Gold-Coated Oligoamide Mimetic of Thin Film Composite Nanofilteration Membrane Synthesized Using Layer Chemistry for Study of Adsorption of Foulants and Surfactants

摘要

Gold-coated Oligoamide Mimetic of Thin Film Composite Nanofilteration Membrane Synthesized using Layer Nanofilteration (NF) membranes play an important role in waste water reclamation technologies. Despite of their huge potential in supplementing world's fresh water need they suffer from the problem of fouling. The fouling leads to the membrane deterioration in time. Cleaning the membranes with various types of surfactants and acid/base wash are helpful but are not fully efficient to reverse the damage caused by fouling. The fouling is highly complex phenomenon that is not precisely understood owing to lack of knowledge of exact surface chemistry. One of the main reasons for this gap is that commercial membranes are not suitable for the sensitive surface analysis [1]. To mitigate the problem of analysis and study of fouling we designed and prepared a surface mimetic of polyamide NF membranes. This mimetic is a films, composed of oligoamide layers on the gold surface using covalent layer chemistry. The oligoamide film has the similar chemistry as of NF membranes, i.e trimesoyl chloride coupled with piperazine as amine moiety. Several oligoamide films ranging from 0-12 layers were synthesized (Fig.l) and characterized using different surface analysis techniques such as contact angle analysis, ellipsometry, ATR-FTIR and XPS. The surface charge of the layers having different excess of amine and carboxylic acid groups were measured using streaming potential analyses. Each of the synthesized oligoamide films showed its characteristic surface chemical properties such as wettability, crosslinking and chemical composition thus providing a way to pre-design the oligoamide film depending upon the type of application and chemistry.