NanoScience and Technology

The present work focuses on the synthesis of silver nanoparticles (AgNPs) using Eggplant (Brinjal), a common vegetable that is preferred for cooking in the Indian household. The phytochemical analysis of the aqueous fruit extract of Solanum melongena Linn. (Solanaceae) reveals that it consists of water soluble phyto-constituents that can act both as reducing agent and capping agent for the conversion of silver nitrate aqueous into silver nanoparticles. This process involves sunlight induced rapid green synthesis of AgNPs which follows bottom-up self-assembly. The detailed characterization studies of the biosynthesised nanoparticles were carried out with UV-Vis spectroscopy, Fourier Transform Infra-Red spectroscopy (FT-IR), Atomic Force Microscopy (AFM), Dynamic Light Scattering (DLS) with particle size analysis, Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-ray spectroscopy (EDX). UV-Vis spectroscopy shows Surface Plasmon Resonance (SPR) from 392-450 nm, confirming the presence of AgNPs. FTIR absorption spectrum reveals the compatibility of the synthesised AgNPs to that of the fruit extract. AFM image shows linear irregular distribution of particles. Zeta sizer gives the average particle size of AgNPs varied from 100 – 150 nm with zeta potential from -8 to -23.3 mV. -23.3 mV corresponds to stable nanoparticles.  FE-SEM reveals various shapes and sizes of AgNPs. EDX confirms the presence of Silver metal ion. Thus, AgNPs were synthesised from silver nitrate by the reducing power of active constituents present in Eggplant fruit extract.

Copper oxide and zinc oxide nanoparticles (NPs) were synthesized using greener electrochemical approach using Cocos nucifera (Coir) extract and deposited on Fe ship strip (FSS). The corrosion inhibitor films were characterized by XRD, SEM, BET, Raman Spectroscopy, FTIR spectroscopy and TGA analysis. Electrochemical corrosion test was performed for the coated samples with 3.5% NaOH as electrolyte and compared with uncoated samples. The corrosion rate was tested using Tafel slope and the interpolation between log of current and voltage proves that corrosion rate in CuO coated sample was lower than ZnO coated sample which can be attributed to the porosity of the ZnO film showing 0.8–0.95 P/P0 as observed for 6 cm2 as inferred from BET analysis. The Nyquist plot suggests the corrosion inhibition rate of CuO coated film in 3.5 % NaOH is improved by a factor of 3 as compared to the uncoated sample (0.9 mA/year for FSS where’s for CuO coated samples 0.3 mA/year). The result of antifouling behavior of CuO/ZnO coatings using BIOVIA simulation tool showed the repulsion of homology modeled protein Aacp20k, an attachment protein found in Amphibalanus Amphitrite which is a most prominent foul species.








Keywords: Green electrochemical one-pot synthesis & deposition, CuO nano leaves, ZnO nanoflakes, anti-corrosion, BIOVIA anti-fouling simulation