Electrohydrodynamic atomization of CNT on PTFE membrane for scaling resistant membranes in membrane distillation
Lijo Francis, Nidal Hilal
Abstract
Abstract In this study, an electrohydrodynamic atomization or electrospraying technique is used for the uniform deposition of carbon nanotubes (CNT) on a commercially available PTFE membrane and employed for Membrane Distillation (MD) process. Modified PTFE-CNT membrane was characterized for water contact angle, liquid entry pressure (LEP), pore size distribution, and surface morphology. The electrospray coating of CNT on the PTFE membrane enhances the turbulence and thereby the temperature polarization coefficient (TPC). The pore size of the micropatterned PTFE-CNT membrane has been reduced and pore size distribution has been narrowed compared to the PTFE membrane. Field-effect scanning electron microscopy images of the membranes were observed before and after the MD process. Functionally graded PTFE-CNT membrane showed superior desalination performance compared to the PTFE membrane with less amount of cake layer formation on the membrane surface. Water vapor flux remained constant during 24-h continuous MD process operation with 99.99% rejection of inorganic salts.