PVDF nanofibers are prepared using electrospinning. The effect of addition of a hydrated salt, nickel chloride hexahydrate (NiCl(2)·6H(2)O), on the phase formation is examined. Addition of the hydrated salt (NC) is found to enhance the polar β phase by about 30%. The peak to peak piezo-voltage generated for PVDF NC is almost 0.762 V, a factor of 3 higher than that for PVDF. The fiber mats exhib...

nowadays, membrane processes are widely used for high purity nitrogen production. separation of air by membranes is a flexible process in which the investment and operational costs are lower than for example adsorption or cryogenic processes. such processes are based on relative permeability of air components which are transported by the pressure difference between two sides of the membrane. ma...

Oily wastewaters from oil refineries and oil distribution centers are one of the most important environmental concerns in recent decades; therefore, it is critical to treat these types of wastewaters. In this study, the performance of different polyethersulfone hollow fiber membranes in oily wastewaters treatment was investigated and the effects of operating conditions such as transmembrane pre...

Steroidal estrogens are a representative type of endocrine-disrupting chemical contaminant that has been detected in surface water. In this paper, modified polyvinylidene fluoride (PVDF) membranes were prepared by adding different amounts of polyvinyl pyrrolidone (PVP) and nano-TiO2 particles. PVDF-PVP membrane adsorption, UV photolysis and PVDF-PVP-TiO2 membrane photocatalysis performance were...

Macromolecular modification of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF) was done with various proportions of sulfonic acid terminated, hyperbranched polysulfone (HPSU) with a view to prepare ion conducting membranes. The PVDF-co-HFP was first chemically modified by dehydrofluorination and chlorosulfonation in order to make the membrane more hydrophilic as well as to introduce uns...

Superhydrophobic poly(vinylidene fluoride) PVDF-SiO2 composite membranes with different % of SiO2 contents were prepared by electrospinning. The surface morphologies of the membranes are characterized by using scanning electron microscopy. The nanofibers in the membranes were stacked in layers to produce fully interconnected pores that resulted in high porosity. The incorporation of SiO2 into t...

The aim of this work is to bring forward a new style heat exchanger about hollow fiber membrane module, and to analyze the performance which can expectantly be applied in the lithium bromide absorption refrigeration system. Polyvinylidene fluoride hollow fiber membrane module was adopted as the new style solution heat exchanger, hot feed solution from the generator flowed into the lumen side of...

A novel polyvinylidene fluoride (PVDF) tree-like nanofiber membrane (PVDF-TLNM) was fabricated by adding tetrabutylammonium chloride (TBAC) into a PVDF spinning solution via one-step electrospinning. The structure of the prepared membranes was characterized by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR) and pore size analysis, and the hy...

TiO₂/g-C₃N₄/PVDF composite membranes were prepared by a phase inversion method. A comparison of the performance and morphology was carried out among pure PVDF, g-C₃N₄/PVDF, TiO₂/PVDF and TiO₂/g-C₃N₄/PVDF composite membranes. The results of permeability and instrumental analysis indicated that TiO₂ and g-C₃N₄ organic-inorganic composites obviously changed the performance and structure of the PVD...

This work describes a new extraction method with hollow-fiber liquid-phase microextraction based on facilitated pH gradient transport for analyzing hippuric acid and mandelic acid in aqueous samples. The factors affecting the metabolites extraction were optimized as follows: the volume of sample solution was 10 mL with pH 2 containing 0.5 mol·L-1 sodium chloride, liquid membrane containing 1-oc...