Amine-functionalized mesoporous silica for urea adsorption

The limitations of the present hemodialysis have led towards the development of several wearable artificial kidney prototypes. The most important component of the miniaturized model, as compared to the hemodialysis, is the closed-system dialysate. Typically, these models utilize activated carbon as adsorbents. With superior adsorbents as replacements, the amount of dialysate required to remove uremic toxins could be reduced and regenerated. Mesoporous silica could perform better than generic activated carbon since the silica surface could be functionalized for target specific adsorption. This paper evaluates the performance of mesoporous silica SBA-15 and amine-functionalized SBA-15 for the removal of major uremic toxin constituent urea. Results are promising as mesoporous silica could potentially replace activated carbon in artificial kidney applications due to the larger urea adsorption capacity and improved adsorption kinetics. Functionalization of mesoporous silica further improved its urea adsorption capacity. Though activated carbon has theoretically higher surface area, its low affinity towards urea remains a drawback. (C) 2016 Elsevier B.V. All rights reserved.