Protein-based Nanofibre Membranes With Functional Nanoparticles

Keratin is the most abundant non-food protein in nature, it can be extracted from wool, then solubilised, after that processed in polar solvent [1] to produce nanofibres by electrospinning. These nanofibres are able to remove toxic substances such as formaldehyde [2], metal ions [2] and dyes efficiently [3]. Moreover, the integration of inorganic nanoparticles like TiO2 and Ag into electrospun nanofibres improves membrane functionalities such as biocidal action and photocatalytic properties. In this work, electrospinnable keratin water solutions doped with inorganic nanoparticles were prepared by mixing keratin solutions with Ag and TiO2 nanosol. These solutions were successfully electrospun into nanofibrous membranes by means of the addition of poly(ethylene oxide). The as-spun keratin/PEO/nanoparticles nanofibres showed a highly interconnected fibrous structure of beaded nanofibers. After thermal treatment and water soaking a mass loss of 9.93±0.70% was measured and nanofibre porous structure was maintained. Antibacterial and photocatalytic properties were tested. Antibacterial tests against Escherichia coli were carried out (AATCC 100 Test Method). Both composite nanofibres showed excellent bacteria reductions (95% for Ag and 97% for TiO2). Photocatalytic degradation of Rhodamine B dye (used as target molecule) was 53% for TiO2-loaded nanofibres in 2 h under 9 W/m2 UV light.