Fabrication Of Special Wettable Surfaces Based On WO₃ Materials And Their Related Performance Studies

Surface wettability is one of the most important characteristics for a solid surface,which is decided collaboratively by surface energy and surface roughness.A series of different special wettable surfaces?such as superhydrophilic surface,superhydrophobic surface,superoleophilic surfaces and superoleophobic surfaces?can be obtained by adjusting surface chemical compositions and surface roughness.In these decades,special wettable surfaces have been attracting great interest of many researchers due to their unique properties and broad applications.WO₃ is a common semiconductor material and has the widespread application prospect in the fields of photochromism,electrochromism,visible light photocatalysis and gas sensing.However,the study on the wettability of WO₃is still not deep enough,which greatly limits its practical application in industry.Hence,with the development of the preparations and application,the combination of WO₃ and wettability has great significance both in theory and reality.In this work,WO₃ has been used to construct microstructures on various substrates and may be modified to regulate surface wettability.In this way,a series of special wettable surfaces based on WO₃ have been successfully fabricated.Besides,we studied their inherent law and potential applications.It is believed to be a new thought for the study of WO₃ as functional materials.It is hoped that these special wettable surfaces based on WO₃ materials with excellent behaviors could help people to design more functional surfaces based on other materials.The main contents are as follows:?1?WO₃ films with different morphologies have been fabricated on 400 meshes stainless steels through a simple hydrothermal process.SEM,XRD and XPS were used to analyze the surface morphology and chemical composition in different pH,respectively.Results showed that pH have great influences on both surface morphology and chemical composition.Furthermore,the underwater oil wettability has also been demonstrated using a contact angle meter.Results showed that the obtained WO₃ films all exhibited high underwater oleophobic.It provides a new idea for the fabrication of special wettable surfaces with controllable morphologies.?2?Based on the previous work,underwater superoleophobic WO₃ films have been fabricated on 2300 meshes stainless steels via a modified hydrothermal process.SEM was used to analyse the surface morphogy and results showed that the original smooth stainless steel surface was covered with a layer of rough structure after the hydrothermal process.By the XRD analysis,it indicated that the rough structure was composed of hexagonal WO₃.Further,the obtained WO₃ films were used to separate oil/water mixture and oil-in-water emulsion through a simple separating unit.Further,the separation efficiency was calculated.And the morphologies of emulsions for both before and after separation have been recorded by a microscope.It provides a new solution to solve the oil pollution problem.?3?Superhydrophobic WO₃ particles have been synthesized by combining a simple acid precipitation process and a subsequent octadecyltrichlorosilane modification.Then,the superhydrophobic coatings with photochromism and mechanical stability were obtained via coating the superhydrophobic particles on glass substrates by virtue of the adhesion of epoxy resin.SEM,XRD,XPS and FTIR were used to analyse the surface morphogy and chemical composition.Results showed that the obtained superhydrophobic coating was covered with a layer of rough structure which was composed of WO₃ particles.Subsequently,the UV-durability and mechanical robustness of coating were evaluated by UV light experiment and abrasion experiment,respectively.Moreover,the self-cleaning behavior of the superhydropobic coating was studied by stain-resistance test and of dirt-removal test.Finally,the applicability of the coating was characterized by coating on various substrates.Results showed that the as-prepared coating can be used on different substrates,such as glass,copper mesh,steel,paper and fiber.Therefore,the facile preparation of the superhydrophobic WO₃coating with excellent properties will be very meaningful for the design and fabrication of high performance superhydrophobic surfaces on different substrates.