Fabrication of polyvinylidene fluoride (PVDF) nanofiber membranes by electro-spinning for direct contact membrane distillation

A novel dual-layer bicomponent electrospun nanofibrous membrane for desalination by direct contact membrane distillation

“…5b). These results are much higher compared to the reported results in the literature [12] [16]. The improvement in flux performance for dual-layer membranes is attributed to: a) increased top surface hydrophobicity, thereby decreasing the potential wetting of the membrane; b) higher porosity of the top surface which increases the available surface area for evaporation; c) and the structure of thinner more hydrophobic surface layer (i.e., PH) (DL2) and thicker less hydrophobic layer (i.e., PAN), which decreases the mass transfer resistance [17].…”

“…S3b) with micronsized diameters and very large pore sizes. By gravimetric method [12], the PH nanofibers were found to have around 90% porosity, which was much higher than that of the commercial PTFE membrane (70% porosity). Of note is that the neat single-layer PH nanofibers have similar properties as with the PH of dual-layer membranes.…”

“…Membrane porosity, defined as the volume of pores divided by the total volume of the membrane was measured via a gravimetric method [12]. Equal sizes of (2 cm x 2 cm) membrane samples were immersed in ethanol (Scharlau).…”

“…Recently, a few research groups have reported on the performance of engineered nanofibers for MD application [5]. Most of these studies involved the use of single-layer nanofibers with or without nanoparticle incorporation or surface modification [6,7].…”

“…The flux was found to decrease with the increase in membrane thickness. Similarly, Liao et al [7] prepared PVDF nanofiber membranes with and without heat press treatment. The heatpressed PVDF nanofiber membrane showed stable permeate flux of about 21 kgm -2 h -1 , which was higher compared to the performance of commercial membranes.…”