Design And Preparation Of The Hydrophilic-hydrophobic Patterned Surface And Performance Study

The hydrophilic-hydrophobic patterned surfaces with unique wetting properties have potential applications in oil-water separation,biomedicine,condensation and heat dissipation.In this paper,superhydrophobic surfaces with different micro-texture structures were prepared on titanium surfaces with different parameters using nanosecond laser etching and modified with fluorosilanes.Then the nanosecond laser was used to etch hydrophilic patterns with different shapes on the superhydrophobic surface to prepare the hydrophilic-hydrophobic patterned surfaces.The effects of micro-texture parameters on the wettability of the superhydrophobic surfaces and the effects of hydrophilic pattern parameters on the wettability of the patterned surfaces were investigated,and friction experiments were conducted to analyze their tribological properties.The specific work is as follows:(1)In this paper,the effects of microweave shape,spacing and edge length on the wettability of titanium-based surfaces were investigated.The results show that the contact angle of the prepared samples decreases with the increase of the weave spacing when the edge length of the weave is constant.The contact angles of the three micro-weave shapes,such as square,triangle and circle,showed different trends when the weave spacing was fixed,and the contact angles of the square weave surface increased and the contact angles of the triangle and circle weave surfaces decreased when the spacing was 0.06 mm.The experiments show that the weave shape also affects the contact angle size,with the same weave spacing and edge length,the contact angles of samples with different weave shapes differ by a minimum of 0.5° and a maximum of 9.4°.Then,the effect of hydrophilic pattern parameters on the contact angle of the hydrophilic-hydrophobic patterned surfaces was investigated.The contact angle of the hydrophilic-hydrophobic patterned surfaces decreases as the edge length of the hydrophilic pattern becomes larger and decreases as the percentage of hydrophilic area increases.(2)The weave edge length,weave spacing and load have important effects on the tribological properties of titanium surfaces.The average friction coefficient of S-D0.06,T-D0.4 and C-D0.6 series samples decreases and then increases with the increase of weave edge length when the weave spacing is certain,the average friction coefficient of S-D0.4 and C-D0.1 series samples increases and then decreases with the increase of weave edge length,and the average friction coefficient of T-D0.6 series samples gradually increases with the increase of weave edge length.When the edge length of the weave is fixed,the average friction coefficient of S-L0.2 and T-L0.4 series samples increases and then decreases with the increase of the weave spacing,while the average friction coefficient of S-L0.08,T-L0.2,C-L0.08 and C-L0.2 series samples decreases and then increases.With the increase of load,the average friction coefficient of titanium-based surfaces both showed a decreasing trend,and the average friction coefficient and wear of superhydrophobic and superhydrophilic samples were smaller than the original samples.The average friction coefficients of superhydrophobic and superhydrophilic samples with the same weave were basically the same when the load was greater than 9N.However,the fluctuation of the friction coefficient curve of the superhydrophobic sample was significantly smaller than that of the superhydrophilic surface,and the wear amount of the superhydrophobic surface was smaller than that of the superhydrophilic surface.After friction,the superhydrophobic surface was damaged and the rolling angle of the samples increased,and the contact angle of most samples decreased,but the contact angle of a few samples became larger.(3)The hydrophilic pattern parameters have an important influence on the tribological properties of titanium-based hydrophilic-hydrophobic patterned surfaces.On the contrary,when the hydrophilic area is a certain percentage,the average friction coefficient of different hydrophilic patterned samples fluctuates to different degrees as the percentage of hydrophilic area increases,but the average friction coefficient of the hydrophilic-hydrophobic patterned surfaces is smaller than that of the original surface,but larger than that of the superhydrophobic surface.The average friction coefficients of different hydrophilic patterned surfaces showed fluctuations.The wear area of the hydrophilic-hydrophobic patterned surfaces is mainly concentrated at the junction of hydrophilic and hydrophobic regions,and the fatigue wear is mainly accompanied by abrasive wear.Compared with the superhydrophobic surface,the wear amount of the hydrophilic-hydrophobic patterned surfaces is significantly reduced.