Detailed Description
The invention provides an application of a temperature-sensitive polymer in a temperature sensor.
The invention also provides a temperature sensor, which comprises a rubbed object and a back electrode stuck on the rubbed object; a temperature sensitive polymer layer coated on the back electrode; the rubbed object and the rubbing body form a rubbing pair; the temperature-sensitive polymer layer is in contact with the friction body, and the back electrode is connected with a current collection system through a lead.
The temperature sensor provided by the invention comprises a rubbed object, wherein the rubbed object is preferably a solid.
The temperature sensor provided by the invention comprises a back electrode adhered to the rubbed object, wherein the material of the back electrode is preferably a copper adhesive tape or an aluminum adhesive tape; the thickness of the back electrode is preferably 0.05-0.10 mm. In the invention, the back electrode is connected with a current collection system through a lead; the current collection system preferably comprises a wire and a charge collector; the lead is preferably located between the temperature sensitive polymer and the back electrode; the diameter of the wire is preferably 0.1-1.0 mm.
In the present invention, the back electrode is capable of conducting electric charges.
The temperature sensor provided by the invention comprises a temperature-sensitive polymer layer coated on the back electrode, wherein the material of the temperature-sensitive polymer layer is preferably poly (N-isopropyl acryloyl), poly (2- (N, N-dimethylamino) methacrylate), N-ethyl morpholine methacrylate, poly (2-carboxyl isopropyl acrylamide) or poly (ethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer), and is further preferably poly (N-isopropyl acryloyl) (PNIPAM).
In the present invention, the poly N-isopropylacryloyl (PNIPAM) is preferably prepared by a method comprising the steps of:
adding N-isopropylacrylamide (NIPAM) and Methyl Methacrylate (MMA) into Dimethylformamide (DMF), adding Azobisisobutyronitrile (AIBN), stirring to dissolve, introducing nitrogen for 220min, and heating in an oil bath at 80 ℃ for 8h to obtain a viscous solution;
and adding water to precipitate the polymer in the viscous solution to form a yellow solid, and washing the yellow solid with methanol to obtain the poly N-isopropyl acryloyl.
In the present invention, the mass ratio of dimethylformamide, N-isopropylacrylamide, methyl methacrylate, and azobisisobutyronitrile is preferably 20:3.39:1: 0.04.
In the present invention, the thickness of the temperature-sensitive polymer layer is preferably 10 to 20 μm.
The temperature sensor provided by the invention comprises a friction body, wherein the friction body is preferably solid or liquid; the thermosensitive polymer layer on the rubbed object is contacted with the rubbing object, and the contacting mode is preferably rubbing.
The temperature sensor is adopted to establish the relationship between the environment temperature of the temperature sensor in the friction electrification process and the friction electrification charge amount, the relationship between the environment temperature of the temperature sensor and the friction electrification charge amount can be directly established, the monitoring of the friction electrification environment temperature is realized, and the application range of the temperature-sensitive polymer is expanded.
The invention also provides a use method of the temperature sensor in the technical scheme, which comprises the following steps:
sequentially adhering a back electrode and coating a temperature-sensitive polymer on the rubbed object; the back electrode is connected with a current collection system through a lead; the temperature-sensitive polymer on the rubbed object is contacted with the friction body to obtain the triboelectrification charge amount;
and monitoring the temperature of the environment where the temperature-sensitive polymer is located based on a standard curve of temperature-charge quantity.
The standard curve of the temperature-charge amount is not limited in the present invention, and the technical means known to those skilled in the art can be adopted.
The method of using the temperature sensor provided by the present invention is specifically described below based on the monitoring of the pond water.
A method of monitoring pond water temperature comprising the steps of:
sequentially fixing a back electrode and a temperature-sensitive polymer layer on the wall of the fishpond; the back electrode is connected with a current collection system;
and the real-time monitoring of the water temperature of the fishpond is realized based on a standard curve of temperature-electric charge quantity.
In the present invention, the means for fixing the back electrode is preferably adhesion, and the adhesive is preferably an AB glue. In the present invention, the manner of fixing the temperature sensitive polymer layer is preferably to coat the temperature sensitive polymer on the back electrode. In the present invention, the thickness of the temperature-sensitive polymer layer and the type of the temperature-sensitive polymer are preferably the same as those in the above technical solution, and are not described herein again. In the present invention, the structure of the current collecting system is preferably consistent with the above technical solution, and is not described herein again.
In the present invention, the method for establishing the standard curve based on the temperature-charge amount preferably includes the steps of:
sequentially fixing a back electrode and a temperature-sensitive polymer layer on the wall of the fishpond; the back electrode is connected with a current collection system;
water with different temperatures is respectively added into the fishpond, and under the action of wave energy, the water in the fishpond and the temperature-sensitive polymer layer are subjected to frictional electrification to obtain the charge quantity of frictional electrification;
and fitting the temperature of the water with the charge quantity to obtain the standard curve based on the temperature-charge quantity.
The preferred mode of fixing the back electrode and the temperature-sensitive polymer layer on the wall of the fishpond is consistent with the technical scheme, and the detailed description is omitted. In the present invention, the connection mode of the back electrode and the current collecting system is preferably the same as the above technical solution, and is not described herein again; the structure of the current collecting system is preferably consistent with the technical scheme, and details are not repeated here.
In the present invention, the water of different temperatures is specifically 20 ℃, 30 ℃, 40 ℃ and 50 ℃.
The fitting method is not particularly limited, and the technical means known to those skilled in the art can be adopted.
In the invention, because the water in the fish pond is in a fluctuating state all the time, when the water fluctuates and rubs with the temperature-sensitive polymer, the friction current is displayed by a computer, and the real-time temperature of the water in the fish pond can be obtained based on a known standard curve, so that the influence of the water temperature in the fish pond on the culture is analyzed, and the culture of the tropical fish becomes more scientific. The sensor avoids the trouble of manually adopting a thermometer for measuring temperature, avoids the support of an external power supply of a common thermocouple for measuring temperature, saves resources and is safe.
In order to verify the application feasibility provided by the invention, a specific intelligent temperature sensor is built in a laboratory, and the specific structure is shown in figures 1 and 2.
The invention specifically provides an intelligent temperature sensor which comprises two sheet electrodes 1, namely a first sheet electrode 1-1 and a second sheet electrode 1-2; a circular tube 2 sandwiched between the two sheet electrodes; the central axis of the circular tube 2 is perpendicular to the two sheet electrodes; the sheet electrode 1-1 comprises a substrate 1-1-1, a back electrode 1-1-2 and a temperature-sensitive polymer layer 1-1-3 which are sequentially stacked; the temperature-sensitive polymer layer of the sheet electrode is in contact with the circular tube; a lead 3 is led out between the back electrode 1-1-2 of the sheet electrode and the temperature sensitive polymer layer 1-1-3; the pipe wall of pipe 2 is equipped with annotates the liquid mouth, it is equipped with the lid that can open and shut to annotate the liquid mouth.
The intelligent temperature sensor provided by the invention comprises two sheet electrodes 1, namely a first sheet electrode 1-1 and a second sheet electrode 1-2, as shown in 1 in figure 1. In the present invention, the first sheet electrode 1-1 includes a substrate 1-1-1, a back electrode 1-1-2, and a temperature sensitive polymer layer 1-1-3, which are sequentially stacked, as shown in fig. 2.
In the present invention, the substrate is preferably made of a poly (p-phenylene terephthalate) Plastic (PET); the thickness of the substrate is preferably 200 mm.
In the present invention, the material and thickness of the back electrode are preferably the same as those of the above technical solution and are not described herein again. In the present invention, the material and diameter of the conducting wire are preferably the same as those of the above technical solution, and are not described herein again.
In the present invention, the thickness and material of the temperature-sensitive polymer layer are preferably the same as those in the above technical solution, and are not described herein again.
The intelligent temperature sensor provided by the invention comprises a circular tube 2, wherein the material of the circular tube 2 is preferably polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl chloride, polypropylene or polycarbonate, and is further preferably polytetrafluoroethylene; the internal diameter of the circular tube is preferably 3cm, the length is preferably 5cm, and the wall thickness is preferably 0.2 cm. In the invention, the pipe wall of the round pipe is provided with the liquid injection port, and the shape and the size of the liquid injection port are not particularly limited as long as liquid can be injected into the round pipe. In the invention, the liquid injection port is provided with a cover which can be opened and closed; the material of the cover is preferably polymethyl methacrylate (PMMA). In the present invention, the circular tube is in contact with the temperature sensitive polymer layer of the electrode; the round tube and the temperature-sensitive polymer layer are connected through an adhesive.
In the invention, the temperature-sensitive polymer in the temperature-sensitive polymer layer is contacted with liquid injected into a round tube, when the temperature of the liquid is different, the hydrophilicity and hydrophobicity of the temperature-sensitive polymer contacted with the liquid are different, and the electric quantity brought by friction when the temperature-sensitive polymer is contacted with the liquid is different due to the change of the hydrophilicity and hydrophobicity of the temperature-sensitive polymer; that is to say, the temperature of the liquid in the round tube and the charge amount of the temperature sensitive polymer layer form a certain linear relation, and then the temperature of the liquid to be measured can be obtained by observing the charge amount of the intelligent temperature sensor.
The invention provides a using method of an intelligent temperature sensor in a laboratory, which comprises the following steps:
connecting a lead of the intelligent temperature sensor with an acquisition card, wherein the acquisition card is connected with a computer; and injecting water into a round pipe in the intelligent temperature sensor, placing the intelligent temperature sensor on a vibrator for vibration, and combining a standard curve of the temperature and the electric charge quantity of the water to obtain the water temperature.
The connection mode of the wire of the intelligent temperature sensor, the acquisition card and the computer is not particularly limited, and only the friction current on the intelligent temperature sensor can be acquired.
In the present invention, the obtaining manner of the standard curve of the temperature-charge amount of water is preferably consistent with the above technical solution, and is not described herein again.
The vibration frequency of the vibrator is not particularly limited, and the temperature-sensitive polymer layer in the intelligent temperature sensor can be in full contact with water to generate friction. In the present invention, the time for which the vibrator vibrates is preferably 1 to 5 seconds, and more preferably 3 seconds. In the present invention, the maximum value of the friction current obtained when the vibrator vibrates is preferably read, as long as the vibrator vibrates and the friction current is generated.
The application of the temperature-sensitive polymer, the temperature sensor and the method of using the same according to the present invention will be described in detail with reference to the following examples, but they should not be construed as limiting the scope of the present invention.
Example 1
Accurately weighing 20 parts of Dimethylformamide (DMF), adding 3.39 parts of N-isopropylacrylamide (NIPAM) and 1 part of Methyl Methacrylate (MMA), adding 0.04 part of Azobisisobutyronitrile (AIBN), stirring to dissolve for 220min, heating in an oil bath kettle at 80 ℃ for 8h to react to obtain a viscous solution, adding water to precipitate a polymer in the viscous solution to form a yellow solid, and finally washing the yellow solid with methanol to obtain PNIPAM;
mixing 5mL of PNIPAM and 15mL of diluent DMF, and putting the mixture on a magnetic stirrer for 10min to change the mixture into diluted PNIPAM for later use;
cutting a copper adhesive tape with the size of 4cm multiplied by 4cm, wiping the surface of the copper adhesive tape with absolute ethyl alcohol, and then putting the copper adhesive tape into an oven for drying. Sticking the treated copper adhesive tape to a substrate PET, sticking a lead wire on the surface of the copper adhesive tape by using AB glue, spin-coating the diluted PNIPAM on the copper adhesive tape for 30s at the rotating speed of 3000rpm, and then drying in an oven at the temperature of 80 ℃ for 2h to remove residual solvent to obtain an electrode;
the two electrodes are placed at two ends of a polytetrafluoroethylene tube (the wall thickness is 0.2cm, the inner diameter is 3cm, the length is 5cm, and the tube wall is provided with a liquid injection hole) in parallel, the PNIPAM layer of the electrodes is contacted with the polytetrafluoroethylene tube and is bonded by AB glue, and the intelligent temperature sensor shown in figure 1 is obtained.
Water with the temperature of 20 ℃, 30 ℃, 40 ℃ and 50 ℃ is respectively injected into the round tube of the intelligent temperature sensor through the liquid injection port, the cover is covered, the intelligent temperature sensor vibrates for 3 seconds by the driving motor, the electric signal of the intelligent temperature sensor is collected by a computer connected with the intelligent temperature sensor through an acquisition card, the maximum current values read by three computers of the vibration of the vibrator 3 are read, and the relation graph of the obtained water temperature and the electric signal is shown in figure 3 and can be seen from figure 3: the intelligent temperature sensor detects a friction current that rises from 0.025 muA to 0.125 muA as the temperature of the water rises from 20 to 50℃, indicating the sensitive temperature response performance of the intelligent temperature sensor. The linear relation between the friction current detected by the intelligent temperature sensor and the water temperature is as follows: y is 400x +10, where x is the triboelectric current, μ a; y is the temperature of water, DEG C.
Verification of the linear relationship:
water of unknown temperature is placed in the intelligent temperature sensor, the vibrator is started to vibrate for 3s to obtain friction current, the friction current is brought into the linear relation, then the actual temperature of the water of the unknown tropical fish pond is measured, and the result is shown in table 1. As can be seen from table 1: the difference between the temperature obtained by calculating the current tested by the intelligent temperature sensor and the temperature actually tested by the thermometer is almost the same, which shows that the accuracy of the temperature sensor is higher.
TABLE 1 Linear relationship Curve verification results
Example 2
30% of the volume of the round tube in the intelligent temperature sensor prepared in the embodiment 1 is immersed in the water of the tropical fish pond, the liquid injection port is placed in the water of the tropical fish pond, the liquid injection port is not covered with a cover, a lead of the intelligent temperature sensor is connected with a collection card and a computer to read friction signals, a standard curve is obtained based on the embodiment 1, the real-time water temperature of the tropical fish pond is obtained, and then the relation between the growth condition of the tropical fish and the culture temperature is analyzed, so that the culture process becomes more scientific.
Example 3
Accurately weighing 20 parts of Dimethylformamide (DMF), adding 3.39 parts of N-isopropylacrylamide (NIPAM) and 1 part of Methyl Methacrylate (MMA), adding 0.04 part of Azobisisobutyronitrile (AIBN), stirring to dissolve for 220min, heating in an oil bath kettle at 80 ℃ for 8h to react to obtain a viscous solution, adding water to precipitate a polymer in the viscous solution to form a yellow solid, and finally washing the yellow solid with methanol to obtain PNIPAM; mixing 5mL of PNIPAM and 15mL of diluent DMF, and putting the mixture on a magnetic stirrer for 10min to change the mixture into diluted PNIPAM for later use;
cutting a copper adhesive tape with the size of 4cm multiplied by 4cm, wiping the surface of the copper adhesive tape with absolute ethyl alcohol, and then putting the copper adhesive tape into an oven for drying. Sticking the treated copper adhesive tape to a substrate PET, leading a lead to be stuck on the surface of the copper adhesive tape, spin-coating the diluted PNIPAM on the copper adhesive tape for 30s at the rotating speed of 3000rpm, and then drying in an oven at 80 ℃ for 2h to remove residual solvent to obtain an electrode;
the two electrodes are parallelly placed on two sides of a polytetrafluoroethylene tube (the wall thickness is 0.2cm, the inner diameter is 3cm, the length is 5cm, and a liquid injection hole is formed in the tube wall), a PNIPAM layer of each electrode is in contact with the polytetrafluoroethylene tube and is bonded through AB glue, and the intelligent temperature sensor is obtained.
Injecting boiled water heated to 100 ℃ into a round tube of the intelligent temperature sensor, starting a middle motor to enable the intelligent temperature sensor to vibrate until the boiled water is naturally cooled to room temperature, collecting electric signals of the intelligent temperature sensor by a computer connected with the intelligent temperature sensor through a collection card, and obtaining a relation graph of water temperature and the electric signals as shown in figure 4. As can be seen from fig. 4: during the natural cooling of the water, the triboelectric current detected by the smart temperature sensor decreased from 0.336 μ a to 0.05 μ a, consistent with the results in example 1.
As can be seen from the above embodiments: the molecular structure of the thermo-sensitive polymer poly N-isopropyl acryloyl (PNIPAM) has hydrophilic group amide (-CONH-) and hydrophobic isopropyl (-CH (CH) simultaneously3)2). At low temperatures, the interaction between PNIPAM and water is mainly hydrogen bonding between the amide group and water, exhibiting hydrophilicity. With the rise of temperature, isopropyl of hydrophobic group starts to play a role, partial hydrogen bonds are broken, a hydrophobic layer is formed, and phase transition is shown. The PNIPAM polymer has a critical temperature (LCST) between 30 and 35 ℃, and when the temperature rises to exceed the LCST, the surface of the thermosensitive polymer changes from hydrophilicity to hydrophobicity, so that the triboelectric magnitude during friction is changed.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.