Synthesis and Characterization of Agri waste Based Superabsorbent Hydrogels and Nanofibers for Wastewater Treatment and Biomedical Applications

Abstract

This thesis reports an investigation on the synthesis and characterization of agri-waste newlinederived superabsorbent hydrogels and nanofibers for wastewater treatment and newlinebiomedical applications. Banana pseudostem, a plant waste obtained from banana newlineplant with over 2.7 M tons being produced annually, was chosen as a source of newlinecellulose. The cellulose was extracted from banana pseudostem via alkaline newlinehydrolysis which was later transformed into water soluble carboxymethyl cellulose newlinethrough combination of alkalization and etherification reactions. This was used as newlinebackbone in synthesis of hydrogels through free radical graft copolymerization. Ionic newlineand neutral monomers such as acrylic acid, acrylamide, N, N-dimethylacrylamide and newline3-acrylamidopropyltrimethylacrylamide were used in the preparation of anionic and newlineampholytic hydrogels. Other series of hydrogels devoid of synthetic monomer/ newlinecrosslinker were prepared from materials of purely biological origin. The hydrogels newlineprepared were used as adsorbent for removal of different azo dyes as well as heavy newlinemetal ions from waste water. The adsorption studies were modeled with selected newlineisotherm and kinetic models and the result indicated that the adsorption of dyes/metal newlineions used in this study could best be described as chemisorption process. Moreover, a newlinestudy on the use of the prepared hydrogels as potential drug carriers was performed newlineand the process was modeled for some selected release mechanisms and the release newlineprocess was found to be concentration dependent with 90 % of the drug released newlinewithin 5 days. Electrospun nanofibers of luminophore-doped polymer matrix (PVA/ newlineDNA) as organic light emitting diode (OLED) material were fabricated using newlineelectrospinning techniques. The nanofibers show good fluorescent property with newlineemission intensity increasing with increase in the concentration of luminophores. newlineHowever, based on the results obtained, the prepared hydrogels are found promising newlineas materials to be utilized in wastewater treatment and biomedical applic