title: Mesoporous Silica Gel-Based Mixed Matrix Membranes for Improving Mass Transfer in Forward Osmosis: Effect of Pore Size of Filler.
abstract: The efficiency of forward osmosis (FO) process is generally limited by the internal concentration polarization (ICP) of solutes inside its porous substrate. In this study, mesoporous silica gel (SG) with nominal pore size ranging from 4-30 nm was used as fillers to prepare SG-based mixed matrix substrates. The resulting mixed matrix membranes had significantly reduced structural parameter and enhanced membrane water permeability as a result of the improved surface porosity of the substrates. An optimal filler pore size of ~9 nm was observed. This is in direct contrast to the case of thin film nanocomposite membranes, where microporous nanoparticle fillers are loaded to the membrane rejection layer and are designed in such a way that these fillers are able to retain solutes while allowing water to permeate through them. In the current study, the mesoporous fillers are designed as channels to both water and solute molecules. FO performance was enhanced at increasing filler pore size up to 9 nm due to the lower hydraulic resistance of the fillers. Nevertheless, further increasing filler pore size to 30 nm was accompanied with reduced FO efficiency, which can be attributed to the intrusion of polymer dope into the filler pores.
authors.affiliation: Nanyang Environment &Water Research Institute, Interdisciplinary Graduate School, Nanyang Technological University, Singapore, 639798.|Singapore Membrane Technology Centre, Nanyang Environment &Water Research Institute, Nanyang Technological University, Singapore, 637141.
authors.forename: Jian-Yuan
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Singapore Membrane Technology Centre, Nanyang Environment &Water Research Institute, Nanyang Technological University, Singapore, 637141.
authors.forename: Yining
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Nanyang Environment &Water Research Institute, Interdisciplinary Graduate School, Nanyang Technological University, Singapore, 639798.|Singapore Membrane Technology Centre, Nanyang Environment &Water Research Institute, Nanyang Technological University, Singapore, 637141.|Department of Civil Engineering, the University of Hong Kong, Pokfulam, Hong Kong.
authors.forename: Chuyang Y
authors.initials: CY
authors.lastname: Tang
authors.affiliation: Key Laboratory of Flexible Electronics (KLOFE) &Institute of Advanced Materials (IAM), Jiangsu National Synergistic Innovation Center for Advanced Materials (SICAM), Institute of Advanced Materials, Nanjing Tech University (NanjingTech), Nanjing 211816, P. R. China.
authors.forename: Fengwei
authors.initials: F
authors.lastname: Huo