title: Tailoring the affinity of organosilica membranes by introducing polarizable ethenylene bridges and aqueous ozone modification.
abstract: Bis(triethoxysilyl)ethylene (BTESEthy) was used as a novel precursor to develop a microporous organosilica membrane via the sol-gel technique. Water sorption measurements confirmed that ethenylene-bridged BTESEthy networks had a higher affinity for water than that of ethane-bridged organosilica materials. High permeance of CO2 with high CO2/N2 selectivity was explained relative to the strong CO2 adsorption on the network with π-bond electrons. The introduction of polarizable and rigid ethenylene bridges in the network structure led to improved water permeability and high NaCl rejection (>98.5%) in reverse osmosis (RO). Moreover, the aqueous ozone modification promoted significant improvement in the water permeability of the membrane. After 60 min of ozone exposure, the water permeability reached 1.1 × 10(-12) m(3)/(m(2) s Pa), which is close to that of a commercial seawater RO membrane. Meanwhile, molecular weight cutoff measurements indicated a gradual increase in the effective pore size with ozone modification, which may present new options for fine-tuning of membrane pore sizes.
authors.affiliation: Department of Chemical Engineering, Hiroshima University, Higashi-Hiroshima, Japan.
authors.forename: Rong
authors.initials: R
authors.lastname: Xu
authors.forename: Masakoto
authors.initials: M
authors.lastname: Kanezashi
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Yoshioka
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Okuda
authors.forename: Joji
authors.initials: J
authors.lastname: Ohshita
authors.forename: Toshinori
authors.initials: T
authors.lastname: Tsuru