Preparation and characterization of electrospun cellulose acetate sub-micro fibrous membranes

Electrospun sub-microfiber membrane of cellulose acetate (CA), with excellent biodegradability, high specific surface area and high porosity, has attracted wide attention in various research fields. Even so, the stable continuous electrospinning of CA sub-micro fibers is affected by the solution parameters and CA acetylation degree dramatically, which still remains challenging. In the present work, electrospun CA sub-micro fibrous membranes have been prepared from four distinct solvent systems, respectively, to explore the proper solution parameters for membrane fabrication. After hydrolysis and electrospinning, the produced CA sub-micro fibrous membranes were analyzed in terms of fiber size distribution, hydrophilicity and porosity. Current analysis has shown that the degree of substitution of CA sub-micro fibers decreases with the increase in hydrolysis time, resulting in increased diameter irregularity, decreased average porosity and increased hydrophilicity of the sub-micro fibrous membrane.

Electrospun Biodegradable Bi-layered Microfiber Membrane for Aluminum Removal in Drinking Water

Aims: This study aimed to eliminate metallic contaminants in drinking water by using electrospunbilayered microfiber membrane. Background: Fast industrialization triggers environmental pollution. Heavy metals like silver, lead and aluminum are the major contaminants that are extremely toxic and accumulate in biological tissues through the food chain and cause a health hazard. Electrospinning is a promising technique among other conventional techniques. Electrospun membranes possess suitable properties for microfiltration purposes. In this study, to fabricate electrospun membranes, polycaprolactone (PCL) and zeolites were used as materials. PCL polymer is biocompatible and biodegradable, and zeolite ismicroporous, which is good for filtration or molecular sieving application. Method: Using the electrospinning technique, PCL, PCL/zeolite, PCL and PCL/zeolite bilayeredelectrospunmembranes were fabricated. The properties of the membranes were evaluated using different techniques. The performance of the membranes was tested by filtering Aluminum (Al)in drinking water. Results: Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analyses confirmed the removal of Al using the membranes. ICP-OES results showed above 90% of Al removal using PCL and PCL/zeolite electrospun membrane. Conclusion: These membranes are non-toxic and biodegradable and have the potential to be used for microfiltration purposes.

Waterproof-breathable PTFE nano- and Microfiber Membrane as High Efficiency PM2.5 Filter

This study shows the feasibility of using electrospinning technique to prepare polytetrafluoroethylene/poly (vinyl alcohol) (PTFE/PVA) nanofibers on PTFE microfiber membrane as substrate. Then, PVA in the fiber membrane was removed by thermal treatment at about 350 °C. Compared to PTFE microfiber substrates, the composite PTFE fiber membranes (CPFMs) have improved filtration efficiency by 70% and water contact angle by 23°. Experimental test data showed that the water contact angle of the sample increased from about 107° to 130°, the filtration efficiency of PM2.5 increased from 44.778% to 98.905%, and the filtration efficiency of PM7.25 increased from 66.655% to 100% due to the electrospun PTFE nanofiber layer. This work demonstrates the potential of CPFMs as a filter for the production of indoor or outdoor dust removal and industrially relevant gas filtration.