Formation And Characterization Of Mixed Crosslinked Chitosan/Polysulfone Positively Charged Composite Nanofiltration Membrane

In this paper, four series of positively charged (glutaraldehyde crosslinked, glutaraldehyde-sulfuric acid mixed crosslinked, glutaraldehyde crosslinked and epichlorohydrin secondly crosslinked, glutaraldehyde-sulfuric acid mixed crosslinked and epichlorohydrin secondly crosslinked) composite nanofiltration membranes were developed by using chitosan as the active layer material and Polysulfone macrofiltration membrane as the support layer. The developing technique and characteristic of the nanofiltration membranes were studied.1 Developing technique of four crosslinked chitosan composite nanofiltration membranes with best characters.(1) Glutaraldehyde crosslinked chitosan composite nanofiltration membrane: 1.0g chitosan solution(2% w/w) in acetic acid(2% w/w) was coated on the surface of 8×8cm2 PSF base membrane. The polymer can be purification by glass sandy filter and this method can efficiently remove indissolved in the system. This membrane, after drying at 25℃for 12h, was treated with aqueous(aq.) NaOH(0.2mol/L) for 3h. The surface crosslinking of chitosan membrane was carried out at 50℃using aq. glutaraldehyde(1%w/w) for 1.5h. After crosslinking, composite membrane was heat treated at 50℃for 15 min.(2) Glutaraldehyde-sulfuric acid mixed crosslinked chitosan composite nanofiltration membranes with best character can be made when 1.0g chitosan solution(2% w/w) in acetic acid(2% w/w) was coated on the surface of 8×8cm2 PSF base membrane. The polymer can be purification by glass sandy filter. This membrane, after drying at 25℃for 12h, was treated with aqueous(aq.) NaOH(0.2mol/L) for 3h. The surface crosslinking of chitosan membrane was carried out at 50℃using aq. glutaraldehyde(1% w/w)-sulfuric acid(1% w/w) mixed solution for 1.5h. After...