My doctoral research, under supervision of Professor Nejati, in the Department of Chemical and Biomolecular Engineering is focused on design and syntheses of polymeric materials. This effort in part will be focused on devising methods to synthesize adsorbents based on non-toxic and environment-friendly polymers. Since the most important outputs of usage of fertilizer are nitrate accumulation in plants and leaching into water sources. Nitrate leaching and N2O emissions from agricultural soils are recognized as significant environmental threats by scientists, environmental groups, and agricultural policymakers and it is responsible for algal blooms and eutrophication and also poses a serious public health risk. Our first step towards this goal is fabricating polymeric adsorbents beads which can be utilized in soil environment. I am particularly interested in using safe, non-toxic, and biodegradable materials to achieve superabsorbent to collect pollutions from environment and solved Bio-environmental problems which can have long term effect on human being and other creatures.
Figure1. Nitrogen cycle (a), Nitrate concentration in shallow, recently recharged U.S. groundwater, as predicted by the GWAVA-S model (2006) (b)
Before joining the TCIL, Elham was working as a research assistant in Polymer Laboratory under supervision of Professor Pourjavadi at Sharif University of technology . Her research focused on synthesis of salep sulfate hydrogels and investigation of its swelling and metal ions adsorption properties. Sulfonation of salep was performed using chlorosulfonic acid–dimethylformamide (HClSO3–DMF) complex as a reagent. The enhanced water absorbency of salep sulfate-based hydrogel appears to be because of the increase in charge density and ionization tendency brought about by the introduction of sulfate anions, in addition to the carboxylate anion in salep-based hydrogel. The heavy metal ion adsorption capacity of the prepared hydrogel can be controlled by adjusting the amount of sulfate groups on adsorbents, which is proportional to the adsorption capacity. (Journal of Applied Polymer Science, 130(4), pp.3001-3008, DOI: 10.1002/app.39515.)
Figure 2. 1H NMR spectra of Salep (a) and Salep sulfate (b). Solvent 5 D2O
Moreover, I worked on a novel tough hydrogels, double network hydrogel (DN), as my master thesis. Double network (DN) hydrogels are usually contain about 60-90 % water. Despite of this amount of water, they are though and strong. DN hydrogels comprise of two networks, the first one as the brittle gel, is generally high density crosslinked and the second one, the loose and stretchable network, is loosely crosslinked or even without crosslinking. Therefore, we used cationic polymer, chitosan, as the first networks, and poly (vinyl alcohol) (PVA), as the second network. Mechanical performance and biocompatibility of these hydrogels were investigated using tensile tests and MTT assay.
Figure 3. Mechanical stability of chitosan/PVA DN hydrogel