Preparation of a gradient wettability surface based on organic-inorganic hybrid coating

A rather simple method to prepare a gradient wettability coating surface was proposed. The gradient surface with contact angle from 12.0° to 85.3° was prepared by slowly adding hexamethoxy methyl melamine (HMMM) and subsequently fluoro-contained acrylic polymer into an organic-inorganic hybrid hydrophilic polymer synthesized by Tetraethoxysilane (TEOS) and Acrylic acid (AA) while gradually lifting the microslide substrate out of the mixture. The method overcomes the limitation of restrictive substrate and reactive conditions, providing potential applications in areas such as heat transfer enhancement, protein absorption and microfluidics.