Fourier Transform Infrared Spectroscopy Spectra Research Articles

Optimisation of the extraction process of pectin polymer from red dragon skin (Hylocereus polyrhizus)

Background: The variation of pectin extracted from red dragon skin (Hylocereus polyrhizus) depends on the type of acid, temperature, and length of extraction time. Objective: This research was conducted to determine the characteristics of pectin produced from red dragon skin based on using citric, oxalic, and acetic acids at pH 4, extraction temperature of 60°C and 75°C, and duration of 120 minutes. Method: A total of six conditions for pectin extraction were performed and the obtained product was dried using the freeze-dryer. Furthermore, the optimisation included yield, moisture content (MC), equivalent weight (EW), methoxyl content (MeO), galacturonic acid content (GA), degree of esterification (DE), sugar and organic acid levels (SO), and Fourier Transform Infrared Spectroscopy (FT-IR) was performed. Result: The EW value of red dragon skin and commercial apple pectin were comparable but the MeO value was slightly different from those extracted with 75°C oxalic acid. Compared to commercial apple and orange skin, the GA value of red dragon pectin extracted with 75°C oxalic acid was not different. Conclusion: FT-IR spectra contained groups -OH, -CH, and C=O and were confirmed to have a GA structure. The best product was obtained by conducting extraction under the condition of 75°C for 120 minutes using oxalic acid.

An Eco-Friendly Synthesis Approach for Enhanced Photocatalytic and Antibacterial Properties of Copper Oxide Nanoparticles Using Coelastrella terrestris Algal Extract.

In the current scenario, the synthesis of nanoparticles (NPs) using environmentally benign methods has gained significant attention due to their facile processes, cost-effectiveness, and eco-friendly nature. In the present study, copper oxide nanoparticles (CuO NPs) were synthesized usingaqueous extract of Coelastrella terrestrisalgae as a reducing, stabilizing, and capping agent. The synthesized CuO NPs were characterized by X-ray diffraction (XRD), UV-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and field emission scanning electron microscopy (FE-SEM) coupled with energy-dispersive X-ray spectroscopy (EDS). XRD investigation revealed that the biosynthesized CuO NPs were nanocrystalline with high-phase purity and size in the range of 4.26 nm to 28.51 nm. FTIR spectra confirmed the existence of secondary metabolites on the surface of the synthesized CuO NPs, with characteristic Cu-O vibrations being identified around 600 cm-1, 496 cm-1, and 440 cm-1. The FE-SEM images predicted that the enhancement of the algal extract amount converted the flattened rice-like structures of CuO NPs into flower petal-like structures. Furthermore, the degradation ability of biosynthesized CuO NPs was investigated against Amido black 10B (AB10B) dye. The results displayed that the optimal degradation efficacy of AB10B dye was 94.19%, obtained at 6 pH, 50 ppm concentration of dye, and 0.05 g dosage of CuO NPs in 90 min with a pseudo-first-order rate constant of 0.0296 min-1. The CuO-1 NPs synthesized through algae exhibited notable antibacterial efficacy against S. aureus with a zone of inhibition (ZOI) of 22 mm and against P. aeruginosa with a ZOI of 17 mm. Based on the findings of this study, it can be concluded that utilizing Coelastrella terrestris algae for the synthesis of CuO NPs presents a promising solution for addressing environmental contamination.

Incidence of microplastics in Indian anchovy Stolephorus indicus from Tuticorin, Southeast coast of India

In the present study, the occurrence of microplastics (MPs) in the gut, gill, and muscle of edible fish Stolephorus indicus sampled from Tuticorin coastal regions of Tamilnadu, India was investigated. We recorded a total of 689 MPs which includes 510 and 179 MPs from males and females respectively. The total abundance of MPs was significantly (P < 0.05) higher in the gut followed by gills and muscle. The sex-wise distribution of average MPs showed high in the females' gut and compared to that in males. Further, the length wise distribution of MPs was higher in the muscle in both male and female fish, followed by other organs. The predominance of MPs in tissues were transparent and blue colour with fibers and fragments in both males and females. Besides, polyethylene terephthalate and nylon were evidenced by the Fourier-transform infrared spectroscopy spectrum in all organs of fishes.

Structural, morphological, and EMI shielding evaluations of Sm-Mn co-doped Sr-based M-type hexaferrite for Ku band applications

High-performance, thin, and lightweight EMI (Electromagnetic interference) materials with outstanding shielding effectiveness were explored over the last years to solve the problems in electronic devices. Magnetic absorbing materials have extensive bandwidth, good impedance matching, and excellent absorption features. In the present study, Sm-Mn Sr-doped M hexaferrites with Sr1-xSmxFe12-yMnyO19 whereas (x= 0.00, 0.025, 0.05, 0.075, y = 0.00, 0.25, 0.5, 0.75) were prepared by the chemical route. XRD, FESEM, HRTEM, FTIR, VSM, and VNA are used to evaluate the properties of the Sm-Mn doped Sr-based M-type hexagonal ferrite. The XRD (X-ray diffraction) results revealed the presence of a hexagonal phase in the prepared samples. Rietveld refinement also confirmed the phase purity for the Sm-Mn doped Sr-based M-type hexagonal ferrites. The FESEM (Field emission scanning electron microscopy) and HRTEM (High-resolution transmission electron microscopy) images revealed the hexagon-type shapes of the particles in the Sm-Mn doped Sr-based M-type hexagonal ferrites. The FTIR (Fourier transform infrared spectroscopy) spectra showed the 446–620 cm-1 lines, confirming the presence of the tetrahedral and octahedral phases of hexagonal ferrites. Dielectric and electromagnetic shielding effectiveness (SE) parameters are evaluated for Sm-Mn doped Sr-based M-type hexagonal ferrite. The electromagnetic parameters, such as complex refractive index, absorption and impedance, are also investigated for the Sm-Mn doped Sr-based hexagonal ferrite powder with x=0.075, y=0.75 having epoxy resin with 20 wt%, 30 wt% and 50 wt% samples, respectively. SE parameters are higher at more extensive filler loading. The green shielding index was found higher for Sm-Mn doped Sr-based hexagonal ferrite powder with x=0.075, y=0.75 having 20 wt% epoxy resin and decreased with filler loading. It is found the epoxy/Sm-Mn doped Sr-based M-type hexagonal ferrites-based composites are excellent absorbers in the Ku band. The investigated absorbers could be the best candidates for next-generation EMI green shielding absorbing devices and applications.

The renoprotective activity of amikacin–gamma-amino butyric acid–chitosan nanoparticles: a comparative study

The development of nanoparticles (NPs) with active components with upgraded stability, and prolonged release helps in enhanced tissue regeneration. In addition, NPs are feasible strategy to boost antibiotic effectiveness and reduce drug side effects. Our study focuses on the use of amikacin (AMK) and gamma amino butyric acid (GABA) unloaded combinations or loaded on chitosan nanoparticles (CSNPs) for kidney protection. The AMK–GABA–CSNPs were prepared with the ionic gelation method, the morphology was studied using transmission electron microscopy (TEM), zetasizer and the Fourier transform-infrared spectroscopy (FT-IR) spectrum of the synthesized NPs was observed. The average size of AMK–GABA–CSNPs was 77.5 ± 16.5 nm. Zeta potential was + 38.94 ± 2.65 mV. AMK–GABA–CSNPs revealed significant in vitro antioxidant, anti-coagulation, non-hemolytic properties and good cell compatibility. To compare the effects of the unloaded AMK–GABA combination and AMK–GABA–CSNPs on the renal tissue, 42 healthy Sprague–Dawley rats were divided into seven groups. G1: normal control (NC), normal saline; G2: low-dose nephrotoxic group (LDN), AMK (20 mg/kg/day; i.p.); G3: unloaded AMK (20 mg/kg/day; i.p.) and GABA (50 mg/kg/day; i.p.); G4: AMK–GABA–CSNPs (20 mg/kg/day; i.p.); G5: high-dose nephrotoxic group (HDN), AMK (30 mg/kg/day; i.p.); G6: unloaded AMK (30 mg/kg/day; i.p.) and GABA (50 mg/kg/day; i.p.) and G7: AMK–GABA–CSNPs (30 mg/kg/day; i.p.). The results showed that AMK–GABA–CSNPs formulation is superior to unloaded AMK–GABA combination as it ameliorated kidney functions, oxidative stress and displayed a significant homeostatic role via suppression of inflammatory cytokines of Th1, Th2 and Th17 types. Hence, AMK–GABA–CSNPs could afford a potential nano-based therapeutic formula for the management of AMK-nephrotoxicity.

Preparation and Characterization of Scolecite/ZnO Nanocomposite by a Novel Chemical Route

This research work has proposed preparation of Scolecite/ZnO nanocomposites (NCs) by a novel aqueous route using Zinc Nitrate Hexahydrate (Zn (NO3)2.6H2O) as a precursor and distilled water were used as solvent without any requirement of calcinations step at high temperature. The comprehensive structural studies carried out using Powder X-Ray diffraction (PXRD) and Fourier Transform Infrared Spectroscopy (FT-IR) PXRD spectrum showed that the ZnO Nanoparticles exhibited crystalline structure. The average crystallite sizes of the prepared NCs calculated by using Debye-Scherrer equation. The sharp peak in the FT-IR spectrum determined the purity of ZnO Nanoparticles

Evaluation of oxidation stability for palm biodiesel with additives using Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry and high-performance liquid chromatography

This paper discusses the potential of tert-butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA) and alpha-tocopherol (α-T) in preventing palm biodiesel oxidation over an extended storage period of twelve weeks. A combination of Fourier transform infrared spectroscopy (FTIR), gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) analyses were carried out. The FTIR spectra showed no significant changes to the carbonyl band at 1740 cm−1 across the storage period for fuels with additives, but the control had increased band intensity, which implied that additives prevented the formation of byproducts which have carbonyl groups or cyclic ether rings. From GC-MS analyses, lower transmittance at C18 methyl esters region was evident of methyl oleate, methyl linoleate and methyl linolenate being consumed to the point where their concentrations dropped below those of methyl palmitate in the sample without additives. Furthermore, the analyses indicated that 3-octyl-oxiraneoctanoic acid ME, E−10,13,13-trimethyl-11-tetradecen-1-ol acetate and 17-octadecynoic acid ME were the major oxidation byproducts. Traces of acetal, carboxylic acid, oxirane and alkylnoic acid were also detected. It was shown through HPLC analyses that TBHQ, BHA and α-T were consumed with α-T samples having the highest consumption compared to TBHQ and BHA. Overall, the findings supported the important role of additives in stabilizing the fuel and preventing oxidation during extended storage.

SYNTHESIS AND CHARACTERIZATION OF CHITOSAN FROM WASTE SHELLS OF Tagelus Plebeiu OBTAINED FROM OYOROKOTOR, RIVERS STATE, NIGERIA

The investigation was carried out to synthesize chitosan using waste shell of Tagelus plebeiu collected from Oyorokotor as an alternative to other kinds of shells. Standard procedures such as demineralization, deproteinization and deacetylation were used. Methods such as fourier transformed infrared spectroscopy (FTIR), X-Ray diffraction (XRD) and scanning electron microscope (SEM) were used for characterization to obtain results. Results reveals FTIR spectra bands at 3637.9 cm-1 for hydroxyl and 3384.4 cm-1 for amino functional group as well as 18.20 at 2 titha from XRD pattern. The degree of deacetylation was recorded as 80.48 %, moisture content as 0.101 %, yield was 53.24 % and ash content was recorded as 25 %. It is therefore concluded that the waste shell of Tagelus plebeiu can be used in producing quality chitosan as an alternative to other kinds of shells.

Steam Explosion-Assisted Extraction of Polysaccharides from Pleurotus eryngii and Its Influence on Structural Characteristics and Antioxidant Activity.

Pleurotus eryngii (PE) has been sought after for its various health benefits and high content of phenolic compounds. This study explored the feasibility of steam explosion (SE)-assisted extraction of polysaccharides with high antioxidant capacities from PE. An orthogonal experimental design (OED) was used to optimize the SE-assisted extraction of PE. The influence of the optimized SE-assisted extraction on the physicochemical properties of PE polysaccharides was determined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), monosaccharide compositional analysis and antioxidant capacity assays. Under optimal SE conditions, SE-assisted extraction increased the polysaccharide yield by 138% compared to extraction without SE-assistance. In addition, SEM demonstrated that SE-assisted extraction markedly altered the spatial structure of Pleurotus eryngii polysaccharides (PEP), and monosaccharide compositional analysis revealed that this pretreatment significantly increased the proportions of some monosaccharides, such as glucose, rhamnose and arabinose, in the isolated PEP. FTIR spectra indicated no change in the major chemical functional groups of PEP. PEP extracted by SE-assisted extraction had significantly increased free radical scavenging and antioxidant capacities. In conclusion, SE-assisted extraction appears to be a novel polysaccharide extraction technology, which markedly increases extraction yields and efficiency and can increase the biological activity of polysaccharide extracts.

The pivotal role of the polyethylene glycol amount as compatibilizing on the morphological features of silica-based blends

Silica-based hybrid blends at different molecular or nanometer scale have gained a lot of interests from the technological point of view. In particular, several inorganic-organic hybrids find application in the biomedical field. In this context, inorganic SiO2 and hybrids made up of SiO2 and polyethylene glycol (PEG) have been synthesised via the sol-gel route and characterised from the morphological (throught the Atomic Force Microscopy - AFM) and spectroscopic point of view to shed light on their features as possible hybrid biomaterials. AFM investigation allowed for an effective quantitative evaluation of surface roughness of bioactive sol-gel-based materials. The results revealed an increase in material porosity as a function of the PEG amount in the systems, thus highlighting the pivotal role of the PEG amount as compatibilizing on the morphological features of silica-based blends. The co-presence of both the inorganic and organic phases was confirmed by the Fourier-transform infrared spectroscopy (FT-IR). Moreover, the influence of PEG was also investigated by analysing the deconvoluted FT-IR spectra in the range of 1600-750 cm−1.

Rapidly identification of ginseng from different origins using three-step infrared macro-fingerprinting technique

Ginseng is widely used all over the world for its unique properties. To evaluate ginseng quality, identifying differences from its origin is necessary. In this experiment, Fourier-transform infrared spectroscopy (FTIR), second-order derivative spectroscopy (SD-IR) with dual-index sequence analysis (DISA) and two-dimensional infrared correlation spectroscopy (2D-IR-COS) were used to investigate the differences in ginseng from 10 origins. In the FTIR spectra, the absorption peaks of these 10 samples showed a certain amount of similarity. S3, S6, and S7 could be successfully distinguished from the other seven samples. In the SD-IR spectra, S3 and S6 had the highest proportion of common peaks at 86.7 %, showing that their compositions and contents were more similar; in contrast, the proportion of variant peaks of the S1 and S8 was 90.9 %, suggesting that they were more distantly related. Using auto peaks combined with Pearson correlation coefficient, the band 1800∼900 cm−1 with large differences among the 10 samples was selected for analysis. This study successfully identified ginseng of 10 samples using SD-IR spectra and 2D-IR-COS. These results are important references to the quality control and traceability of ginseng. They are also useful for the analysis of other herbs and natural products.

Mineralogy and a New Fertility Index of Alunite in the Fanshan Lithocap, Luzong Basin, Anhui Province, China

Alunite is used as a representative mineral for indicating deposits in lithocaps, and lithocaps are generally related to the porphyry–(high-sulfidation) epithermal mineralization system. The study of alunite is of theoretical and exploration significance for prospecting potential underlying porphyry and epithermal deposits. Studies on alunite geochemistry have made breakthroughs, but there is little research on alunite mineralogy, for example, using scanning electron microscopy (SEM) images, differential thermal analysis (DTA), and Fourier-transform infrared spectroscopy (FT-IR). This study mainly focuses on alunite micromorphological characteristics, weight loss changes with temperature, and ionic group structure, aiming to identify the relationship between these features and indications for prospecting. The Fanshan lithocap is located in the northwest part of the Luzong basin, Anhui province of China, and it can potentially be used for exploring porphyry and epithermal deposits. Fanshan alunite is formed in two stages with three types of alunite. IA alunite is formed in the early hydrothermal stage and replaces felsic minerals in the Zhuanqiao Formation, IB alunite is formed in the later hydrothermal stage and fills in open spaces with bladed particles, and II alunite is the product of pyrite oxidation and reaction with other minerals in the supergene stage. Alunite electron microprobe data and energy-dispersive spectroscopy data further confirm temperature decreases with hydrothermal evolution, and the presence of a high-sulfidation epithermal system in the Luzong basin. Aside from the forming environment, SWIR, and geochemistry of alunite, there are other indication indexes; for example, the larger peak values at 3480 cm−1 and smaller peak values at 1080 cm−1 in FT-IR spectra and the deeper exothermic valleys at 750 °C and steeper weight loss slopes in the DTA curve suggest a favorable formation environment for alunite and provide valuable indications for deposit exploration and assessments of mineralization potential.

Structural investigation of solid biopolymer electrolytes: 2-hydroxyethyl cellulose doped ammonium formate as a promising proton conductor

Fabrication of solid biopolymer electrolytes (SBEs) was mainly to cater the drawbacks of lithium-ion electrolytes in terms of leakage, high cost, and toxic material. In this present work, solid biopolymer electrolytes system comprises of 2-Hydroxyethyl Cellulose (2-HEC) as polymer host, and various weight percentage (wt.%) of Ammonium Formate (AF) as ionic doping salt are produced by using solution casting technique. The relation between structural and ionic conductivity of 2-HEC/AF was analyzed and investigated by using X-Ray Diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), and Electrical Impedance Spectroscopy (EIS). Through the analysis of XRD, it can be observed that the amorphous region of SBEs increases as the concentration of AF salt increases. The amorphous region of SBEs can be confirmed due to the interaction of salt concentration and polymer. However, in this present work, the broadest peak in XRD of the sample does not necessarily correlate with the highest conductivity among the samples. The interaction between polymer-salt complexes is proved through FTIR spectrum at the range of 700 cm−1 to 1300 cm−1. The highest ionic conductivity of 2-HEC/AF achieved is 2.40 × 10−3 S/cm at room temperature for SBEs containing 40 wt.% of AF. The findings from this study made it clear that the concentration of Ammonium Formate salt affects the increase in ionic conductivity.

Iron oxide nanoparticles synthesized using Mentha spicata extract and evaluation of its antibacterial, cytotoxicity and antimigratory potential on highly metastatic human breast cells

Iron oxide nanoparticles (Fe2O3 NPs) were synthesized utilizing Mentha spicata sourced from Cyprus as a stabilizing agent. The study delved into assessing the antimicrobial, cytotoxic, anti-proliferative, and anti-migratory potential of Fe2O3 NPs through disc diffusion, trypan blue, and 3-[4, 5-dimethylthiazol-2-yl]−2, 5-diphenyltetrazolium bromide (MTT) assay, respectively. Characterization of the synthesized Fe2O3 NPs was conducted using Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), UV–vis spectroscopy (UV–vis), scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDX). The FTIR, XRD, and SEM-EDX spectra confirmed the successful formation of Fe2O3 NPs. The analysis of UV–vis spectra indicates an absorption peak at 302 nm, thereby confirming both the successful synthesis and remarkable stability of the nanoparticles. The nanoparticles exhibited uniform spherical morphology and contained Fe, O, and N, indicating the synthesis of Fe2O3 NPs. Additionally, the Fe2O3 NPs formed through biosynthesis demonstrated antimicrobial capabilities against Escherichia coli and Bacillus cereus. The significant anti-migratory potential on MDA-MB 231 human breast cancer cells was observed with lower concentrations of the biosynthesized Fe2O3 NPs, and higher concentrations revealed cytotoxic effects on the cells with an IC50 of 95.7 μg/ml. Stable Fe2O3 NPs were synthesized using Mentha spicata aqueous extract, and it revealed antimicrobial activity on E. coli and B. cereus, cytotoxic, anti-proliferative and anti-migratory effect on highly metastatic human breast cancer cell lines.

Evaluation of disparate multiplicities of copper oxide nanoparticles integrated feed on the growth and hematology of koi carp

The aim of the present study was to assess the effects of different multiplicities of integrated feed containing copper oxide nanoparticles (CuO NPs) on the morphology and growth of Koi carp. UV-visible spectroscopy (UV-Vis), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDAX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) were used to produced and characterize the CuO nanoparticles. Different copper oxide nanoparticle multiplicities, including 25, 50, 100, 150, and 200 mg, were added to the 100 g feed. After 21 days, the Koi carp’s feed consumption and hematological parameters were assessed. CuO NPs were examined at 200–300 nm wavelengths, according to the UV–visible absorption spectra. At wavelengths ranging from 9.18 mm (scale bar 10 µm) to 9.18 mm (scale bar 2 µm), SEM pictures were observed. Two peaks in the spectrum at 0.9 KeV and 8 KeV were detected by the EDAX spectrum. The wavelength range for the XRD picture observation was 75 nm. The 400 to 4000 cm–1 wavelength range was used to observe the FT-IR spectra. The Koi carp’s condition factor and feed utilization metrics were greater in feed VI. From feed I to feed VI, all other parameters are gradually reduced while the WBC count is steadily increased. The study came to the conclusion that Koi carp might grow well with 200 mg of copper oxide nanoparticles mixed with diet.

Antifungal efficacy of chitosan extracted from shrimp shell on strawberry (Fragaria × ananassa) postharvest spoilage fungi

The strong demand for biological materials in the food industry places chitosan at the forefront of other biopolymers. The present study aims to evaluate the antifungal properties of chitosan extracted from shrimp shell waste (Parapenaeus longirostris) against post-harvest strawberry (Fragaria × ananassa) spoilage fungi. The physicochemical characteristics (DD, Mw, and solubility) of extracted chitosan were determined. In addition, functional characteristics were studied by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The antifungal effect of chitosan on mycelial growth and spore germination of Aspergillus niger, Botrytis cinerea, Fusarium oxysporum, and Rhizopus stolonifer was evaluated. Yield, degree of deacetylation, molecular weight, and solubility were 21.86%, 83.50%, 180 kDa, and 80.10%, respectively. A degree of deacetylation of 81.27% was calculated from the FTIR spectrum and a crystallinity index of 79.83% was determined from the X-ray diffraction pattern. SEM images of extracted chitosan showed a combination of fibrous and porous structure. At 3% chitosan, mycelial growth inhibition rates of A. niger, B. cinerea, F. oxysporum, and R. stolonifer ranged from 81.37% to 92.70%. At the same chitosan concentration, the percentages of spore germination inhibition of the isolated fungi ranged from 65.47% to 71.48%. The antifungal activity was highly dose-dependent. As a natural polymer, chitosan offers a convincing alternative to synthetic antimicrobials for the post-harvest preservation of strawberries. Its potential lies in its ability to inhibit the growth of spoilage fungi.

Synthesis and characterization of bi-functional Cu and Ni co-doped ZnO photocatalysts for organic pollutant degradation and antimicrobial activity

The study of visible light active photocatalysts for organic pollutants degradation and antimicrobial activity has gained significant attention in recent years. Herein, we report the synthesis of pure ZnO, Ni-doped ZnO (Ni-ZnO), Cu-doped ZnO (Cu-ZnO), and Cu and Ni co-doped ZnO (CuNi-ZnO) photocatalysts via a facile coprecipitation method. These photocatalyst materials were characterized using various analytical techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscope (HR-TEM), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV–Vis), photoluminescence (PL), and total organic carbon (TOC) analysis. XRD patterns confirm the presence of a mixed phase in the CuNi-ZnO sample. The presence of Cu, Ni, and Zn in CuNi-ZnO was verified through the XPS spectra. The nanoparticle-like morphology of the CuNi-ZnO photocatalyst was confirmed using HRTEM analysis. The FTIR spectra reveal the chemical bonds present in the materials. UV–visible spectroscopy was employed to determine the band gap of the materials, revealing a value of 3.10 eV for CuNi-ZnO. The mitigation in recombination of excited electrons (e−) and holes (h+) in CuNi-ZnO is validated through photoluminescence (PL) studies. The synthesized materials were used for the degradation of Indigo carmine (IC) dye and antimicrobial activity. The results showed that the optimized CuNi-ZnO sample displayed a better visible light photocatalytic performance (93.32 % IC dye degradation efficiency in 60 min) than the other samples. A notable degree of mineralization was observed with a reduction in total organic carbon (TOC) reaching 65.91 %. Additionally, the photocatalyst showed antimicrobial activity against both S. aureus and E. coli. Furthermore, a plausible visible light photocatalytic mechanism was proposed for the degradation of IC dye using the CuNi-ZnO photocatalyst.

Dielectric Analysis of Amine Modified Nano-graphite: Effects of Thickness, Temperature and Frequency

Amine modified nano-graphite (NH2-NG) has been produced from nanographite (NG) powder via liquor ammonia (NH3) aqueous solution by microwave, ultrasonic methods. The surface modified NG have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) techniques which clearly demonstrate that synthesis of NH2-NG was successful. The crystalline characteristics of amine modified nanographite powder have been studied through XRD technique. The morphology structure of synthesized surface modified nanoparticles has been determined by SEM analysis. FTIR spectra confirmed the existence of amine groups on the surface of produced nano-graphite powder. NH2-NG pellet was prepared to analyse its dielectric properties as a function of thickness (1, 2, 3, 5 and 7 mm), frequency (range 10−2-105 Hz) and temperature (25, 50, 75 and 100 °C). As a function of frequency, the dielectric loss tangent and permittivity each exhibit a distinct relaxation peak that grows up to a thickness of 5 mm then decreasing. Because nanoparticles are capacitive, the capacitance values of NG and NH2-NG increase with thicknesses up to 5 mm and drop with frequency. The drop in dielectric permittivity of NG and NH2-NG pellets after 5 mm may be caused by an increase in resistivity. Positive temperature coefficient (PTC) of increased conductance is confirmed by the continuous increase in electrical conductivity of NG and NH2-NG with temperature. The degree of temperature has a significant impact on the dielectric loss tangent, dielectric permittivity, and electrical conductivity of NG, and NH2-NG.

In‐situ Synthesis of Highly Potent Antibacterial Copper‐Based MOFs/Sodium Alginate Composite Beads

AbstractThe present study reports an environmentally friendly in‐situ synthesis of novel antibacterial copper‐based MOFs within the hydrogel network of sodium alginate. Two different copper‐based MOF/sodium alginate composite beads were prepared via the post‐treatment of copper‐ion‐crosslinked alginate hydrogels with two different ligand solutions, namely, tartaric acid and oxalic acid, at 100 °C for 24 h. The structural, thermal, and morphological properties of the prepared samples were investigated using Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM), and their antibacterial activities against gram‐positive (Staphylococcus aureus and Bacillus) and gram‐negative (Escherichia coli and Pseudomonas aeruginosa) strains were examined using the conventional disc diffusion method. The results demonstrated the success of the in‐situ synthesis of two distinct copper‐based MOFs with FTIR spectra, confirming the existence of characteristic bands of the ligands complexed to the sodium alginate matrix. Moreover, the XRD diffractograms revealed the formation of two distinct crystalline structures with well‐defined morphologies observed in the SEM images. In addition, thermal analysis showed that the prepared composite beads had enhanced thermal stability compared to the copper‐ion‐crosslinked alginate beads. Antibacterial testing revealed the strong capacity of the copper‐based MOFs/sodium alginate composite beads to deactivate the growth of all the bacterial strains used, with a minimum inhibition zone of 23 mm, which highlights the potential of the synthesized materials as highly potent antibacterial agents.

The Physicochemical Properties and Antioxidant Activities of the Hawthorn Pectin Extracted Using Ultra-High Pressure Assisted Acid Extraction (UPAAE).

This study aims to investigate the positive effects of ultra-high pressure assisted acid extraction (UPAAE) on both physicochemical properties and antioxidant activities of hawthorn pectin. The basic indicators, structure characterization, and antioxidant activities were measured, which could indicate the disadvantages and advantages among traditional water extraction (WE), acid extraction (AE), and UPAAE. The results show that the hawthorn pectin of UPAAE has a decrease in esterification degree, protein content, and total polyphenols, but has an increase in total galacturonic acid aldehyde compared to the hawthorn pectin of AE. In the Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM) analyses, the hawthorn of UPAAE has typical pectin absorption peaks in the FT-IR spectrum and a distinct layered structure in the SEM surface image. The ion chromatography profiles show that the molar ratio of galacturonic acid to arabinose in the hawthorn pectin of UPAAE increases and 5.50 μg/mg ribose appears compared to the pectin of AE and WE. The high performance gel permeation chromatography (HPGPC) profile indicates that the molecular weight distribution of hawthorn pectin of UPAAE is more concentrated and has the highest molecular weight compared to the pectin of the other two extraction methods. In the vitro antioxidant activity analysis, the pectin of UPAAE exhibits the highest scavenging rate against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals (93.70%), which is close to the scavenging rate of vitamin C (96.30%). These findings demonstrated that UPAAE is a more efficient and environmentally friendly method for pectin extraction from hawthorn. It is also an effective way to enhance its antioxidant activity, which has great application prospects in the food industries.