Membranes of Polyvinylidene Fluoride and PVDF Nanocomposites with Carbon Nanotubes via Immersion Precipitation

Abstract

Microporous polyvinylidene fluoride (PVDF) and PVDF nanocomposite membranes were prepared via an isothermal immersion precipitation method using two different antisolvents (ethanol and water). The structure and morphology of the resulting membranes were investigated by wide angle X-ray diffraction (WAXD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). The effects of the type of the antisolvent and the presence of multiwalled carbon nanotubes (MWNTs) on membrane morphology and the crystal structure developed within the membranes were studied. The crystallization of the PVDF upon immersion precipitation occurred predominantly in the α-phase when water is used as the antisolvent or in the absence of the carbon nanotubes. On the other hand, β-phase crystallization of the PVDF was promoted upon the use of ethanol as the antisolvent in conjunction with the incorporation of the MWNTs. The morphology and the total crystallinity of the PVDF membranes were also affected by the incorporation of the MWNTs and the antisolvent used, suggesting that the microstructure and the ultimate properties of the PVDF membranes can be engineered upon the judicious selection of crystallization conditions and the use of carbon nanotubes.

Preparation and properties of PVDF composite hollow fiber membranes for desalination through direct contact membrane distillation

“…where H f is the experimental heat of fusion ( H m ) or the experimental heat of crystallization ( H c ), W is the weight fraction of polymer in the PVDF/CaCO 3 mixture and H * f is the heat of fusion of the 100% crystalline PVDF, which is reported to be about 105 J/g [42].…”

Preparation and Characterization of Polyvinylidene Fluoride/Graphene Superhydrophobic Fibrous Films

“…In addition to the above, electrospinning is also a predominant and promising technique to develop superhydrophobic surfaces from some polymers with low surface energies and introducing the hierarchical structure to them. In recent years, several types of superhydrophobic surfaces, produced by electrospinning of PVDF, have been reported in the literature [21][22][23][24][25][26]. Additionally, it will be a good task to obtain a kind of novel film with PVDF/graphene electrospun thin layers coated on the surface of porous supports like polypropylene (PP) and polytetrafluoroethylene (PTFE).…”

Structural and Ion Transport Studies in (100-x) PVdF + xNH<sub>4</sub>SCN Gel Electrolyte

“…Initially as concentration of salt increases free ion concentration augment leading to increase in electrical conductivity. Another possible reason for increase in conductivity is the presence of trapped liquid within the pores of polymer matrix [23]. As evidenced in XRD and IR studies, the interaction between salt with fluorine group in PVdF matrix is likely to enhance the conductivity of gel electrolyte.…”