Back Cover: PDMS with Tunable Side Group Mobility and Its Highly Permeable Membrane for Removal of Aromatic Compounds (Angew. Chem. Int. Ed. 6/2022)

Abstract

Aromatics-permeable membranes ……made from polydimethylsiloxane with tunable side group mobilities are reported by Gongping Liu and co-workers in their Research Article (e202111810). Phenyl groups were introduced as rigid molecular spacers to endow the methyl groups with high mobility and reconstruct the polymer conformation, creating ah ighway for the fast transport of aromatic molecules,a nd thus realizing efficient removal of aromatic compounds from aqueous solution.

Bifunctional role of PDMS membrane in designing humidity-tolerant H2S chemiresistors with high selectivity

“…12 PDMS possesses both robust hydrophobicity under harsh operation conditions (chemically stable up to 480 1C in air 15 ) and intriguing (tunable) gas permeable properties (with abundant nanopore pathways for the permeation of the target gas molecules to the MOS surface). 16 Our previous work has indicated that Pt-anchored CCO with abundant Pt single atoms exhibits superior catalytic properties, which facilitates the spillover of molecule-type O 2…”

“…PDMS possesses both robust hydrophobicity under harsh operation conditions (chemically stable up to 480 °C in air 15 ) and intriguing (tunable) gas permeable properties (with abundant nanopore pathways for the permeation of the target gas molecules to the MOS surface). 16 Our previous work has indicated that Pt-anchored CCO with abundant Pt single atoms exhibits superior catalytic properties, which facilitates the spillover of molecule-type O 2 − into more active atom-type O − ions (reaction (1)) and dissociation of the H 2 S molecule into a SH radical and H. The catalyzed surface redox reaction (reaction (2)) between SH and O − results in an excellent response under a dry air atmosphere. 12 O 2(ads) + e − ↔ O 2 − (ads) 2SH (ad) + 5O − (ad) → 2SO 2(ad) + H 2 O (ad) + 5e − Herein, an ultra-thin PDMS overlayer has been proposed as a moisture-resistant molecular sieve for a Pt-anchored CCO-based H 2 S chemiresistor.…”

“…It is well-known that PDMS has been widely used in the membrane for (gas) molecules separation; its gas permeability is mainly dependent on the size and chemical properties of the gas molecule. 16,25 As H 2 S and CH 3 SH share quite similar chemical properties, the relatively small kinetic diameter of H 2 S (0.36 nm) in comparison with CH 3 SH (0.40 nm) 17,35 facilitates the (selective) sieving of target H 2 S molecules into the underlying MOS layer, and it blocks larger molecules (CH 3 SH) from contacting the sensing layer, resulting in excellent selectivity. With the recent advances in chain network engineering of PDMS, 16,36 plenty of room should exist for designing PDMS multifunctional layers with different pore sizes and gas permeability for sieving other target molecules.…”

“…16,25 As H 2 S and CH 3 SH share quite similar chemical properties, the relatively small kinetic diameter of H 2 S (0.36 nm) in comparison with CH 3 SH (0.40 nm) 17,35 facilitates the (selective) sieving of target H 2 S molecules into the underlying MOS layer, and it blocks larger molecules (CH 3 SH) from contacting the sensing layer, resulting in excellent selectivity. With the recent advances in chain network engineering of PDMS, 16,36 plenty of room should exist for designing PDMS multifunctional layers with different pore sizes and gas permeability for sieving other target molecules. Furthermore, long-term stability operating under humid air is another challenging issue for H 2 S chemiresistors.…”

Controllable hydrogen-bonded poly(dimethylsiloxane) (PDMS) membranes for ultrafast alcohol recovery

“…Efficient recovery of bio-alcohols from biomass fermentation broth has significant environment and economic impacts. 1,2 On the one hand, bio-alcohols as one of the new sustainable energy sources hold the promise of replacing fossil fuels and alleviating environmental pollution. 3,4 On the other hand, they are important raw materials and common solvents in the medical, chemical, and pharmaceutical industries.…”