Carbon nanotube immobilized membrane with controlled nanotube incorporation via phase inversion polymerization for membrane distillation based desalination

In this paper, we present an optimized method for carbon nanotube immobilization on membrane surface for seawater desalination via direct contact membrane distillation (DCMD). Carbon nanotube immobilized membranes (CNIM) are fabricated via phase inversion technique using a controlled approach for carbon nanotube (CNT) incorporation which provides additional pathways for water vapor diffusion. Surface morphology differed for membranes fabricated with varying PVDF concentrations which altered the CNT distribution and its interaction with water vapor. The water vapor flux by CNIM membrane was as high as 51.4 L/m2 hr, which was 76% higher than the unmodified support membrane at 60 °C. No significant salt leakage was observed with modified membrane. The overall mass-transfer coefficient for phase inversion membrane was nearly 1.8 times higher than unmodified membrane.