Silane‐Crosslinked Asymmetric Polythiosemicarbazide Membranes for Organic Solvent Nanofiltration

Abstract

Crosslinked polythiosemicarbazide (PTSC) membranes with a positively charged surface are fabricated via a reaction with (3‐glycidyloxypropyl)trimethoxysilane. The integrally asymmetric ultrafiltration membranes discussed here can be easily prepared by water‐induced phase separation using a PTSC solution in dimethylsulfoxide (DMSO). The crosslinked PTSC membranes are stable in DMSO, N,N‐dimethylformamide, and tetrahydrofuran and they reject molecules of molecular weights (MW) above 1300 g mol−1. The influence of the crosslinking agent on the surface charge, membrane solvent resistance, and membrane performance is discussed. The crosslinked asymmetric PTSC membranes totally reject Direct Red dye (MW 1373 g mol−1), while the pristine PTSC membrane does not show any rejection for this dye. This finding suggests that an inorganic‐type‐network is formed during the crosslinking reaction, which tunes the pore size of the prepared membranes.

Multifunctional Bioinspired Bredigite-Modified Adhesive for Bone Fracture Healing

“…The stretching vibrations of C–N groups and vinyl groups (CC) were detected at 1015 and 1603 cm –1 , respectively. The typical bands at 951 and 810 cm –1 corresponding to out-of-plane (OOP) bend vibrations of vinyl groups (C–H) and positions of substituents on the catechol ring were also displayed well . After copolymerization, the broad bond in the range of 3031–3702 cm –1 was related to the stretching vibration convergence of N–H and −OH; meanwhile, secondary amines had one weak peak in this region .…”

“…The typical bands at 951 and 810 cm −1 corresponding to out-of-plane (OOP) bend vibrations of vinyl groups (C−H) and positions of substituents on the catechol ring were also displayed well. 32 After copolymerization, the broad bond in the range of 3031−3702 cm −1 was related to the stretching vibration convergence of N−H and −OH; meanwhile, secondary amines had one weak peak in this region. 33 In addition, the absorption peak at 1407 cm −1 was attributed to the bending vibration of methyl groups (−CH 3 ) in the PDA precursor.…”

From waste to wealth: chelating polymeric membranes for precious palladium recovery from wastewater

“…The PTSC spectrum shows a strong absorption band at 1523 cm −1 and a moderate band at 722 cm −1 that represents the CS. 41,42,54 The aromatic C–H and aromatic CC absorption peaks are exhibited at 2821 cm −1 , 1611 cm −1 , respectively. The absorption band at 1003 cm −1 is assigned to the aliphatic C–N stretch.…”

“…PTSC was synthesized following the literature [41][42][43] by reacting equimolar amounts of N,N ′ -diaminopiperazine and methylenebis(4-phenylisothiocyanate) monomers in dimethyl sulfoxide (DMSO) at 70 °C as presented in Scheme 1a. PTSC membranes were prepared using non-solvent induced phase inversion, Fig.…”

“…Fig.3Shows the FTIR spectra of PTSC and Pd complexed PTSC membranes. The PTSC spectrum shows a strong absorption band at 1523 cm −1 and a moderate band at 722 cm −1 that represents the C]S 41,42,54. The aromatic C-H and aromatic C]C absorption peaks are exhibited at 2821 cm −1 , 1611 cm −1 , respectively.…”