Protective structure

Abstract

A protective structure is provided, which includes a porous layer and a surface layer disposed on the porous layer. The porous layer includes a first copolymer, a plurality of pores, and a plurality of first silica particles, wherein the first copolymer is polymerized from a first monomer composition. The first monomer composition includes N,N-dimethylacrylamide and N-vinylpyrrolidone. The surface layer includes a second copolymer, a plurality of fibers, and a plurality of second silica particles, wherein the second copolymer is polymerized from a second monomer composition. The second monomer composition includes N,N-dimethylacrylamide and N-vinylpyrrolidone.

Dependencies are inferred from the claim text.