Study On Fabrication Of Bio-mimic Surfaces With Special Wettability Via Functional Particles Assisted Breath Figure Method

Breath figure (BF) method is a fast and effective way to fabricate patterned porous surfaces.Based on BF method, for the first time, we have tried to blend responsive PNIPAm-co-AAmicrogels and amphiphilic Janus silica nanoparticles with the polymer casting solution to develop anovel surface patterning method of functional particle assisted BF (FPABF) method. By utilizingthe FPABF method and mimicking the micro-nanoscale composite structure with specialwettability from nature, we fabricated two kinds of films, which are responsive patterned porousfilms and strong hydrophobic films with convex patterning. Both films are having the micro-nanoscale composite structure. We, therefore, provide a new idea as well as method towards novelfunctional polymer film fabrications.Through adding PNIPAm-co-AA microgels into the BF casting solution, searching forappropriate ratio of components as well as improving film fabrication devices and processingmethod, we made responsive patterned porous polymer films with bio-mimic micro-nanoscalecomposite structure. Those films could be able to present morphological transitions in pores from acontinuously layered roughness to arrays of nano-convex after being treated by water with atemperature above the critical temperature (VPTT). At the same time, the distinct switches ofwettability and ability of water absorption accompanying with those morphological transitionswere detected.When the film exhibited the layered morphology in pores at room temperature, theyalso showed strong ability of water absorption and water contact angles dropped dramaticallyduring the contact angle test, as well. And when treated by water with a temperature above VPTT,film morphology turned into continuously convex arrays and switched to a status of hydrophobicwith barely decreasing water contact angles (around90°). Those morphologically and functionallyresponsive patterned porous films with bio-mimic micro-nanoscale composite structure were firstlyfabricated by microgel involved BF and might be able to have potential application on highlyefficient biocatalysis, targeting and control release of medicine.In the research of fabricating bio-mimic films with patterning of convex arrays via Janusparticles assisted BF method, we firstly improved the processing technique of amphiphilic Janussilica particles fabrication in the aspect of colloidsome preparation, hydrophobic modification and so on. Then, we also, for the first time, applied synthesized Janus particles into BF method.Through adjusting ratio of components of casting solution as well as the processing method, weexplored a new Janus assisted BF method, and therefore, made highly ordered porous films.Finally, depending on PDMS replica and chemical precipitation of Ag nanoparticles through silvermirror reaction, patterned convex films with bio-mimic micro-nanoscale composite structure weresuccessfully achieved. Comparing to patterned convex films with microscale structure only, thefilms has a much higher water contact angle of140°, and could be able to find applications atwater-proof and anti-fouling areas.