F-KCW-Department Publications
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Item BIOSYNTHETIC GREENER MOVE TOWARDS NANOSIZED SILVER BY DIOSPYROS MONTANA LEAF EXTRACT AND THEIR ANTIMICROBIAL AND ANTIOXIDANT ACTIVITIES(Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP), 2020-01-05) Kanchana, P; Arunadevi, N; Hemapriya, V; Shanmuga Sundari, S; Prabha Devi, BSynthesis of nanomaterials by eco-friendly method is being exploited by chemists because of several advantages over other conventional techniques. The current investigation reports the green approach for Diospyros Montana(DM) silver nanosized particles which has high antimicrobial and antioxidant activities. The synthesized nanosized particles were investigated by several techniques such as IR, Ultra violet, X-Ray Diffraction, Transmission Electron Microscope and AFM studies. Crystalline size of the silver nanoparticle is in the range of 47.05 nm which was clear from the powder X-rd studies. The silver nanoparticls prepared were tested for their antimicrobial potential against E.coli, B.subtilis, C.albicans and A.flavus species and was found to reveal excellent activity because of its volume ratio and high surface.The DPPH assy was used to find scavenging activity of free radicals. In this work we report the silver nanoparticles by aqueous Diospyros Montana leaf extract and its potential for free radical scavenging.Item INHIBITIVE EFFECT OF AN ALCOHOLIC EXTRACT OF A SEAWEED SARGASSUM MUTICUM IN CONTROLLING CORROSION OF MILD STEEL IN 0.5 N HCL(International Journal of Corrosion and Scale Inhibition, 2021-10) Jeslina, V; Kirubavathy, S J; Al-Hashem, A; Rajendran, S; Lacnjevac, C; Joany, R MThe inhibitive effect of an alcoholic extract of a seaweed, namely, Sargassum Muticum, in controlling corrosion of mild steel in 0.5 N HCl has been evaluated by weight loss method (immersion period 1 day) and electrochemical techniques such as polarization study and AC impedance spectra. The protective film has been investigated by AFM and Vickers Hardness test. Weight loss method reveals that 500 ppm of inhibitor offers 99% inhibition efficiency to mild steel immersed in 0.5 N HCl. The adsorption of inhibitor molecules on the metal surface follows Langmuir adsorption isotherm. The R2 value is very high, 0.998. Polarization study reveals that the corrosion potential is slightly shifted to anodic side. It is inferred that the inhibitor solution functions as mixed type corrosion inhibitor. In the presence of the inhibitor, the linear polarization resistance (LPR) increases and the corrosion current decreases. Because of the Blanket effect (formation of a protective film on the metal surface blocking the anodic sites and cathodic), electron transfer from the metal to the bulk of the solution is blocked. AC impedance spectra confirm the formation of a protective film on the metal surface. As the inhibitor concentration increases, the Rct value increases and the double layer capacitance (Cdl) decreases, the impedance increases and the phase angle increases due to the blocking effect on the metal surface. It is found to be a monolayer of protective film. The Vickers hardness of the inhibited metal surface is lower than that of polished metal but higher than that of corroded surface. The average roughness, RMS roughness and maximum peak-to-valley height of inhibited metal surface are lower than those of corroded metal surface but higher than those of polished metal surface. The outcome of the study may be used in pickling industry where HCl is used to remove rust and at the same time metal surface is protectedItem ANTI-CORROSIVE POTENTIAL OF CYPERUS ROTUNDUS AS A VIABLE CORROSION INHIBITOR FOR MILD STEEL IN SULPHURIC ACID(Pigment & Resin Technology, 2020-04-17) Rajan, Anitha; Chan, Basha Nusrath Unnisa; Venkatesan, Hemapriya; Selvaraj, Mohana Roopan; Subramanian, Chitra; Ill-Min, Chung; Seung-Hyun, Kim; Prabakaran, MayakrishnanOver the past decade, plant extracts are ultimate green candidatures to substitute the expensive and noxious synthetic corrosion inhibitors. In this regard, this study aims to focus on evaluating anti-corrosion properties of green inhibitor Cyperus rotundus (C. rotundus), a perennial herb found throughout India.The biocompatible components present in C. rotundus extract was analyzed by gas chromatography–mass spectroscopy analysis. The corrosion inhibitory effect of C. rotundus was assessed by impedance, polarization and surface morphometric study [atomic force microscopy (AFM)]. Density functional theory (DFT) study was carried using DFT/B3LYP, and basis set used for calculations was 6-31G (d, p) using Gaussian 03 program packageItem UTILIZATION OF BIOWASTE AS AN ECO-FRIENDLY BIODEGRADABLE CORROSION INHIBITOR FOR MILD STEEL IN 1 MOL/L HCL SOLUTION(Science Direct, 2020-12) Venkatesan, Hemapriya; Mayakrishnan, Prabakaran; Subramanian, Chitra; Manoharan, Swathika; Seung-Hyun, Kim; Ill-Min, ChungThis report focuses on the application of a biodegradable biowaste [human hair-(HHR)], to produce a mild steel corrosion inhibitor. The performance of HHR extract in inhibiting metallic corrosion in 1 mol/L HCl was investigated. The analysis of the metal corrosion behavior using electrochemical and weight loss techniques revealed that HHR exhibits an efficient corrosion-mitigating effect via adsorption on the metal surface following a Langmuir isotherm. Tafel-plot results revealed the mixed-mode corrosion protection behavior of HHR. Surface analysis using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and Fourier transform infrared (FT-IR) spectroscopy provided evidence for the precipitation of a protective HHR film on the metal surface.Item THE INFLUENCE OF SWELLING ON ELASTIC PROPERTIES OF POLYACRYLAMIDE HYDROGELS(Frontiers in Materials, 2020-07-23) Ramesh, Subramani; Alicia, Izquierdo-Alvarez; Pinaki, Bhattacharya; Mathieu, Meerts; Paula, Moldenaers; Herman, Ramon; Hans, Van OosterwyckPolyacrylamide (PAM) hydrogels are commonly used as substrates for cell mechanical and mechanobiological studies because of their tunable stiffness and ease of handling. The dependence of bulk rheological and local elastic properties (assessed by Atomic Force Microscopy, or AFM) of PAM hydrogels on its composition and polymerization temperature has been extensively studied. PAM hydrogels swell when immersed in media, but the influence of swelling on local elastic properties is poorly characterized. Direct measurements of the effect of swelling on PAM elastic properties are scarce. We report here, for the first time, the direct measurements of volumetric swelling and local elastic properties of PAM gels throughout the post-polymerization swelling process until equilibrium. First, local and global elastic properties (measured by rheology), were obtained during polymerization in the absence of swelling, and showed good agreement with each other. Four PAM hydrogel compositions were characterized thus, with corresponding storage shear moduli (as measured immediately after polymerization) of 4,530 Pa (termed stiffest), 2,900 Pa (stiff), 538 Pa (soft), and 260 Pa (softest). Next, all compositions were subjected to swelling in phosphate buffered saline. Swelling ratios and local elastic moduli were measured at 0, 3, 6, 9, 12, and 24 h post-polymerization for the soft and softest compositions, and once daily till 6 days post-polymerization for all four compositions. For the stiffest and stiff gels, swelling ratio, and local elastic modulus changed negligibly with time, while for the soft and softest gels, substantial changes between Day 0 and Day 1 were found for both swelling ratio (increased by 21.6 and 133%, respectively), and local elastic modulus decreased (by 33.7 and 33.3%, respectively), substantially. Experimental data were analyzed by a model that combined ideal elastomer mechanics and poroelastic swelling kinetics model. Model predictions confirmed the validity of present measurements with respect to past studies where swelling and elastic properties were not measured simultaneously. The present study underlines the important effect swelling can have on PAM elastic properties and provides detailed quantitative data to guide the duration taken to reach equilibrium—a useful information for cell mechanics experiments. In addition, the simultaneous measurements of swelling and local elastic moduli provide novel data for the validation of theoretical models.Item BIOSYNTHETIC GREENER MOVE TOWARDS NANOSIZED SILVER BY DIOSPYROS MONTANA LEAF EXTRACT AND THEIR ANTIMICROBIAL AND ANTIOXIDANT ACTIVITIES(Blue Eyes Intelligence Engineering & Sciences Publication, 2020-01-04) Kanchana P; Arunadevi N; Hemapriya V; Shanmuga Sundari S; Prabha Devi BSynthesis of nanomaterials by eco-friendly method is being exploited by chemists because of several advantages over other conventional techniques. The current investigation reports the green approach for Diospyros Montana(DM) silver nanosized particles which has high antimicrobial and antioxidant activities. The synthesized nanosized particles were investigated by several techniques such as IR, Ultra violet, X-Ray Diffraction, Transmission Electron Microscope and AFM studies. Crystalline size of the silver nanoparticle is in the range of 47.05 nm which was clear from the powder X-rd studies. The silver nanoparticls prepared were tested for their antimicrobial potential against E.coli, B.subtilis, C.albicans and A.flavus species and was found to reveal excellent activity because of its volume ratio and high surface.The DPPH assy was used to find scavenging activity of free radicals. In this work we report the silver nanoparticles by aqueous Diospyros Montana leaf extract and its potential for free radical scavenging.