| With the rapid development of thin film technology,the requirements for surface films in modern life are also increasing,and with the rapid rise and rapid development of micro and nano devices,micro and nano films are also transforming into functional surfaces.As a common polymer material,polytetrafluoroethylene(PTFE)has been used on the surface of various functional films because of its good chemical and mechanical stability.But at the moment of PTFE film or composite film in the form of existence,without coating for PTFE particles research,based on the PTFE coating particles as a starting point,the PTFE particles by means of spin coating,its wetting and wettability were characterized,and studied the PTFE micro particle texture for lens anti-reflection effect,obtained the following results:(1)PTFE coatings with different mass fraction and different rotational speed were prepared by using spin coating method in addition to borosilicate.The effects of mass fraction and rotational speed on the surface morphology were studied.The particles on the coating surface with a mass fraction of 5 wt.% are distributed in an island shape,and the dispersion degree is obvious.The surface of the coating with mass fraction of 10 wt.% and 15 wt.%shows a pore structure,and the pore ratio decreases with the increase of mass fraction,but increases with the increase of rotating speed.When the mass fraction is 20 wt.% and 30 wt.%,the surface of the coating is completely covered by PTFE particles,and the color halo appears in the center.The higher the mass fraction is,the more obvious the color distribution is.(2)The water contact Angle was measured on each coating.The surface contact Angle of the coating with mass fraction of 5 wt.% increased due to the existence of island morphology,but could not reach the hydrophobic surface.The overall contact Angle of the coating was smaller than that of the coating with mass fraction of 10 wt.% and 15 wt.%.The surface of the coating with mass fraction of 10 wt.% and 15 wt.% becomes hydrophobic due to the existence of pores.The contact Angle of the coating with mass fraction of 10 wt.% is the maximum when the rotation speed is 2 000 rpm.When the mass fraction of the coating is 15 wt.%,the maximum contact Angle is about 105°?107° at medium and low rotating speeds when the porosity ratio is 30%?35%.The coating surfaces with mass fraction of 20 wt.% and 30 wt.%are covered by dense PTFE particles,and the coating surfaces with mass fraction of 20 wt.%and 30 wt.% exhibit different wetting states due to the influence of evaporation temperature and evaporation time.With the increase of evaporation temperature,the water-based groups on the coating surface are fully volatilized,the overall hydrophobicity is greatly improved,and the adhesion with the substrate is also greatly enhanced.(3)The electrowetting experiments were carried out on the coating surface at a speed of3 000 rpm and an evaporation temperature of 250 ?.The results show that the threshold voltage of electrowetting on the coating surface increases with the increase of mass fraction.During the period of electrowetting,the suspension of coating particles in the droplet was observed.After the electrowetting,the loss of coating particles,the superposition of coating and the emergence of tree structure on the diffusion surface of three-phase contact line were observed.(4)The insertion of the microstructure does realize the anti-reflection effect of the microlens,and the overall effect of the coating with the mass fraction of 10 wt.% is better than that of the coating surface with the other mass fraction.When the mass fraction is 10 wt.%,the rotation speed is 2 000 RPM,and the evaporation temperature is 80 ?,the transmittance of the coating ? zone and the microstructure of the Fe zone is the best,that is,the transmittance is the highest when the porosity is 27.82% to 35.69%. |
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