introduction: preterm birth is still a major health problem throughout the world, which results in 75% of neonatal mortality. preterm labor not only inflicts financial and emotional distress, it may also lead to permanent disability. the present study was conducted to determine the related risk factors and preventive measures of preterm labor. methods: this retrospective cross-sectional study a...

Polyvinylidene fluoride/polyvinylpyrrolidone (PVDF/PVP) hollow fiber membranes were fabricated by dry-jet wet-spinning process. The correlated effects of the air gap length and PVP concentration ((1) the air gap length effect at the low and high PVP concentration in the dope solutions, as well as (2) the effect of the PVP concentration at the same air gap length) on the cross-section structure ...

In this study, polystyrene ethylene butylene polystyrene (PSEBS) was functionalized to prepare mono and bipolar ion exchange membranes. In the case of the bipolar membrane, platinum was used as the intermediate layer. NaCl solution of concentration ranging from 5 g/L to 25 g/L was used as the feed solution. A commercially procured ion exchange membrane made of polystyrene divinyl benzene was al...

Polyacrylonitril (PAN)-supported chitosan (CS) nanocomposite membranes were prepared by cross-linking the CS with 3-aminopropyl-triethoxysilane (APTEOS) via sol-gel method. Pervaporative performances of the CS-SiO2/PAN membrane for dehydration of aqueous alcohol solutions were investigated. From SEM cross-sectional images of the membrane, the spongy pores and the finger-like pores we...

Modified cellulose acetate (CA) membranes were prepared by dissolving the polymers in a mixture of acetone (AC) and N, N dimethylacetamide (DMAc) (70:30) solvent and deionized (DI) water was used in the coagulation bath. The introduction of polyethylene glycol (PEG) additive and TiO2 nanoparticles (NPs) into the casting solution has changed the structures of the resulting membranes during the p...

In this research, process asymmetric polyetherimide hollow fiber membranes using ethanol (0, 2 and 4 wt%) as non-solvent additive in the polymer dope via phase inversion method were fabricated. Aqueous solution of 1-methyl-2-pyrrolidine (NMP) (90%) was applied as a bore fluid to avoid inner skin layer formation and water was used as the external coagulant. The morphology of fabricated membranes...

Reverse osmosis is a commonly used process in water desalination. Due to the scarcity of freshwater resources and wastewater problems, a lot of theory and experimental studies have been conducted to optimize this process. In the present study, the performance of reverse osmosis membrane module of salt–water separation was simulated based on computational fluid dynamics technique and solution-di...

In this study, the applicability of nanofiltration (NF) membranes as a pretreatment prior to reverse osmosis (RO) in seawater desalination was investigated. The membranes used wereNF270 and NF90 as the NF membranes, while the brackish water (BW) RO membrane BW30 was used as the RO membrane. In desalination tests, permeates of the NF membraneswere collected and used as the feed to th...

This paper investigates effects of different additives on morphology and subsequently, separation performance of asymmetric flat sheet Polyvinylidene fluoride (PVDF) membranes to separate CO2 using membrane contractor. Five different additives from different chemical families including Lithium chloride (salt), Polyethylene glycol 400 (polymer), glycerol (weak anti-solvents), methanol...