| dc.description.abstract |
Nanomaterials (NMs) are used in wide ranging applications (such as medicine and pharmaceutical industry, textile industry, and food industry) due to their unique and often exceptional properties such as mechanical, chemical, electrical, magnetic etc. Hence there is inevitable release of nanoparticles in the environment, which eventually will interact with living organism. Emerging studies do highlight the toxicity aspect of nanomaterials at various trophic levels. Hence, it is required to produce safer NMs for preventing their risk to humans and the surrounding environment. Reactivity of NMs play an important role in ecotoxicity of NMs, which provide an approach to understand ecotoxicity of NMs. In this work, the reactivity of nanoparticles has been studied on the basis of their agglomeration and stability in selected media: Deionized water (DIW), 1 mM sodium nitrate (NaNO3), Artificial Sea Water (ASW), Simulated Body Fluid (SBF) and Dulbecco's Modified Eagle's Medium (DMEM) with dynamic light scattering and disc centrifuge sedimentation techniques. DIW, 1mM NaNO3 and ASW are chosen to represent environmental condition while SBF and DMEM are the biological media. In present work two types of NPs; 40 nm zinc oxide, and 130 nm silica nanoparticles are synthesized and characterized. Two types of ZnO nanoparticles are synthesized in present study one is ZnO powder form and Colloidal ZnO nanoparticles in DEG. In this study, it is observed that the dispersion conditions affect agglomeration kinetics and stability of NPs in the selected media. The effect of concentration of nanoparticles on agglomeration rate and stability has been studied. It is observed that ZnO nanoparticles agglomerate and settle down within few seconds in all selected media except DIW. While for silica NPs small variation was observed in agglomeration rate with respect to concentration variation in electrolyte media (SBF, ASW). However, Silica NPs were stable in DIW for four days of study. In case of cell culture media of DMEM ZnO NPs were agglomerated within few seconds while SiO2 NPs agglomerated very slowly. |
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