阅读说明：本技术 一种与x射线散射联用的湿度环境拉伸装置及其实验方法 (Humidity environment stretching device combined with X-ray scattering and experiment method thereof ) 是由 李良彬 叶克 孟令蒲 王道亮 张前磊 李亚慧 于 2020-06-15 设计创作，主要内容包括：本发明提供一种与X射线散射联用的湿度环境拉伸装置及其实验方法,该装置包括力学采集系统,升温装置,蒸汽发生装置,样品腔以及拉伸夹具。该装置的腔体可以根据需要进行切换,实现湿度环境和溶液环境的拉伸,通过氮气气路中氮气流量的调控实现腔体湿度在20-98％RH。该装置设计5mm通光光路,有效减少溶液及蒸汽环境对于X射线的吸收。该装置的样品最小间距为20mm,并增加拉伸腔体长度,能够获得10倍以上的拉伸倍率。该装置电机转动由Labview软件控制,通过可编译运动控制器实现单轴拉伸、循环往复拉伸、应力松弛等多种外场施加模式。上述湿度环境拉伸装置拆卸和安装简便,适合与X射线检测装置进行联用,获得有效指导生产的科学理论。(The invention provides a humidity environment stretching device combined with X-ray scattering and an experimental method thereof. The cavity of the device can be switched as required to realize the stretching of a humidity environment and a solution environment, and the humidity of the cavity is controlled at 20-98% RH by regulating and controlling the nitrogen flow in the nitrogen gas circuit. The device designs 5mm and leads to light path, effectively reduces solution and steam environment to the absorption of X ray. The minimum sample spacing of the device is 20mm, and the length of the stretching cavity is increased, so that the stretching ratio of more than 10 times can be obtained. The motor rotation of the device is controlled by Labview software, and various external field application modes such as uniaxial stretching, cyclic reciprocating stretching, stress relaxation and the like are realized by a compliable motion controller. The stretching device in the humidity environment is simple and convenient to detach and install, is suitable for being combined with an X-ray detection device, and obtains a scientific theory for effectively guiding production.)

1. A humidity environment stretching device used in combination with X-ray scattering is characterized in that: comprises a ball screw (1), a tension sensor (2), a sample cavity cover handle (3), a chuck (4), a sample cavity cover (5), a bearing (6), a temperature and humidity sensor (7), a heating rod (8), a water valve (9), a nitrogen gas circuit (10), a sample water tank (11), a liquid level meter (12), a coupler (13) and a high-precision servo motor (14), wherein,

the ball screw (1) is fixed on the base through a positioning frame, the ball screw (1) is connected with a high-precision servo motor (14) through a coupler (13), threads at two ends of the ball screw (1) are opposite, two screw bearings are respectively sleeved at two ends of the ball screw (1), one end of a chuck is directly connected with the screw bearings, the other end of the chuck is connected with a tension sensor (2), and the tension sensor is connected with the screw bearings; a temperature and humidity sensor (7) is arranged in the stretching cavity; in the sample water tank (11) below, the outside of the nitrogen gas path (10) is connected with a nitrogen valve, and the inside of the nitrogen gas path (10) is arranged in the sample water tank (11); the heating rod (8) is fixed at one end of the sample water tank (11) through threads, and the liquid level meter (12) is fixed at the other end of the sample water tank (11) through threads;

the high-precision servo motor (14) drives the ball screw (1) to move, the high-precision servo motor (14) is converted into linear motion in a rotating mode, the ball screw (1) drives the longitudinal chuck (4) to move, the film sample is stretched, the running speed is continuously adjustable, and the response of different materials to the stretching speed can be well matched; in the stretching process, the tension sensor (2) tracks tension change, a Labview software control system integrates control of a high-precision servo motor (14) and signal acquisition of the tension sensor (2) and can perform synchronous control and data acquisition, the tension data acquisition uses an NI-USB6008 data acquisition card produced by American national instruments, the stretching temperature of a film is accurately controlled by a temperature controller, a heating rod (8) is arranged in a sample water tank (11), temperature information detected by a temperature and humidity sensor (7) is fed back to the temperature controller, the temperature controller automatically adjusts the working state to achieve the aim of accurate temperature control, and the uniformity of the humidity of a stretching cavity at 20-98% RH and the temperature of the cavity is controlled by regulating and controlling the flow rate of introduced nitrogen.

2. A humidity environment stretching apparatus used in combination with X-ray scattering as claimed in claim 1, wherein: the cavity of the device can be switched as required, so that the stretching of a humidity environment and a solution environment is realized.

3. A humidity environment stretching apparatus used in combination with X-ray scattering as claimed in claim 1, wherein: the device effectively reduces the absorption of the solution and steam environment to X-rays by designing a 5mm optical path.

4. A humidity environment stretching apparatus used in combination with X-ray scattering as claimed in claim 1, wherein: the minimum sample spacing of the device is 20mm, and the length of the stretching cavity is increased, so that the stretching ratio of more than 10 times can be obtained.

5. A humidity environment stretching apparatus used in combination with X-ray scattering as claimed in claim 1, wherein: a plurality of external field application modes such as uniaxial stretching, cyclic reciprocating stretching, stress relaxation and the like are realized through the compilable motion controller.

6. A humidity environment stretching apparatus used in combination with X-ray scattering as claimed in claim 1, wherein: when the device simulates the stretching processing condition of a humidity environment, the stretching ratio and the stretching multiplying power of the film are accurately regulated, the film can be ensured to be in a saturated humidity environment, meanwhile, the change of the tensile force in the stretching process can be collected, the structural evolution of the film after in-situ detection stretching is carried out, and the relationship between the structural evolution behavior and the processing performance in the film processing is explained.

7. An experimental method of a humidity environment stretching device used in combination with X-ray scattering, wherein the humidity environment stretching device as claimed in claim 1 is used in combination with a synchrotron radiation small-angle X-ray scattering experimental station to study the relationship between the structural evolution behavior and the processing performance in the film stretching processing in situ, and the main experimental steps when the device is used in combination with the X-ray experimental station are as follows:

step 1, a motor driver is respectively connected with a device motor and a control computer host, a tension acquisition control cabinet is respectively connected with a sensor and the control computer host, a temperature controller and a device heating rod are connected, a power supply is started, water is added into a device water tank, and a nitrogen gas circuit is connected;

step 2, clamping a polymer film sample;

step 3, opening a Labview software control interface, and setting the stretching speed and the stretching time of the motor;

step 4, setting the film stretching temperature, introducing nitrogen, starting an X-ray light source when the sample reaches the set temperature, stretching the sample, and simultaneously recording the tension change in the stretching process and the structural evolution of the stretched film sample;

and 5, carrying out different stretching rates and stretching ratios on different films, systematically researching the influence of molecular parameters and external field parameters on the film structure evolution, and coupling the data to obtain the relation of processing parameters-film structure-product performance.

8. The experimental method of the stretching device in the humid environment used in combination with the X-ray scattering as claimed in claim 7, wherein different stretching rates and stretching ratios are precisely achieved by controlling the rotation speed and time of the motor based on Labview control software.

9. The experimental method of the humidity environment stretching device used in combination with the X-ray scattering as claimed in claim 7, wherein the flow rate of the introduced nitrogen gas is controlled during the stretching process to ensure that the film processing is in a specific humidity environment, and the experimental method is used for simulating the actual humidity environment film stretching processing conditions in a laboratory.

10. The experimental method of the stretching device in the humidity environment used in combination with the X-ray scattering as claimed in claim 7, wherein the device can realize the precise temperature control of the film sample and the surface temperature uniformity of the film sample; while the Labview controls the motor to rotate, the change of the tensile force of the film sample can be collected to obtain different samples, and the influence of different external field parameters on the tensile rheological property of the film; the device can be used together with a synchrotron radiation X-ray experiment station to track the structural evolution of the film in situ.

Technical Field

The invention relates to the technical field of online research characterization in a polymer film processing process, in particular to a humidity environment stretching device combined with X-ray scattering and an experimental method thereof.

Background

The complexity of the processing mode and the use environment of the high polymer material and the change of the multi-scale structure involved in the processing mode and the use environment under the coupling effect of the complex external field require research means capable of providing the external field parameters as comprehensive as possible and a characterization method needing time resolution.

Hydrogel materials are considered as excellent candidates for artificial skin, flexible electrodes, etc. because of their excellent biocompatibility and flexibility, but hydrogels exhibit completely different mechanical properties in the presence and absence of water, and thus their processing and use requires water involvement. Processing in a pure water bath environment is easy to cause excessive swelling to cause reduction of mechanical properties and dissolution of part of materials. The processing mode under the steam humidity environment can ensure that the water of the hydrogel is not easy to lose, and meanwhile, the swelling degree of the hydrogel material can be controlled and the dissolution of the hydrogel can be inhibited by regulating and controlling the steam pressure, so that the processing and the use of the hydrogel material are realized. Therefore, the problems of crack propagation inhibition mechanism and the like in the hydrogel are researched by simulating the deformation and phase change behavior of the hydrogel under the external steam field, and the development of a humidity environment stretching processing experimental device capable of being combined with X-ray scattering is urgently needed.

Disclosure of Invention

The invention provides a uniaxial stretching device and an experimental method which are used together with X-ray scattering, and can provide a humidity stretching environment which is not available in the prior art.

In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides a humidity environment stretching device with combined use of X ray scattering, includes high accuracy servo motor, ball screw, heating rod, level gauge, temperature and humidity sensor, sample basin, nitrogen gas circuit and force transducer, wherein: comprises a ball screw, a tension sensor, a sample cavity cover handle, a chuck, a sample cavity cover, a bearing, a temperature and humidity sensor, a heating rod, a water valve, a nitrogen gas circuit, a sample water tank, a liquid level meter, a coupling and a high-precision servo motor, wherein,

the ball screw is fixed on the base through the positioning frame, the ball screw is connected with the high-precision servo motor through the coupler, threads at two ends of the ball screw are opposite, two screw bearings are respectively sleeved at two ends of the ball screw, one end of the chuck is directly connected with the screw bearings, the other end of the chuck is connected with the tension sensor, and the tension sensor is connected with the screw bearings; a temperature and humidity sensor is arranged in the stretching cavity; in the sample water tank below, the outside of the nitrogen gas path is connected with a nitrogen valve, and the inside of the nitrogen gas path is arranged in the sample water tank; the heating rod is fixed at one end of the sample water tank through threads, and the liquid level meter is fixed at the other end of the sample water tank through threads.

The high-precision servo motor drives the ball screw to move, the rotation of the high-precision servo motor is converted into linear motion, the ball screw drives the longitudinal chuck to move, the stretching of a film sample is realized, the running speed is continuously adjustable, and the response of different materials to the stretching speed can be well matched; in the stretching process, a tension sensor tracks tension change, a Labview software control system integrates control of a high-precision servo motor and signal collection of the tension sensor, synchronous control and data collection can be performed, an NI-USB6008 data collection card produced by American national instruments is used for tension data collection, the stretching temperature of a film is accurately controlled by a temperature controller, a heating rod is arranged in a sample water tank, temperature information detected by a temperature and humidity sensor is fed back to the temperature controller, the temperature controller automatically adjusts the working state to achieve the aim of accurate temperature control, and the humidity of a stretching cavity is controlled to be 20-98% RH and the uniformity of the temperature of the cavity through flow rate regulation and control of nitrogen.

When the device simulates the stretching processing condition of the humidity environment, the stretching ratio and the stretching ratio of the film are accurately regulated and controlled, and the film can be ensured to be in the required humidity environment. Meanwhile, the change of the tensile force in the stretching process can be collected, the structural evolution of the film after stretching is detected in situ, and the relationship between the structural evolution behavior and the processing performance in the film processing is explained.

The invention also provides an experimental method of the humidity environment stretching device combined with the X-ray scattering, which is used for in-situ research of the relationship between the structure evolution behavior and the processing performance in the film stretching processing by using the humidity environment stretching device and a synchrotron radiation small-angle X-ray scattering experimental station.

The main experimental steps when the device is used together with an X-ray experiment station are as follows:

step 1, connecting a motor driver with a control computer host respectively at a device motor, connecting a tension acquisition control cabinet with a sensor and the control computer host respectively, connecting a temperature controller with a device heating rod, starting a power supply, adding water into a device water tank, and connecting a nitrogen bottle;

step 2, clamping a polymer film sample;

step 3, opening a Labview software control interface, and setting the stretching speed and the stretching time of the motor;

step 4, setting the film stretching temperature, introducing nitrogen, starting an X-ray light source when the sample reaches the set temperature, stretching the sample, and simultaneously recording the tension change in the stretching process and the structural evolution of the stretched film sample;

and 5, carrying out different stretching rates and stretching ratios on different films, systematically researching the influence of molecular parameters and external field parameters on the film structure evolution, and coupling the data to obtain the relation of processing parameters-film structure-product performance.

Based on Labview control software, different stretching rates and stretching ratios are accurately realized by controlling the rotating speed and time of a motor.

And in the stretching process, the nitrogen introducing speed is controlled, the film is ensured to be processed in a required humidity environment, and the method is used for simulating the film stretching processing conditions in an actual humidity environment in a laboratory.

The device can realize accurate temperature control of the film sample and can realize the surface temperature uniformity of the film sample.

The tensile force change of the film sample can be collected while the Labview controls the motor to rotate, so that different samples can be obtained, and the influence of different external field parameters on the tensile rheological property of the film can be obtained.

The device can be used together with a synchrotron radiation X-ray experiment station to track the structural evolution of the film in situ.

The invention has the following beneficial effects:

(1) the invention is easy to disassemble and assemble and convenient to be used with a synchrotron radiation X-ray scattering experiment station.

(2) The invention can provide a humidity environment and realize uniaxial stretching in the humidity environment.

(3) The invention can realize double-channel continuous temperature control and accurate temperature.

(4) The invention can realize the control of the nitrogen gas introduction speed in the stretching cavity and provide a stretching environment with the humidity of 20-98% RH.

(5) The invention has continuously adjustable stretching speed and stretching ratio and accurate control.

(6) The invention can accurately acquire tension data in real time through multiple channels.

(7) The invention can realize the stretching of the humidity environment and the solution environment by switching the cavities.

(8) The invention effectively reduces the absorption of the solution and steam environment to X-rays by designing the 5mm optical path.

(9) The minimum sample interval designed by the invention is 20mm, and the length of the stretching cavity is increased, so that the stretching ratio of more than 10 times can be obtained.

(10) The invention realizes a plurality of external field applying modes such as uniaxial stretching, cyclic reciprocating stretching, stress relaxation and the like through the translatable motion controller.

(11) The invention can set parameters aiming at different polymer film materials, and has universality for disclosing the scientific problem of polymer film stretching.

(12) The application prospect of the invention is as follows: 1) the system is used together with a synchrotron radiation X-ray scattering experiment station to systematically research the basic scientific problem in the stretching process of the polymer film; 2) the film stretching processing conditions under the humidity environment are simulated, the relationship between the structure evolution behavior and the processing performance and the final use performance in the film stretching processing is revealed, and the film stretching processing method has an inspiration effect on the film industrial processing.

In conclusion, the invention can research the structure evolution behaviors of different polymer materials in different stretching modes under the humidity environment and different stretching temperatures, and research the influence of different types of external field parameters on the structure and the mechanical behavior of the high polymer material. The relationship between the external flow field and the phase change process and the performance of the final product can be obtained by coupling the lamella crystal length period, the fiber period, the holes and the orientation degree of the film sample obtained by the small-angle X-ray experiment with the tensile mechanical data.

Drawings

FIG. 1 is a schematic representation of a stretching apparatus for use in a humid environment in conjunction with X-rays according to the present invention.

Wherein: the device comprises a ball screw 1, a tension sensor 2, a sample cavity cover handle 3, a chuck 4, a sample cavity cover 5, a bearing 6, a temperature and humidity sensor 7, a heating rod 8, a water valve 9, a nitrogen gas circuit 10, a water tank 11, a liquid level meter 12, a coupler 13 and a high-precision servo motor 14.

FIG. 2 is a tensile ratio strain curve of a stretching device in a humid environment according to an embodiment of the present invention;

fig. 3 is a two-dimensional diagram of a small angle of a stretching device in a humid environment according to an embodiment of the present invention.

Detailed Description

In order to clearly explain the technical features of the present invention, the present invention will be explained below with reference to the embodiments.

As shown in fig. 1, the humidity environment stretching device used in conjunction with X-ray scattering comprises a ball screw 1, a tension sensor 2, a sample cavity cover handle 3, a chuck 4, a sample cavity cover 5, a bearing 6, a temperature and humidity sensor 7, a heating rod 8, a water valve 9, a nitrogen gas circuit 10, a water tank 11, a liquid level meter 12, a coupler 13 and a high-precision servo motor 14.

The ball screw 1 is fixed on the base through the positioning frame, the ball screw 1 is connected with the high-precision servo motor 14 through the coupler 13, threads at two ends of the ball screw 1 are opposite, two screw bearings are respectively sleeved at two ends of the ball screw 1, one end of the chuck is directly connected with the screw bearings, the other end of the chuck is connected with the tension sensor 2, and the tension sensor is connected with the screw bearings. And a temperature and humidity sensor 7 is arranged in the stretching cavity. In the sample water tank 11 below, the outside of the nitrogen gas path 10 is connected with a nitrogen valve, and the inside of the nitrogen gas path 10 is arranged in the sample water tank 11; the heating rod 8 is fixed at one end of the sample water tank 11 through threads, and the liquid level meter 12 is fixed at the other end of the sample water tank 11 through threads.

The high-precision servo motor 14 drives the ball screw 1 to move, and the rotation of the motor is converted into linear motion. The ball screw drives the chuck 4 to move, so that the film sample is stretched. The running speed is continuously adjustable, and the response of different materials to the stretching speed can be well matched. The humidity environment in the cavity is regulated and controlled through an inlet of a nitrogen gas path 10 in the water tank. During the stretching process, the tension sensor 2 tracks the tension change. The device adopts a Labview software control system to integrate the control of the servo motor and the signal acquisition of the tension sensor, and can carry out synchronous control and data acquisition. The tensile force data acquisition uses an NI-USB6008 data acquisition card produced by American national instruments, the sampling rate is 10Ks/s, the sampling rate of 1Ks/s is generally adopted in the experimental process, the high-speed data acquisition is very important for the tensile sample, the tensile force acquisition time resolution reaches 1ms, and the data processing complexity caused by excessive data points is avoided.

The device adopts Labview software to compile a servo motor motion control program, sends a control instruction to an encoder through a motor driver, and controls the motor to accurately move.

The device adopts the operating condition of binary channels temperature controller control heating rod to realize controlling the temperature to the sample, and temperature probe has the feedback effect. The temperature of the cavity and the temperature rise and fall rate are accurately controlled by adjusting PID parameters.

The device is designed by adding a water tank, and a nitrogen gas circuit is added to control the flow rate of nitrogen gas and provide a humidity stretching environment.

Experimental examples:

and (3) in-situ researching the influence of tensile strain on crack propagation in the hydrogel stretching process by using synchrotron radiation X-rays.

Purpose of the experiment:

hydrogel materials are considered as excellent candidates for artificial skin, flexible electrodes, etc. because of their excellent biocompatibility and flexibility. Hydrogels have been considered as an effective model for studying biological tissue structures because of their similarity to biological tissue structures. The X-ray is one of important means for structure detection, is an indispensable characterization method in the field of polymer material research, and with the discovery and application of synchrotron radiation X-ray, the detection time resolution is shortened to the millisecond order from the past dozens of hours. Considering that the hydrogel material has a structure with a plurality of scales, the influence of stretching on the expansion of cracks in the hydrogel material and the like under a humidity environment is researched by utilizing synchrotron radiation X-rays, and the understanding of people on the structure change rule of a biological tissue structure under the condition of responding to external action can be improved.

The experimental process comprises the following steps:

adding water into a water tank, fixing the cut PA gel on a chuck 4, introducing nitrogen, setting the rotating speed of a motor, and setting the corresponding strain rate to be 1s^-1And after the saturated vapor pressure is reached, starting a motor, stretching the sample, simultaneously starting a synchrotron radiation X-ray light source, and tracking the evolution of cracks in the stretching process in situ.

The experimental results are as follows:

fig. 2 shows the measured stress of the hydrogel in response to the strain under the external tensile field, and it can be seen that the mechanical curve of the hydrogel is closer to that of the rubber material, and the hydrogel does not have obvious yield phenomenon, and when the strain reaches a larger level, the hydrogel material is strain hardened.

FIG. 3 is a comparison of the 2D-SAXS of a PA hydrogel during stretching, where it can be seen that the hydrogel material is isotropic in the initial stage, and gradually orients as the stretching progresses, and that the long period of the periodic structure remains stable after stretching to a certain strain.

And (4) experimental conclusion:

the hydrogel is stretched in a humidity environment, so that the structural evolution law of cracks and soft and hard segments with periodic structures in different scale structures in the hydrogel can be found, the response of biological tissues to external signals in an actual environment can be effectively simulated, and effective guidance is provided for researching the structural change of the biological tissues.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to the embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.