From Fourier Transform Infrared Spectroscopy Research Articles

Investigation on the thermochemical characteristics, kinetics and evolved gases for typical kitchen waste pyrolysis

Kitchen waste is a complex biomass waste, whose composition and properties vary with factors such as source, season and region. It is challenging to classify and characterize it. A thermogravimetric and kinetic study was performed to estimate pyrolysis characteristics and gas emissions of starch, peel, nut shell, and vegetables. Samples underwent pyrolysis in the Simultaneous Thermal Analysis from room temperature to 1200 K at different heating rates of 10, 20, 30 and 50 K/min. The starch had the narrowest pyrolysis temperature range, while nut shell exhibited the highest residual rate. The average activation energy for pyrolysis process calculated using Coats–Redfern method was in order of starch > vegetable ≈ nut shell > peel. The gaseous products and typical functional groups of the released volatiles were identified using specific information from Fourier Transform Infrared Spectroscopy (FTIR) and Mass Spectrometry (MS). These primarily included small inorganic molecules, aldehydes, aromatics, ethers, furans, ketones, organic acids, and phenols. Aliphatic hydrocarbons significantly contributed to the total gas yield and were the most abundant for all samples. The characteristic ion fragment with m/z = 60 was only observed in peel and nut shell, while m/z = 58 ion fragments were exclusive to starch and vegetables. The practical research can provide theoretical basis for the resource utilization and environmental management of kitchen waste.

Antibacterial and sunlight-driven photocatalytic activity of graphene oxide conjugated CeO2 nanoparticles

This work focuses on the structural, morphological, optical, photocatalytic, antibacterial properties of pure CeO2 nanoparticles (NPs) and graphene oxide (GO) based CeO2 nanocomposites (GO-1/CeO2, GO-5/CeO2, GO-10/CeO2, GO-15/CeO2), synthesized using the sol–gel auto-combustion and subsequent sonication method, respectively. The single-phase cubic structure of CeO2 NPs was confirmed by Rietveld refined XRD, HRTEM, FTIR and Raman spectroscopy. The average crystallite size was calculated using Debye Scherrer formula and found to increase from 20 to 25 nm for CeO2 to GO-15/CeO2 samples, respectively. The related functional groups were observed from Fourier transform infrared (FTIR) spectroscopy, consistent with the outcomes of Raman spectroscopy. The optical band gap of each sample was calculated by using a Tauc plot, which was observed to decrease from 2.8 to 1.68 eV. The valence state of Ce (Ce3+ and Ce4+) was verified using X-ray photoelectron spectroscopy (XPS) for CeO2 and GO-10/CeO2. The poisonous methylene blue (MB) dye was used to evaluate the photocatalytic activity of each sample in direct sunlight. The GO-15/CeO2 nanocomposite showed the highest photocatalytic activity with rate constant (0.01633 min–1), and it degraded the MB dye molecules by 100% within 120 min. The high photocatalytic activity of this material for degrading MB dye establishes it as an outstanding candidate for wastewater treatment. Further, these nanocomposites also demonstrated excellent antimicrobial activity against Pseudomonas aeruginosa PAO1.

Black Rice Anthocyanins as An Effective Antioxidant of Inhibition of Oil Oxidative Based on Molecular Modification.

This present work investigated the influence of black rice anthocyanins as antioxidants on the oxidation stability of oil. Malonic acid, succinic acid and succinic anhydride were grafted on black rice anthocyanins through acylation method to improve their antioxidant activity in oil. The results from fourier transform infrared spectroscopy (FTIR) showed new absorption peaks near 1744 cm -1 and 1514 cm -1 , which implied that malonic acid, succinic acid and succinic anhydride grafted on the -OH of glucoside and rutinoside through esterification reaction and resulted that the polarity of these were reduced. Total content of anthocyanin (TAC) decreased to 166. 3 mg/g, 163.7 mg/g and 150.2 mg/g, respectively after modification with succinic acid, malonic acid and succinic anhydride. Compared with native anthocyanins, the acylation of black rice anthocyanins partially reduced its antioxidant activity. In addition, DPPH clearance of molecular modified anthocyanins decreased to 62.6% (San-An). As revealed in the oil stability through the determination of primary oxidation products (PV) and secondary oxidation products (p-AV), Sa-An, Ma-An and San-An showed stronger antioxidant activity in Schaal oven accelerated oxidation test during 12 days than native black rice anthocyanin in both corn oil and flaxseed oil. Molecular modified black rice anthocyanins are expected to be used as colorants, antioxidants, etc. in oil-rich food.

DNA binding peptide CF-14 enhances bactericidal efficacy of eugenol/carvacrol nanoparticles to Escherichia coli.

To evaluate the bactericidal action of antimicrobial peptide CF-14, Eugenol (EU) and carvacrol (CAR) nanoparticles (NPs) less than 200nm were surface-modified with CF14, gaining approximately 200nm of EU-CF and CAR-CF NPs with swollen morphology. EU-CF and CAR-CF NPs were bactericidal to E. coli at dosage of 0.09% and 0.07% (v/v), respectively; while they were just bacteriostatic to Staphylococcus aureus at 0.10% and 0.08% (v/v). Spectral variations in bacterial carbohydrates (1185-900cm-1), lipids (3000-2800cm-1) and DNA (1500-1185cm-1) were obvious as evident from Fourier transform infrared spectroscopy (FTIR). A higher percentage of membrane damaged (non-revivable) E. coli than S. aureus was found, which indicated electrostatic interactions between Gram-negative E. coli with cationic CF conjugated NPs leading to DNA disintegration. Interestingly, EU-CF and CAR-CF NPs inhibited E. coli growth in orange juice without impacting flavour compounds.

Estimation of Carbon Content in High-Ash Coal Using Mid-Infrared Fourier-Transform Infrared Spectroscopy

The carbon content of different types of coal determines its utility in industries and thermal power generation. The most popular and widely used is the conventional method (ultimate analysis) to determine coal’s carbon content (C, wt.%), along with H, N, and S. In the present study, the authors attempted to analyze the carbon content (C in %) in coals via data from Fourier-transform infrared (FTIR) spectroscopy, which can be a promising alternative. As a reference, the carbon content in the coal samples, referred to as CCHNS (in wt.%), was determined from the ultimate analysis. The mid-infrared FTIR spectroscopic data were used to investigate the response of functional groups associated with carbon or its compounds, which were used to model and estimate the carbon content in coal samples (referred to as CFTIR, in wt.%). FTIR spectral signatures were utilized in specific zones (between wavenumbers 4000 and 400 cm−1) from a total of 18 coal samples from the Johilla coalfield, Umaria district, Madhya Pradesh, India. These 18 coal samples were used to produce 126 Coal+KBr pellets (at seven known dilution factors for each coal sample), and the spectral response (absorbance) from each pellet was recorded. For model development and validation, the training set and test set were formed using a 17:1 split (K-fold cross validation). The carbon content in the coal samples was modeled using the training set data by applying the piecewise linear regression method employing quasi-Newton (QN) with a breakpoint and least squares loss function. The model was validated using an independent test set. A pairwise comparison of estimates of carbon in the laboratory from the CHNS analyzer (CCHNS) and modeled carbon from FTIR data (CFTIR) exhibited a good correlation, relatively low error, and bias (coefficient of determination (R2) up to 0.93, RMSE of 23.71%, and MBE of −0.52%). Further, the significance tests for the mean and variance using the two-tailed t-test and F-test showed that no significant difference occurred between the pair of observed CCHNS and the model’s estimated CFTIR. For high-ash coals from the Johilla coalfield, the model presented here using mid-infrared FTIR spectroscopy data performs well. Thus, FTIR can potentially serve as an important method for quickly determining the carbon content of high-ash coals from various basins and can potentially be extended to soil and shale samples.

Influence of Salt Concentration on Alkaline Extracted Refined Kappa- carrageenan and Its Characterization

Kappaphycus alverazii remains as a predominant source of kappa-carrageenan which is farmed extensively in Indonesia, Philippines and South East Asia. The current research focuses on the influence of concentration of salts and approach to dialysis on properties of carrageenan. Carrageenan due to its pronounced gelling and viscosifying properties, has gained significant usage in the areas of food, cosmetics, textiles, pharmaceutics, biomedicine, and numerous others. The process of extraction was conducted in a hot, alkaline condition at 80 oC for a duration of 2 hours. The alkaline substance used was KCl with 2% and 4% concentration and solvent to seaweed ratio was 20:1.Further, the resultant extracted samples were subjected to dialysis to evaluate the effect of dialysis on the quality of carrageenan. The absorbance peak at 849 cm–1 from Fourier Transform Infrared-Spectroscopy (FTIR) at all extraction conditions indicated D-galactose-4 sulphate related to kappa carrageenan obtained with no traces of \(\mu\)-precursor. The study demonstrated that the concentration of salts and the approach of dialysis have influenced the quality of yield, viscosity, gel strength, moisture content and ash content for the extracted carrageenan, which remains ideal for commercial applications.

Crystallinity in polymer electrolyte membranes used in H2 generators: Degradation mechanism from the perspective of recycling

Methanol-based electrolysis can be a prospective alternative for the reduction of energy consumption. Developing highly durable methanol-based electrolysers with small CO2 release can help achieve cheaper hydrogen. Further, to arrive at a circular economy in H2, recycling the precious components would play a major role. Several studies on catalyst recycling have overshadowed the need for recycling the proton exchange membrane. Membrane, which forms 25% of the device cost, need to be studied for its degradation and optimizing the operating parameters of the device have a big role to play in establishing recycling. Our previous studies concluded that the change in crystallinity of membrane from fuel cell was closely related to membrane properties. Herein, for the first time, we have correlated the crystallinity of the membrane retrieved from an electrochemical methanol-reformer to its degradation mechanism. The average crystallinity on the anode and cathode sides was observed to be increased drastically compared to a fuel cell. As observed from Fourier Transform Infrared Spectroscopy (FTIR), the presence of sulfonic acid anhydrides was considered one of the reasons for this increase in crystallinity. X-ray photoelectron spectroscopy (XPS) showed that carbon peaks in the side chain was devoid of α-OCF2, –CF3, indicating severe degradation. The probability of finding a degraded area on the anode side of the scanned recycled membrane was 88% and 55% for the cathode side. The severe degradation of amorphous side chains and formation of short chains had considerably increased the crystallinity. The disparity in the intensity of degradation on the anode and cathode sides of the membrane was confirmed by the percentage of crystallinity and XPS studies. Further, the severity of degradation on either side of the membrane from methanol-based Proton Exchange Membrane electrolysers makes them difficult for further reuse in hydrogen-based energy systems.

Cellulose acetate/silica composites: Physicochemical and biological characterization

Cellulose acetate is of remarkable scientific interest, becoming more useful when is used in obtaining of the composite materials containing nanoparticles, as result of its improved properties. Thus, cellulose acetate/silica composite films obtained by casting the solutions of cellulose acetate (CA)/tetraethyl orthosilicate (TEOS) in different mixing ratios were analyzed in this paper. The impact of TEOS addition, and implicitly of the silica nanoparticles on the mechanical strength, water vapor sorption properties and antimicrobial activity of the cellulose acetate/silica films were mainly monitored. The results of the tensile strength tests were discussed in correlation with data obtained from Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. It was found that samples with low TEOS content show improved mechanical strength compared to samples with high amounts of TEOS. The microstructural characteristics of the studied films affect their moisture sorption capacity so that the weight of the adsorbed water increases with the addition of TEOS. These features are complemented with the antimicrobial activity against Staphylococcus aureus and Escherichia coli bacterial species. The obtained data show that the cellulose acetate/silica films, and especially those with low silica content have improved properties that can recommend them for applications in the biomedical field.

Hydrolytic and thermal stability of urea‐formaldehyde resins based on tannin and betaine bio‐fillers

AbstractIn this work, betaine (trimethyl glycine) and tannin (complex biomolecules of polyphenolic nature) were used as bio‐fillers. Urea‐formaldehyde (UF) resin with a molar ratio of formaldehyde versus urea (FA/U) of 0.8 was synthesized in situ with tannin and betaine as bio‐fillers, to obtain UF resin with reduced free FA content and increased hydrolytic and thermal stability by the principles of sustainability. The samples TUF (with tannin) and BUF (with betaine) were characterized by using X‐ray diffraction analysis (XRD), non‐isothermal thermogravimetric analysis (TGA), and differential thermal analysis (DTA), supported by data from Fourier Transform Infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). The percentage of free FA in modified BUF resin is 0.1%, while the percentage of free FA in tannin‐modified resin is 0.8%. The hydrolytic stability of the modified UF resins was determined by measuring the concentration of liberated FA in the modified UF resins, after acid hydrolysis. The modified BUF resin is hydrolytically more stable because the content of released FA is 3.6% compared to the modified TUF resin, where it was 7.4%. Based on the value for T5%, the more thermally stable resin is the modified TUF resin (T5% = 123.1°C), while the value of the T5% for the BUF resin is 83.1°C. This work showed how UF bio‐composite with reduced free FA content and increased hydrolytic and thermal stability can be obtained using tannin and betaine as bio‐fillers.

Lignin from Brewers' Spent Grain: Structural and Thermal Evaluations.

Lignocellulose is a renewable ubiquitous material that comprises cellulose, hemicellulose, and lignin. Lignin has been isolated from different lignocellulosic biomass via chemical treatments, but there has been little or no investigation carried out on the processing of lignin from brewers' spent grain (BSG) to the best of authors' knowledge. This material makes up 85% of the brewery industry's byproducts. Its high moisture content hastens its deterioration, which has posed a huge challenge to its preservation and transportation; this eventually causes environmental pollution. One of the methods of solving this environmental menace is the extraction of lignin as a precursor for carbon fiber production from this waste. This study considers the viability of sourcing lignin from BSG with the use of acid solutions at 100 °C. Structural and thermal analyses were carried out on extracted samples, and the results were compared with other biomass-soured lignin to assess the proficiency of this isolation technique. Wet BSG sourced from Nigeria Breweries (NB), Lagos, was washed and sun-dried for 7 days. Tetraoxosulphate (VI) (H2SO4), hydrochloric (HCl), and acetic acid, each of 10 M, were individually reacted with dried BSG at 100 °C for 3 h and designated as H2, HC, and AC lignin. The residue (lignin) was washed and dried for analysis. Wavenumber shift values from Fourier transform infrared spectroscopy (FTIR) show that intra- and intermolecular OH interactions in H2 lignin are the strongest and possess the highest magnitude of hydrogen-bond enthalpy (5.73 kCal/mol). The thermogravimetric analysis (TGA) results show that a higher lignin yield can be achieved when it is isolated from BSG, as 82.9, 79.3, and 70.2% were realized for H2, HC, and AC lignin. The highest size of ordered domains (0.0299 nm) displayed by H2 lignin from X-ray diffraction (XRD) informs that it has the greatest potential of forming nanofibers via electrospinning. The enthalpy of reaction values of 133.3, 126.6, and 114.1 J/g recorded for H2, HC, and AC lignin, respectively, from differential scanning calorimetry (DSC) results affirm that H2 lignin is the most thermally stable with the highest glass transition temperature (Tg = 107 °C).

Preparation of porous calcium carbonate biochar and its beryllium adsorption performance

Wastewater disposal from beryllium production has become a significant problem in the industry. Therefore, this paper designed porous calcium carbonate biochar (CC-LBC) using Na2CO3 and CaCl2 to modify the biochar innovatively, after which we understudied the Be(II) adsorption effect of CC-LBC at different concentrations. The results from Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), and other characterization analyses showed that when CC-LBC particles were immersed in the Be(II) waste liquid, several O elements accumulated because of its loose and porous structure, generating more beryllium precipitates on the surface of the adsorbent. According to kinetic data fitting, investigations also revealed that both physical and chemical reactions controlled CC-LBC/Be(II) adsorption process, indicating that the CC-LBC/Be(II) adsorption system is suitable for the intraparticle diffusion model. Furthermore, when the beryllium on activated carbon was desorbed by 10% NaOH, the desorption effect was above 80%, and the saturation adsorption capacity of CC-LBC for Be(II) was up to 55 mg/g. However, when the initial concentration of Be(II) was equal to 0.5–1 mg/L, the concentration of beryllium after treatment was lower than 10 μg/L, confirming that CC-LBC had a better selective adsorption performance for beryllium in the binary system.

Chemotaxonomy, biomechanics, and paleophysiology of Alethopteris ambigua and Neuropteris ovata var. simonii (Late Pennsylvanian, Canada). A chemometric approach

Medullosales was a highly diverse and ecologically differentiated group of plants that flourished in the Late Carboniferous and Early Permian tropical wetlands of Euramerica and China. Although the Medullosales have been extensively studied, some aspects of their life habits are still not fully understood. This study focuses on the relationships between chemical composition and biomechanical /physiological characteristics of the two largest-known frond segments of Alethopteris ambigua (45 cm long) and Neuropteris ovata var. simonii (65 cm long) from the Late Pennsylvanian of the Sydney Coalfield, Canada. Additionally, this study provides new data obtained from Fourier transform infrared spectroscopy (FTIR) analysis that, in conjunction with morphological features, could be used to efficiently distinguish species and genera of fossil plants. The density of the different frond parts is calculated using a 3D multivariate model derived from FTIR data. Tensile strength, tensile modulus of elasticity, flexural stiffness, and leaf mass per area for the different frond parts are estimated using trait relationships linking density and structural properties established for modern plant-leaf tissues. Key results include the cognition of continuous variation of geomacromolecular compounds throughout the different-order rachises and pinnules from proximal to distal frond sections. In the proposed, theoretical fronds, these diagenetically-modified biomacromolecules would represent tannin-, lignin-, and resin-related compounds. Overall, pinnules and rachises of A. ambigua are characterized by high contents of aliphatic-rich structures, whereas those of N. ovata are mostly aromatic in composition. The chemical composition of the two fronds is hierarchically partitioned, indicating density dependence on the frond parts. This is reflected in the metabolic construction costs that, in the two species, differ significantly among pinnules and rachises. These results indicate “flexibility” of resource allocation, resulting into two different, architectural frond designs. The costs of building harder, stiffer, and more expensive pinnules in the N. ovata frond are compensated for by the metabolically inexpensive rachises. The opposite holds for the A. ambigua frond, i.e., relatively cheaper pinnules and more expensive rachises. This reveals the complexity of the biomechanical and physiological strategies employed by these two taxa to construct mechanically resistant and physiologically efficient, longer-lived fronds. Results suggest that these plants were likely stress-tolerant and opportunistic colonizers that dominated eutrophic habitats, which were typical of some tropical ecosystems of the Late Pennsylvanian.

Flexible self-healing nanocomposite based gelatin/tannic acid/acrylic acid reinforced with zinc oxide nanoparticles and hollow silver nanoparticles based on porous silica for rapid wound healing

In this research, gelatin (Ge), tannic acid (TA), acrylic acid (AA) as a matrix are used. Zinc oxide (ZnO) nanoparticles (10, 20, 30, 40 and 50 wt%) and hollow silver nanoparticles along with ascorbic acid (1, 3, and 5 wt%) are considered as reinforcement. In order to prove the functional groups of nanoparticles made from Fourier-transform infrared spectroscopy (FTIR), and determine the existing phases of the powders in the hydrogel, X-ray diffraction (XRD) is used, also to investigate the morphology, size, and porosity of the holes and in the scaffolds, scanning electron microscope analysis is used (FESEM). Then, mechanical tests such as tension and compression test are performed to determine the most optimal state of the composite. Also, the antibacterial test is performed for the manufactured powders and hydrogel, as well as the toxicity test for the fabricated hydrogel. The results show that the sample (30 wt% of zinc oxide and 5 wt% of hollow nanoparticles) is the most optimal hydrogel based on mechanical tests and biological properties.

Effects of Incorporating Alkaline Hydrogen Peroxide Treated Sugarcane Fibre on The Physical Properties and Glycemic Potency of White Bread.

The consumption of dietary fibres can affect glycemic power and control diabetes. Sugarcane fibre (SCF) is known as insoluble dietary fibre, the properties of which can be affected by physical, chemical, and enzymatic treatments. In this study, alkaline hydrogen peroxide (AHP) treatments were conducted over time (0.5, 1, 3, and 5 h) at 12.6% (w/v) SCF and the effects on the physicochemical and structural properties of the SCF were evaluated. After making dough and bread with the SCF, with and without AHP treatments, the glycemic responses of the bread samples were evaluated. Shorter durations of AHP treatment (0.5 and 1 h) reduced lignin effectively (37.3 and 40.4%, respectively), whereas AHP treatment at 1 and 3 h duration was more effective in increasing particle sizes (50.9 and 50.1 μm, respectively). The sugar binding capacity, water holding capacity (from 2.98 to 3.86 g water/g SCF), and oil holding capacity (from 2.47 to 3.66 g oil/g SCF) increased in all AHP samples. Results from Fourier-transform infrared spectroscopy (FTIR) confirmed the polymorphism transition of cellulose (cellulose I to cellulose II). The morphology of SCF detected under scanning electron microscopy (SEM) indicated the conversion of the surface to a more porous, rough structure due to the AHP treatment. Adding SCF decreased dough extensibility but increased bread hardness and chewiness. All SCF-incorporated bread samples have reduced glycemic response. Incorporation of 1, 3, and 5 h AHP-treated SCF was effective in reducing the glycemic potency than 0.5 h AHP-treated SCF, but not significantly different from the untreated SCF. Overall, this study aims to valorize biomass as AHP is commonly applied to bagasse to produce value-added chemicals and fuels.

The counterion-mediated controllable coacervation of nano-ions with polyelectrolytes

Nano-ions can complex with polyelectrolytes for coacervates with hierarchical structures; however, the rational design of functional coacervations is still rare due to the poor understanding of their structure–property relationship from their complex interaction. Herein, 1 nm anionic metal oxide clusters, PW12O403-, with well-defined, mono-disperse structures are applied to complex with cationic polyelectrolyte and the system shows tunable coacervation via the alternation of counterions (H+ and Na+) of PW12O403-. Suggested from Fourier transform infrared spectroscopy (FT-IR) and isothermal titration studies, the interaction between PW12O403- and cationic polyelectrolytes can be modulated by the bridging effect of counterions via hydrogen bonding or ion–dipole interaction to carbonyl groups of polyelectrolytes. The condensed structures of the complexed coacervates are explored by small angle X-ray and neutron scattering techniques, respectively. The coacervate with H+ as counterions shows both crystallized and discrete PW12O403- clusters, with a loose polymer-cluster network in comparison to the system of Na+ which shows a dense packing structure with aggregated nano-ions filling the meshes of polyelectrolyte networks. The bridging effect of counterions helps understand the super-chaotropic effect observed in nano-ion system and provides avenues for the design of metal oxide cluster-based functional coacervates.

A comparative study on characterizations of biomass derived activated carbons prepared by both normal and inert atmospheric heating conditions

In the present study, cost effective activated carbon from wasteland biomass of Calotropis gigantea stem was prepared at 400 °C, 600 °C, 750 °C and 900 °C carbonization temperatures in normal atmosphere (NA) and at 600 °C, 750 °C in inert atmosphere (IA) of nitrogen by using Potassium Carbonate (K2CO3) as chemical activating agent in the impregnation ratios of 0.5, 1 and 2. Activated carbons prepared under NA and IA were characterized and compared. Field Emission Scanning Electron Microscopy (FESEM) study confirmed presence of micropores and mesopores. While Xray Diffraction (XRD) analysis confirmed presence of both disordered amorphous carbon humps and graphitic crystallite peaks. Presences of functional groups were more prominent in NAC; found from Fourier Transform Infra-Red Spectroscopy (FTIR) analysis. BET surface area at 750 °C at chemical impregnation ratio 1 under NA was recorded highest containing both micropores and mesopores. Disordered carbon structure was confirmed from RAMAN spectroscopic analysis and nanoporous structure of activated carbon was confirmed from HRTEM analysis. NA activated carbons processed from wasteland weed can be preferred for different adsorption related applications as they are reasonable with improved properties.

Multifunctional properties of gadolinium doped annealed zinc oxide nanoparticles

In the present study, Zn1−x Gdx O (x = 0.02) nanoparticles have been synthesized by chemical route (Sol-Gel Method) using polyvinyl alcohol (PVA) as chelating agent. These materials are annealed from 500 °C−1000 °C with a step size of 100 °C temperature. The multifunctional properties of the prepared materials have been studied in view of their structural, morphological, optical, magnetic, and mechanical characteristics. X-ray diffraction (XRD) studies have shown that ZnO (zinc oxide) nano powders are crystallized in the Wurtzite hexagonal structure, and the structural parameters have been determined. Transmission Electron Microscopy (TEM) study conducted on a sample annealed at 900 °C revealed nanoparticles size as ∼22 nm. Spherical nanoparticles with irregular particle morphology was observed from SEM (Scanning Electron Microscopy) images. Energy dispersive spectroscopy (EDS) accorded the existence of elementary components of the prepared samples. The characteristic peaks of ZnO are evident from Fourier transform infrared spectroscopy (FTIR) study. The bandgap energies from UV–visible studies levied to decrease from 3.31 eV to 3.13 eV with annealing temperatures. Near band edge emission exhibited redshift from Photoluminescence (PL) study with the increase in annealing temperature. The Dilute Magnetic Semiconductor (DMS) nature was observed on the studied materials, making them promising materials for multifunctional spin-based applications. The study of Mechanical properties suggests that these materials may find applications as cutting fluids, nanofillers and nanolubricant additives.

Enzymatic pretreatment of palm oil empty fruit bunch

Fibers from Palm Oil Empty Fruit Bunch (OPEFB) are high in cellulose, lignin, hemicelluloses, small wax depositions, and inorganic components. Intractable lignin in lignocellulosic biomass (LCB) is a main hindrance to cellulose extraction. As a result, it must be removed from LCB before production of value-added products such as cellulose nano crystal (CNC), fermentable sugar, and biofuels. When compared to chemical and physical methods, enzyme-mediated lignin breakdown is considered a “green” technique since it does not create any harmful intermediates. An attempt was taken to reduce (delignify) lignin from OPEFB through laccase enzyme pretreatment process without usage any hazardous chemicals like alkali, bleaching agents. After 12 h incubation period at 50 °C, laccase's delignification potential from OPEFB was 66.5 %. According to the findings, the laccase was successful at breaking down lignin and has the potential to enhance the quantity of cellulose in lignocellulosic biomass as OPEFB in a sustainable and environmental favorable way. The morphological results from Scanning Electron Microscopy (SEM) image, functional group from Fourier Transform Infrared Spectroscopy (FTIR) results and crystalline nature of X-ray Diffraction (XRD) graph was proved the reduction of lignin from raw OPEFB after enzymatic pretreatment. In the future, this approach would be used to extract additional types of cellulose from other lignocellulosic waste biomass which is environmentally friendly and sustainable to obtain value-added products.

Multiscale Approach to Studying Biomolecular Interactions in Cellulose-Casein Adhesion.

Casein finds application as an eco-friendly adhesive for paper, wood, glass, etc. Casein being a protein can undergo conformational and microstructural changes during various processing steps involved in interfacial bonding. This study aims at understanding the multiscale contributions of these changes in casein to its adhesion to cellulose pressboards. Investigations spanning from molecular structure to macroscopic adhesion characteristics have been used in this work. The lap shear strength of casein bonded cellulose pressboards is found to increase with the increase in casein concentration. It was observed from Fourier transform infrared spectroscopy (FTIR) investigations along with microscopy and rheological studies that casein dispersions result in more α-helical conformations during the preconcentration process of casein dispersions. This results in increased hydrophobicity of the casein particles/aggregates, which in turn affects the wetting characteristics and the adhesion behavior. Casein compositions lacking α-helices were found to enhance the bonding strength of casein with cellulose. The present study shows that the adhesion between casein and microporous cellulose substrate has contributions at the multiscale originating from the polar-polar interactions of casein and cellulose molecules, conformational changes in the protein structure of casein during drying, microstructure of casein particles in the dispersion, and the microporous nature of the cellulose boards. These interactions at multiple scales can be tuned to suit different adhesive applications using casein.

Phytofabrication of Silver Nanoparticles and Their Potent Antifungal Activity against Phytopathogenic Fungi

Fungal plant pathogens cause huge losses in agricultural production by decreasing crop yield and quality. To reduce crop loss from fungal damage, various synthetic fungicides are applied indiscriminately in agricultural practice. The majority of synthetic fungicides are non-biodegradable, and several critical human health risks are associated with them. Green synthesis nanotechnology offers an effectual, cost-effective, ecofriendly, and innocuous method for the synthesis of green nanofungicides, an excellent replacement for synthetic chemical fungicides. Origanum majorana is an aromatic herb with immense pharmacological and medicinal properties. In this context, the present study used the leaves of O. majorana to synthesize silver nanoparticles. The biosynthesized particles showed an absorption peak at 441 nm with ultraviolet-visible spectrophotometry (UV-Vis). The spectra obtained from Fourier transform infrared spectroscopy (FT-IR) of O. majorana extract and AgNPs showed a myriad of functional groups corresponding to vital biomolecules that act as capping and reducing agents. The synthesized silver nanoparticles were spheroidal, and their size measured between 8 nm and 42 nm, as depicted by transmission electron microscopy (TEM). The energy-dispersive X-ray spectrum (EDX) showed a silver peak at 3 keV. The phytofabricated silver NPs demonstrated robust inhibitory activity on the mycelial growth of A. alternata f sp. lycopersici (87%), followed by Pestalotiopsis mangiferae (85%), Macrophomina phaseolina (78%), and Colletotrichum musae (75%). The minimum inhibitory concentration value for A. alternata. f sp. lycopersici and Pestalotiopsis mangiferae was 2 μg/mL, while the minimum fungicidal concentrations were 4 and 8 μg/mL, respectively. Additionally, the fabricated AgNPs induced severe damaging and destructive effects to the morphology of hyphae and conidia, as witnessed by scanning electron microscopy studies.