Polyphenol Coating as an Interlayer for Thin-Film Composite Membranes with Enhanced Nanofiltration Performance

Abstract

Thin-film composite (TFC) nanofiltration membranes are prepared via interfacial polymerization with a polyphenol coating as an interlayer for the thin and smooth polyamide selective layer. The polyphenol interlayer is simply fabricated by the codeposition of tannic acid and diethylenetriamine without changing the surface morphology of the polysulfone ultrafiltration substrate. An interfacial polymerization is conducted from piperazidine and trimesoyl chloride on the polyphenol interlayer to construct the polyamide selective layer. The as-prepared TFC nanofiltration membranes show nearly tripled fold of water permeation flux as compared with those prepared at the same condition without an interlayer. They also exhibit a high rejection to NaSO (>98%) because the thin and defect-free polyamide selective layer is formed on the polyphenol interlayer. These nanofiltration properties have high reproducibility, which means the TFC nanofiltration membranes are suitable for scale-up industrial applications.

Bioinspired Strategy for Controlled Polymerization and Photopatterning of Plant Polyphenols

“…Plant derived polyphenols were recently introduced for particle and surface modification. 1−3 Numerous applications in materials science have been already demonstrated including self healing materials, 4 surface modification of membranes, 5 designing novel antioxidants, 6,7 anticancer drugs, 8 and bio adhesives, 9 as well as development of drug delivery systems, 10 antibacterial coatings and surfaces with reduced biofouling, 11 energy storage devices, 12 thin film 13−15 and bulk 16 hybrid functional materials, and immobilization of enzymes. 17,18 Phenolic compounds, similar to polycatecholamines such as dopamine (DA), can undergo autoxidation process in the presence of oxidizing agents, 10 high redox potential enzymes which are suitable for use in oxidative processes, 19 or in alkaline pH condition.…”

Plant‐Inspired Pyrogallol‐Containing Functional Materials

“…The codeposition process dramatically enhanced the surface wettability and water permeation capability of microfiltration membranes. The TA coating is also useful as an adhesive interlayer to fabricate a polyamide thin film as a secondary top layer . The hydrophilic TA is able to easily diffuse into layers to facilitate interfacial polymerization processes.…”

Preparation of a novel zwitterionic striped surface thin-film composite nanofiltration membrane with excellent salt separation performance and antifouling property

“…The high Na 2 SO 4 rejection and the reduction of MgCl 2 rejection can be rationalized by the Donnan effect and size exclusion effect, as there was a charge shielding effect in the charged membrane surface and the hydration radii of Na + and Cl À are too small to be rejected. 53 The sulfonic acid groups were taken into the membrane with the unreacted amino groups of PEI to construct a zwitterionic surface, which altered the surface potential. The taurine content increased, enhancing the negative potential, so the rejection of Na 2 SO 4 rst increased.…”