A method for measuring the static contact angle of liquid droplets

A static contact angle and measurement method technology, applied in the field of measurement, can solve problems such as large calculation errors and poor anti-interference ability, and achieve the effects of strong anti-interference ability, increased adaptability range, and high calculation accuracy

Inactive Publication Date: 2017-07-18
NORTH CHINA ELECTRIC POWER UNIV (BAODING)
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The purpose of the present invention is to provide a method for measuring the static contact angle of liquid droplets in view of the disadvantages of the prior art, so as to overcome the shortcomings of the existing polynomial fitting method, which have relatively large calculation errors and poor anti-interference ability

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  • A method for measuring the static contact angle of liquid droplets
  • A method for measuring the static contact angle of liquid droplets
  • A method for measuring the static contact angle of liquid droplets

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Experimental program
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Embodiment 1

[0067] This embodiment verifies the effect of the simulated water drop image.

[0068] Such as Figure 2a-3a As shown, the simulated water drop image with a contact angle of 5° and a water drop volume of 1 microliter, the calculation accuracy of the original polynomial fitting method is higher, the result is 3.8 degrees, and the error is -1.2 degrees. At this time, the calculation result of the present invention is 3.1 degrees, and the error is only -1.9 degrees, and the obtained edge is in good agreement with the real water drop image, that is to say, the accuracy of the two methods is relatively high at this time.

[0069] Such as Figure 2b-3b As shown, the simulated water drop image with a contact angle of 30° and a water drop volume of 2 microliters, the calculation accuracy of the original polynomial fitting method is higher, the result is 28.5 degrees, and the error is -1.5 degrees. At this time, the calculation result of the present invention is 29.4 degrees, and the...

Embodiment 2

[0074] The water droplet image in this embodiment was obtained on the RTV silicone rubber coating with deionized water droplets, and 1, 2 and 10 microliters of water droplets were dropped into the coatings with different surface treatments, and the images were taken.

[0075] The water droplet edge calculated by the original polynomial fitting method for the above three images is shown in the attached Figure 4a~6a As shown, the water drop edge calculated by the method of the present invention is as attached Figure 4b-6b shown. Considering the real contact angle of the image and the size of the water drop volume, the above three images are the circle fitting method, the circle fitting method and the ellipse fitting method, which have relatively high accuracy. Their calculation and fitting results are as follows: attached Figure 4c-6c shown.

[0076] Such as Figure 4a As shown, the image of water droplets with a volume of 1 microliter, the calculation result of the origi...

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Abstract

A method for measuring the static contact angle of a droplet. First, drip water on the surface of a material, and then use a digital imaging device to take pictures of the droplet on a plane perpendicular to the surface of the material to obtain an image of the droplet, and use an edge detection operator to measure the droplet. The droplet image is processed to obtain the droplet edge; then the droplet edge point data is transformed from the Cartesian coordinate system to the polar coordinate system, and then the polynomial fitting method is used to fit the droplet edge, and then the droplet edge is transformed from the polar coordinate system to Cartesian coordinate system, and finally calculate the slope of the droplet edge at the solid, liquid, and gas three-phase junction point, and obtain the static contact angle from the slope. In the present invention, the rectangular coordinate system is converted into the polar coordinate system first, and then the edge of the droplet is fitted. Since the edge of the droplet is closer to a polynomial in the polar coordinate system, the calculation accuracy of the contact angle is higher, and it is converted into polar coordinates. The number of points involved in fitting the edge after the system is more, and the anti-interference ability is stronger.

Description

technical field [0001] The invention relates to a method capable of accurately measuring the static contact angle of water droplets on a material surface, belonging to the technical field of measurement. Background technique [0002] Hydrophobicity is an important parameter to characterize the wettability of a material surface. The better the hydrophobicity of the surface of the material, the less likely dirt and water will be adsorbed on the surface of the material, and the better the anti-fouling, waterproof and ice-proof properties of the material. The less hydrophobic the surface of the material, the stronger the adsorption between liquid and solid. Therefore, the detection of hydrophobicity has extremely wide applications in science and engineering. [0003] Hydrophobicity is usually measured by the contact angle (that is, the angle between the solid-liquid interface and the liquid interior to the gas-liquid interface at the junction of solid, liquid, and gas), but th...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01N13/00
Inventor 徐志钮
Owner NORTH CHINA ELECTRIC POWER UNIV (BAODING)
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