فهرست مطالب آرش یونس نیا

Textile industry wastewater in additions toxicity for organisms led to changes as decreased of water transparency and sunlight penetration and increase in chemical oxygen demand. Therefore, this study was carried out with the aim of removal of cationic red 46 dye from aqueous solution. For this purpose, the magnetic polymeric composite of graphite oxide nanoparticles (GO) and magnetic nanoparticles (MNP) in the matrix of polyacrilonitrile fiber (WPAN) at micro size by electroespining method was prepared. The XRD and SEM tests were used to determine the polymeric adsorbent characteristics. Magnetic properties of magnetic nanoparticles and polymeric adsorbent were measured at using vibrating sample magnetometer (VSM) analysis. Batch adsorption tests were optimized using the L16 orthogonal array of Taguchi method. The effects of variables including pH, adsorbent dosage, initial dye concentration and contact time on the dye removal were examined and the most influential factor in the removal of dye was pH. The adsorption isotherm data were well-fitted to Freundlich isothermal model (R^2= 0.99). Furthermor, adsorption kinetics of the dye followed pseudo-second-order model. Basic on these results, the polymeric composites was effective adsorbent for dye removal with efficiency over 96% and with quick separation for dye removal from aquatic solution.

Scaffold has therole of the extracellular matrix in regulating cell survival and it is an important component in tissue engineering techniques. One of the scaffolds that was used in this field, was PLLA (poly L-lactic acid) which was usually prepared by electro spinning method. The purpose of this study was to evaluate the biocompatibility of nano-porous PLLA membrane on proliferation of mesenchymal stem cells. PLLA nano-porous membranes were prepared by phase separation process. To identify the type of polymer used in its construction, FTIR analysis was performed. Then, dental pulp mesenchymal cells were cultured on a nano-membrane and nano-membrane-free environments, simultaneously. After attachment of the cells on the bottom of the plate, the biocompatibility and cell proliferation was assessed in a two-week period using MTT test on the fifth, seventh and ninth days of cell culture. The ultra-structure and adhesion of mesenchymal cells on the membrane were evaluated using scaning electron microscopy(SEM). Nano Membrane potential had good biocompatibility and the cells had penetrated into the surface membranes properly. The viability of mesenchymal cells cultured on nano-membranes were significantly higher than the control group. The highest effect of nano-membrane on cell viability was seen on the ninth day and the lowest effect was seen on the fifth day. Due to the biodegradable and non-toxic properties of nano PLLA membrane, it could increase the adhesion and proliferation of mesenchymal stem cells and these effects will exacerbated over time.