| 摘要 |
PURPOSE:To obtain a reverse-osmosis membrane with improved performance, especially water permeability, of the title composite membrane by bringing an ultrathin membrane consisting of cross-linked aromatic polyamide obtained by an interface reaction into contact with an aq. chlorine-contg. soln. at 6-13pH under ordinary pressure. CONSTITUTION:The ultrathin membrane is obtained by the interface reaction between an aromatic amine having >=2 reactive amino groups and a multifunctional aromatic acid halide. when the ultrathin membrane is dipped in the aq. chlorine-contg. soln. at 6.0-1.3pH, the performance, especially water permeability, of the obtained semipermeable composite membrane is improved. Gaseous chlorine, bleaching powder, sodium hypochlorite, chlorine dioxide, chloramine B, etc., are used as the chlorine generating reagent. The chlorine treatment must be carried out under ordinary pressure, and only the dipping of the membrane in the aq. chlorine-contg. soln. is required. The concn. of free chlorine is preferably controlled to 10-2,000ppm, and the treating time is adjusted to 2min-20hr. |
