Surface modification and applications of electrospun polyacrylonitrile fiber matrices

Abstract

Ultrafine polyacrylonitile (PAN) fiber mates were prepared by electrospinning technique. Due to their important properties such as high surface area to volume ratio, high gas permeability and porosity, they were further modified their surface to improve their adsorption properties. To proof initial concept, the electrospun PAN nanofiber mat was treated with sodium hydroxide which is a simple reaction. This was achieved through the conversion of the nitrile functional groups on the surface of the PAN fibers into imine conjugated sequences. The chelating property of the hydrolyzed electrospun PAN fiber mats was evaluated against Cu(II) ions. For further improve adsorption propertiex of nanofibers adsorbent, the electrospun PAN was modified with diethylenetriamine (DETA) to contain amidino diethylenediamine groups on their surface via heterogeneous reaction. These nanofiber mats were investigated for the removal of silver, copper, iron, and lead ions in aqueous solution individually and under competitive adsorption condition. The effects of initial pH, contact time, initial ion concentration on adsorption of those ions were studied. In addition, one of the electrospinning highlight is its ability to produce binder-free plates and gives the scientist control of mat thicknesses and chemical functionality present using a minimal amount of materials. Therefore, electrospun PAN nanofiber mat also suitable to use as stationary for Ultra-thin layer chromatography. A manganese-activated zinc silicate was used as fluorescent indicator (UV254) by mixing directly into polyacrylonitrile solution prior electrospinning process to visualize the UV-actived compounds.