Effective Antibacterial Glass Fiber Membrane Prepared by Plasma-Enhanced Chemical Grafting

This paper reports a novel glass fiber membrane with an effective antibacterial performance by chemical grafting of quaternary ammonium salt (QAS) which is enhanced by a plasma bombardment technique. Plasma bombardment as a pretreatment of the membrane can increase the QAS anchored on the membrane from 0.8 to 1.3 wt %. The chemical grafting technique can increase the membrane zeta potential from negative values to positive values in aqueous solutions at various pHs. Furthermore, the plasma-enhanced chemical-grafting membrane has more positive zeta potentials (49.0 mV at pH = 7) than the chemical-grafting membrane without the plasma bombardment technique (38.9 mV at pH = 7). In the antibacterial performance evaluation, the Escherichia coli survival rate decreased from 127.0% of the pristine membrane to 4.1 and 11.3% of the plasma-enhanced chemical-grafting membrane and the chemical-grafting membrane, respectively. In addition, the plasma-enhanced chemical-grafting membrane shows durable antibacterial activity against E. coli with copious water rinsing as much as 3 L·cm^-2.