Hybrid Microporous Membranes Intended for Protective Clothing

Electrospun nanofiber containing titanium dioxides (TiO2) was investigated as a self-detoxifying system. The material system was developed using polyacrylonitrile(PAN)-metal oxide composite fibers containing anatase TiO2. Fibers were prepared by uniaxial and coaxial electrospinning to compare the detoxification activities of the photocatalyst in different fiber morphologies. Monoaxial nanofibers were formed by conventional electrospinning of PAN/DMF solution containing TiO2 nanoparticles, while coaxial nanofibers had the metal oxide selectively placed in the sheath layer by electrospinning pure PAN solution and PAN/TiO2 solution as core and sheath layer, respectively. Location of nanoparticles relative to fiber morphology was determined by SEM and TEM. It was demonstrated that the coaxial approach resulted in location of nanoparticles in the sheath of the fibers rather than the uniform distribution obtained for monoaxial fibers. Photocatalytic activity of the PAN/TiO2 fibers under UV irradiations was demonstrated by degradation of aldicarb, a carbamate pesticide, as measured by HPLC. In terms of degradation kinetics, surface distribution density of TiO2 nanoparticles on the electrospun fiber affected initial degradation rates while the final decomposition amounts did not differ for the submicron fibers.