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Synthesis of a biocomposite based on N-maleated chitosan immobilized in amino-carbamated alginate matrix (NMC-PSC) was carried out. Facile chemical modifications of sodium alginate and chitosan were executed using maleic anhydride and 4-phenylsemicarbazide as chemical modifiers, respectively. NMC-PSC hydrogel beads were employed for Cu(II) biosorption from aqueous media. Study of surface characterization, morphology and chemical structure of the sorbent indicated the successful surface functionalization and attachment of Cu(II) ions. Sorption parameters like pH, time of contact, sorbent dosage and adsorbate content significantly influenced the sorption capacity. Kinetic results demonstrated that copper sorption on NMC-PSC was governed by chemisorption and ion-exchange rather than merely mass transfer. Equilibrium sorption data closely fitted with Langmuir model and maximum Langmuir monolayer binding capacity (q m ) was determined as 207 mg/g. The negative ΔG o values indicated the spontaneity of Cu(II) sorption process while ΔH o and ΔS o parameters indicated the exothermic nature of sorption which proceeds with rise in entropy.

In present work, facile synthesis of a biocompatible hybrid biosorbent based on diethylenetriaminepentaacetic acid (DTPA) modified chitosan immobilized in organo-functionalized sodium alginate matrix (DTPA-MCSA) was carried out. DTPA-MCSA was casted in microspherical hydrogel beads. Three dimensional microporous geometry of the biosorbent remained well preserved as observed in SEM analysis which revealed the improved mechanical strength of the alginate matrix. Surface functionalization of base biopolymers was confirmed by FTIR and SEM analysis. Equilibrium sorption studies using DTPA-MCSA for Cu(II) from aqueous medium were carried out in batch mode and found considerably dependent on pH, contact sorption time, temperature and initial copper concentration. Isothermal sorption data showed close correlation with Langmuir model as evident from nonlinear fitting of data (R 2 ˜ 0.99) at different temperatures. The experimental sorption capacity (q e) was found nearly 67 mg/g using 100 mg/L initial concentration of copper ions. Kinetic studies were conducted using different initial concentrations for better elucidation of results and it showed better correlation with pseudo second order rate equation which unveiled that strong ion pair coordination and complexation exist between Cu(II) and newly grafted chelating sites of DTPA-MCSA. Thermodynamic parameters suggested that the adsorption process is spontaneous and endothermic. The results concluded that DTPA-MCSA could be a better candidate for adsorptive remediation of copper ions from liquid waste.

Abstract: Hypericum oblongifolium is a potent source of bioactive constituents. A series of pharmacological properties, ranging from wound healing and antiseptic to antiviral, anti-inflammatory, anticancer, ethanol intake inhibition, and apoptosis-inducing activities have been associated with this plant. The current research project was designed to investigate the new secondary metabolites in H. oblongifolium having excellent pharmaceutical potential. In the present investigation two new cholestane-type steroids, hyperinoate A (1) and hyperinoate B (2) were isolated from a chloroform soluble fraction of the whole plant of H. oblongifolium. Structures of isolated new compounds were elucidated based on spectroscopic data including 1D (1HNMR, 13CNMR) and 2D (HMBC, COSY, NOESY) NMR and mass spectrometry (EIMS, HREIMS) data. After structure elucidation, new compounds were named 6α-hydroxy-14α-methyl Cholestan-3-yl-acetate and 6α,25-dihydroxy-14α-methyl Cholestane-3-yl-acetate. Both steroids showed promising inhibitory activity against lipoxygenase (LOX) and acetylcholinesterase (AChE) enzymes. Especially hyperinoate A (1) inhibited the lipoxygenase (LOX) enzyme with IC50 41.7± 0.15 µM whereas Baicalein (positive control) had IC50 42.3 ± 0.20 µM. Similarly, Hyperinoate B (2) (56.3 ± 0.33 µM) showed higher inhibition than Galantamine (positive control) 53.8 ± 0.54 µM. These results were validated with in-silico molecular docking investigations. The greater binding affinity of hyperinoate A (1) (-9.2 Kcal/mol) against LOX-5(PDB ID 3V99) showed higher inhibition as compared to baicalein (positive control) (-7.7 Kcal/mol). The binding affinities of hyperinoate B (2) (-10.5 Kcal/mol) were close to galantamine (-10.6 Kcal/mol). All in-vitro and in-silico results revealed that both newly isolated compounds showed moderate inhibition against lipoxygenase (LOX) and acetylcholinesterase (AChE) enzymes.

Medicinal herbs are promising source of biologically active phytochemicals, many of which possess antifungal activities against phytopathogens. This research presents in vitro antifungal activity and analysis of a medicinally important herb Centaurium erythraea Rafn extracts against a highly problematic pathogen of tomato namely Fusarium oxysporum f. sp. lycopersici (FOL). In-vitro results prominently disclosed that the extracts showed good percentage growth inhibition (PGI) against FOL. Methanolic extract of C. erythraea at 200 mg mL-1 showed growth inhibition 93.3% while the synthetic fungicide benomyl showed highest growth inhibition of 90.2% at the same concentration. Phytochemical analysis indicated that methanolic extracts of this plant possess phytochemicals of all the major classes such as alkaloids, steroids, terpenoids, saponins etc. This study concludes that the extracts of C. erythraea are the best alternatives to fungicides to control Fusarium wilt pathogen of tomato.

In this research work, a hybrid biocomposite based on N-maleated chitosan, amino-thiocarbamate functionalised calcium alginate and anhydrous Titania nanoparticles (NMC-MCA-TiO

The main objective of this study was to examine the impact of cellulose nanocrystals (CNCs) in advanced waterborne wood coatings such as polycarbonate urethane (PCU) and hybrid alkyd varnish (HAV) in terms of coating performance, mechanical properties, optical properties, and water permeation and uptake properties. The influence of CNCs on the overall quality of the various waterborne wood coatings was investigated by incorporating different percentages of CNCs. Varying CNC content in coating formulations showed that CNCs are effective for waterborne wood coatings; CNCs offer both higher scratch and impact resistance as compared to neat coatings and have a significant reduction in water vapor permeation through a film with little increase in water vapor uptake at high concentrations. It was observed that the CNC darkened and reduced gloss in the coatings and viscosified the dispersion. These research findings suggest that CNCs are well-dispersed at lower concentrations, but at high concentrations, agglomeration occurred. Thus, while CNCs can give better mechanical and permeation performances at contents of up to 5 wt %, at 1 wt % CNCs can still provide modest scratch and chip resistance improvement without loss of optical properties (gloss and color) while retaining a similar water uptake. Overall, it can be concluded that CNCs have the potential to be used as a reinforcement filler in high-performance waterborne wood coatings.

In this study, chemical modification of chitosan has been carried out using epichlorohydrin as crosslinking agent and ethyl acetoacetate as a modifier to graft acetoacetyl moiety. The said organo-functionalization on chitosan and sodium alginate not only offered a novel support for TiO2 immobilization but also enhanced sorption performance for Ni(II) recovery from aqueous medium. So, a composite consisting of acetoacetyl moiety grafted chitosan, sodium alginate and titanium oxide (EAA-MCS/TiO2) was prepared and characterized by fourier transform-infra red (FT-IR) spectroscopy and scanning electron microscopy (SEM). The hybrid composite (3EAA-MCS/TiO2) which had TiO2 to EAA-MCS mass ratio of 20.0% by weight showed maximum sorption efficiency. The formulated sorbent was conditioned in the form of hydrogel beads for operation. Isothermal sorption and kinetics studies were performed at pH = 6.0 to configure the nature of sorption. Pseudo-2nd order rate expression better explained the sorption kinetics and chemisorption is the predominant mode of uptake. Langmuir adsorption model better explained the sorption process (R 2 ∼ 0.99) and maximum monolayer sorption capacity (q m ) at sorption/desorption dynamic equilibrium was computed as 403 mg/g at optimized pH.

This study presents the volatile constituents from leaves of Trifolium alexandrinum from Pakistan. The dried leaves were subjected to hydrodistillation for extraction and extracted volatile oil was subsequently characterized by gas chromatography-mass spectrometry technique. A total of 22 compounds were identified where the most dominant constituents were: phytol (46.00%), palmitic acid (9.26%), phytol acetate (6.44%), and linolenic acid (3.47%). Most of these are well-known constituents to exhibit antibacterial, antioxidant, antitumor, and anti-inflammatory activities.

In this study, organo-funtionalization of sodium-alginate has been carried out using phenylsemicarbazide as modifier to graft N, O-donor atoms containing functional groups (amino-carbamate moieties) to offer novel support for TiO2 immobilization. Hybrid composite made of aminocarbamated alginate, carboxymethyl chitosan (CMC) and titanium oxide TiO2 (MCA-TiO2) was prepared for the promising adsorptive remediation of Ni(II). FT-IR, SEM-EDX were employed to characterize MCA-TiO2. The optimization of TiO2 to modified alginate mass ratio was carried out and hydrogel beads with TiO2/MCA mass ratio of 10.0% (2MCA-TiO2) revealed highest sorption efficiency. The produced sorbents were adapted in the form of hydrogel beads for operation. Organic functionalization based on aminocarbamate ( O CO NHNH2) moieties on linear chains of alginate embedded additional chelating functional sites which enhanced sorption and selectivity. Batch mode experiments were conducted for optimization of pH and sorbent dose. Equilibrium sorption, kinetic and thermodynamic studies were performed to pattern the nature of sorption. Kinetic data was found in close agreement with pseudo-second order rate expression (PSORE). Isothermal equilibrium sorption data was well fitted with Langmuir adsorption model. Maximum sorption capacity was evaluated as 229 mg/g at 298 K and pH = 6.0.

Mixed superalkali clusters are a better source of excess electrons, as their vertical ionization energies (2.81–3.36 eV) are much lower than those of alkali metals (even cesium (∼3.85 eV)) and the superalkali Li3O (3.42 eV).

Vegetables are significant edible crops, and human beings are dependent upon them as a diet for their survival, and uptake of metals through vegetable roots can be piled up at higher levels in their comestible parts which can cause harmful effects upon human health. The present study aimed to determine the composition of essential (Mn, Fe, Cu, and Zn) and non-essential/toxic trace (Al, Cr, As, Cd, and Pb) metals in the edible parts of some common vegetables (carrot, reddish, cauliflower, pumpkin, and spinach) by FAAS and ICP-OES. A simple and fast ultrasound-assisted extraction (UAE) procedure combined with dilute acids was developed. The extraction condition adequate to obtain the maximum response was a pre-sonication time of 5 min, 6 min of sonication time at 90 % sonication amplitude, 60 °C temperature, and 5.0 mL of HNO3 (0.5 M)-H2O2 (10 %) for 500 mg sample. Certified reference materials (NIST 1515 and NIST 1570a) were also analyzed for accuracy studies in terms of % recovery which were obtained in range between 96.0 and 108.3 %, while the precision was performed in repeatability (n = 10) study, yielding % RSD ≤ 2.61. The proposed UAE procedure was the efficient, reliable, and valid alternative to conventional acid digestion method, with the advantage of short analysis time and less consumption of reagents for sample preparation. As far as the concern of human health risk assessment, THQ value for Cd in all vegetables is ≥ 1 which indicated the Cd ingested with vegetables suggesting that the consumers may be facing health risk, especially the children are more vulnerable, whereas CR value of Cr for cauliflower, pumpkin, and spinach obtained ranged between 3.5 and 9.5 × 10−3 posed a slight threat to carcinogenic health risk.

A novel hybrid biocomposite based on amino-thiocarbamate derivative of alginate, carboxymethyl chitosan and TiO2 (TiO2/TSC-CMC) was fabricated and characterized using Fourier transform Infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX). The TiO2/TSC-CMC mass ratio (5.0–30.0%) was optimized and 3TiO2/TSC-CMC (hydrogel beads with TiO2/TSC-CMC mass ratio of 20.0%) was selected as the best sorbent for effective biosorption of Ni(II). Batch sorption experiments were conducted, instantaneous and equilibrium sorption capacities were investigated as function of pH, sorbent dose, initial metal concentration, contact time and temperature. Kinetic data could be well explained through pseudo second order rate equation (PSORE) depicting that the rate determining step involves the transfer of electron density from sorbent functional sites to central metal ion. Langmuir model fitted well with isothermal sorption data and maximum monolayer sorption capacity (qm) was computed as 172 mg/g at pH 6.0 and temperature 298 K. The values of thermodynamic parameters such as standard enthalpy change (16.94 kJ/mol) and standard Gibbs energy change (−18.67, −19.48, −20.57, and −21.38 kJ/mol) and standard entropy change (0.12 kJ/mol·K) concluded that sorption process is endothermic, spontaneous and resulted with increase in randomness. Hence, 3TiO2/TSC-CMC was found efficient and reusable sorbent.

The present study is based on the synthesis of a novel hybrid biosorbent using 1,2-cyclohexylenedinitrilotetraacetic acid modified crosslinked chitosan and amino-thiocarbamate moiety functionalized sodium alginate (CDTA-CS/TSC-CA). The fabricated sorbent was employed to investigate the efficient recovery of Cu(II) from aqueous media. CDTA-CS/TSC-CA was characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Analysis confirmed the successful modification of both biopolymers and subsequent loading of Cu(II) ions. CDTA-CS/TSC-CA was casted in the form of hydrogel beads having different CDTA-CS to TSC-CA mass ratios i.e., 10.0-40.0% by mass. The hydrogel beads 4CDTA-CS/TSC-CA with CDTA-CS/TSC-CA mass ratio of 40.0% was found most effective for copper sorption. Equilibrium sorption results showed that initial concentration of copper, medium pH, contact time, sorbent dosage and temperature influenced the sorption capacity (q

This chapter introduces an advanced and new type of Three-Dimensional (3D) numerical method called the InterSection Marker (ISM) method. The ISM method - a hybrid Lagrangian–Eulerian 3D front-tracking algorithm specifically crafted for multi-phase flow simulation. The method was used to simulate rising vapour bubble behaviour in Convective boiling conditions. Two applications: bubble growth and bubble condensation due to the convective action, were investigated. Numerically obtained bubble properties, such as size, shape and velocity, are compared well against the past works, and the ISM method proved to be an efficient numerical tool for the interface tracking of multi-phase flow CFD simulations involving heat and mass transfer.

In the present study, a novel biosorbent clay composite, based on carboxymethyl-chitosan/sodium alginate grafted with amino-carbamate moiety/bentonite clay (CA-CMC/Bt) was prepared. The produced sorbent was conditioned in the form of hydrogel beads by ionotropic gelation with Ca(II) ions, and thoroughly characterized using FTIR, XRF, XRD, SEM and zeta potential measurements. FTIR and SEM confirmed the successful grafting and intercalation of clay mineral into modified biopolymer. Hydrogel beads were observed to be very integrated and stable under a wide pH working range (from 2.0 to 12.0). CA-CMC/Bt was employed for adsorptive remediation of Ni(II) from aqueous media. Sorption process was found as a function of various parameters such as sorbent dosage, contact time, pH and initial concentration. Kinetic data could be well explained by pseudo second order rate equation (PSORE), suggesting that complexation or valence forces are playing significant role in the uptake of Ni(II) ions. Isothermal sorption data was analysed using different sorption models such as Langmuir, Freundlich and Sips. Data was well fitted with Langmuir and Sips model, maximum monolayer sorption capacity (qm) was calculated (by non-linear fitting of data) as 159 mg/g at 298 K and pH 5.5. Separation factor (RL) was found as 0 < RL < 1 which indicated favourable sorption. Thermodynamic parameters i.e. ΔGo, ΔHo and ΔSo were quantified and patterned the sorption process as exothermic, spontaneous with increase in system entropy. CA-CMC/Bt was found cost-effective, efficient and reusable material in Ni(II) competitive recovery.

The present work is focused on pyrolysis of polystyrene waste for production of combustible hydrocarbons. The experiments were performed in an indigenously made furnace in the presence of a laboratory synthesised copper oxide. The pyrolysis products were collected and characterised. The Fourier transform infrared spectra showed that the liquid fraction contains C–H, C–O, C–C, C=C and O–H bonds, which correspond to various aliphatic and aromatic compounds. Gas chromatography–mass spectrometry traced compounds ranging from C1 to C4 in the gaseous fraction, whereas in the liquid fraction 15 components ranging from C3 to C24 were detected. From the results it has been concluded that CuO as a catalyst not only increased the liquid yield but also reduced the degradation temperature to great extent. Fuel properties of the pyrolysis oil were determined and compared with standard values of commercial fuel oil. The comparison suggested potential application of pyrolysis oil for domestic and commercial use.

Poly(N-isopropylacrylamide-co-acrylamide) (PNA-BIS-2) microgels were synthesized by free radical precipitation polymerization in aqueous medium. Spherical Ag nanoparticles with diameter of 10–20 nm were fabricated inside the PNA-BIS-2 microgels by in-situ reduction of silver nitrate using sodium borohydride as reducing agent. The Ag nanoparticles- loaded hybrid microgels were characterized by Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Energy dispersive X-ray (EDX), Scanning transmission electron microscopy (STEM), Ultraviolet visible spectroscopy (UV Visible), Thermogravimetric analysis (TGA) and X-ray diffraction (XRD). Ag contents in the hybrid system were determined by inductively coupled plasma - optical emission spectrometry (ICP-OES). Various nitroarenes were successfully converted into their respective aromatic amines with good to excellent yields (ranging from 75% to 97%) under mild reaction conditions. The catalyst has ability to successfully convert substituted nitroarenes into desired products keeping many functionalities intact. The catalyst can be stored for long time without any sign of aggregation and can be used multiple times without any significant loss in its catalytic activity.

In this study, organo-funtionalization of sodium-alginate has been carried out using phenylsemicarbazide as modifier to graft N, O-donor atoms containing functional groups (amino-carbamate moieties) to offer novel support for TiO

In this paper, the growth of a rising vapor bubble in superheated water was numerically studied using an advanced interface tracking method, called the intersection marker (ISM) method. The ISM method is a hybrid Lagrangian–Eulerian front-tracking algorithm that can model an arbitrary three-dimensional (3D) surface within an array of cubic control volumes (CCV). The ISM method has cell-by-cell remeshing capability that is volume conservative, maintains surface continuity, and is suited for tracking interface deformation in multiphase flow simulations. This method was previously used in adiabatic bubble rise simulation with no heat and mass transfers to or from the bubble were considered. This work will extend the ISM method's application to simulate vapor bubble growth in superheated water with the inclusion of additional physics, such as the convective heat transfer mechanism and the phase-change. Coupled with an in-house variable-density and variable-viscosity single-fluid flow solver, the method was used to simulate vapor bubble growth due to the convective action. The forces such as the surface tension and the buoyancy were included in the momentum equation. The source terms for the mass transfer were also modeled in the computational fluid dynamics governing equations to simulate the growth. Bubble properties such as size, shape, velocity, drag coefficient, and convective heat transfer coefficient were predicted. Effects of surface tension and temperature on the bubble characteristic were also discussed. Obtained numerical results were compared against the analytical and past works and found to be in good agreement.

This study describes the adsorption of Cu (II), Co (II) and Ni (II) ions from wastewater on Vigna radiata husk biomass. The ability of adsorbent to capture the metal ions has been found to be in the order of Ni (II)>Co (II) and Cu (II) depending upon the size and nature of metal ions to be adsorbed. It has been observed that percentage removal of Cu (II), Co (II) and Ni (II) ions increases with increase of adsorbent dosage, contact time and pH of the medium but up to a certain extent. Maximum adsorption capacity (qmax) for Cu (II), Co (II) and Ni (II) ions has been found to be 11.05, 15.04 and 19.88 mg/g, respectively, under optimum conditions of adsorbent dosage, contact time and pH of the medium. Langmuir model best fits the adsorption process with R2 value approaches to unity for all metal ions as compared to other models because adsorption sites are seemed to be equivalent and only monolayer adsorption may occur as a result of binding of metal ion with a functional moiety of adsorbent. Pseudo second order kinetic model best interprets the adsorption process of Cu (II), Co (II) and Ni (II) ions. Thermodynamic parameters such as negative value of Gibbs energy (∆G°) gives information about feasibility and spontaneity of the process. Adsorption process was found to be endothermic for Cu (II) ions while exothermic for Co (II) and Ni (II) ions as signified by the value of enthalpy change (∆H°). Husk biomass was recycled three times for removal of Ni (II) from aqueous medium to investigate its recoverability and reusability. Moreover V. radiata husk biomass has a potential to extract Cu (II) and Ni (II) from electroplating wastewater to overcome the industrial waste water pollution.

The first synthesis of all-cis-1,2,3,4,5,6-hexafluorocyclohexane (C6H 6 F 6 = 1), a facially polarized molecule, opened up new avenues for designing novel nonlinear optical (NLO) materials. In the present work, face specific superalkali based alkaline earthides M3O+-1-M’₋ (M = Li,Na,K & M’ = Be,Mg,Ca) have been designed theoretically. The NBO analysis and HOMOs electron density confirmed their alkaline earthide nature. The thermodynamic stability was confirmed by their interaction energies (−16.11 to −115.51 kcal/mol). Non-covalent interactions were confirmed through NCI and QTAIM analyses. The maximum absorption in UV-VIS-NIR region confirmed that the complexes are deep UV transparent. The maximum first and second hyperpolarizabilities of 5.2 × 106 au and 5.7 × 108 au confirmed their enhanced NLO response. The maximum SHG, EOPE and hyper-Rayleigh scattering coefficient (βHRS) are 1.41 × 107 au, 3.13 × 106 au and 2.1 × 106 au, respectively. The EFISHG and EOKE at 4.17 × 1011 au and 1.51 × 1011 au have been obtained. The results of quadratic nonlinear refractive index up to 2.16 × 10−7 au indicated their increased NLO response. These results suggest that designed complexes provide a new insight towards the rational design of stable high performance NLO materials.

Deep frying with repeated use of same edible oil leads to the formation of lipid oxidation products. The presence of these oxidized products formed during frying at elevated temperature is hazardous for human health and therefore, requires prompt analysis for ensuring its fitness/quality. In this study, oxidative degradation of thermally stressed edible oils canola, sunflower and palm olein shortening was studied at 180&#176C ± 5&#176C up to 48 hours. Palm olein shortening remained stable during this period as the increase in its acid value was significantly less than canola and sunflower seed oils. The shortening samples were further studied by attenuated total reflectance Fourier transformation infrared (ATR-FTIR) and gas chromatography mass spectrometry (GC-MS) to evaluate the formation of various oxidation products due to thermal stress. ATR-FTIR indicates the formation of free fatty acids (FFAs), aldehyde groups and change in degree of unsaturation while GC-MS gives important information about profile of FFAs. The combination of these analytical techniques is useful for rapid and highly sensitive analysis of oxidized edible oil thus, ensuring its quality and fitness for safe use.

Acrylamide and N-isopropylacrylamide were copolymerized in the presence of a N,N-methylenebisacrylamide crosslinker to obtain poly(N-isopropylacrylamide-co-acrylamide) [P(NA)] polymer colloidal particles. Pd nano crystals with diameter of 4–8 nm were loaded into the [P(NA)] microgels by reduction of [PdCl4]-2 within dispersion of polymer microgels. The Pd NPs-loaded hybrid microgels were analysed by TEM, STEM, EDX and XRD. The catalytic ability of the Pd-[P(NA)] system was investigated towards reductive transformation of nitroarenes into corresponding aryl amines and Suzuki coupling transformation in a green solvent, H2O. The progress of catalytic reaction was examined by thin layer chromatography (TLC). Different reactants were effectively converted into their corresponding products with great to fabulous yields (extending from 75 to 97%) under gentle reaction conditions. The Pd-[P(NA)] catalyst is stable for long time and can be utilized numerous times without any notable loss in its catalytic action.

This study focuses on the synthesis of iron molybdate [Fe2(MoO4)3] nanoparticles (NPs) using simple co-precipitation process. The catalyst synthesized was characterized by advanced instrumental techniques such as XRD, SEM, EDX, TGA and FTIR, which confirmed the successful synthesis of NPs. Organic compound Rhodamine B (Rh. B) dye was selected for photo-degradation due to its complex structure and carcinogenic nature. Results exhibited that at neutral pH, the synthesized catalyst is highly effective for the degradation of Rh. B. For 20 mg/L initial concentration with an initial pH of 6.7, the degradation efficiency of Rh. B reaches 98 % within 180 min. Furthermore, the solution pH (1 to 11) affects the catalytic activity. This indicates that at neutral and/or alkaline pH, the usage of iron molybdate overwhelms the efficiency of Fenton-like reaction. It has been observed that Fe2(MoO4)3 showed excellent stability as after recycling it for 9 times its performance remained effective. Based on these data, the synthesized catalyst could be conveniently employed for degradation of toxic pollutants.

A novel hybrid biocomposite based on amino-thiocarbamate derivative of alginate, carboxymethyl chitosan and TiO

In present study, pure and amino-carbamate moiety grafted calcium alginate hydrogel beads (CA, PSC-CA) were prepared for their biosorption performance in the recovery of silver ions. The produced sorbents were characterized using FTIR, SEM, EDX and TGA. FTIR and SEM-EDX confirmed the successful modification and loading of silver ions onto hydrogel beads. When compared with CA, PSC-CA showed enhanced sorption but comparable kinetics. Equilibrium sorption studies showed that pH, sorbent dose, contact time and adsorbate concentration influenced the sorption capacity. The uptake kinetic data was well demonstrated by pseudo second order rate equation (PSORE). Elovich equation and the resistance to intra-particle diffusion model (RID) suggested that there were two phases of sorption, first one was rapid followed by relatively slow uptake step. Equilibrium isothermal sorption data was well fitted by Langmuir and Sips models. The separation factor RL was found as 0

Monodisperse multi-responsive poly(N-isopropylacrylamide-acrylic acid-acrylamide) [P(NIPAM-AAc-AAm)] polymer microgels were synthesized by precipitation polymerization in aqueous medium. Silver nanoparticles were fabricated inside the microgels by in situ reduction method. Poly(N-isopropylacrylamide-acrylic acid-acrylamide) [P(NIPAM-AAc-AAm)] microgels and Ag-poly(N-isopropylacrylamide-acrylic acid-acrylamide) [Ag-P(NIPAM-AAc-AAm)] hybrid microgels were characterized by Fourier transform infrared spectroscopy (FTIR), UV–vis spectroscopy (UV–vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The hybrid microgels were found to be temperature and pH sensitive in aqueous medium. They have long term stability under various conditions of pH of the medium. The hybrid microgels were used as catalysts for simultaneous reduction of various nitro compounds in aqueous medium. Nitroarenes like o-nitroaniline (o-NA), p-nitroaniline (p-NA), p-nitrophenol (p-NP) and nitrobenzene (NB) were individually and simultaneously reduced to corresponding aminoaromatic compounds by sodium borohydride in the presence of Ag-poly(N-isopropylacrylamide-acrylic acid-acrylamide) hybrid microgels catalyst. Catalytic activity of the hybrid microgels for individual and simultaneous reduction of nitroarenes was compared with each other. The retardation in catalytic reduction of each nitroarene in the presence of other nitroarenes was explained on the basis of simultaneous adsorption. Various factors affecting the catalytic reduction of p-nitroaniline (p-NA) like catalyst dose and pH of the medium were also investigated. Rate of reduction of p-nitroaniline was found to be increased with increase of catalyst dose and pH of the medium.

Manganese doped Sm–Cd nanoparticles with manganese content varying from 0 to 30 mol % were synthesized using chemical reduction method. The structural and compositional analyses were carried out using x-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD analysis indicated the formation of single phase cubical structure of all the samples. The crystallite size was observed to vary from 47 to 21 nm as the manganese content was increased. The effect of Mn substitution on the frequency and temperature dependent electric properties (dielectric constant, dielectric & tangent loss) of Sm–Cd nano alloys with nominal composition Sm11Cd45-x Mnx (where x = 0.0, 20, 25 and 30) was measured. The increase in AC conductivity with frequency may be attributed to the tremendous increase of mobility of the charge carriers. DC conductivity linearly decreases with temperature indicating metallic behavior of nano alloys. The room temperature conductivity of the materials increases from 6.2 × 10−5 to 1.37 × 10−4 S/cm with the increase in Mn content.

Benzocaine is well-known for its role as an anesthetic agent and largely used in oral ulcers, ear pain and dental complications. Along with lidocaine and other local anesthetics, benzocaine has marked it as an anesthetic agent in surgical procedures and as Na+ channels blocker, as well. Analogues of benzocaine have been found to possess biological potentials including antibacterial, antifungal and anti-cancer. Some derivatives were found to have conspicuous action against tuberculosis. The current review focuses to explore the century-long potential of the molecule and its analogs that have appeared in the literature. Furthermore, highlighting the biological potential of benzocaine and its analogues shall open-up new dimensions of future research to design more potent analogues.

Water contamination is a worldwide critical issue for the present society to avoid competition and maintain an environmentally friendly scenario. Removal of various pollutants including inorganic and organic compounds from water is a big challenge nowadays. Worldwide attention to promote polluted water and technologies related to its treatment has been adversely increased. The utilization of metal/metal oxide nanoparticles (NPs) for this purpose has gained much attention due to its exceptional properties imparted by reduced size and effective surface area. Moreover, metal/metal oxide NPs-based innovation for improved expulsion productivity is an ingenious area for research and development but the use of such NPs presents some serious risks. Herein, the advanced requisition of NPs for polluted water treatment is highlighted along with the difficulties related to them and their toxic impacts when used as water purifiers. Additionally, the plausible fate of metal/metal oxide NPs incorporated in the water for purification and salient future challenges are deliberated.

Hydroxyapatite (HA) shows diverse biomedical applications as bone filler and coating material for metal implants to enhance osteoconduction. Four different PVAHA composites were synthesized in situ by an economical co-precipitation wet methodology. The FTIR spectra of PVAHA composites showed characteristic signals of HA and PVA. The BET surface area of PVAHA composites were in range of 41.3–63.7 m 2 /g. The composites showed type IV nitrogen adsorption/desorption isotherm, a characteristic for mesoporous material. The pore diameter range (6.3–8.1 nm) of PVAHA composites also confirmed their mesoporous nature. The Barrett–Joyner–Halenda (BJH) pore size distribution curves indicated a narrow pore size distribution. To obtain a homogeneous crack free coating with EPD on stainless steel (SS) plates, different parameters such as PVA percentages in PVAHA composites, solvent, deposition time and voltage were optimized. The PVAHA composites were stable after EPD as confirmed by FTIR spectra recorded before and after EPD. The SEM images of the coating showed a homogeneous morphology. The thickness of the coating was controlled by varying voltage and time. The best results were obtained with c-PVAHA composite at 30 volts for 5–10 min and current density was around 4.5 to 5 mA. The adhesion strength of c-PVAHA coating was measured by using ASTM standard F1044-99. The average value was approximately 9.328 ± 1.58 MPa.

Poly(N-isopropylacrylamide-co-methacrylic acid) microgels [p(NIPAM-co-MAAc)] were synthesized by precipitation polymerization of N-isopropylacrylamide and methacrylic acid in aqueous medium. These microgels were characterized by dynamic light scattering and Fourier transform infrared spectroscopy. These microgels were used as micro-reactors for in situ synthesis of copper nanoparticles using sodium borohydride (NaBH4) as reducing agent. The hybrid microgels were used as catalysts for the reduction of nitrobenzene in aqueous media. The reaction was performed with different concentrations of cat­alyst and reducing agent. A linear relationship was found between apparent rate constant (kapp) and amount of catalyst. When the amount of catalyst was increased from 0.13 to 0.76 mg/mL then kapp was increased from 0.03 to 0.14 min-1. Activation parameters were also determined by performing reaction at two different temperatures. The catalytic process has been discussed in terms of energy of activation, enthalpy of activation and entropy of activation. The synthesized particles were found to be stable even after 14 weeks and showed catalytic activity for the reduction of nitrobenzene.