Polyacrylonitrile/silver nanoparticle electrospun nanocomposite matrix for bacterial filtration

Abstract

A study on anti-bactericidal filter is carried out using electrospun polyacrylonitrile (PAN) nanofibres by incorporating different weight percentages of silver (Ag) nanoparticles. Dimethylformamide (DMF) plays dual role, as solvent for PAN and as reducing agent for the formation of Ag nanoparticles, and the Ag nanoparticles were characterized using UV-Visible Spectroscopy, X-ray diffraction, and transmission electron microscopy. Then, PAN solutions with Ag nanoparticles were electrospun to produce nanofibres. Areal density of nonwoven substrate, electrospinning time, and Ag% were taken as independent variables to design the experiment for the preparation of filter. Box-Behnken method has been used to derive the experimental plan and the filters were prepared according to the plan. Later, the developed filters were studied for bacterial filtration efficiency (BFE) as well as the anti-bactericidal activity against two commonly studied grampositive S. aureus and gram-negative E. coli bacteria. From the study, the developed Ag nanoparticle incorporated PAN electrospun nanofibre filters possess 99 % BFE with good anti-bactericidal activity, which enhances the potential application in protective mask.

Electrospun Nanofibers Membranes for Effective Air Filtration

“…Electrospinning is a highly versatile technique for producing nanofibers that has been reported in the literature for more than 60 years . The effort to utilize electrospun nanofiber membranes for air filtration started in the early 1980s because electrospun nanofibers were recognized to exhibit outstanding surface properties such as excellent surface adhesion, high porosity, high specific surface area and low basis weight with uniform fiber size, fulfilling the requirements of preparing high‐performance filters. Since the first demonstration of nanofibers membrane air filtration in 1980, this field has witnessed ongoing development and has supplied a great many commercial air filters made of polymers over the last 35 years .…”

“…To inhibit pathogen transmission and epidemic disease outbreak, many efforts have been devoted to the preparation of antibacterial membranes by exploiting additives, which are mainly divided into two types, i.e., inorganics such as Ag, Cu, CNTs, and TiO 2 , and some natural plants extracts (e.g., Melaleuca alternifolia extracts, Sophora flavescens extracts, eucalyptus extracts, and green soy protein). Selvam et al performed a study on antibacterial filters by incorporating diverse weight percentages of Ag nanoparticles in electrospun PAN fibers, where the PAN solvent (dimethylformamide), also serves as a reducing agent for Ag nanoparticle formation. The PAN fibers were investigated by estimating the Colony Forming Units (CFU) in the suspension of gram‐positive S. aureus and Gram‐negative E. coli.…”

“…For example, an Ag wt% of 10–12.5 was sufficient to reach 99% bacterial filtration efficiency. The interaction of the Ag nanoparticles (NPs) with bacteria is indicated in Figure a . Silver (Ag) is a nontoxic metal for humans, but it is the most toxic element for microorganisms .…”

“…a) Schematic of the interaction of the Ag Nps with bacteria . Reproduced with permission . Copyright 2015, The Korean Fiber Society and Springer Science.…”

Advanced electrospun filters to protect building environments from pollution

“…Several PAN/Ag composite filters were electrospun in a research investigation and found that a 10-12.5 wt% of Ag was sufficient to achieve 99% bacterial filtration efficiency. 11 The combination of Ag with metal oxides has been found to enhance the antibacterial performance. A hybrid hydrophobic composite PVDF/Ag/ Al 2 O 3 showed a high antimicrobial efficiency of 99.66% and a sound chemical detoxification efficiency of 36.47%.…”