Polymer-Graphene Oxide Nanocomposites for use in Dialysis Membranes

<p class="p1">Hemodialysis is the most common way to treat chronic kidney disease (CKD). Despite this, patients on hemodialysis have a high mortality rate when compared to those with other chronic diseases. To develop a more permeable and selective membrane for use in a wearable artificial kidney device, a Poly(2,2&rsquo;-disulfonyl-4,4&rsquo;-benzidine terephthalamide) (PBDT) and Graphene Oxide (GO) nanocomposite was developed because of the ordered nature of the nanocomposite. This membrane can be chemically modified to alter the spacing between PBDT rod-like self-assemblies and the GO platelets, allowing the selectivity and permeability of the membrane to be tuned. Initially, the nanocomposite membrane had promising results. Salt rejection values of -1.94% and 0.5% were observed for the 2.4% and 4.8% GO weight relative to (w.r.t.) PBTD membranes, respectively. Urea rejection values of -9.37% and -1.13% were observed for the 2.4% and 4.8% GO w.r.t. PBDT membranes, respectively. These results are ideal for a dialysis membrane which seeks to clear urea and salts from the blood to dialysate.The membranes still had low lysozyme rejection fractions at 6.9% and 10.6% for the 2.4% and 4.8% GO w.r.t. PBDT membranes, respectively; both membranes had 100% rejection of bovine serum albumin. These values were promising for a potential dialysis membrane, demonstrating clearance of middle weight molecular toxins and rejection of albumin. However, the nanocomposite was unstable when exposed to physiological levels of sodium, suggesting the cross-linkages between PBDT rods were broken, preventing the nanocomposite from functioning as a dialysis membrane. Ultimately, the phosphate buffer saline necessary to dissolve these proteins dissolved PBDT, thereby destroying the membranes despite initial promising results.