Fabrication and photoactivity of a tunable-void SiO2–TiO2 core–shell structure on modified SiO2 nanospheres by grafting an amphiphilic diblock copolymer using ARGET ATRP

摘要: SiO2-based composites have important applications in various technological fields. In this work, a tunable-void SiO2–TiO2 core–shell structure was successfully prepared for the first time using SiO2–polymethyl methacrylate (PMMA)–polyoligo(ethylene glycol)methyl ether (PO(EO)nMA) (n = 2, 5, and 8). An amphiphilic copolymer used as template, calcination performed tetrabutyl titanate (TBT) titanium source. SiO2–PMMA-b-PO(EO)nMA microspheres were synthesized through activators regenerated by electron transfer-atom transfer radical polymerization. Methyl O(EO)nMA grafted with different EO unit numbers onto surface of halogen functional group SiO2. TBT hydrolyzed along PO(EO)nMA chain hydrogen bonding, then acquired to remove polymer. Simultaneously, amorphous TiO2 crystallized during calcination. A series characterizations indicated that block SiO2 mesoparticle surfaces, titania samples existed only anatase phase, had hierarchically nanoporous structures. The gradient hydrophilicity PMMA-b-PO(EO)nMA template facilitated hydrolysis molecules PMMA segments, thereby tuning space between core shell. addition, about 6 nm when number 10 5 8. photocatalytic activities materials tested on photodegradation methyl orange.