Chlorine degradation of aromatic polyamides

Pulsed marker method for real-time detection of reverse osmosis membrane integrity loss

“…3), increased marker passage through the membrane may be attributed to increased convective marker transport across the membrane. It is interesting to note that the above findings are consistent with previous work [40], where it was suggested that reduced cross-linking in the membrane polymer matrix could potentially result in increased water and solute across the membrane. Although the PM-MIM approach does not reveal the cause of membrane integrity loss, breach detection can be carried out in essentially real-time.…”

Recent Advances in the Design of Polymerizable Lyotropic Liquid‐Crystal Assemblies for Heterogeneous Catalysis and Selective Separations

“…In addition, many commercially available RO membranes are based on aromatic polyamides, which are very susceptible to oxidative chain degradation by the ClO -typically added to disinfect municipal drinking water. [66] Given the promise of our first-generation LLC membranes in size-selective NF, we thought that the same systems might show promise in RO applications. The ionic nanochannels in the LLC membranes might afford an effectively more narrow pore size for small ion separation, and the absence of aromatic amide linkages might afford a more ClO --resistant membrane.…”

Degradation of polyamide reverse osmosis membranes in the presence of chloramine

“…Chlorine solutions are also used to slow the fouling of polyamide (PA) reverse osmosis (RO) membranes and to enhance their permeability by periodically cleaning these when they are partially or completely fouled [8]. However, prolonged or sometimes infrequent exposure to chlorine solutions can be detrimental resulting in PA degradation and consequently reducing the service lifetime of the membrane [9][10][11][12]. It is therefore important to understand the mechanisms of the changes that result from chemical degradation in order to minimize and potentially prevent premature membrane failure as a result of chlorine exposure.…”