Fluid boundary control-based quantitative measurement method for fluid slippage on super-hydrophobic surface

Abstract

The invention discloses a fluid boundary control-based quantitative measurement method for fluid slippage on a super-hydrophobic surface, which is characterized by comprising the following steps: preparing the super-hydrophobic surface, treating the prepared super-hydrophobic surface, clamping the treated super-hydrophobic surface on a rheological test platform, and calibrating the position of a clamp and mapping the clamp; and performing rheological test operation on the super-hydrophobic surface and performing rheological test operation on the fluid on a smooth hydrophobic surface under the same test condition to acquire torques applied to the clamp when the fluids are at the same shear speed under the two conditions, and calculating the slippage length according to the measured torques. The method has a wider test range, and not only can measure the length of the fluid slippage on the super-hydrophobic surface on which the super-hydrophobic area is circular and the outside of the super-hydrophobic area is the smooth hydrophobic surface, but also can measure the length of the fluid slippage on the prepared common super-hydrophobic surface.

Description

technical field [0001] The present invention relates to the technical field of fluid slippage and drag reduction on superhydrophobic surfaces, in particular to a measurement technology for fluid slippage on superhydrophobic surfaces based on fluid boundary control, which is applicable to the slippage of fluids that can be in a superhydrophobic state on superhydrophobic surfaces Length measurement and research. Background technique [0002] Due to its special super-hydrophobic effect, super-hydrophobic surfaces have received extensive attention in recent years. There have been a large number of reports on the preparation of super-hydrophobic surfaces, such as the report on super-hydrophobic surfaces by the Jiang Lei research group of the Chinese Academy of Sciences. On this basis, superhydrophobic surfaces have been gradually applied to engineering to prevent liquid adhesion and keep surfaces clean. Existing studies have shown that the unique superhydrophobic effect of super...

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Problems solved by technology

However, since the filling of the liquid in the gap between the superhydrophobic surface and the hydrophobic surface (test fixture) has a cross-sectional inhomogeneity characteristic, such as figure 2 As shown, the side appearance profile of the fluid 1 between the fixture 3 and the superhydrophobic surface 5 is not the standard drum-shaped profile required for the test, therefore, a large slip length deviation is brought about when the method of Choi is used for testing (following The slip length test deviation caused by the wettability of the superhydrophobic surface)

The Bocquet research group also questioned Choi's method in this regard. They believed that the deviation of the slip length test caused by the wettability of the superhydrophobic surface was far greater than the true value of the slip length, and the test results could not explain the fluid reduction on the superhydrophobic surface. Resistivity, but they don't give a way to improve it

In Chinese Science Bulletin No. 24 in 2009, Li Jian et al. proposed a method to test the fluid slip length on superhydrophobic surfaces by controlling the boundary method, but their test objects were limited to specially processed superhydrophobic surfaces (to ensure superhydrophobic surface during processing). The area of ​​the hydrophobic region is smaller than the area of ​​the clamp, while the other regions are smooth hydrophobic surfaces), it is difficult to test the fluid slippage on the prepared superhydrophobic surface with irregular boundaries

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