Metal/metal oxide-carbohydrate polymers framework for industrial and biological applications: Current advancements and future directions.

Recently, the development and consumption of metal/metal oxide carbohydrate polymer nanocomposites (M/MOCPNs) are withdrawing significant attention because of their numerous salient features. Metal/metal oxide carbohydrate polymer nanocomposites are being used as environmentally friendly alternatives for traditional metal/metal oxide carbohydrate polymer nanocomposites exhibit variable properties that make them excellent prospects for a variety of biological and industrial uses. In metal/metal oxide carbohydrate polymer nanocomposites, carbohydrate polymers bind with metallic atoms and ions using coordination bonding in which heteroatoms of polar functional groups behave as adsorption centers. Metal/metal oxide carbohydrate polymer nanocomposites are widely used in woundhealing, additional biological uses and drug delivery, heavy ions removal or metal decontamination, and dye removal. The present review article features the collection of some major biological and industrial applications of metal/metal oxide carbohydrate polymer nanocomposites. The binding affinity of carbohydrate polymers with metal atoms and ions in metal/metal oxide carbohydrate polymer nanocomposites has also been described.

Polythiophene (PTh)-TiO2-Reduced Graphene Oxide (rGO) Nanocomposite Coating: Synthesis, Characterization, and Corrosion Protection Performance on Low-Carbon Steel in 3.5 wt % NaCl Solution.

The ternary nanocomposite polythiophene (PTh)-TiO2-reduced graphene oxide (rGO) (PTh-TiO2-rGO) was synthesized by chemical oxidative polymerization with FeCl3 used as the oxidizing agent. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to characterize the synthesized nanocomposite, followed by its casting on a low-carbon steel (LCS) substrate using N-methyl-2-pyrrolidone (NMP) as a solvent and an epoxy resin and triethyl tetraamine as a binder and curing agent, respectively. Anticorrosion properties of the PTh-TiO2-rGO nanocomposite in 3.5 wt % NaCl solution were established using open-circuit potential (OCP), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), salt spray test, immersion test, contact angle (CA) measurements, water uptake test, and SEM. Additionally, PTh and PTh-TiO2 were separately synthesized, characterized, and subjected to anticorrosion tests following identical synthesis routes for comparison purposes. The results of the investigations demonstrated that the PTh-TiO2-rGO nanocomposite coating provides superior protection in 3.5 wt % NaCl solution compared to pure PTh and PTh-TiO2 coatings, which are evident from its lowest corrosion current density (I corr) (0.570 × 10-6 A cm-2), highest positive shift in corrosion potential (E corr) (-0.578 V), highest impedance and phase angle (3.56 × 103 Ω cm2 and 70°, respectively), highest hydrophobicity (CA 94°), and highest protection efficiency (99%). These results show that the proposed nanocomposite coating provides better corrosion protection in a 3.5 wt % NaCl solution than other coatings.

An investigation on the synthesis, characterization and anti-corrosion properties of choline based ionic liquids as novel and environmentally friendly inhibitors for mild steel corrosion in 5% HCl.

The development of green corrosion inhibitors is a challenging task as it has to comply with strict environmental regulations. Ionic liquids (ILs) have recently been proposed as promising corrosion inhibitors. The present paper reports on two ILs designed to act as green and efficient high-temperature corrosion inhibitors. The prepared ILs, namely, choline formate (ChF) and choline acetate (ChA), are composed of biologically active ions. To elucidate their structure and corrosion inhibition effect on mild steel in 5% HCl the ILs were subjected to characterization tests like proton nuclear magnetic resonance (1H NMR), carbon nuclear magnetic resonance (13C NMR) and Fourier Transform infra-red (FT-IR) spectroscopy and corrosion tests like weight loss measurements, potentiodynamic polarization measurements (PDP), and electrochemical impedance spectroscopy (EIS). The effectiveness of the inhibition (%IE) increased with increasing concentrations and temperature up to 50 °C. ChF and ChA exhibited the highest inhibition efficacies of 96.9% and 99.5%, respectively at a temperature of 50 °C and concentration of 2 × 10-3 M. Above 50 °C their inhibition performance diminished, displaying an efficacy of 77.6% for ChF and 79.3% for ChA at 80 °C. The results of polarization measurements suggested mixed type behavior of inhibitors, and adsorption followed Langmuir adsorption isotherm. Furthermore, surface studies like scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) revealed protecting capability of the investigated inhibitors. FT-IR, and Raman spectroscopic studies revealed the adsorption of ILs on the Fe surface, and an ultra-violet visible (UV-vis.) spectroscopy study confirms the formation of Fe2+- ILs complex. X-ray Photoelectron Spectroscopy (XPS) was conducted to study the formation of corrosion products and protective film over the mild steel surface. Density functional theory (DFT) calculations and molecular dynamics (MD) simulations were also done to understand the inhibition mechanism of ILs.

Novel ZrO2-glycine nanocomposite as eco-friendly high temperature corrosion inhibitor for mild steel in hydrochloric acid solution.

We report the green synthesis of novel ZrO2-Glycine nanocomposite referred to as ZrO2-Gly NC followed by its characterization using X-ray diffraction (XRD), Fourier transforms infrared (FT-IR) spectroscopy, SEM/EDX, and transmission electron microscopy (TEM) techniques. Further, the inhibition effect of the varying concentration of ZrO2-Gly NC on the corrosion of mild steel (MS) in 1 M HCl was investigated by weight loss and electrochemical measurements at 40-80 °C. The percentage inhibition efficacy of NC increased with the increase of concentration and temperature and reached about 81.01% at 500 ppm at 70 °C which decreased at 80 °C and exhibited 73.5% inhibition efficiencies. According to the polarization measurements, the investigated ZrO2-Gly NC works as a mixed-type inhibitor with predominantly inhibiting cathodic reaction. Also, the adsorption isotherm analysis indicated that the adsorption was spontaneous and followed the Langmuir adsorption isotherm. Furthermore, the contact angle measurement revealed the water-repelling property of the investigated inhibitor. The surface morphological study via SEM-EDS micrograph affirmed the appearance of a smooth surface in presence of inhibited media suggesting the formation of protective film by the adsorption of ZrO2-Gly NC on the surface of the MS even at higher temperature.

A bibliometric analysis of pandemic and epidemic studies in economics: future agenda for COVID-19 research.

With the rapid global spread of the COVID-19 pandemic, researchers from diverse fields of study have contributed markedly in different research aspects. Considering the substantial economic significance of the pandemic at the micro and macro level throughout the world, we review the scientific publications in the discipline of Economics. To draw a broad inference, we analyze a total of 1,636 scientific publications starting from 1974, which covers the period of earlier pandemics or epidemics that have a close association with COVID-19 using bibliometric analysis. Our analysis and mapping reveal key information related to the contributors at different levels, including author, institution, country, and publication sources. Besides, we identify the historical concentration of research using scientific clustering and illustrate transformations at different times. Moreover, recognizing the underlying inadequacy of economics research, we propose several areas of future research. Our findings and suggestions are expected to act as a roadmap to potential research opportunities and notable implications for business and policymakers.

Tailoring a robust nanozyme formulation based on surfactant stabilized lipase immobilized onto newly fabricated magnetic silica anchored graphene nanocomposite: Aggrandized stability and application.

Candida rugosa lipase (CRL) was treated with surfactants and immobilized onto the novel formulated magnetic graphene anchored silica nanocomposite (Fe3O4/SiO2/Gr NC). For this purpose, the surface of lipase was initially coated with Triton-X 100 and cetyltrimethylammonium bromide surfactants, to stabilize enzyme in its open form and was then adsorbed onto aminated Fe3O4/SiO2/Gr NC. Glutaraldehyde (GA) was then utilized to cross-link the adsorbed lipase onto the NC. The fabricated NC and conjugated lipase was characterized by various techniques such as FT-IR, XRD, TGA, SEM, TEM, CLSM, CD and Fluorescence spectroscopy. The magnetic character of the as-synthesized NC was verified by AGM investigation. CD and fluorescence spectroscopic analysis demonstrated slight structural rearrangements in lipase upon conjugation. The surfactant stabilized immobilized lipase demonstrated significantly enhanced thermostability, tolerance to various metal ions and inhibitors. The immobilization yield obtained owing to lipase interfacial activation by Triton X 100 and CTAB was remarkably enhanced by 6-folds and 3-folds, respectively which were remarkably higher in comparison to free immobilized lipase. The fabricated nanobiocatalysts were employed to synthesise green apple flavour ester, ethyl valerate via esterification reaction. Triton X 100 stabilized immobilized lipase was a better performer in yielding green apple flavour ester, demonstrating about 90% ester yield as compared to 78% yield obtained by CTAB stabilized immobilized lipase preparation. The obtained outcomes suggested that enzyme structure was stabilized by the GA treatment if executed in the absence or in the presence of detergent, and that, in the company of detergent, a conformation of the lipase with the exposed active center to the medium provided an aggrandized catalytic performance.

Cysteine-silver-gold Nanocomposite as potential stable green corrosion inhibitor for mild steel under acidic condition.

Cysteine based silver-gold nanocomposite (Cys/Ag-Au NCz) was synthesized, this was followed by its characterization using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Ultraviolet-visible spectroscopy (UV-Vis), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDAX), Thermogravimetric analysis (TGA) and Transmission electron microscopy (TEM). Cys/Ag-Au NCz was studied as novel green corrosion inhibitor for mild steel in 1M HCl solution at varying concentration and temperature using gravimetric, Potentiodynamic polarization (PDP), Electrochemical impedance spectroscopy (EIS), SEM, EDAX and FTIR. Weight loss, PDP and EIS studies confirmed Cys/Ag-Au NCz as efficient corrosion inhibitor at moderately low concentration. The maximum inhibition efficiency of 96 % was observed at 303 K at 300 ppm. Cys/Ag-Au NCz acted by affecting both anodic and cathodic processes and its adsorption on steel surface followed the Langmuir adsorption isotherm. EIS data displayed the existence of protective film at mild steel/solution interface in Cys/Ag-Au NCz inhibited system. SEM micrograph in presence of Cys/Ag-Au NCz inhibited acid solution displayed better morphology as compared to blank solution. The UV-Vis and FTIR data indicates good interaction between the Cys/Ag-Au NCz and steel surface.

Enhanced Insecticidal Activity of Thiamethoxam by Zinc Oxide Nanoparticles: A Novel Nanotechnology Approach for Pest Control.

Indiscriminate and unregulated application of pesticides produces deleterious effect in various groups of organisms including humans and the environment. To solve these issues, it has been reported that the residue-free green nanocomposite synergistically enhances the pesticide efficacy. In this study, ZnO nanoparticles (NPs) with a thiamethoxam nanocomposite were synthesized and we investigated their synergistic effect on 4th instar larvae of Spodoptera litura (Lepidoptera: Noctuidae). These larvae were allowed to feed on the composite of ZnO NPs with thiamethoxam (10-90 mg/L) and thiamethoxam-impregnated castor leaves. Observations showed an increased larval mortality (27% increased mortality), a malformation in pupae and adults, overdue emergence, and reduced fecundity and fertility. A significant dose-dependent variation in the biochemical parameters such as superoxide dismutase (SOD), glutathione-S-transferase (GST), and thiobarbituric acid-reactive substances (TBARS) in the treated larvae was also observed. A decline of 72.42 and 33.82% in SOD and GST activity ,respectively, was observed at higher concentration as compared to the control. On the contrary, it enhanced the TBARS level up to 56.7%. The synthesized nanocomposite was characterized by different biophysical techniques such as X-ray diffraction (average crystalline size 34 nm), scanning electron microscopy, transmission electron microscopy (average particle size 30 nm), and Fourier transform infrared spectroscopy (Zn-O stretching peaks at 432 cm-1 and 503 cm-1). The observation of the present study suggests that ZnO NPs pave the way for developing cost-effective, eco-friendly, and capable nanomaterial for its applications in the field of biological sciences.

L-proline mixed with sodium benzoate as sustainable inhibitor for mild steel corrosion in 1M HCl: An experimental and theoretical approach.

Following standard experimental (gravimetric measurements, potentiodynamic polarization measurements, electrochemical impedance measurements, spectroscopic measurements, scanning electron microscopy technique) and theoretical (DFT) approach, inhibition effect of L-proline (LPr) and LPr mixed with sodium benzoate (LPr + NaBenz) for mild steel (MS) corrosion in 1M HCl was studied at 30, 40, 50 and 60 °C. The concentration of LPr was varied between 100-600 ppm, whereas that of NaBenz was fixed at 10 ppm. LPr lowered the corrosion rates of MS to a considerable extent. Corrosion mitigating efficacy of LPr is synergistically enhanced on adding NaBenz at all concentrations. Evaluation of polarization parameters suggested that both LPr and LPr + NaBenz act as mixed type inhibitor with more control on cathodic reaction whereas impedance parameters suggested inhibition of metal corrosion by adsorption at the MS/solution interface. Surface microscopic examination of corroded and uncorroded MS coupons supported the protective effect of adsorbed inhibitor layer at the MS surface. Spectroscopic studies are suggestive of the complex formation between inhibitor molecules and the metal. When LPr is combined with NaBenz, the corrosion inhibition rate was improved greatly. Corrosion mitigating efficacy of LPr or LPr mixed with NaBenz obtained by different techniques are in good agreement and correlate well with theoretical quantum chemical descriptors.

Sugar based N,N'-didodecyl-N,N'digluconamideethylenediamine gemini surfactant as corrosion inhibitor for mild steel in 3.5% NaCl solution-effect of synergistic KI additive.

The inhibitory behaviour of non-ionic sugar based N,N'-didodecyl-N,N'-digluconamideethylenediamine gemini surfactant, designated as Glu(12)-2-Glu(12) on mild steel (MS) corrosion in 3.5% NaCl at 30-60 °C was explored using weight loss, PDP, EIS and SEM/EDAX/AFM techniques. The compound inhibited the corrosion of mild steel in 3.5% NaCl and the extent of inhibition was dependent on concentration and temperature. The inhibiting action of Glu(12)-2-Glu(12) is synergistically enhanced on addition of potassium iodide (KI) at all concentrations and temperatures. The inhibiting formulation comprising of 2.5 × 10-3 mM of Glu(12)-2-Glu(12) and 10 mM of KI exhibits an inhibition efficiency of 96.9% at 60 °C. Quantum chemical calculations and MD simulation were applied to analyze the experimental data and elucidate the adsorption behaviour and inhibition mechanism of inhibitors. MD simulation showed a nearly parallel or flat disposition for Glu(12)-2-Glu(12) molecules on the MS surface providing larger blocking area to prevent the metal surface from corrosion.

In Vitro and in Vivo Antimicrobial Evaluation of Graphene-Polyindole (Gr@PIn) Nanocomposite against Methicillin-Resistant Staphylococcus aureus Pathogen.

Nowadays, the infection caused by the methicillin-resistant Staphylococcus aureus (MRSA) and countless different types of bacterial infection cause the death of millions of people worldwide. Thereby, several strategies have explored for the advancement of better and active antimicrobial agents; one of these lies in the form of two-dimensional carbon-based nanocomposites. Herein, we demonstrate the synthesis of the graphene-polyindole (Gr@PIn) nanocomposite and polyindole (PIn) and significantly enhance the proficiency against MRSA strains which are immune to most antibiotics. The synthesized Gr@PIn and PIn have been characterized by the various biophysical techniques, especially X-ray diffraction (XRD), electron microscopy [scanning electron microscopy (SEM) and transmission electron microscopy (TEM)], Fourier transform infrared, Raman, UV-vis spectroscopy, and thermogravimetric analysis. Electron microscopic investigations unveiled the disintegration of bacterial cell wall upon interaction with Gr@PIn. Significantly, the Gr@PIn found to be very potent in the eradication of the MRSA strain with minimal toxicity to the mammalian cells. Assessment of the antibacterial mechanism revealed that the Gr@PIn adhered toward the bacterial surface, irreversibly interrupted the membrane layer structure of the bacteria, eventually penetrated cells, and efficiently impeded protein activity, which inherently turns into bacterial apoptosis in vitro. Moreover, last, the synthesized Gr@PIn efficiently treated the S. aureus-mediated experimental skin infection in BALB/c mice as well. This work magnifies our comprehending antibacterial mechanism of nonmetallic graphene-based PIn nanocomposite and provides the support to activity anticipation.

Photosynthetic activity, pigment composition and antioxidative response of two mustard (Brassica juncea) cultivars differing in photosynthetic capacity subjected to cadmium stress.

Photosynthetic performance, contents of chlorophyll and associated pigments, cellular damage and activities of antioxidative enzymes were investigated in two mustard (Brassica juncea L.) cultivars differing in photosynthetic capacity subjected to cadmium (Cd) stress. Exposure to Cd severely restricted the net photosynthetic rate (P(N)) of RH-30 compared to Varuna. This corresponded to the reductions in the activities of carbonic anhydrase (CA) and ribulose-1,5-bisphosphate carboxylase (Rubisco) in both the cultivars. Decline in chlorophyll (Chl) (a+b) and Chl a content was observed but decrease in Chl b was more conspicuous in Varuna under Cd treatments, which was responsible for higher Chl a:b ratio. Additionally, the relative amount of anthocyanin remained higher in Varuna compared to RH-30 even in the presence of high Cd concentration, while percent pheophytin content increased in RH-30 at low Cd concentration. A higher concentration of Cd (100 mg Cd kg(-1) soil) resulted in elevated hydrogen peroxide (H(2)O(2)) content in both the cultivars. However, Varuna exhibited lower content of H(2)O(2) in comparison to RH-30. This was reflected in the increased cellular damage in RH-30, expressed by greater thiobarbituric acid reactive substances (TBARS) content and electrolyte leakage. The enhanced activities of antioxidative enzymes, ascorbate peroxidase (APX), catalase (CAT) and glutathione reductase (GR) and also lower activity of superoxide dismutase (SOD) in Varuna alleviated Cd stress and protected the photosynthetic activity.

Polysaccharide from Plantago as a green corrosion inhibitor for carbon steel in 1M HCl solution.

Polysaccharide from Plantago ovata was investigated for its inhibition characteristics for carbon steel corrosion in 1M HCl. The mucilage of the Plantago is comprised of a highly branched polysaccharide, arabinosyl (galaturonic acid) rhamnosylxylan (AX), which is mainly responsible for the corrosion inhibition of the carbon steel. The techniques that were used to assess the inhibition and adsorption properties of the AX in the acid solution are gravimetric method, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), atomic force microscopy (AFM), UV-vis spectroscopy and FTIR. Thermodynamic and activation parameters revealed that the spontaneous adsorption of AX on carbon steel was mixed type and predominantly chemical in nature. Quantum chemical analysis supports the proposed mechanism of inhibition. AX from Plantago could serve as a green corrosion inhibitor for the carbon steel in hydrochloric medium with good inhibition efficiency but low risk of environmental pollution.

Adsorption and corrosion inhibition behavior of hydroxyethyl cellulose and synergistic surfactants additives for carbon steel in 1M HCl.

The inhibitory effect of hydroxyethylcellulose (HEC) on A1020 carbon steel corrosion in 1M HCl solution was evaluated at different concentrations and temperatures using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), UV-vis spectrophotometry, scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), atomic force microscopy (AFM) and quantum chemical analysis. Inhibition efficiency was found to increase with increase in concentration of HEC but decreased with increasing temperature. Inhibitory effect of HEC mixed with minimal concentration of surfactants, triton X 100 (TX), cetyl pyridinium chloride (CPC) and sodium dodecyl sulfate (SDS) was also evaluated. HEC gets adsorbed onto the mild steel surface via mixed type adsorption. Ea, ΔH, ΔS and ΔG°ads, the thermodynamic and activation parameters, were calculated and discussed. Adsorption of inhibitor on the steel/solution interface follows Langmuir adsorption isotherm. EIS suggests formation of protective layer over the carbon steel surface. Results of different experimental techniques pertaining to the inhibitory effect of HEC and HEC mixed with surfactants are in good agreement with theoretical quantum chemical investigation.

Biopolymer from Tragacanth Gum as a Green Corrosion Inhibitor for Carbon Steel in 1 M HCl Solution.

A biopolymer from tragacanth gum, arabinogalactan (AG), was investigated for its adsorption and corrosion inhibition traits for carbon steel corrosion in 1 M HCl. Gravimetric method, potentiodynamic polarization measurements, electrochemical impedance spectroscopy, UV-visible spectroscopy, scanning electron microscopy, and atomic force microscopy were used to judge the adsorptive nature of AG in the acid solution. The inhibition efficiency improved with an increase in AG concentration and temperature of the acid solution. Thermodynamic and activation parameters (ΔG ads, E a, ΔH, and ΔS) were also calculated and discussed. The adsorption of AG favored Langmuir adsorption isotherm. The results of corrosion tests confirmed that AG could serve as an efficient green corrosion inhibitor for the carbon steel in 1 M HCl, yielding high efficiency and a low risk of environmental pollution. Theoretical quantum chemical and Monte Carlo simulation studies corroborated the experimental results.

N,N'-Dialkylcystine Gemini and Monomeric N-Alkyl Cysteine Surfactants as Corrosion Inhibitors on Mild Steel Corrosion in 1 M HCl Solution: A Comparative Study.

Gemini surfactant, N,N'-dialkylcystine 2(C12Cys), derived from cystine, and a monomeric N-alkyl cysteine counterpart, (C12Cys), were synthesized and purified. The characterization of surfactants 2(C12Cys) and (C12Cys) was made by Fourier transform infrared, 1H NMR, and elemental analysis. The effect of 2(C12Cys) and (C12Cys) on mild steel (MS) corrosion in 1 M HCl solution was explored as a function of their concentration and electrolyte temperature by means of gravimetric and electrochemical experiments (potentiodynamic polarization and Electrochemical impedance spectroscopy), surface analytical techniques (scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDAX) and atomic force microscopy (AFM)) and theoretical study. The investigated compounds exhibited surface active properties and performed as good inhibitors for corrosion control of mild steel (MS) in acid solution. However, compared to monomeric (C12Cys), Gemini surfactant 2(C12Cys) showed high corrosion inhibiting ability at very low concentration. The EIS results revealed a greater charge transfer resistance in 2(C12Cys) solution compared to that in (C12Cys) solution. SEM/EDAX observations validate the development of an inhibitive film by the adsorbed molecules of surfactant on the MS surface. The AFM micrographs supported the SEM/EDAX results and exhibited a lowering in the roughness of the corroded MS surface in the presence of both (C12Cys) and 2(C12Cys) surfactants. Further, quantum chemical calculations and Monte Carlo simulations were used to study the dependence of corrosion inhibiting efficacy on the molecular structure and adsorption strength.

Co-precipitation synthesis and characterization of Co doped SnO2 NPs, HSA interaction via various spectroscopic techniques and their antimicrobial and photocatalytic activities.

Sn1-xCoxO2 (x=0.00, 0.01, 0.03, 0.05) nanoparticles (NPs) of average size ∼30-40nm were synthesized by co-precipitation method. The interaction of Co doped SnO2 NPs with human serum albumin (HSA) and their photocatalytic and antimicrobial properties were studied. The structural analysis and morphology of Co doped SnO2 NPs were analysed via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), high resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FT-IR). Besides the structural and morphological analysis, the interaction of Co doped SnO2 NPs with HSA were studied by UV-vis, Circular dichroism (CD) and fluorescence spectroscopy. Fluorescence quenching results suggest that Co doped SnO2 NPs interact with an HSA molecule through static mechanism. CD indicates that α-helicity of HSA increases due to the interaction of Co doped SnO2 NPs. The photocatalytic activities of the NPs with increased doping concentration were evaluated through a degradation process in the presence of methylene-blue (MB) dye under UV light irradiation, which exhibited that the surface area of NPs with increased doping concentration plays a major role in improving the photocatalytic activity. The antimicrobial effect of undoped and Co-doped SnO2 NPs was determined using agar-well diffusion method and analyzed against gram-positive bacteria (Bacillus Cereus MC 2434). In our results, we have found that as the doping concentration increases into NPs, zone of inhibition increases, which could be ascribed to the production of ROS and large surface area of the NPs.

Inhibitory effect of xanthan gum and synergistic surfactant additives for mild steel corrosion in 1M HCl.

Natural polymer xanthan gum (XG) was investigated as eco friendly corrosion inhibitor for mild steel in 1M HCl at 30 °C, 40 °C, 50 °C and 60 °C, respectively. The inhibition studies were performed using gravimetric analysis, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), quantum chemical calculations, scanning electron microscopy (SEM), and UV-visible spectrophotometry. XG significantly reduces the corrosion rates of mild steel. The inhibition efficiency (IE) of the XG increased with increase in concentration, but decreased with temperature; the maximum IE of 74.24% was obtained at concentration of 1000 ppm at 30 °C. The inhibiting action of XG is synergistically enhanced on addition of very small amount of surfactants sodium dodecyl sulfate (SDS), cetyl pyridinium chloride (CPC) and Triton X-100 (TX). The effect of SDS is more pronounced than other surfactants. Potentiodynamic polarization studies confirm XG as a mixed type inhibitor. Results of weight loss measurements are in good agreement of the results of electrochemical measurements. The UV-visible spectroscopic results indicate the formation of complex between XG and Fe(2+) ions during corrosion reaction. Mechanism of inhibition was also investigated by calculating the thermodynamic and activation parameters like ΔG(0), Ea, ΔH and ΔS. The adsorption of inhibitor on mild steel surface obeys Langmuir adsorption isotherm. SEM micrographs show a clearly different morphology in presence of XG and XG-surfactant additives and confirmed the existence of an adsorbed protective film on the mild steel surface.

Kinetic Study on Mutagenic Chemical Degradation through Three Pot Synthesiszed Graphene@ZnO Nanocomposite.

The study was taken up with the objective to synthesize graphene-zinc oxide nano particles (NPs) nanocomposite (Gr@ZnO-Nc) via In-situ synthesis method. The structural, optical, thermal, electrical and photocatalytic properties of the synthesized Gr@ZnO-Nc were studied. The characterization data confirmed that the ZnO NPs were successfully incorporated into the graphene sheets. Further, TGA/DTA results exhibited an enhanced thermal stability of the Gr@ZnO-Nc compared with the graphene. The Gr@ZnO-Nc, graphene sheets were uniformly wrapped by ZnO NPs, which can protect graphene and delay their oxidation in air. The synthesized Gr@ZnO-Nc was used for the efficient photodegradation of a carcinogenic methyl orange (MO) dye. The results exhibited promising photodegradation of the MO dye under UV light irradiation through the production of reactive oxygen species (ROS). The promising effect of Gr@ZnO-Nc on the photodegradation properties was conferred by the large surface area which increased adsorption capacity, and the strong electron transfer ability. Thus, it is encouraging to conclude that the synthesized Gr@ZnO-Nc has environmental significance with its utility in remediation in the hazardous MO dye.