Abstract:
Abstract: Water scarcity is still a pressing issue in many regions. The application of membrane
technology through water desalination to convert brackish to potable water is a promising technology
to solve this issue. This study compared the performance of templated TEOS-P123 and ES40-P123
hybrid membranes for brackish water desalination. The membranes were prepared by the sol–gel
method by employing tetraethyl orthosilicate (TEOS) for the carbon-templated silica (soft template)
and ethyl silicate (ES40) for the hybrid organo-silica. Both sols were templated by adding 35 wt.% of
pluronic triblock copolymer (P123) as the carbon source. The silica-templated sols were dip-coated onto
alumina support (four layers) and were calcined by using the RTP (rapid thermal processing) method.
The prepared membranes were tested using pervaporation set up at room temperature (~25 ◦C)
using brackish water (0.3 and 1 wt.%) as the feed. It was found that the hybrid membrane exhibited
the highest specific surface area (6.72 m2·g−1), pore size (3.67 nm), and pore volume (0.45 cm3·g−1).
The hybrid ES40-P123 was twice thicker (2 μm) than TEOS-P123-templated membranes (1 μm). Lastly,
the hybrid ES40-P123 displayed highest water flux of 6.2 kg·m−2·h−1. Both membranes showed
excellent robustness and salt rejections of >99%.
Keywords: mesoporous silica; rapid thermal processing; sol–gel process; brackish water desalination
