Poly(2-hydroxyethyl acrylate-co-methyl acrylate)/SiO2/TiO2 hybrid membranes

Random copolymers of 2-hydroxyethyl acrylate (HEA) and methyl acrylate (MA) and homopolymer PHEA were prepared by free radical polymerization. The hydroxyl groups of PHEA were reacted with 3-(triethoxysilyl)propyl isocyanate to introduce triethoxysilyl (TREOS) groups. Co-hydrolysis and condensation of the TREOS groups with titanium tetrabutoxide yielded polymer/SiO2/TiO2 hybrid materials. Water vapor permeability across such hybrid membranes could be changed by varying the PHEA content and was very high for PHEA/SiO2/TiO2 membranes. Incorporation of MA into the hybrid allowed membrane properties, such as water uptake and brittleness, to be controlled. Such hybrid materials may be of interest for biomedical applications and for development of perm-selective barriers used in commercial and military technologies.