Fabrication of PEG Crosslinked Organosilica Hybrid Membranes for Reverse Osmosis Desalination

doi:10.15541/jim20180019

Abstract

Abstract:

A series of poly(ethylene glycol)(PEG) crosslinked organosilica hybrid membranes were fabricated via co-polymerization with PEG as crosslinker and bis(triethoxylsilyl)ethane(BTESE) as the Si precursor, using porous α-Al₂O₃ membranes as the support. The membrane structure and physicochemical properties were characterized by atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and water contact angle measurements (CA). The prepared BTESE/PEG hybrid membranes were applied to desalination by reverse osmosis (RO). The effects of PEG content, operating pressure, feed concentration, and operating temperature on RO performances of the membrane were investigated. Compared with the un-modified BTESE membrane, the BTESE/PEG hybrid membrane with an optimum PEG content of 10wt% exhibited higher water permeability and observed NaCl rejection in RO experiments. In addition, the observed NaCl rejection increased whereas the water permeability remained almost constant with an increase in operating pressure and a decrease in salt concentration. Moreover, the BTESE/PEG-10 membrane exhibited high hydrothermal stability in temperature cycles up to 70℃, always delivering high NaCl rejections of >97% and excellent water permeabilities of up to 1.2×10^-12m³/(m²·s·Pa).

Key words: poly(ethylene glycol), organosilica, reverse osmosis, desalination

CLC Number:

TQ028

XU Rong, JIANG Wan, QI Lv, ZHANG Qi, ZHONG Jing. Fabrication of PEG Crosslinked Organosilica Hybrid Membranes for Reverse Osmosis Desalination[J]. Journal of Inorganic Materials, 2018, 33(11): 1154-1160.

Figures/Tables 10

Fig. 1 Schematic structure of the BTESE/PEG hybrid membrane

Fig. 2 Scheme of the RO experimental apparatus

Fig. 3 AFM images of (a) BTESE and (b) BTESE/PEG-10 membranes

Fig. 4 Cross-sectional SEM image of the BTESE/PEG-10 membrane

Fig. 5 (a) FT-IR spectra of the BTESE and BTESE/PEG-10 membranes and (b) TG curve for the BTESE/PEG-10 membrane

Fig. 6 Contact angles of BTESE/PEG membranes

Fig. 7 Effect of PEG content in BTESE membranes on water permeability and salt rejection (25℃, 1.2 MPa, 2000 mg/L)

Fig. 8 Effect of pressure on the RO performance of BTESE/ PEG-10 membrane (25℃, 2000×10-6 mg/L NaCl feed)

Fig. 9 Influence of NaCl concentration on the RO performance of BTESE/PEG-10 membrane (25℃, 1.2 MPa)

Fig. 10 Effects of (a) operating temperature and (b) time on RO performance of the BTESE/PEG-10 membrane (1.2 MPa and 2000 mg/L NaCl feed)

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