High flux and ultra‐thin poly‐dimethyldiethoxysilane/poly(vinylidene fluoride) composite membrane for alcohols recovery from aqueous solution by pervaporation

Abstract

Pervaporation (PV) of membrane separation technology has become an efficient approach to separate alcohols from aqueous solution. In this study, focusing on increasing the total flux and breaking the trade‐off in PV, an ultra‐thin and high flux poly‐dimethyldiethoxysilane (PDMDES)/poly(vinylidene fluoride) (PVDF) composite membrane was prepared. By employing various means, the characterizations of PDMDES/PVDF composite membrane were extensively investigated and the promising results indicated the high hydrophobicity and good affinity to alcohols. To be specific, PDMDES selective layer with different thicknesses, the thinnest of which was approximately 265 nm, were fabricated, and better PV performance can be achieved in a thickness range of 1.10 ~ 1.69 μm. The optimal PV performance of PDMDES/PVDF composite membrane was obtained in separating methanol from 5 wt% methanol/water solution at 40°C, resulting in a total high permeation flux of 5.38 kg m−2 h−1 and a higher pervaporation separation index (PSI) of 18.63 kg m−2 h−1.Highlights The ultra‐thin and high flux composite membranes for alcohols recovery via pervaporation (PV) are prepared by using monomer in membrane preparation through a simple fabrication method. The trade‐off is broken in the ultra‐thin composite membrane compared with traditional composite membrane. The influence between membrane thickness and PV performance is investigated through experimental tests, and the results show that the ultra‐thin composite membrane has a total high permeation flux of 5.38 kg m−2 h−1.

Enhancing Pervaporation Performance for Alcohol Recovery from Aqueous Solutions with Silicalite-1/Polydimethyldiethoxysilane (PDMDES) Nanocomposite Membranes

“…The PV performance of the silicalite-1/PDMDES nanocomposite membranes was evaluated by employing a batch apparatus, as reported in our previous work . A detailed representation of this apparatus is provided as Figure S1 in the Supporting Information.…”

“…The PV performance of the silicalite-1/PDMDES nanocomposite membranes was evaluated by employing a batch apparatus, as reported in our previous work. 16 A detailed representation of this apparatus is provided as Figure S1 in the Supporting Information. In the experiments, a methanol/water or ethanol/water binary solution was stored in a 2 L feed tank, with the alcohol concentration adjusted by controlling the weight of the alcohol in mixture.…”

“…Its high permeation flux and ultrathin selective layer make it particularly suitable for recovering alcohols from aqueous solutions, especially in applications targeting the efficient recovery of alcohols. 16 Unfortunately, the PDMDES membranes lack sufficient separation factors, which urgently need to be modified. The advent of organic−inorganic hybrid materials, blending the high permeability of inorganic substances with the hydrophobicity of organic materials, 17 has led to the creation of composite selective layers that enhance the separation performance of PV membranes.…”

“…Given this backdrop, polydimethyldiethoxysilane (PDMDES), a newly developed membrane material derived from PDMS with a unique structure, has been identified as a promising candidate for PV membranes. Its high permeation flux and ultrathin selective layer make it particularly suitable for recovering alcohols from aqueous solutions, especially in applications targeting the efficient recovery of alcohols . Unfortunately, the PDMDES membranes lack sufficient separation factors, which urgently need to be modified.…”

Poly(vinylidene fluoride‐hexafluoropropylene)/mesoporous graphitic carbon nitride composite membranes for photocatalytic methylene blue degradation and sensing applications

“…65 Although various polymer and their mpg-C 3 N 4 composite have been used by few researchers, to the best of our knowledge, no work has been done using poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP)/mpg-C 3 N 4 for MB detection and degradation. [66][67][68][69][70][71] The electrospun polymer has been used, which has increased surface area. This innovative strategy combines mpg-C 3 N 4 's distinctive photocatalytic capabilities with electrospinning, a tried-and-true method for producing fiber webs of polymer.…”