Preparation and characterization of fluoroalkyl activated carbons/PVDF composite membranes for water and resources recovery by membrane distillation

Membrane distillation is a promising technology for recovering resources and water from brackish water and wastewater. However, characteristics of current membranes limit the employment of membrane distillation in these areas. In this paper, activated carbon modified membrane has been studied. Agglomeration of activated carbon (AC) particles in the membrane matrices has negative influence on the performance of AC/PVDF composite membrane. To solve this problem in this study, the AC was functionalized with fluoroalkyl groups via the reaction between carboxylic activated carbons and octafluoropentanol (OFP). The AC-OFP/PVDF composite membrane was prepared by blending PVDF and the functionalized AC-OFP particles via a conventional phase-inversion method. In comparison with the AC particles, the dispersion of AC-OFP particles in membrane matrix was improved greatly. The maximum DCMD flux increased from 29.8 kg/m2h (AC/PVDF membrane) to 40.4 kg/m2h (the AC-OFP/ PVDF membrane) by just adding 0.15 wt% AC-OFP particles.