Nanoparticles Decorated Fibrous Silica Membranes Exhibiting Biomimetic Self-cleaning And Highly Flexible Property

The wettability is an important properties for solid surface, some self-cleaning p Exist in nature, has sparked some concern and research for materials with wetting properties. Contact angle in solid surface is commonly used to characterize the wetting properties, greater than 150°is called super-hydrophobic surface. For water and oil, the contact angle in solid surface, which is greater than 150°, is called Ultra Dual sparse surface. And the materials with Super-Hydrophobic Surface have bright futrure for various applications both in industrial world and people's daily life, for example: energy, military, medical, clothing, communication, building, automobile, etc. Conventionally, there are henomena two approaches to produce the super-hydrophobic surfaces: One is to create routh surface on a hydrophobic surface. And the other is to modify the surface with materials of low surface free energy.In this paper, inspired by the self-cleaning lotus leaf, here we report the fabrication of flexible fluorinated silica nanofibrous membranes with biomimetic non-wettable surfaces by electrospinning the blend solutions of poly(vinyl alcohol) (PVA) and silica gel in the presence of silica nanoparticles, followed by the calcination and fluoroalkylsilane (FAS) modification. The resultant silica nanofiber exhibited a lotus-leaf-like structure with numerous nano-protrusions decorated on the fiber surfaces due to the rapid phase separation in electrospinning and calcinations processing. The content of silica nanoparticles incorporated into the fibers proved to be the key factor affecting the fiber surface morphology and wettability. The fluorinated silica fibrous membranes containing 38.8wt% silica nanoparticle showed the highest water contact angle (WCA) of 155°, oil contact angle (OCA) of 143°, orange juice contact angle (OJCA) of 142°, and milk contact angle (MCA) of 137°. Additionally, the fluorinated silica membranes exhibited good flexibility and the flexibility was also characterized by the KES-FB2S. We believe that this new class of inorganic membranes is particularly promising for the development of high-temperature filtration, high-temperature protection, novel easy-cleaning coatings, and even flexible electronics.In addition, physical techniques including the Field Emission Scanning Electron Microscopy, Contourgraph, Water contact angle, Fourier Transform infrared spectroscopy, X-ray diffraction are used to charaterise the properties of the fibrous membranes. Meanwhile, Wenzel and Cassie theories are also applied to analyze the results of the wetting properties, which is to explore the influence of its surface morphology, chemical composite and crystal structure to wetting property.