Monodisperse fusiform microporous silica formed by evaporation-induced self assembly of polyamino acid copolymer template

A amphiphilic and biodegradable block copolymer is obtained by introducing hydrophilic polyethylene glycol segments into the segments of polyamino acids through copolymerization. And the block copolymers, poly(L-phenylalanine)-b-poly(ethylene glycol), are used to fabricate silica materials through Evaporation-Induced Self-Assembly method. In the synthesis procedure, anilino-methyl triethoxy silane is used as an intermedium, on the one hand it interacts with polypeptide-based copolymer through π-π interaction between the phenyl groups of phenylalanine segments and anilino-methyl triethoxy silane; on the other hand, anilino-methyl triethoxy silane can co-condense with tetraethoxylsilane through hydrolysis process. The prepared silica possesses supermicropores and it is proposed that the supermicropores are templated by the polypeptide segments. It is proved that both polypeptide-based block copolymer and anilino-methyl triethoxy silane play important roles in the formation of mesoscale short-range-order and hierarchical structure. When the phenylalanine segment of block copolymer is longer, it can induce a well-defined shuttle-like morphology of polymer/silica hybrid particles.