Summary of problems related to the preparation of NF and RO membranes by interfacial polymerization

I have worked in a domestic listed company for three years on the preparation of NF and RO membranes by interfacial polymerization method, and I think I have a certain depth of understanding of interfacial polymerization process. During this period, I have also helped many students with small wood worms. Now, I summarize the common problems as follows. In order to work together to promote the real industrialization and marketization of domestic NF and RO membrane products from monomer synthesis to membrane component design (this idea is too naive, a realistic word is to help everyone take some detdettions, easily and clearly do experiments, issue papers, get a graduation certificate, find a job)
1) The most critical thing in the interface polymerization process is the drying treatment of the base film after water phase infiltration - personally understand that the most ideal state is the feeling of tide like a towel dried by a washing machine, tide but not wet - how to achieve personal thinking;
2) The reagent purity of aqueous and oil-phase monomers has a great influence on the desalting rate (retention rate or crosslinking degree). MPD is easy to oxidize, TMC is extremely easy to hydrolyze (every time the lid is opened to provide the possibility for TMC hydrolysis), the oxidation denaturation possibility of piperazine is relatively low, MPD becomes dark after oxidation, which is simple and easy to determine; After hydrolysis, TMC changes from transparent to white opaque or oil phase solution turbidity, and the hydrolysis of other acyl chlorides such as TMC will directly reduce the degree of crosslinking (the desalting rate will be worse, the flux will be lower).
3) Constant pressure and flow rate must be maintained when testing the desalting rate, especially the flow rate must be constant - for specific reasons, please refer to the literature on concentration polarization;
4) Students who use polyether sulfone material as the base film can use Rhodamine B as the reagent to test the integrity of the interface polymerization -- the specific usage can be consulted in the relevant literature;
-- The above is only a summary of the initial stage of interface polymerization related processes, there are inevitably shortcomings and mistakes, welcome to correct you

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