetric signal. The thermal analysis device forming part of the apparatus of the present invention has been described as a power-corrected differential scanning calorimeter (DSC). This DSC is Perkin-Elmer
Model DSC-2 (US Patent No. 3263484 and
No. 3732722) and is publicly known. Although this one is suitable for the present purpose, other types of differential scanning calorimeters known in the literature can also be used.
For example, commercially available DuPont DSC, Mettler
DSC-20 and Setaram Model DSC.
Additionally, other thermal analysis units that are not strictly calorimeters are also useful. For example, Mettler Model TA10
and a differential thermal analyzer (DTA) such as the DuPont DTA. As mentioned above, the present invention can be applied to any individual DSC.
Nor is it limited to DTA. It is only necessary that the analyzer has a device for controlling the temperature of the sample to be studied and a detection device for measuring and recording parameters indicating the thermodynamic behavior of the sample as it changes. "Thermodynamic properties" are a broad range of calorimetric properties of a sample that can be measured using a DSC or DTA instrument. For DSC, this generally means measuring enthalpy change or specific heat capacity. Also for DTA, this generally means the qualitative or semi-quantitative measurement of exothermic and endothermic events as a function of some temperature of the study sample. The method of operation of the apparatus of the present invention, which is believed to be largely obvious from the foregoing, will be described in further detail below. The apparatus and method are useful for simultaneously measuring thermodynamic and structural properties of materials. Single crystal solids, polycrystalline solids, inorganic substances, drugs, organic substances, and mixed substances, or lumps or powders,
It is advantageous for studying solid or semi-solid plastics in film form as well as liquid plastics and the like. In operation, the sample 20 is first placed in the sample holder 96. At the same time, the control sample is also placed in the control dish 2 in the control sample holder 96'.
Put it in 2'. This sample holder device 18
provides at the same time to hold the sample in place relative to the X-ray diffractometer and to constitute a calorific chamber for thermal analysis. The sample holder containing the sample and control sample is carefully adjusted and mounted so that the sample is in the X-ray beam path at a point in the focal circle of the X-ray diffraction unit. The control and readout circuits for both the diffractometer and calorimeter are then prepared. Further preparations are made if the gas atmosphere is to be circulated into the sample chamber. Controls are then programmed to heat the sample and reference material to the measurement temperature range, and the heating rate is also preset. Once all preparations are complete, use the X-ray diffractometer and calorimeter. Scanning is then automatically started. The diffractometer reading indicates that the X diffracted from the sample
Measure and record the angle and intensity of the line. (These are the magnitudes of the angular positions of the diffraction peaks). This recording is displayed by a plotter 94 whose intensity is shown as a function of the diffraction angle. This plot is repeated at predetermined time intervals. The same data is visible on video terminal 88 for immediate monitoring by the operator. At the same time, the scanning calorimeter measures and records both the temperature of the sample at each time during the scan and the differential power if necessary to equilibrate the sample and reference temperatures. This record is displayed as a chart by recorder 115 with differential power shown as a function of temperature. The temperature line is also checked hourly. If desired, this data can be viewed visually on the terminal. The scan continues until a predetermined end temperature is reached, at which point the measurement ends. To analyze the results, the analytical operator compares the diffraction and calorimetric data. Time marks in the data confirm simultaneous events. Therefore, if the calorimeter data indicates a thermal event when a certain temperature is reached in the scan, then
The corresponding diffraction data will show what changes have occurred in the diffraction pattern at the same time. The analyst examines the diffraction patterns and compares them to standard reference patterns known in the literature as identifying numerous crystalline samples. This comparison identifies the phases involved in the change and the nature of the change. With the device of the present invention, diffraction spectra and thermal events are rapidly detected and recorded, so that
The entire scan over a percentage of Thus, the analyst can detect rapid crystallographic events such as the appearance and disappearance of transient phases with short-lived spans that could not be captured by prior art methods. Furthermore, analysts have tested complex mixtures and found that only 2
It is also possible to detect and identify continuous phase changes in individual components that occur within temperatures of ~3°C. It is also possible to investigate chemical interactions of mixtures in multicomponent mixtures. Moreover, with the apparatus and method of the present invention, thermal structural changes, molecular orientation, crystallization, deformation stress, and deformation as a function of temperature can all be measured in a single experiment with precise temperature control and rapid analysis. can. In prior art methods, these measurements were not possible or such indications were overlooked or misinterpreted. A further advantage of the present invention is that it can be operated upon again when a thermal event or phase change occurs at a temperature and is observed in the first span, but not all details of the event are known. That is, when the temperature of interest is approached, the temperature increase can be stopped or its rate can be made very small and another scan can be started using the same sample or a new sample. This requires only simple control circuit adjustments, so that the temperature rise can be stopped or its rate changed mid-scan if a change is clearly needed. By performing X-ray and thermal measurements over a wide range while holding or gradually increasing the temperature, scientists can capture critical details that would otherwise be undetectable with rapid spans. The ability to perform interaction analyzes that are mechanical in that test parameters can be adjusted during testing allows for the identification and characterization of previously unresolved or unknown structural and thermal relationships. It became possible to The method of the invention is particularly useful when passing a reactant gas through the sample to be analyzed. The scan can be interrupted at any time so that the thermal and structural changes caused by the reaction with the gas can be measured in detail while the changes are taking place. Although the above description is based on the temperature scanning heating the sample, it is equally possible in the present invention to scan the temperature down. Measurements can be started with increasing temperature and further cooling occurs naturally or at a rapid rate. Artificial cooling can be applied to investigate the range below room temperature. The device can operate from temperatures as low as liquid nitrogen to temperatures of 600 degrees Celsius or more. EXAMPLE 1 The use or operation of the present invention is further illustrated in the following example. X-ray diffractometer (XRD) 17 (Figures 1 and 7)
In Figure), the incident X-ray beam 28 was generated by a Phillips generator providing a Cu X-ray line source.
A Guinier diffraction system with a Huber curved focal germanium crystal monochromator was used to separate CuX〓 ₁ radiation from CuK〓 ₂ and CuK〓 ₃ radiation. Generated incident beam 3 focused on the sample
2 was monochromatic (wavelength = 1.5406 Å). A Braun curved position-sensitive proportional counter tube was used as the detection tube. This detector, having a voltage supply 86 and a multichannel spectrometer 40, simultaneously collected diffracted X-rays over approximately 20 degrees (2θ). 0 to 70° by moving the detector to various positions around the column
The operating angle of 2θ was adjusted to a range that could be touched. Differential scanning calorimeter (DSC) is Perkin-Elmer
DSC-2 was used. Sample holder device 18
was made from the DSC-2 oven. The X-ray inlet and outlet were made by drilling holes in the aluminum block and covering them with 0.1 mm thick Mylar film to seal them. Sample 20, typically about 20 mg, was placed in 0.02 mm aluminum foil and placed in sample holder 96. Holes were punched in the foil to provide a full beam if the x-ray intensity was otherwise insufficient. The operating parameters of the X-ray machine were as follows. X-ray source Cu line source, long and sharp focus. Current: 20mA Voltage: 40KV PSPC gas: 90% argon, 10% methane Gas pressure: 11~12bar Gas flow rate: 1.0cc/hr PSPC voltage: 4.0~4.4KV The multi-channel analyzer 40 receives continuously measured diffraction data generated via a video terminal. collected. After collection, the X-ray data file was transferred via a commercially available computer interface 87 to the hard disk of a PDP-11/34 computer for storage and analysis. After the test is finished,
The patterns were processed in a known manner by inputting them into peak fitting and data reduction means to obtain parameters such as peak position, area, half-width, etc. (JW
Advance in X-Ray Analysis by Edmonds et al.
22, p. 143 (1979)). Migration time was approximately 30 seconds for a 1200 point data file. The DSC in operation of this device was scanned at a preset speed. Normally 20℃/min
~1.25°C/min. X-ray diffraction patterns were assembled at the desired temperature along the scan with an acquisition time of less than 5 minutes per pattern. Example 2 In a demonstration test, a sample of polyethylene was heated until it melted (Figures 12A and 12B).
Cooled to room temperature (Figures 13A and 13B)
figure). This cycle was performed at 2.5°/min, and X-ray diffraction data were taken at 2 minute intervals. Correlation between caloric and structural data indicates the crystallinity of the sample as a function of temperature and caloric behavior. Example 3 In another example, DSC/XRD was used to investigate the interconversion of two organic polymorphs. A representative rapid DSC scan of this compound is shown in Figure 14A. This compound was known to exhibit two polymorphic forms with melting points differing by 3-4°C. Previous laboratory analyzes of X-ray diffraction and differential scanning calorimetry, performed separately, have shown that quantification of polymorphs by these methods gives similar but not identical results. DSC/XRD to investigate measurement differences
We conducted simultaneous tests. Conventional microscopic measurements during the heating stage indicated that the low-temperature melting form ( ) would slowly transform into the high-temperature melting form ( ) during heating, but microscopy could not discern the difference between the two structures. Because I was unable to do so, I was unable to clearly understand the phenomenon. In order to investigate the state of deformation, a sample of the pure low-temperature melt form () was placed in the device and an XRD scan was taken. When the sample was heated slowly (1.25°C/min), a melting exotherm was first observed at the DSC altop at 145°C (Figure 14B). Then, while keeping the temperature constant for 3 minutes,
An XRD scan was taken (Figure 15). The sample was subjected to a cycle in which the temperature was gradually increased until the DSC indicated that the endothermic peak was reached, then held constant and another XRD scan was taken. At this point, further XRD scans were taken while keeping the sample temperature constant. Finally, the temperature was lowered to 100°C at a rate of 10°C/min, and further XRD scanning was performed. The total operation time required only 25 minutes. The data obtained from this operation is shown in FIG. Comparing the peaks in the diffraction spectra of the first scan at room temperature and the last scan at 100°C reveals that the () shape is transformed into ().
Furthermore, it can be seen that the two scans taken at the melting endothermic peak show a small ( )-shaped crystalline peak that remains superimposed on the background. Analysis of these peaks using a computer peak fit procedure indicates that the final conversion from one phase to the other during testing was approximately 88%. The implementation of the present invention allows for precise temperature control that allows X-ray diffraction detectors to measure interconversion of polymorphs. If the temperature is too high, both polymorphs melt without interconverting. Also, if the temperature is too low, both substances remain solid and do not convert. Interconversion will occur if the temperature is between 145-148°C. of interaction
The DSC data indicates to the experimenter the exact point of endothermic melting and potential interconversion. X-ray data is used to identify not only interconversion, but also the rate and termination of conversion. In short, DSC provides precise temperature control and indicates the onset of endotherms, while X-ray data identifies and measures the rate of polymorph interconversion. This is done in one experiment, one sample. These results demonstrate that quantification of polymorphs by conventional DSC was misinterpreted due to polymorphs melting and even interconverting during tests to match conventional DSC and XRD data. It shows. The apparatus and method of the present invention can be used to study the correlation between simultaneous structural (eg crystallographic) and thermodynamic changes in materials and to elucidate a variety of phenomena. In the plastics industry, the stress relief of the crystal lattice is tested during the quenching of thermoplastics such as molded polyethylene: the crystal size, structure and crystallinity are all measured here. Combined DSC/
The XRD test is shown below. This example is a simultaneous
This shows that DSC/XRD testing can provide information not available using either device alone. Example 4 DSC data for polymer analysis shows one endothermic peak at 185°C. However, X-ray data taken at the same time shows two structural events at the same temperature. One of the events is crystallization (heat generation) of a portion of the sample. Therefore, the device of the invention (DSC/XRD) shows that the observed DSC endotherm is actually a combination of a large endotherm and a small exotherm (i.e. two thermal events instead of one). . A phenomenon in which the precise temperature control of the instrument allows X-ray detection and measurement of two events at the same temperature, and the heat transfer at 185 °C is associated with two events of opposite heat flow (i.e. exotherm and endotherm) is being elucidated. Example 5 A multicomponent product containing a mixture of inorganics, organics and polymers was analyzed with the apparatus of the invention. Furthermore, tests were conducted under the same temperature, atmosphere heating time, and heating rate conditions as in conventional methods. The samples were rapidly heated and cooled in cycles from 23 to 300 °C. The total test time was 90 minutes.
DSC data shows three events. Conventional comparisons of the multicomponent product with standards for each of the materials that make up the product have only identified the glass transition of the polymer. Two other events, an exotherm and an endotherm, could not be identified by comparison with standards. DSC/XRD tests showed that the exotherm was due to crystallization of organic matter in the polymer matrix. The endothermic transfer was shown by X-ray diffraction data to be the dissolution of organics into the sample matrix. Dissolution of organics into the product was carried out at 70°C, which is below the melting point of pure organics. When the tests were performed at different acceleration rates or under different atmospheres, the exothermic and endothermic shifts shifted up to 40°C. Therefore, in order to identify the structural nature of heat transfer, it is necessary to be able to obtain both X-ray diffraction and calorimetric data simultaneously. Prior art devices have not been able to provide the same speed or temperature control as the device of the present invention. Furthermore, this test demonstrates how complex mixtures can be analyzed by the apparatus of the invention and how the chemical interactions between the components of the mixture (i.e. crystallization and dissolution in situ at a melting point of 70°C) ). Additionally, the present invention is critical because other tests have shown that impact strength is affected by the degree to which each component is mixed into the mixture. Example 6 A copper compound mixed with several copper compounds and additives for potential use in catalysts was analyzed using the DSC/XRD apparatus of the present invention.
The test usually consists of three parts; the first is careful preheating in a controlled atmosphere (N ₂ or an oxidizing gas mixture), the second is reduction under a mixed H ₂ /N ₂ atmosphere, and the third is A catalyst regeneration program that includes oxidation and reduction. DSC/XRD equipment carefully controls temperature during all testing steps. In catalysis research, this temperature control prevents undesirable rapid exothermic reactions (such as those in the reduction of metal catalysts).
can be prevented. in the preheating stage
DSC/XRD equipment can accurately measure thermal decomposition by correlating DSC data with the measured X-ray diffraction pattern. Correlative data on multicomponent mixtures fix the thermal changes of substances and the degree and rate of that change. Catalysts generally consist of an active material, a multicomponent substrate, and other materials such as a binder and a pellet lubricant. DSC in reduction test performed at constant temperature
The data shows the beginning and end of the reduction. This is important because the X-ray diffraction data is the result of large changes and is not sensitive to the small changes seen in the DSC data (ie, very late stages of initiation and termination of reduction). Typically, X-ray diffraction methods are sensitive to crystalline changes of 1% of the total weight. DSC data shows amorphous changes in substances and 1%
It is also possible to detect certain changes that do not exceed .
XRD data is used to determine that the material is being reduced. In the same manner as in Example 3, the reductive exotherm at high temperature was generated in one step.
Tests were conducted in which combinations of CuO, Cu ₂ O and Cu salts were all reduced to Cu (metal) at the same time. Additionally, >50% of reducing (or oxidizing) substances are reduced (or oxidized) in less than 5 seconds.
Tests were also conducted. Thus, the speed of the apparatus of the present invention allows for the identification and reaction rates of thermal-structural materials that were previously impossible to identify or measure. The times and temperatures in all stages of the catalytic cycle (oxidation, reduction, regeneration) can be optimized using the present invention. For example, if a catalyst with a large surface area is desired, the apparatus of the present invention can be used to optimize the cycle described above to obtain the desired physical properties in a very short production time or in a very inexpensive manner. be able to.

[Brief explanation of drawings]

FIG. 1 is a top view of a combined X-ray diffraction analyzer and differential scanning calorimeter according to the present invention, with the electronic control and recording system omitted. The figure shows the equipment according to the arrangement of the Haber-Guinier system. FIG. 2 is a partial side view of the central portion of the device of FIG. 1, enlarged to show the sample container and its attachment; FIG. 3 is a perspective view showing the inside of the sample container of FIG. 2; FIG. 4 is a cross-sectional elevational view of the sample container taken along line 4--4 of FIG. 3, showing the sample holder with heating and temperature sensing elements. Additionally, the figure shows the gas inlet and outlet. FIG. 5 is a sectional view of the linear position-sensitive proportional counter used as the X-ray detector shown in FIG. 6a and 6b are cross-sectional views of a curved position sensitive proportional counter used as a replacement for the counter of FIG. Additionally, this figure shows the typical errors associated with these types of detectors.
FIG. 7 is a block diagram illustrating the detector control and recording system of an X-ray diffractometer of an instrument according to the present invention. Figure 8 shows Bragg-
FIG. 3 is a schematic diagram of another X-ray diffractometer using the Bentano system arrangement. FIG. 9 is a block diagram of a differential scanning calorimeter electronic sensitivity and control system forming another part of the instrument of the present invention. FIG. 10 is an elevational view of an alternative device configuration in which the x-ray beam is directed vertically upwards. FIG. 11 is a block diagram illustrating the relationship of the control and recording system of the entire apparatus according to the present invention, including the system for delivering gas to the sample container and analyzing the effluent gas from the container. Figures 12A and 12B
The figure shows a typical X-ray diffraction pattern (Figure 12B) created by the device of the present invention during a heating cycle.
and the corresponding DSC scan (Fig. 12A). Figures 13A and 13B are the same as the records in Figures 12A and 12, respectively, except that they were made during the cooling cycle. Figures 14A-C show polymorphic organic compounds.
These are the DSC scans before the DSC/XFD test, during the test, and after the test. FIG. 15 shows an X-ray diffraction pattern produced by the apparatus of the present invention showing the interconversion of polymorphs from low melting point to high melting point. Figure 5 shows the PSPC gas chamber. Figure 6A shows a curved PSPC. Figure 6B shows a curved PS.
Shows PC. The left side of FIG. 9 shows the differential temperature control loop, and the right side shows the average temperature control loop. Figure 11 shows the DSC/XRD system. Figure 12A is the heating cycle (25°C/min). Figure 13A is the cooling cycle (2.5℃/min)
It is. Figure 14A shows a rapid (20°/min) scan of the original sample. Figure 14B shows a rapid (20°/min) scan of the sample after the internal action experiment.
In Figure 14B, the internal action DSC/XRD experiment used for internal conversion formed and the material was heated continuously and held isothermally for 3 minutes, then heated to a slightly elevated temperature and held for 3 minutes. The only selected X-ray diffraction corresponding to this DSC scan is shown in FIG. 15th
Figure legend, from bottom to top, X-ray diffraction data were obtained during internal action DSC/XRD experiments. Each data scan represents two detailed data collection periods for position sensitive sensing. Diffraction peaks unique to a particular polymorphic structure are indicated as and. exhibits a high melting polymorphism, and exhibits a low melting point profile.

Claims (1)

[Scope of Claims] 1. An X-ray diffractometer having an X-ray beam source and a detector; a temperature-controlled sample holder device for the measurement sample located in the path of the X-ray beam emanating from the diffractometer; and the measurement sample. In an apparatus for simultaneously measuring the structural and thermodynamic properties of a substance, including a thermal analyzer for the purpose of at least one receptacle and an inlet and an outlet for the passage of the X-ray beam into and out of the holder device for diffraction of the X-ray beam by the measurement sample, the X-ray transparent material at the inlet; and an outlet, and the thermal analyzer is a differential scanning calorimeter or a differential thermal analyzer for determining the thermodynamic properties of a sample. 2. The device of claim 1, wherein the sample holder device has a substantially gas-tight enclosure and the X-ray transparent material covering the opening is beryllium or polyethylene terephthalate. 3. The apparatus of claim 1 or 2, wherein each of the measurement sample and control sample is located in a holder, and the holder has a resistive heater and a temperature sensor, respectively. 4. Each of said holders is mounted within said receptacle on a post and is provided in a gas receptacle with a passageway permeable to gas contacting the sample contained in said sample holder. equipment. 5. Apparatus according to any one of claims 1 to 4, including a monochromator placed in the path of the x-ray beam to provide a focused monochromatic beam. 6. The apparatus of any of claims 1 to 5, wherein the X-ray source is a source with a Guinier diffraction system and a curved focusing crystal monochromator. 7 a position-sensitive detector is located on the focal circle, the measurement sample is located at a point along the focal circle, and the detector is movably mounted along the focal circumference and the multichannel analyzer The device according to any one of claims 1 to 6, which is connected to the device. 8 a position-sensitive detector is located on the focal circle, the measurement sample is located at a point in the center of the focal circle;
8. The apparatus of claim 1, wherein the detector is mounted along the circumference of the focal point and is connected to a multichannel analyzer. 9 an X-ray diffractometer with an X-ray beam source and a detector, a temperature-controlled sample cell for the measurement sample in the X-ray path of the diffractometer, and a thermal analyzer for the measurement sample in the sample cell; In an apparatus for simultaneously measuring the structural and thermodynamic properties of a containing substance, said detector is a position-sensitive detector, and the provided closed sample holder block has two parts for a measurement sample holder block and a control sample holder. two receptacles or one common receptacle, an inlet for the X-ray beam to the sample cell and an outlet for the X-ray beam diffracted by the measurement sample from the sample cell and said inlet and outlet. having an inlet and an outlet for an X-ray transparent material in the chamber, said one or two chambers being connected to a gas supply to provide a controlled gas atmosphere, and said differential scanning calorimeter or differential thermal analyzer is connected to its measurement sample holder and its reference sample holder.