Surface Morphology Regulation And Multifunctional Integration Of Layer-by-Layer (LbL) Assembled Films

Layer-by-layer(LbL) assembly has been demonstrated to be a convenient and versatile method to fabricate composite films with well-tailored composition and structures.It is of great significance to realize dynamic regulation of structure and integration of multiple functions of Lb L-assembled films.Therefore,we carried out the following research works:1.We develop a new type of dynamic Lb L assembled system to achieve films with hierarchical wrinkle structures.The resultant films were fabricated through Lb L assembly of poly(ethylene oxide)-b-poly(acrylic acid)(PEO-b-PAA)block copolymers and poly(allylamine hydrochloride)(PAH).When the PEO-b-PAA/PAH films achieve a certain thickness,the structure of the films can be tuned by the layer evenly covering the films.When PEO-b-PAA nanoparticles evenly covering on the surface of wrinkled underlying layer,the films exhibit hierarchical structures.However,such hierarchical structures can be erased by further PAH deposition,leading to a uniform and smooth film structure when PAH is the outmost layer of the films.Tailoring of hierarchical wrinkle morphology can be facilely achieved by tuning the film deposition cycles.2.We first demonstrate a highly transparent film integrating antifogging,antifouling,and self-healing properties through Lb L assembly of branched poly(ethylenimine)(b-PEI)and zwitterionic carboxyl betaine grafted alginate(ALG-CB).The resultant films exhibit satisfying long-term stability and high transparency.Meanwhile,the films exhibit excellent anti-frost and antifogging performance even placed in a harsh frost and fog environment.As the CB is a favorable antifouling molecule,the antifouling ability was also integrated into the films.The films almost showed no bacterial adhesion after being immersed in a bacteria-laden culture solution.More importantly,the films exhibit excellent self-healing properties,which can rapidly and repeatedly heal several tens of micrometers wide of cuts and scratches with the assistance of water.