Fourier Transform Infrared Spectroscopy Studies Research Articles

Role of CeO2 in promoting the spillover in CO oxidation reaction over platinum nanoparticle-supported CeO2 catalyst

CeO2 has been extensively studied as a support material for platinum group metals because of the high catalytic activity of CeO2-supported catalysts in oxidation reactions. In particular, it has been reported that the Pt/CeO2 catalyst exhibits high CO oxidation activity after reductive treatment, thereby lowering the temperature of 50 % CO conversion to 150 ℃ or less. Such high activity of Pt/CeO2 has been attributed to the formation of active sites at the interface between the Pt nanoparticles (NP) and CeO2 surface. In this study, we attempt to deepen our understanding of the catalytic activity of Pt/CeO2 by studying the spillover of CO and O species at the interface. Combined kinetics and in situ CO-diffuse reflectance infrared Fourier transform spectroscopy studies reveal that CO spills over from Pt NPs to the CeO2 surface; this contributes to circumventing Pt poisoning by CO at low temperatures. Moreover, the CO oxidation activity of the Pt/CeO2 catalyst was considerably enhanced by simply mixing CeO2 particles with the Pt/CeO2 catalyst. This is explained by the formation of more reactive O atoms on the CeO2 surface after the reductive treatment. This study demonstrates that understanding the dynamic mobility of reactants is vital for discerning catalyst activity and designing more reactive catalysts.

Fabrication, in Vitro, and in Vivo Characterization of Mucoadhesive Berberine-Loaded Blended Wafers for Treatment of Chemotherapy-Induced Oral Mucositis.

This study aims to design and characterize berberine-loaded wafers for the treatment of chemotherapy-induced oral mucositis. Wafers were prepared by lyophilization of hydrogels of various ratios of chitosan (CS)/sodium alginate (SA) as well as CS/hydroxypropyl methylcellulose (HPMC). In vitro release, in vitro mucoadhesion, porosity, and swelling studies were conducted to select the optimized formulations. Moreover, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and mechanical properties studies were also performed for further characterization. The efficacy of optimized berberine-loaded wafers in the treatment of oral mucositis was investigated in a 5FU-induced oral mucositis rat model. F2-CS-SA and F6-CS-HPMC wafers exhibited sustained release profile and excellent mucoadhesion strength. Therefore, these wafers were selected as the optimized formulations. SEM confirmed the porous structure of these wafers and is in agreement with the results of porosity and swelling studies. XRD and FTIR studies indicated that berberine was incorporated into the wafer matrix in the amorphous form. In vivo studies demonstrated that topical application of berberine-loaded optimized wafers reduced significantly the severity of 5FU-induced oral mucositis and decreased the expression of inflammatory markers (TNF-α and IL-1β). The results of in vitro and in vivo studies revealed that berberine-loaded F2-CS-SA and F6-CS-HPMC wafers can be effective in the treatment of chemotherapy-related oral mucositis.

The effect of niosome preparation methods in encapsulating 5-fluorouracil and real time cell assay against HCT-116 colon cancer cell line

The formulation of niosomes is influenced by a number of variables, and these variables may eventually affect the formulation’s outcome. One of the elements that can influence the physico-chemical properties of niosomes is the method used in preparation of the formulation. In this study, we established if various methods of preparation have any impact on the prepared vesicles when loaded with 5-fluorouracil. Thereafter, a real-time cell assay (an in vitro cytotoxicity test) against HCT-116 colon cancer cell lines was done on an optimised batch. 5-fluorouracil loaded niosomes were prepared with either Tween 60 or Span 60 by four different methods - namely thin film hydration (TFH), reverse phase evaporation (RPE), evaporation/sonication (EVP/SON), and the ethanol injection method (EIM). In vitro evaluations were done on the formulations, and these included particle size analysis, entrapment efficiency, scanning electron microscopy (SEM), photomicrography, drug release, polydispersity index, and Fourier transform infrared spectroscopy (FTIR). The effects of the preparation method and type of non-ionic surfactants on encapsulation efficiency, particle size, and in vitro drug release of the niosomes at pH 7.4 were evaluated. An in vitro cytotoxicity test (real time cell assay (RTCA)) against HCT-116 cells was carried out using the optimised formulation. Results showed physically stable formulations. The TFH method produced the smallest particle sizes (187 nm and 482 nm), while the EVP/SON method produced the largest particle sizes (4476 nm and 9111 nm). The Tween-based niosomes prepared by TFH or RPE had higher drug entrapment. The FTIR studies of niosomal formulations showed broad peaks at wavenumbers above 3000 cm−1, indicating strong hydrogen bonds. The RTCA showed 5-fluorouracil-loaded niosomes caused more sustained cell death compared to the pure drug and blank niosomes. The methods of preparation affected the particle size, polydispersity index, entrapment efficiency, and the physical stability of the vesicles. The thin film hydration method was more robust in the entrapped 5-fluorouracil and showed lower particle sizes when compared to all the other methods. RTCA showed sustained cell death in real time.

Spectroscopic evidence of the radioresistance of Chroococcidiopsis biosignatures: A combined Raman, FT-IR and THz-TDs spectroscopy study

In the last decades, Mars has been widely studied with on-site missions and observations, showing a planet that could have hosted life in the past. For this reason, the recent and future space missions on the red planet will search for traces of past and, possibly, present life. As a basis for these missions, Space Agencies, such as the European Space Agency, have conducted many experiments on living organisms, studying their behavior in extraterrestrial conditions, learning to recognize their biosignatures with techniques remotely controllable such as Raman spectroscopy. Among these organisms, the radioresistant cyanobacterium Chroococcidiopsis was irradiated during the STARLIFE campaign with strong radiative insults. In this article we have investigated this cyanobacterium using Raman spectroscopy and extended the characterization of its biosignatures and its response to the radiative stress to the mid- Infrared and Terahertz spectral region using the Fourier Transform InfraRed (FT-IR) and Terahertz Time Domain spectroscopy (THz- TDs), which demonstrates the compatibility and suitability of these techniques for future space missions.

Synthesis of Al and In dual-doped CuO nanostructures via SILAR method: Structural, optical and electrical properties

In this article, we investigated the doping characteristics of Al-doped CuO (ACO), and Al/In co-doped CuO (AICO) thin films, which were synthesized on glass substrates, via the solution-based successive ionic layer adsorption and reaction (SILAR) technique. The surface morphological, chemical composition, structural, optical, and electrical properties of the nanocrystalline films were characterized by Field Emission Scanning Electron Microscopy (FE-SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier-transform Infrared Spectroscopy (FTIR), Ultraviolet–visible (UV–vis.) spectrophotometry, and Transmission Line Method (TLM), respectively. Surface morphology studies exhibited that a decrease in the films' thickness caused an increment in the optical transmittance. XRD patterns displayed that the obtained samples were polycrystalline and crystallized in a bare CuO monoclinic structure. FTIR studies of the CuO samples displayed that Al and In co-doping influenced the forms and the violence of the absorption bands. The optical bandgap energy of bare CuO was determined to increase from 1.45 to 1.78 eV as a result of the co-doping. The substitution of In displayed in the irregularity of the morphology, owing to its wide ionic radius, which caused an increase in band gap energy and a decrease in resistance. The co-doping of Al and In is hence anticipated to ensure an extensive range of physical and optical properties of nanostructured metal oxide samples for a variety of technological applications.

An investigation on demineralization induced modifications in the macromolecular structure and its influence on the thermal behavior of coking and non-coking coal

Eight coking and non-coking coals have been studied by Wide Angle X-ray Scattering (WAXS), Fourier Transform Infrared Spectroscopy (FTIR), and TG/DTG (Thermogravimetry/Derivative Thermogravimetry) – DSC (Differential Scanning Calorimeter). The FTIR study shows that the demineralization treatment significantly influences –OH, aliphatic (–CH3, –CH2), aromatic (C=O), and aromatic nucleus (C=C) functional groups of the raw coals. The structural parameters like interlayer spacing (d002), crystallite size (Lc), lateral size (La), aromaticity (fa)XRD, and rank (I26/I20) are determined from WAXS. The WAXS results of demineralized coal show that d002 (range 3.75–3.51 Å) decreases, but (fa)XRD (range 0.69–0.88) increases with the increase of elemental carbon percentage (Cdaf) and rank of coals. The combustion and kinetic parameters of these coals have been evaluated by TG/DTG – DSC analysis. The ignition temperature (Ti), DTG Tpeak, DSC Tpeak, and burnout temperature (Tb) vary in the range of 338–410 °C, 475–551 °C, 490–555 °C, and 579–641 °C, respectively for demineralized coals however variations of these parameters for raw coals are 345–361 °C, 462–621 °C, 467–631 °C, and 560–675 °C, respectively. The TG/DTG – DSC and FTIR results show that demineralization influences the thermal behaviors and functional groups vis-à-vis structural moieties of coals.

Multivariate Data Analysis and Central Composite Design-Oriented Optimization of Solid Carriers for Formulation of Curcumin-Loaded Solid SNEDDS: Dissolution and Bioavailability Assessment.

The study was initiated with two major purposes: investigating the role of isomalt (GIQ9) as a pharmaceutical carrier for solid self-nanoemulsifying drug delivery systems (S-SNEDDSs) and improving the oral bioavailability of lipophilic curcumin (CUN). GIQ9 has never been explored for solidification of liquid lipid-based nanoparticles such as a liquid isotropic mixture of a SNEDDS containing oil, surfactant and co-surfactant. The suitability of GIQ9 as a carrier was assessed by calculating the loading factor, flow and micromeritic properties. The S-SNEDDSs were prepared by surface adsorption technique. The formulation variables were optimized using central composite design (CCD). The optimized S-SNEDDS was evaluated for differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), microscopy, dissolution and pharmacokinetic studies. The S-SNEDDS showed a particle size, zeta potential and PDI of 97 nm, -26.8 mV and 0.354, respectively. The results of DSC, XRD, FTIR and microscopic studies revealed that the isotropic mixture was adsorbed onto the solid carrier. The L-SNEDDS and S-SNEDDS showed no significant difference in drug release, indicating no change upon solidification. The optimized S-SNEDDS showed 5.1-fold and 61.7-fold enhancement in dissolution rate and oral bioavailability as compared to the naïve curcumin. The overall outcomes of the study indicated the suitability of GIQ9 as a solid carrier for SNEDDSs.

The Conformation and Thermal Characteristic Of Different Species Of Bamboo Cellulose

Bamboo is a fast-growing biomaterial indigenous to Asia and Oceania that is also a high-yielding renewable resource. Bamboo, which has mechanical properties similar to wood, may be treated with currently available methods. The purpose of this study was to determine the characteristics chemical and thermal characteristic of three bamboo species of Schizostachyum brachycladum, Bambusa vulgaris, and Bambusa oldhamii. Bamboo cellulose was extracted chemically via dewaxing, delignification, and mercerization. The bamboo cellulose species employed were S. brachycladum, B. vulgaris, and B. oldhamii. The bamboo celluloses were characterised using Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). FT-IR and TGA studies confirmed the chemical treatment’s removal of hemicellulose and lignin. The FT-IR measurement demonstrated an increase in the peak intensity at 1020 cm-1, which corresponds to the vibration of the C-O-C pyranose ring, showing that the yield of isolated cellulose increased following chemical treatment. In a TGA test, bamboo celluloses were found to be thermally stable.

Synchrotron FTIR investigations of kerogen from Proterozoic organic-walled eukaryotic microfossils.

Fourier transform infrared spectroscopy (FTIR) provides a rapid non-destructive molecular characterization of organic and inorganic material in geological samples. Combination of qualitative and semi-quantitative approaches are routinely used in FTIR study of kerogen and coals. A diversity of descriptors provides straightforward tools to characterize kerogen type, composition and structure. However, only a few of these descriptors are applied in the chemical investigation of Precambrian organic-walled microfossils. Synchrotron radiation-based Fourier transform infrared microspectroscopy (SR-FTIR) permits high spatial resolution investigations of organic matter in a large range of applications in biology, geochemistry and cosmochemistry, but remains rarely applied in Precambrian microfossils studies. Here we show that SR-FTIR spectroscopy combined with an integrative approach of kerogen description is particularly relevant for the study of minute organic-walled microfossils of unknown biological origin. The analyses of five morphospecies from three different Proterozoic formations in northwestern Canada highlight kerogen signatures rich in aromatic, aliphatic and oxygenated moieties. This is evidenced by the combined use of spectrum qualitative descriptions (band assignments and positions) and the calculations of semi-quantitative parameters using intensities and integrated areas of absorption bands (CH2/CH3, R3/2, Al/CC, CO/CC, A factor, C factor). Altogether, this study demonstrates the interest of an integrative approach when investigating the chemistry of organic-walled microfossils with FTIR spectroscopy.

Preparation of polyvinyl chloride (PVC) membrane blended with acrylamide grafted bentonite for oily water treatment

The current work aims to advance the hydrophilicity, morphology, and antifouling characteristics of polyvinyl chloride (PVC) membranes for oily wastewater separation by incorporating modified bentonite. The surface of bentonite nanoparticles is altered by adopting the “grafting from” method using the surface-initiated atom transfer radical polymerization (SI-ATRP) approach. The PVC-based membrane is first prepared by blending acrylamide grafted bentonite (AAm-g-bentonite). AAm is grafted on bentonite in the presence of 2,2′-Bipyridyl and copper (I) bromide as a catalyst. The modified bentonite nanoparticles are studied using multiple techniques, such as fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), sedimentation tests, field emission scanning electron microscope (FE-SEM), etc. Flat-sheet PVC-based membrane is prepared by blending AAm-g-bentonite using the nonsolvent induced phase separation (NIPS) technique. Different methods, including FE-SEM, FTIR, sedimentation test, contact angle, porosity, antifouling property, and filtration studies of pure and oily water, are used to characterize and determine the performance of mixed-matrix membranes. Membrane performance is improved in the presence of modified bentonite (i.e., AAm-g-bentonite), with the best result achieved at PVC/AAm-g-ben-8 (i.e., 8 wt % of AAm-g-bentonite). Enhanced pure water flux (293.14 Lm−2h−1), permeate flux (123.96 Lm−2h−1), and oil rejection >93.2% are obtained by the reduced contact angle (49.1°) and improved porosity (71.22%).

Fabrication, In Vitro, and In Vivo Assessment of Eucalyptol-Loaded Nanoemulgel as a Novel Paradigm for Wound Healing.

Wounds are the most common causes of mortality all over the world. Topical drug delivery systems are more efficient in treating wounds as compared to oral delivery systems because they bypass the disadvantages of the oral route. The aim of the present study was to formulate and evaluate in vitro in vivo nanoemulgels loaded with eucalyptol for wound healing. Nanoemulsions were prepared using the solvent emulsification diffusion method by mixing an aqueous phase and an oil phase, and a nanoemulgel was then fabricated by mixing nanoemulsions with a gelling agent (Carbopol 940) in a 1:1 ratio. The nanoemulgels were evaluated regarding stability, homogeneity, pH, viscosity, Fourier-transform infrared spectroscopy (FTIR), droplet size, zeta potential, polydispersity index (PDI), spreadability, drug content, in vitro drug release, and in vivo study. The optimized formulation, F5, exhibited pH values between 5 and 6, with no significant variations at different temperatures, and acceptable homogeneity and spreadability. F5 had a droplet size of 139 ± 5.8 nm, with a low polydispersity index. FTIR studies showed the compatibility of the drug with the excipients. The drug content of F5 was 94.81%. The percentage of wound contraction of the experimental, standard, and control groups were 100% ± 0.015, 98.170% ± 0.749, and 70.846% ± 0.830, respectively. Statistically, the experimental group showed a significant difference (p < 0.03) from the other two groups. The results suggest that the formulated optimized dosage showed optimum stability, and it can be considered an effective wound healing alternative.

Vanadium sulfide decorated graphitic carbon nitride nanocomposite for the enhanced photocatalytic activity towards organic pollutants

A simple, efficient and fast two-step hydrothermal approach was used to synthesize novel dandelion like vanadium sulfide (VS4) decorated graphitic carbon nitride (GCN) nanocomposite photocatalyst. Numerous characterization techniques like X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy were used to investigate the physicochemical aspects such as crystallinity, morphology, optical properties and functional groups of the prepared pure GCN, pure VS4 and VS4/GCN nanocomposite. From the XRD analysis, the formation of VS4/GCN nanocomposite was confirmed with monoclinic structure. The optical characteristics were revealed by UV–vis Spectroscopy and bandgap energy values for pure GCN, pure VS4 and VS4/GCN nanocomposite were found to be 2.74 eV, 1.63 eV and 2.21 eV respectively. FTIR studies confirmed the functionalities in the nanocomposite formation. The dandelion like surface morphology of the prepared VS4 were confirmed by FE-SEM. Photocatalytic degradation process was carried out for the removal of organic dyes (Rhodamine B, methylene blue) from factitious wastewater under visible light irradiation. From the obtained results, a possible mechanism for the improvement of photocatalytic performance was discussed.

Photocatalytic efficiency of sol–gel synthesized Mn‐doped TiO2 nanoparticles for degradation of brilliant green dye and mixture of dyes

AbstractThe Mn‐doped TiO2 nanoparticle photocatalysts have been prepared by a simple sol–gel method. 1, 3, and 5 mol% Mn‐doped TiO2 nanoparticles have been prepared by using a stoichiometric amount of manganese acetate and titanium isopropoxide as precursors of Mn and Ti respectively. The physico‐chemical characterization of the prepared samples has been studied by x‐ray diffraction (XRD), Brunauer–Emmett–Teller surface area analysis, field emission scanning electron microscope, energy dispersive x‐ray analysis, high‐resolution transmission electron microscopy, x‐ray photoelectron spectroscopy, Ultraviolet–visible spectroscopy, photoluminescence spectroscopy, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). XRD study reveals the formation of pure anatase phase of TiO2 and decrease in crystalline size of TiO2 on increasing the Mn doping content. TGA reveals minimum weight loss in the high‐temperature region of 500–1,000°C, showing the thermal stability of the catalyst. FTIR study shows highly bonding in metal atoms. These samples have been tested for photocatalytic degradation of brilliant green dye. 5 mol% Mn‐doped TiO2 is having nearly four times more photocatalytic activity than pure TiO2. In addition, Mn‐doped TiO2 has shown excellent photodegradation of a mixture of three dyes namely, rhodamine B, brilliant green, and methylene blue.

Optimization of the synthesis of silver nanoparticles using the leaf extract of Ocimum sanctum and evaluation of their antioxidant potential

This work investigates the green synthesis of silver nanoparticles (AgNPs) utilizing the aqueous leaf extract of Ocimum sanctum L. A change in colour to dark brown from yellow and an absorption maximum at 460 nm provided evidence for the synthesis of AgNPs. Several reaction conditions namely leaf extract volume, AgNO3 concentration and duration of incubation were optimized. Maximum synthesis of AgNPs could be achieved with 1 ml of 5% aqueous leaf extract, 1 mM AgNO3 and 2.5 h incubation period. DPPH (2, 2—diphenyl − 1 - picrylhydrazyl) assay revealed that AgNPs are better than the leaf extract in terms of antioxidant potential. These results strongly recommend the application of green-synthesized AgNPs as effective antioxidants against oxidative stresses associated with degenerative diseases. Characterization of AgNPs were then carried out using certain methods namely as x-ray diffraction (XRD) measurement, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). XRD study confirmed the synthesis of face-centered cubic-shaped AgNPs that are of crystalline nature. The mean particle size of the synthesized AgNPs computed employing the Debye–Scherrer formula, was 22 nm. FTIR study demonstrated that the AgNPs consisted of certain functional groups of O. sanctum which might have helped in reducing AgNO3 and capping AgNPs. SEM images showed the synthesis of AgNPs of various shapes viz. globular, cubical and flaky. The scattered AgNPs were found to have a size close to 20 nm, which roughly matches with the XRD analysis of the current study.

Characterization, Antiplasmodial and Cytotoxic Activities of Green Synthesized Iron Oxide Nanoparticles Using Nephrolepis exaltata Aqueous Extract.

The use of non-toxic synthesis of iron oxide nanoparticles (FeO NPs) by an aqueous plant extract has proven to be a viable and environmentally friendly method. Therefore, the present investigation is based on the FeO NPs synthesis by means of FeCl3·6H2O as a precursor, and the plant extract of Nephrolepis exaltata (N. exaltata) serves as a capping and reducing agent. Various techniques were used to examine the synthesized FeO NPs, such as UV-Visible Spectroscopy (UV-Vis), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray (EDX). The FT-IR studies were used to identify different photoactive biomolecules at 3285, 2928, 1415, 1170, and 600 cm−1 in the wavenumber range from 4000 to 400 cm−1, indicating the -OH, C-H, C-O, C-C, and M-O groups, respectively. The XRD examination exhibited crystallinity, and the average diameter of the particle was 16 nm. The spherical nature of synthesized FeO NPs was recognized by SEM images, while the elemental composition of nanoparticles was identified by an EDX spectrophotometer. The antiplasmodial activity of synthesized FeO NPs was investigated against Plasmodium parasites. The antiplasmodial property of FeO NPs was evaluated by means of parasite inhibitory concentration, which showed higher efficiency (62 ± 1.3 at 25 μg/mL) against Plasmodium parasite if compared to plant extracts and precursor. The cytotoxicity of FeO NPs was also assessed in human peripheral blood mononuclear cells (PBMCs) under in vitro conditions. The lack of toxic effects through FeO NPs keeps them more effective for use in pharmaceutical and medical applications.

Selective photothermal CO2 reduction to CO, CH4, alkanes, alkenes over bimetallic alloy catalysts derived from layered double hydroxide nanosheets

Photothermal catalytic reduction of CO2 with H2 as the reducing agent holds great promise for the conversion of combustion-derived CO2 into hydrocarbon fuels and other valuable commodity chemicals. Whilst a number of promising photothermal catalysts have been developed for CO2 reduction, reaction mechanisms remain elusive, and the factors controlling product selectivity are unclear. In this work, three distinct transition metal alloy nanoparticle catalysts, each supported by amorphous alumina, were fabricated by hydrogen reduction of CoFeAl-layered double hydroxide (CoFeAl-LDH), NiFeAl-LDH and NiCoAl-LDH nanosheet precursors at 650 °C. By using the different alloy nanoparticles (CoFe, NiFe or NiCo) and tuning the reaction parameters including temperature and gas flow rate during photothermal CO2 reduction with H2, different product distributions (CH4, CO, light olefins, paraffins) were obtained, with the distribution depending strongly on the alloy catalyst composition. A reaction pathway for CO2 reduction consisting of multiple steps was discovered and confirmed by in-situ diffuse reflectance infrared Fourier transform spectroscopy studies and a series of control catalytic experiments. Findings provide valuable new insights about the reaction mechanism of photothermal catalytic CO2 reduction to hydrocarbon products over metal catalysts and the factors regulating product selectivity.

Processing and physico‐mechanical characterization of sponge iron slag filled ramie fiber reinforced epoxy‐based composites

AbstractThe present research focuses on developing a new class of hybrid composites with woven ramie fiber mats reinforced in epoxy resin filled with different proportions of sponge iron (SI) slag. These multi‐layered composites are fabricated using conventional hand layup method. The cured composite samples are subjected to various physical, mechanical and micro‐structural characterization tests. Properties such as composite density, void content, tensile strength, flexural strength, impact and inter‐laminar shear strength, micro‐hardness, and so forth, are evaluated under controlled laboratory conditions. The compositional/micro‐structural features are identified with the help of scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), stereo‐microscopy, X‐ray diffraction, and so forth. Scanning electron microscopy reveals the shape, size and distribution pattern of the filler particles in the composites. The FTIR study is done to identify the functional groups present in the filler, fiber and in the resulting composite to get an insight to the chemistry of composite formation. Similarly, X‐Ray diffraction curve reveals the presence of hard phases such as silica, magnesioferrite, graphite, hematite, and so forth. This work suggests that successful fabrication of natural fiber composites is possible with additional reinforcement of an industrial waste like sponge iron slag and that most of the mechanical properties improve with increase in the content of SI slag in the composite.

Characterization and Evaluation of Antimicrobial Potential of Trigonella incise (Linn) Mediated Biosynthesized Silver Nanoparticles.

The goal of the research was to explore a new green method used to synthesize silver nanoparticles (Ag NPs) from an aqueous extract of Trigonella incise, which serves as a reducing and stabilizing agent. The obtained results showed an 85% yield of nanoparticles by using 2:5 (v/v) of 5% plant extract with a 0.5 M solution of AgNO3. Different techniques were used to characterize the synthesized Ag NPs, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and UV–visible spectroscopy. The UV–visible spectra of green synthesized silver nanoparticles showed maximum absorption at a wavelength of 440 nm. The FT-IR studies revealed the stretching oscillation frequency of synthesized silver nanoparticles in the absorption band near 860 cm−1. Similarly, the bending and stretching oscillation frequencies of the NH function group were assigned to the band in the 3226 cm−1 and 1647 cm−1 regions. The bending vibration of C-O at 1159 cm−1 confirmed the carbonyl functional group that was also assigned to the small intensity band in the range of 2361 cm−1. The X-ray diffraction analysis of Ag NPs revealed four distinct diffraction peaks at 2θ of 38°, 45°, 65° and 78°, corresponds to (111), (200), (220) and (311) of the face-centered cubic shape. The round shape morphology of Ag NPs with a mean diameter in the range 20–80 nm was analyzed via SEM images. Furthermore, the nanoparticles showed more significant antimicrobial activity against Salmonella typhi (S. typhi) and Staphylococcus aureus (S. aureus) with an inhibition zone of 21.5 mm and 20.5 mm at 6 μg/mL concentrations, respectively, once compared to the standard reference. At concentrations of 2 µg/mL and 4 µg/mL, all of the bacterial strains showed moderate activity, with inhibition zones ranging from 11 mm to 18.5 mm. Even at high concentrations of AgNPs, S. typhi showed maximum resistance. The best antifungal activity was observed by synthesized Ag NPs against Candida albicans (C. albicans) with 21 mm zone of inhibition, as compared to a standard drug which gives 22 mm of inhibition. Therefore, we conclude that the antibacterial and antifungal activities showed satisfactory results from the synthesized Ag NPs.

Structural characteristics and opto-electrical properties of in-situ synthesized polyaniline films

In the present study, polyaniline (PAni) thin films have been deposited on glass substrates by in-situ chemical polymerization method using simple dip-coating technique and their opto-electrical properties have been studied. The structure of deposited films have been analysed with Fourier transform infrared (FTIR) and Raman spectroscopic techniques to investigate the effect of deposition times on the conjugation length, polaron/bipolaron concentrations and other molecular structure conformations. FTIR and Raman spectroscopy studies reveal increase in both the conjugation length and the polaron/bipolaron carrier concentration with increasing deposition time of the prepared PAni films. The optical properties and optical band-gap of the deposited films have been estimated through UV–visible spectroscopy. The optical band-gap of the deposited films has been found to decrease from 3.31 eV to 3.13 eV with increase in deposition time from 1.5 h to 2.5 h, and further it has been increased slightly to 3.19 eV for the PAni film deposited for 3 h. The electrical conductivity of the deposited films has been found to increase with decrease in optical band gap. The parameters estimated from FTIR, Raman, UV–visible spectroscopy and electrical measurements are in good agreement with each other. It has been observed that the optical and electrical properties of the deposited films depend on the conjugation length of PAni. The polymerization time of 2.5 h has been found to be optimum for obtaining PAni thin films with good electrical conductivity and low optical band gap.

Study on the interactions of two models of enzymes as eco-friendly depressants in flotation separation of apatite from hematite

Two models of hydrolytic enzymes, namely α-amylase and lipase, were investigated as eco-friendly depressants of hematite to separate apatite from hematite by reverse flotation, utilizing oleate as a collector. The effect of both enzymes on the flotation behaviors of apatite and hematite minerals was studied through a series of micro-flotation tests. The interactions between oleate and the enzymes with the surfaces of both minerals were studied through zeta potential, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analyses. Micro-flotation tests of single minerals revealed that the recovery of hematite decreased remarkably upon adding α-amylase or lipase, especially at alkaline pH (8.0–11.2), while that of apatite was not affected. For mixed minerals, selective flotation of apatite from hematite was successfully achieved, and α-amylase showed better selectivity than lipase. Zeta potential and FTIR studies revealed that oleate adsorbed more intensively onto apatite than hematite at pH 10.0, which might have influenced the subsequent adsorption of the enzymes and their depressing effect. XPS analyses further indicated that α-amylase could adsorb more strongly and selectively onto hematite than apatite by means of chemical interactions with the active Fe sites on the hematite surface, which depressed the flotation of hematite.