Method for synchronously measuring temperature, surface tension and contact angle of droplet by controlling temperature and humidity

Abstract

The invention belongs to the technical field of chemical measurement. A temperature and humidity control system is adopted to accurately control the environment in a sample case, namely the temperature ranges from minus 80 DEG C to plus 300 DEG C and the accuracy is + / -0.1 DEG C, the relative humidity ranges from 0%-100% and the accuracy is + / -2%-+5%. A high-speed data acquisition system and a high-speed camera system are adopted to synchronously measure the temperature and profile image of a droplet accurately. The sampling frequency of the temperature can be as high as 1MHz and the sampling speed of the image can reach 420 frames / s. Sample data are transmitted to a computing system through data lines and the temperature of the droplet is obtained. The image data are fitted according to the Bashforth-Adams equation and Yong-laplace equation to obtain such numerical values as surface tension and contact angle, etc. The device has simple operation, high testing accuracy and good repeatability of experimental results and is suitable for synchronously measuring the temperature, surface tension and contact angle under the conditions of wide temperature range and total humidity.

Description

technical field [0001] The invention relates to a device for synchronously measuring droplet temperature, surface tension and contact angle in a wide temperature range and full humidity range, and belongs to the technical field of chemical measurement. Background technique [0002] The wetting phenomenon is a macroscopic manifestation of the microscopic properties of solid surface structure and properties, liquid surface and interface properties, and the interaction between solid-liquid two-phase molecules. The study of wetting phenomena can provide useful information for understanding the properties of solid surfaces, and the measurement of liquid surface tension and contact angle can better understand the interaction between solid-liquid and liquid-liquid. Adhesion, material wettability, biocompatibility, and lubricity of solid surfaces, as well as wettability, detergency, diffusion, and adsorption of liquids are important. When using modern complex surface engineering te...

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Problems solved by technology

[0004] (1). There is no part to measure the temperature of the melt in the quartz sealing sleeve, and it is not accurate to judge the state of the melt only by image observation;

[0005](2). There is no device to accurately control temperature and humidity, and the measured surface tension and contact angle values ​​are greatly affected by the environment;

[0006](3). Only the surface tension and contact angle of the melt can be measured, which not only limits the applicable range of temperature, but also limits the selection range of test liquids

However, the surface tension and contact angle are closely related to the temperature and humidity of the measurement environment. The sample stage is directly connected to the outside world, which is seriously affected by the outside temperature and humidity, and the measurement accuracy cannot be guaranteed. In addition, the droplet temperature is affected by factors such as evaporation rate and phase change. , has a large difference from the ambient temperature, and as one of the important parameters, it cannot be measured under the existing conditions

The measurement of surface tension and contact angle in the range of room temperature to 250°C can be realized by adding an electric heating temperature-controlled measuring chamber. However, for highly volatile liquids, it is necessary to provide a low-temperature environment and perform measurements under the premise of reducing their volatilization rate. Significantly limits the choice of test liquids

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