Polyamide Semipermeable Membrane Crosslinking for Chemical Cleaning

The patent applies preliminary action by performing the bonding reaction between amino compounds and carboxyl groups on the membrane surface before the membrane is exposed to chemical cleaning solutions. This pre-established bonding structure creates a more resistant membrane that can withstand subsequent chemical cleaning without significant loss of removal performance. The amino compounds are introduced in advance to modify the membrane surface, forming a protective layer that maintains functionality after cleaning cycles.

The patent converts the harmful effect of oxidizing agents into a beneficial process by utilizing controlled oxidation to generate carboxyl groups on the polyamide membrane surface, which then react with amino compounds to form stable amide bonds. The oxidizing agent, which would normally deteriorate the membrane, is instead used to create reactive sites that enable beneficial crosslinking and structural stabilization through subsequent amino compound bonding.

The patent applies local quality by introducing amino compounds specifically at the membrane surface and interface regions where fouling occurs and separation performance is critical. The bonding of amino compounds to carboxyl groups creates localized crosslinked structures at the active separation layer without extensively modifying the bulk membrane structure. This localized modification improves removal performance at the critical interface while minimizing impact on overall water permeability through the membrane matrix.