Device for monitoring material surface contact angle and liquid drop bounce in low-pressure environment

Abstract

The invention belongs to the technical field of material surface wettability measurement in a low-pressure environment, and particularly relates to a material surface contact angle and liquid drop bounce monitoring device in a low-pressure environment, which comprises a vacuum box, and the vacuum box is provided with a pressure control device, an intelligent temperature and humidity control device and a height-adjustable liquid dropping device. A sample table is arranged below the liquid dropping device, a sample table temperature control device is arranged at the lower part of the sample table, and a vibration device is arranged at the lower part of the sample table temperature control device and is hinged in the vacuum box; a light source and a high-speed camera which are mutually aligned are distributed around the sample table. Through the device, the contact angle and the bounce behavior of the liquid drop under different air pressures, temperatures, humidity and speeds at different temperatures, vibration amplitudes, frequencies and inclination angles can be observed.

Description

Technical Field

[0001] The invention belongs to the technical field of measuring wettability of material surfaces in low-pressure environments, and in particular relates to a device for monitoring contact angles and droplet bounces on material surfaces in low-pressure environments. Background Art

[0002] Low-pressure environments involve the aerospace field. Due to the lack of atmospheric pressure, liquid droplets cannot rely on air pressure to stabilize their shape when contacting solid surfaces, so the wettability of the material surface may change significantly. The contact angle refers to the angle between the solid-liquid interface through the liquid interior to the gas-liquid interface at the junction of solid, liquid, and gas. It is an important parameter to measure the wetting properties of the liquid on the material surface. In a low-pressure environment, the stability of the droplet morphology and contact line will be challenged. The larger the contact angle of the material surface, the more hydrophobic the material surface is. However, the effect of atmospheric pressure on the contact angle of the material surface is still unclear.

[0003] The wettability of the material surface is mostly under dynamic conditions, and the contact process between the droplet and the surface often involves the spreading, contraction and rebound of the droplet. It is extremely important to study the bouncing process of the droplet under different atmospheric pressures. In addition, it is extremely important to study the influence of the material surface temperature and the impact velocity of the droplet on the bouncing process of the droplet under different ambient pressures. On the other hand, by synchronously observing the bouncing process of the droplet from multiple angles, the contact behavior between the droplet and the solid surface can be accurately captured. The motion trajectory and morphological changes of the droplet are recorded simultaneously from different angles to obtain more comprehensive data. Sometimes, because the test equipment cannot directly meet the test requirements, some special methods are often required to achieve the test purpose, and the operation is more complicated. For example, when the angle of the droplet impacting the surface, the ambient temperature and humidity change, these external factors may have a greater impact on the bouncing of the droplet, and these parameters need to be controlled to conduct the test.

[0004] However, there is a lack of research on devices for dynamic and synchronous observation and measurement of the contact angle of droplets on the surface of materials at multiple angles under low pressure, and it is impossible to observe the surface contact angle and the droplet bouncing process during the experiment. In addition, the impact of low pressure on the solid-liquid contact process is still unclear. In summary, it is urgent to develop a device for monitoring the contact angle and droplet bouncing of materials under low pressure. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a device for monitoring the contact angle of a material surface and the bounce of a droplet in a low-pressure environment.

[0006] The purpose of the present invention is to be achieved by adopting the following technical solutions. According to a device for monitoring the contact angle of a material surface and the bounce of a droplet in a low-pressure environment proposed by the present invention, a device for monitoring the contact angle of a material surface and the bounce of a droplet in a low-pressure environment comprises a vacuum box, on which a pressure control device, an intelligent temperature and humidity control device, and a height-adjustable dripping device are provided, a sample stage is provided below the dripping device, a sample stage temperature control device is provided below the sample stage, a vibration device is provided below the sample stage temperature control device, and the vibration device is hinged inside the vacuum box; mutually aligned light sources and high-speed cameras are distributed around the sample stage.

[0007] Furthermore, a transparent observation window is detachably nested on the wall of the vacuum box.

[0008] Furthermore, a vacuum box sealing cover is arranged on the top of the vacuum box, and a pressure control device is arranged on the vacuum box sealing cover.

[0009] Furthermore, the dripping device includes a piston shaft clamp, a second screw stepper motor, a slider, a second screw base, a second screw, a first screw stepper motor, a first screw, a first screw base, and a dripper. The dripper includes a tube and a piston shaft slidably arranged in the tube. The second screw base is fixed on the first bracket. The second screw is vertically arranged and rotatably cooperates with the second screw base. When the second screw stepper motor is running, it drives the second screw to rotate. The second screw is connected to the first slider through a screw nut. The first slider is slidably connected to the vertically arranged optical axis. The piston shaft clamp is fixed on the first slider; the first screw base is fixed on the second bracket. The first screw is rotatably cooperated with the first screw base. The first screw stepper motor drives the vertically arranged screw to rotate. The first screw is connected to the second slider through a screw nut. The second slider is slidably connected to the vertically arranged optical axis. The tube is arranged on the second slider.

[0010] Furthermore, the pressure control device includes a vacuum pump, a check valve, a vacuum gauge, a pressure relief valve, and an exhaust port. The vacuum pump is connected to the check valve, the check valve is connected to the interior of the vacuum box, the probe of the vacuum gauge is arranged in the vacuum box, the pressure relief valve is connected to the exhaust port, and is connected to the interior of the vacuum box.

[0011] Furthermore, the intelligent temperature and humidity control device includes a temperature heating / cooling medium storage tank, an air heating / cooling medium circulation pump, a temperature monitoring / display instrument, a temperature heating / cooling pipeline, a humidity control device, and a humidifier. The temperature heating / cooling pipeline extends to the interior of the vacuum box, and the two ends of the temperature heating / cooling pipeline are respectively connected to the inlet and outlet of the temperature heating / cooling medium storage tank. An air heating / cooling medium circulation pump is installed on the temperature heating / cooling pipeline. The temperature heating / cooling medium storage tank is connected to the heat exchange system, and the probe of the temperature monitoring / display instrument is arranged inside the vacuum box; the humidifier is connected to the humidity control device.

[0012] Furthermore, the sample table temperature control device includes an electromagnetic heating controller, an electric heating module, a liquid delivery pipe, a refrigeration module, and an industrial refrigerator. The electromagnetic heating controller is connected to the electric heating module, the sample table is arranged on the top of the electric heating module, the refrigeration module is arranged at the bottom of the electric heating module, the liquid delivery pipe connects the refrigeration module and the industrial refrigerator, and a liquid delivery pipeline is arranged inside the refrigeration module.

[0013] Furthermore, the vibration device includes a motor, an eccentric shaft, an articulation device, a cam adjuster, a connecting shaft, a face gear one, a base, a face gear two, bolts, a motor bracket, and a vibration housing. The eccentric shaft is connected to the shaft of the motor, and the other end of the eccentric shaft is connected to an eccentric wheel. A articulation device is provided under the motor, and the articulation device includes an upper hanging ear, a lower hanging ear, and an articulation shaft. The upper hanging ear is installed at the lower part of the motor, and the lower hanging ear is installed at the upper part of the motor bracket. Articulation holes are provided on the upper hanging ear and the lower hanging ear, and the articulation shaft passes through the articulation hole and connects the upper hanging ear and the lower hanging ear together. There is a gap between the articulation shaft and the articulation hole, and the articulation shaft is detachable. At least three articulation devices that are not in the same straight line are arranged between the motor and the motor bracket, and a vibration housing is provided on the upper cover of the motor; the motor bracket is rigidly connected to the face gear two, and the face gear two is rigidly connected to the motor bracket. Gear 2 is in the shape of a disk, one side of which is provided with a plurality of teeth distributed circumferentially. Face gear 2 is rotatably arranged on a base. A cam adjuster is rotatably arranged and has an elliptical cam at one end and a handle at the other end. Face gear 1 is provided at the end of the elastic cantilever structure on the base. Face gear 1 is in the shape of a disk, one side of which is provided with teeth distributed circumferentially. The toothed side of face gear 1 faces the toothed side of face gear 2. The cam adjuster is located on one side of face gear 1 and is close to the toothless side of face gear 1. In a natural state, a portion with a smaller radius on the cam adjuster abuts against face gear 1 and face gear 1 does not mesh with face gear 2. By rotating the cam adjuster so that a portion with a larger radius of the cam adjuster abuts against face gear 2, face gear 1 can be made to approach face gear 2 and mesh with face gear 2. A sample table is provided on the top of the vibration housing.

[0014] Compared with the prior art, the present invention is beneficial in that:

[0015] 1. The present invention can accurately control the pressure in the vacuum box through a pressure control device, thereby realizing the contact angle measurement of droplets under different air pressure environments, and observing the bouncing behavior of droplets under different air pressure environments;

[0016] 2. The present invention can accurately control the humidity and temperature in the vacuum box through an intelligent temperature and humidity control system, which is convenient for measuring the contact angle of the material surface under different temperature and humidity environments, and observing the bouncing behavior of droplets under different temperature and humidity environments;

[0017] 3. The present invention can complete the low-temperature and high-temperature adjustment of the sample stage surface through the sample stage temperature control system, which is convenient for measuring the influence of surface temperature on contact angle in a low-pressure environment, and observing the influence of material surface temperature on droplet bouncing behavior in a low-pressure environment;

[0018] 4. The present invention uses a vibration device under the sample stage to observe the influence of different inclination angles and vibrations of the material surface on the bouncing behavior of the droplet in a low-pressure environment, and measure the corresponding contact angle;

[0019] 5. The present invention can observe the influence of droplets of different speeds on the contact angle and droplet bouncing behavior by adjusting the height of the droplet device;

[0020] 6. The present invention realizes multi-angle synchronous observation of the droplet bouncing process through a high-speed camera, so as to fully understand the droplet bouncing process.

[0021] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites a preferred embodiment and describes it in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is an overall schematic diagram of an embodiment of a device for monitoring the contact angle of a material surface and the bounce of a liquid droplet in a low-pressure environment of the present invention;

[0023] Figure 2 for Figure 1 Schematic diagram of the medium droplet device;

[0024] Figure 3 for Figure 1 Schematic diagram of the medium pressure control device;

[0025] Figure 4 for Figure 1 Schematic diagram of the intelligent temperature and humidity control device;

[0026] Figure 5 for Figure 1 Schematic diagram of the temperature control device of the middle sample stage;

[0027] Figure 6 for Figure 1 Schematic diagram of the vibration device.

[0028] [Reference Signs]

[0029] 1-vacuum box sealing cover; 2-intelligent temperature and humidity control device; 3-liquid dripping device; 4-bracket one; 5-light source one; 6-high-speed camera one; 7-high-speed camera bracket one; 8-sample stage; 9-sample stage temperature control device; 10-vibration device; 11-high-speed camera bracket two; 12-high-speed camera two; 13-light source two; 14-bracket two; 15-transparent observation window; 16-vacuum box; 17-pressure control device; 21-temperature heating / cooling medium storage tank; 22-air heating / cooling medium circulation pump; 23-temperature monitoring / display instrument; 24-temperature heating / cooling pipeline; 25-humidity control device; 26-humidifier; 31-piston shaft clamp; 32-screw stepper motor two; 33-screw base two; 34-screw two; 35-screw stepper motor one; 36-screw one; 37-screw base; 38-dripper; 381-empty cylinder; 382-piston shaft; 91-electromagnetic heating controller; 92-electric heating module; 93-liquid delivery pipe; 94-refrigeration module; 95-industrial refrigerator; 101-motor; 102-eccentric shaft; 103-upper hanging ear; 104-lower hanging ear; 105-cam adjuster; 106-connecting shaft; 107-face gear one; 108-base; 109-face gear two; 110-bolt; 111-motor bracket; 112-hinged shaft; 113-vibration housing; 171-vacuum pump; 172-check valve; 173-vacuum gauge; 174-pressure relief valve; 175-exhaust port. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] An embodiment of a device for monitoring the contact angle of a material surface and the bounce of a droplet under a low pressure environment of the present invention is as follows: Figures 1 to 6As shown. The device includes a vacuum box 16, and an observation transparent window 15 is nested on the wall of the vacuum box 16 for real-time observation of the internal state. In this embodiment, the front, back, left and right walls of the vacuum box 16 are all provided with an observation transparent box 15. A vacuum box sealing cover 1 is provided on the top of the vacuum box 16 for sealing the vacuum box 16. A pressure control device 17 is provided on the vacuum box sealing cover 1. The pressure control device 17 is connected to the inside of the vacuum box 16 for controlling the atmospheric pressure inside the vacuum box 16. An intelligent temperature and humidity control device 2 is provided inside the vacuum box 16 for controlling the temperature and humidity of the internal environment of the vacuum box 16. A dripping device 3 is provided at the upper middle position of the vacuum box 16 for dripping liquid onto the surface of the material. A sample stage 8 is provided at the lower middle position of the vacuum box 16. The sample stage 8 is located directly below the dripping device 3 for placing and fixing the material to be tested. A sample stage temperature control device 9 is provided below the sample stage 8. The sample stage temperature control device 9 is close to the sample stage 8 for controlling the temperature of the material. A vibration device 10 is arranged below the sample stage temperature control device 9, which is used to vibrate the material and simulate the test conditions of the material in a vibration environment; the vibration device 10 is hinged inside the vacuum box 16, and the angle of the vibration device 10 can be adjusted simultaneously to adjust the angles of the sample stage temperature control device 9 and the sample stage 8, thereby simulating the test conditions of the material at different angles.

[0032] The sample stage 8 is surrounded by light source 15, light source 2 13, high-speed camera 16, and high-speed camera 2 12, wherein light source 15 is facing high-speed camera 2 12, and is used to fill in the light for high-speed camera 2 12, and light source 2 13 is facing high-speed camera 16, and is used to fill in the light for high-speed camera 16. Light source 15, light source 2 13, high-speed camera 16, and high-speed camera 2 12 are all facing the space above the sample stage 8. Light source 15 is arranged on bracket 14, and high-speed camera 2 12 is arranged on high-speed camera bracket 2 11; high-speed camera 16 is arranged above high-speed camera bracket 17, and light source 2 13 is arranged on bracket 2 14.

[0033] like Figure 2As shown, the dripping device 3 includes a piston shaft holder 31, a screw stepper motor 2, a slider 1 32, a screw base 2 33, a screw 2 34, a screw stepper motor 1 35, a screw 1 36, a screw base 1 37 and a dripper 38. The dripper 38 is in the shape of a syringe and includes a cylinder 381 and a piston shaft 382. The screw base 2 33 is fixed on the bracket 1 4, the screw 2 34 is vertically arranged and rotated with the screw base 2, and the screw stepper motor 2 drives the screw 2 34 to rotate when it is running. The slider 1 32 is connected to the screw 2 34 through a screw nut, and is slidably connected to the optical axis 1 parallel to the screw 2 34, and the optical axis is vertically arranged on the bracket 1 4. The screw 2 34 rotates, driving the slider 1 32 to move up and down on the screw 2 34. The piston shaft holder 31 is fixed on the slider 1 32, and the slider 1 32 moves up and down, driving the piston shaft 382 to move up and down in the barrel 381. The screw base 1 37 is fixed on the bracket 2 14, and the screw 1 36 rotates with the screw base 1 37; the screw stepper motor 1 35 can drive the screw 1 36 to rotate, and the screw 1 36 is vertically arranged. The slider 2 is connected to the screw 1 36 through the screw nut. The slider 2 is slidably arranged on the optical axis 2 at the same time. The optical axis 2 is vertically arranged on the bracket 2 14. The screw 1 36 rotates to drive the slider 2 to move up and down. The barrel 381 is arranged on the slider 2. As the slider 2 moves up and down, the height of the barrel 381 is adjusted, and then the height of the dropper 38 is adjusted. At different heights, the speed at which the released droplets contact the material surface is different. The barrel 381 is used to hold liquid, and the piston shaft 382 moves up and down to realize the absorption and dripping of droplets.

[0034] like Figure 3 As shown, the pressure control device 17 includes a vacuum pump 171, a check valve 172, a vacuum gauge 173, a pressure relief valve 174 and an exhaust port 175. The vacuum pump 171 is connected to the check valve 172, and the check valve 173 is connected to the inside of the vacuum box 16. The vacuum pump 171 is used to evacuate the vacuum box 16. The check valve 172 prevents the air in the vacuum pump 171 from entering the vacuum box 16. The probe of the vacuum gauge 173 is arranged in the vacuum box 16 for real-time observation of the air pressure inside the vacuum box 16. The pressure relief valve 174 is connected to the exhaust port 175 and is connected to the inside of the vacuum box 16. When the internal pressure is too low, the pressure relief valve 174 is opened, and the external air enters the vacuum box 16, increasing the pressure inside the vacuum box 16, so as to adjust the internal pressure of the vacuum box 16. In this embodiment, the pressure regulation range of the vacuum box 16 is 90Pa-101KPa.

[0035] like Figure 4As shown, the intelligent temperature and humidity control device 2 includes a temperature heating / cooling medium storage tank 21, an air heating / cooling medium circulation pump 22, a temperature monitoring / display instrument 23, a temperature heating / cooling pipeline 24, a humidity control device 25 and a humidifier 26. The temperature heating / cooling pipeline 24 extends to the interior of the vacuum box 16, and the two ends of the temperature heating / cooling pipeline 24 are respectively connected to the inlet and outlet of the temperature heating / cooling medium storage tank 21. The air heating / cooling medium circulation pump 22 is installed on the temperature heating / cooling pipeline 24. The air heating / cooling medium circulation pump 22 is located near the outlet of the temperature heating / cooling medium storage tank 21, so that the temperature heating / cooling medium circulates in the temperature heating / cooling pipeline 24. The temperature heating / cooling medium storage tank 21 is connected to the heat exchange system to control the temperature of the temperature heating / cooling medium. The air heating / cooling medium circulation pump 22 is connected to the temperature monitoring / display instrument 23, which is used to monitor and display the temperature of the temperature heating / cooling medium. The probe of the temperature monitoring / display instrument 23 is also arranged inside the vacuum box 16 to realize real-time monitoring and control of the temperature inside the vacuum box 16. The heat exchange system and the air heating / cooling medium circulation pump 22 can be controlled by the control panel of the intelligent temperature and humidity control device 2, and then the temperature inside the vacuum box 16 can be adjusted according to the data of the temperature monitoring / display instrument 23. The humidifier 26 is connected to the humidity control device 25, and the button of the humidity control device 25 is integrated on the control panel, which is used to control the humidity inside the vacuum box 16 in real time. The humidifier 26 and the temperature heating / cooling pipeline 24 in the intelligent temperature and humidity control device 2 are arranged inside the vacuum box 16, and the other devices are arranged outside the vacuum box 16. When adjusting the temperature, set the required temperature on the control panel, the air heating / cooling medium circulation pump 22 starts working, and the temperature heating / cooling medium enters the vacuum box 16 through the temperature heating / cooling pipeline 24 for heat exchange. When the temperature in the vacuum box reaches the set value, the air heating / cooling medium circulation pump 22 stops working until the temperature is no longer within the set range, and then restart the air heating / cooling medium circulation pump 22 to achieve constant temperature in the vacuum box. When adjusting the humidity in the vacuum box, set the humidity value on the control panel, turn on the humidity control device 25, and control the humidity in the vacuum box 16 through the humidifier 26 until the humidity reaches the set value. In this embodiment, the temperature adjustment range in the vacuum box is -20°C-20°C, and the humidity adjustment range is 10%-90%.

[0036] like Figure 5As shown, the sample stage temperature control device 9 includes an electromagnetic heating controller 91, an electric heating module 92, a liquid delivery pipe 93, a refrigeration module 94 and an industrial refrigerator 95. The electromagnetic heating controller 91 is connected to the electric heating module 92. The electromagnetic heating controller 91 generates a high-speed changing alternating magnetic field by passing a high-speed changing current through a coil. When the magnetic lines of force in the magnetic field pass through a magnetically conductive metal material, countless small eddy currents are generated in the metal body, causing the metal material itself to heat up at a high speed, thereby causing the electric heating module 92 to heat up. The sample stage 8 is arranged on top of the electric heating module 92, so as to further realize the heating of the sample on the sample stage 8 and obtain a sample surface with a higher temperature. The refrigeration module 94 is arranged at the bottom of the electric heating module 92, and the liquid delivery pipe 93 connects the refrigeration module 94 and the industrial refrigerator 95. The refrigeration module 94 is provided with a liquid delivery pipeline, and the industrial refrigerator 95 is used to cool and deliver the liquid. The liquid can be industrial alcohol. The outside of the liquid delivery pipe 93 adopts a heat-insulating material, so that the industrial alcohol circulates between the refrigeration module 94 and the industrial refrigerator 95, and the temperature of the refrigeration module 94 is reduced. Through the cooperation of the liquid delivery pipe 93, the refrigeration module 94 and the industrial refrigerator 95, the sample stage 8 is cooled, and the surface temperature of the sample is reduced when the sample stage 8 is cooled. The sample stage 8, the electric heating module 92, and the refrigeration module 94 are all made of materials that are easy to conduct heat, so as to facilitate the transfer of the temperature rise and fall to the sample. In summary, the sample stage temperature control device 9 can achieve the regulation of high and low temperatures on the sample surface. In this embodiment, the electric heating module adjusts the temperature range of the sample stage to 20°C-320°C, and the refrigeration module adjusts the temperature range of the sample stage to 20°C~-30°C. Therefore, the temperature setting range of the sample stage is -30°C-320°C.

[0037] like Figure 6As shown, the vibration device 10 includes a motor 101, an eccentric shaft 102, an upper hanging ear 103, a lower hanging ear 104, a cam adjuster 105, a connecting shaft 106, a face gear 107, a base 108, a face gear 2 109, a bolt 110, a motor bracket 111, a hinge shaft 112 and a vibration housing 113. The eccentric shaft 102 is connected to the shaft of the motor 101, and an eccentric wheel is connected to the other end of the eccentric shaft 102, so that the rotation center and the mass center of the eccentric shaft 102 do not coincide. When the motor 101 rotates at a high speed, the eccentric shaft 102 will generate a strong centrifugal force to vibrate, and at the same time, the eccentric shaft 102 acts on the motor 101 in the reverse direction, so that the motor 101 vibrates. An articulation device is provided below the motor 101, and the articulation device includes an upper cantilever 103, a lower cantilever 104 and a hinge shaft 112. The upper cantilever 103 is installed below the motor 101, and the lower cantilever 104 is installed above the motor bracket 111. Hinge holes are provided on the upper cantilever 103 and the lower cantilever 104, and the hinge shaft 112 passes through the hinge hole to connect the upper cantilever 103 and the lower cantilever 104 together. There is a gap between the hinge shaft 112 and the hinge hole to provide space for vibration; the hinge shaft 112 is detachable and easy to replace with a hinge shaft 112 of different diameters, thereby changing the gap with the hinge hole, and then changing the amplitude of the vibration device 10, so that it can be tested at different amplitudes; in order to stably set the motor 101 on the motor bracket 111, at least three articulation devices that are not on the same straight line are set between the motor 101 and the motor bracket 111. The upper cover of the motor 101 is provided with a vibration housing 113, and the motor 101 is connected to the vibration housing 113. The motor 101 vibrates, thereby causing the vibration housing 113 to vibrate. The motor bracket 111 is rigidly connected to the face gear 109. The face gear 109 is in the shape of a disk, and a plurality of teeth are distributed circumferentially on one surface. The face gear 109 is rotatably set on the base 108 by means of a bolt 110. The bolt 110 passes through the hole on the base 108 and the center hole of the face gear 109 in sequence and is limited by a nut, so that the face gear 109 can rotate around the bolt 110. One end of the cam adjuster 105 is an elliptical cam and the other end is a handle. The cam part of the cam adjuster 105 is provided with a connecting hole, and the connecting shaft 106 is passed through the connecting hole and fixedly set. By turning the handle, the cam can be rotated around the connecting shaft 106. A face gear 107 is provided on the base 108. The face gear 107 is in the shape of a disc, one side of which is provided with circumferentially distributed teeth. The toothed side of the face gear 107 faces the toothed side of the face gear 2 109. The face gear 107 is provided at an elastic cantilever structure end on the base 107, and the face gear 107 can mesh with the face gear 2 109. In a natural state, the face gear 107 is disengaged from the face gear 2 109.The cam adjuster 105 is located on one side of the face gear 107 and close to the non-toothed side of the face gear 107. In the natural state, the smaller radius part of the cam adjuster 105 is against the face gear 107, and the face gear 107 is not meshed with the face gear 2 109. The cam adjuster 105 is rotated to make the larger radius part of the cam adjuster 105 against the face gear 2 107, so that the face gear 107 approaches the face gear 2 109 and meshes with the face gear 2 109. The top of the vibration housing 113 is sequentially provided with a refrigeration module 94, an electric heating module 92, and a sample stage 8. The motor bracket 111 is rotated to make the vibration housing 113, the refrigeration module 94, the electric heating module 92, and the sample stage 8 deflected at a certain angle, and then the cam adjuster 105 is rotated to mesh with the face gear 2 109 through the face gear 107 to achieve fixation. The vibration device 10 can adjust the angle of the sample stage 8 through the angle adjustment device at the bottom (including the face gear and the cam adjuster 105). When adjusting the angle, the part above the motor bracket 111 is rotated left and right, and then the handle of the cam adjuster 105 is rotated downward by 90°, so that the cam surface and the elastic cantilever structure on the base 108 are closely fitted, the face gear is meshed, and the motor bracket 111 is fixed to achieve the angle adjustment of the sample stage 8. In this embodiment, the tilt angle of the sample stage is 0°-80°.

[0038] Test process: remove the transparent observation window 15 on the left, take the liquid and place it under the dripping device 3, turn on the screw stepper motor 1 35, move the dripper 38 downward, and stop moving downward after touching the liquid below; turn on the screw stepper motor 2, and when the screw stepper motor 2 is working, it drives the piston shaft 382 to move upward to complete the suction of the liquid by the cylinder 381; take out the liquid, place the material to be tested on the surface of the sample table 8, and fix it on the sample table 8; adjust the inclination angle of the sample table 8; install the transparent observation window 15 on the left; open the check valve 172, close the pressure relief valve 174, turn on the vacuum pump 171, and stabilize the pressure in the vacuum box 16; close the check valve 172; turn on the intelligent temperature and humidity control device 2, set the vacuum The temperature and humidity in the empty box 16; turn on the sample stage temperature control device 9 to adjust the temperature of the material surface; operate the motor 107 to drive the eccentric shaft 106 to operate, and the eccentric shaft 106 can make the sample stage 8 vibrate when it is operating, or make the motor 107 stationary to perform a test without vibration; turn on the high-speed camera 16, the high-speed camera 2 12, the light source 15 and the light source 2 13; start the screw stepper motor 1 35 to adjust the height of the dropper 38, start the screw stepper motor 2 to release the liquid in the cylinder 381, and start the high-speed camera 1 6 and the high-speed camera 2 12 continuous shooting function to capture multiple groups of images at the moment the droplets fall, thereby realizing multi-angle synchronous recording and analysis of the droplet bouncing process on the material surface.

[0039] The present invention provides a device for monitoring the contact angle of a material surface and the bouncing of a droplet under a low-pressure environment. The device can measure the contact angle of a material surface under different pressure environments and observe the bouncing behavior of a droplet by controlling the pressure of a vacuum box. The device can adjust the height of the droplet by a dropper to facilitate measuring the influence of the impact speed of different droplets on the bouncing behavior of the droplet and the contact angle. The device can adjust the temperature and humidity inside the vacuum box by an intelligent temperature and humidity control device, so as to explore the influence of the ambient temperature and humidity on the bouncing behavior of the droplet and the contact angle. The device can adjust the temperature of the sample surface by a sample stage temperature control device, so as to achieve precise control of the low and high temperatures on the material surface, so as to explore the influence of the material surface temperature on the bouncing behavior of the droplet and the contact angle. The device can test the influence of vibration and tilt angle on the contact angle of the droplet and the bouncing behavior of the droplet by a vibration device when the sample contacts the droplet. The device can adjust the height of the dropper to observe the influence of droplets of different speeds on the contact member and the bouncing behavior of the droplet. The device can control the above parameters to observe the influence of each parameter on wettability.

[0040] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A device for monitoring the contact angle of a material surface and the bounce of a droplet under a low pressure environment, characterized in that: It comprises a vacuum box, on which a pressure control device, an intelligent temperature and humidity control device, and a height-adjustable dripping device are provided. A sample stage is provided below the dripping device, a sample stage temperature control device is provided below the sample stage, a vibration device is provided below the sample stage temperature control device, and the vibration device is hinged inside the vacuum box; mutually aligned light sources and high-speed cameras are distributed around the sample stage.

2. The device for monitoring the contact angle of a material surface and the bounce of a droplet under a low pressure environment according to claim 1, characterized in that: A transparent observation window is detachably nested on the wall of the vacuum box.

3. The device for monitoring the contact angle of a material surface and the bounce of a droplet under a low pressure environment according to claim 1, characterized in that: A vacuum box sealing cover is arranged on the top of the vacuum box, and a pressure control device is arranged on the vacuum box sealing cover.

4. The device for monitoring the contact angle of a material surface and the bounce of a droplet under a low pressure environment according to claim 1, characterized in that: The dripping device includes a piston shaft clamp, a second screw stepper motor, a slider, a second screw base, a second screw, a first screw stepper motor, a first screw, a first screw base, and a dripper. The dripper includes a tube and a piston shaft slidably arranged in the tube. The second screw base is fixed on the first bracket. The second screw is vertically arranged and rotatably matched with the second screw base. When the second screw stepper motor is running, it drives the second screw to rotate. The second screw is connected to the first slider through a screw nut. The first slider is slidably connected to the vertically arranged optical axis. The piston shaft clamp is fixed on the first slider; the first screw base is fixed on the second bracket. The first screw is rotatably matched with the first screw base. The first screw stepper motor drives the vertically arranged first screw to rotate. The first screw is connected to the second slider through a screw nut. The second slider is slidably connected to the vertically arranged optical axis. The tube is arranged on the second slider.

5. The device for monitoring the contact angle of a material surface and the bounce of a droplet under a low pressure environment according to claim 1, characterized in that: The pressure control device includes a vacuum pump, a check valve, a vacuum gauge, a pressure relief valve, and an exhaust port. The vacuum pump is connected to the check valve, the check valve is connected to the interior of the vacuum box, the probe of the vacuum gauge is arranged in the vacuum box, and the pressure relief valve is connected to the exhaust port and is connected to the interior of the vacuum box.

6. The device for monitoring the contact angle of a material surface and the bounce of a droplet under a low pressure environment according to claim 1, characterized in that: The intelligent temperature and humidity control device includes a temperature heating / cooling medium storage tank, an air heating / cooling medium circulation pump, a temperature monitoring / display instrument, a temperature heating / cooling pipeline, a humidity control device, and a humidifier. The temperature heating / cooling pipeline extends to the interior of the vacuum box, and the two ends of the temperature heating / cooling pipeline are respectively connected to the inlet and outlet of the temperature heating / cooling medium storage tank. An air heating / cooling medium circulation pump is installed on the temperature heating / cooling pipeline. The temperature heating / cooling medium storage tank is connected to the heat exchange system, and the probe of the temperature monitoring / display instrument is arranged inside the vacuum box; the humidifier is connected to the humidity control device.

7. The device for monitoring the contact angle of a material surface and the bounce of a droplet under a low pressure environment according to claim 1, characterized in that: The sample table temperature control device includes an electromagnetic heating controller, an electric heating module, a liquid delivery pipe, a refrigeration module, and an industrial refrigerator. The electromagnetic heating controller is connected to the electric heating module, the sample table is arranged on the top of the electric heating module, the refrigeration module is arranged at the bottom of the electric heating module, the liquid delivery pipe connects the refrigeration module and the industrial refrigerator, and a liquid delivery pipeline is arranged inside the refrigeration module.

8. The device for monitoring the contact angle of a material surface and the bounce of a droplet in a low pressure environment according to claim 1, characterized in that: The vibration device comprises a motor, an eccentric shaft, an articulation device, a cam adjuster, a connecting shaft, a face gear one, a base, a face gear two, bolts, a motor bracket, and a vibration housing. The eccentric shaft is connected to the shaft of the motor, and the other end of the eccentric shaft is connected to an eccentric wheel. A articulation device is provided under the motor, and the articulation device comprises an upper hanging ear, a lower hanging ear, and an articulation shaft. The upper hanging ear is installed at the lower part of the motor, and the lower hanging ear is installed at the upper part of the motor bracket. Articulation holes are provided on the upper hanging ear and the lower hanging ear, and the articulation shaft passes through the articulation hole and connects the upper hanging ear and the lower hanging ear together. There is a gap between the articulation shaft and the articulation hole, and the articulation shaft is detachable. At least three articulation devices that are not in the same straight line are arranged between the motor and the motor bracket, and a vibration housing is provided on the upper cover of the motor; the motor bracket is rigidly connected to the face gear two, and the face gear two It is disc-shaped, with multiple teeth distributed circumferentially on one side, face gear two is rotatably set on the base, the cam adjuster is rotatably set and one end of it is an elliptical cam and the other end is a handle, face gear one is provided at the end of the elastic cantilever structure on the base, face gear one is disc-shaped, one side of which is provided with teeth distributed circumferentially, the toothed side of face gear one faces the toothed side of face gear two, the cam adjuster is located on one side of face gear one and close to the toothless side of face gear one, in a natural state, the smaller radius part of the cam adjuster abuts against face gear one and face gear one does not mesh with face gear two, and the cam adjuster is rotated to make the larger radius part of the cam adjuster abut against face gear two, so that face gear one can approach face gear two and mesh with face gear two; a sample table is provided on the top of the vibration shell.

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