Fourier Transform Infrared Spectroscopy Peak Research Articles

Silver Recovery from E-Waste Printed Circuit Board Using Binary and Ternary Deep Eutectic Solvents

Printed Circuit Boards (PCBs) are essential components of electronic devices containing valuable silver metal. Using sustainable methods, silver recovery from electronic trash, like PCBs, demonstrates excellent promise. This research’s objective is to determine the optimum leaching time and solid-to-liquid (S/L) ratio for extracting silver from PCB using deep eutectic solvent (DES) composed of choline chloride and glycerol (glyceline DES). The binary DES’s leaching performance was then compared to choline chloride, glycerol, and citric acid ternary systems. Fourier Transform Infrared Spectroscopy (FTIR) was carried out to analyze the bond interactions. X-ray fluorescence spectrometry (XRF) was employed to determine the PCB’s metal concentration prior to and after the leaching process. Ternary DES was viscous, colorless, stable for 60 days, and less acidic than binary DES, with a 1.21 g/mL density. FTIR peak broadening and shifting indicated the formation of a new hydrogen bond and proved a successful synthesis of ternary DES. XRF result showed that PCB’s initial silver metal content was 2.32%. The optimal silver leaching from PCB using glyceline DES was achieved after 16 hours, with a 1/20 solid-to-liquid ratio. Ternary DES demonstrated a silver leaching efficiency of 93.65%, surpassing 86.77% of glyceline. Ternary DES synthesized in this study has the potential to serve as an efficient and environmentally friendly solvent for extracting silver from PCB, providing a sustainable approach to managing electronic waste.

Silica-Based 1,3-Diphenyl-1,3-Propanedione Composites: Efficient Uranium Capture for Environmental Remediation

Introduction:: This study synthesizes and characterizes a novel hybrid composite, SGdpm, to capture UO2 2+ ions from water. The composite has successfully formed by hosting covalently diphenylmethane-1,3-dione (dpm) within an inorganic silica gel matrix, showing promising potential for environmental remediation and nuclear waste management. Methods:: The preparation involved the reaction of tetraethylorthosilicate (TEOS) with diphenylmethane- 1,3-dione (dpm) under acidic conditions, resulting in white solids. The doped composite was characterized by Fourier Transform Infrared Spectroscopy (FTIR), revealing the presence of siloxane and Si-O-C bonds. The application of SG-dpm for capturing UO2 2+ ions from water was investigated, showing a shift in FTIR peaks and confirming the formation of SG-dpm-UO2 2+ as inner-sphere complexes. Scanning Electron Microscopy (SEM) revealed a non-uniform distribution of particles, essential for consistent behavior in applications such as adsorption. Results and Discussion:: Batch sorption experiments demonstrated temperature-dependent sorption behavior with increased efficiency at higher temperatures (T = 55 °C). The study also explored the influence of pH and initial concentration on UO2 2+ sorption, revealing optimal conditions at pH 5 and lower initial concentrations (1.0 mg L-1). Kinetic studies using pseudo-second-order models indicated a high efficiency of UO2 2+ ion removal (99 %) as a chemisorption process. Intraparticle diffusion models highlighted three distinct sorption stages. Sorption isotherm studies favored the Langmuir model, emphasizing monolayer adsorption. The thermodynamic analysis suggested an endothermic (ΔH = + 16.120 kJ mol-1) and spontaneous (ΔG = −25.113 to − 29.2449 kJ mol-1) sorption process. Selectivity studies demonstrated high efficiency in capturing Cu2+, Co2+, and Cr3+ ions, high degree selectivity of UO2 2+ ions (74 %), moderate efficiency for Fe3+ and Zn2+, and lower efficiency for Pb2+, Ni2+, and Cd2+, and poor efficiency for Mn2+ ions. In Conclusion,: SG-dpm exhibits promising potential for selective UO2 2+ ion removal, demonstrating favorable characteristics for various applications, including environmental remediation and nuclear waste management.

Brucine Entrapped Titanium Oxide Nanoparticle for Anticancer Treatment: An In Vitro Study.

Backgroundand Objective. The public's health has been seriously threatened by cervical cancer during recent times. In terms of newly diagnosed cases worldwide, it ranks as the ninth most prevalent malignancy. Multiple investigations have proven that nanoparticles can effectively combat cancer due to their small dimensions and extensive surface area. In the meantime, bioactive compounds which are biocompatible are being loaded onto nanoparticles to promote cancer therapy. The current study investigates the anticancerous potential of Brucine-entrapped titanium oxide nanoparticles (TiO2 NPs) in cervical cancer cell line (HeLa). Materials and Methods. The physiochemical, structural, and morphological aspects of Brucine-entrapped TiO2 NPs were evaluated by UV-visible spectrophotometer, Fourier transform-infrared spectroscopy (FT-IR), dynamic light scattering (DLS), scanning electron microscopy (SEM), and energy dispersive X-ray (EDAX). The cytotoxic effect against the HeLa cell line was assessed using a tetrazolium-based colorimetric assay (MTT), a trypan blue exclusion (TBE) assay, phase contrast microscopic analysis, and a fluorescence assay including ROS and DAPI staining. Furthermore, estimation of antioxidant markers includes catalase (CAT), glutathione (GSH), and superoxide dismutase (SOD). Results. The UV spectrum at 266 nm revealed the formation of TiO NPs. The FT-IR peaks confirmed the effective entrapment of brucine with TiO2 NPs. The average size (100.0 nm) of Brucine-entrapped TiO2 NPs was revealed in DLS analysis. The micrograph of the SEM revealed the formation of ellipsoidal to tetragonal-shaped NPs. The Ti, O, and C signals were observed in EDAX. In MTT assay, Brucine-entrapped TiO2 NPs showed inhibition of cell proliferation in a dose-wise manner and IC50 was noticed at the concentration of 30 µg/mL. The percentage of viable cells gradually reduced in the trypan blue exclusion assay. The phase contrast microscopic analysis of Brucine-entrapped TiO2 NP-treated cells showed cell shrinkage, cell wall deterioration, and cell blebbing. The intracellular ROS level was increased in a dose-wise manner when compared to control cells in ROS staining. The condensed nuclei and apoptotic cells were increased in treated cells, as noted in DAPI staining. In treated cells, the antioxidant markers such as CAT, GSH, and SOD levels were substantially lower compared to the control cells. Conclusion. The synthesized Brucine entrapped TiO2 NPs exhibited remarkable anticancer activity against the HeLa cell line.

Deciphering the synergistic potential of mycogenic zinc oxide nanoparticles and bio-slurry formulation on phenology and physiology of Vigna radiata

Abstract Nanobiofertilizers have emerged as an innovative tool for enhancing crop productivity. In the current research, zinc oxide nanoparticles (ZnONPs) were mycosynthesized using cell-free supernatant of Trichoderma harzianum and optimized for physical parameters. Characterization using UV-Visible spectroscopy, dynamic light scattering analysis, zeta potential analysis, X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy-EDX, and HR-Transmission electron microscopy confirmed the formation of ZnONPs with flower-like morphology and average size of 314 nm. The average zeta potential value of the ZnONPs was +1.9 mV indicating the formation of neutral NPs. FTIR peak at 401 cm−1 revealed the presence of ZnONPs. XRD analysis confirmed the hexagonal wurtzite crystalline nature of the ZnONPs. The effect of ZnONPs at 10–1,000 ppm combined with liquid bio-slurry (BS) was studied on seed germination and growth of Vigna radiata. Combination of 250 ppm ZnONPs and BS at 1:2 ratio showed 22.6% increase in shoot length as well as 18.4% increase in root length as compared to control in in vitro studies. In Vivo pot experiments showed no significant difference in secondary metabolites after 60 days, but the root length increased by 38.9% and shoot length increased by 46.95% compared to the control.

Investigation of gold-amino acid interactions using Fourier Transform Infrared spectroscopy and correlation with gold dissolution; Studies at different pH values

Recent developments in the field of gold leaching using amino acids have generated an interest in understanding the bonding/interactions involved in gold amino acid complexation. So far, only Density Function Theory (DFT) models have predicted the bonding of gold with amino acids, and there has been limited experimental work to verify the postulated quantum models. This study therefore aims to address the identification of amino-gold interactions using Fourier Transform Infrared spectroscopy (FTIR) and interrogate the predicted DFT interactions of gold and amino acids. The selected amino acids for this investigation were glycine, alanine, cysteine and histidine. Interactions were investigated at different pH levels corresponding to the isoelectric point and deprotonation points of respective amino acids. In addition to the FTIR investigation, gold dissolution experiments were conducted to establish a possible relationship between the interactions and gold dissolution at the explored pH points. FTIR analysis indicated that gold forms complexes with amino acids through N–Au, O–Au, and S–Au bonds. These bonds were evidenced by observed peak changes in the NH3+, COO−, and S-associated IR vibration peaks during the complexation process. In turn, the IR vibration peaks supported the DFT predictions of the active site for the bonding between gold and amino acids. Notably, the analysis revealed significant vibrational shifts in the characterization peaks of ligands at the deprotonation pH across all four amino acids, signifying a high interaction between gold and amino acids with high pH levels. Moreover, the dissolution of pure gold using the four amino acids at 0.5 M concentration of amino acid, 187 mg/L solid w/v, 1 % H2O2 and 300 rpm agitation indicated that gold dissolution was more favourable at the deprotonation pH compared to the isoelectric ph. Overall, the results showed that high dissolution was observed at deprotonation pH that corresponded to high FTIR peak shifts observed on deprotonated amino acid complexation. Lastly, the study hints at a possible correlation between the nature of gold amino-acid complexation and the extent of gold dissolution, which could require further investigation.

Antiseptic Chitosan-Poly(hexamethylene) Biguanide Hydrogel for the Treatment of Infectious Wounds.

Topical wound infections create the ideal conditions for microbial colonization and growth in terms of moisture, temperature, and nutrients. When they are not protected, numerous types of bacteria from the internal microbiota and the external environment may colonize them, creating a polymicrobial population. Treatment of these wounds often necessitates the use of antibiotics that may have systemic harmful effects. Unlike antibiotics, topical antiseptics exhibit a wider range of activity and reduced systemic toxicity and resistance. In order to address this issue, we developed an antiseptic Chitosan-Poly (hexamethylene) Biguanide (CS-PHMB) hydrogel. The prepared hydrogel was characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). SEM images showed the smooth morphology and characteristic FTIR peaks of PHMB and confirmed the incorporation of the antiseptic into the chitosan (CS) hydrogel. A Water Vapor Permeation Rate study confirms the moisture retention ability of the CS-PHMB hydrogel. Rheological studies proved the gel strength and temperature stability. The prepared hydrogel inhibited the growth of S. aureus, P. aeruginosa, E. coli, methicillin-resistant Staphylococcus aureus (MRSA), and K. pneumoniae, which confirms its antibacterial properties. It also inhibited biofilm formation for S. aureus and E. coli. CS-PHMB hydrogel is also found to be hemo- and cytocompatible in nature. Thus, the developed CS-PHMB hydrogel is a very potent candidate to be used for treating infectious topical wounds with low systemic toxicity.

Antibacterial and Antibiofilm Activity of Ficus carica-Mediated Calcium Oxide (CaONPs) Phyto-Nanoparticles.

The significance of nanomaterials in biomedicines served as the inspiration for the design of this study. In this particular investigation, we carried out the biosynthesis of calcium oxide nanoparticles (CaONPs) by employing a green-chemistry strategy and making use of an extract of Ficus carica (an edible fruit) as a capping and reducing agent. There is a dire need for new antimicrobial agents due to the alarming rise in antibiotic resistance. Nanoparticles' diverse antibacterial properties suggest that they might be standard alternatives to antimicrobial drugs in the future. We describe herein the use of a Ficus carica extract as a capping and reducing agent in the phyto-mediated synthesis of CaONPs for the evaluation of their antimicrobial properties. The phyto-mediated synthesis of NPs is considered a reliable approach due to its high yield, stability, non-toxicity, cost-effectiveness and eco-friendliness. The CaONPs were physiochemically characterized by UV-visible spectroscopy, energy-dispersive X-ray (EDX), scanning-electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The biological synthesis of the calcium oxide nanoparticles revealed a characteristic surface plasmon resonance peak (SPR) at 360 nm in UV-Vis spectroscopy, which clearly revealed the successful reduction of the Ca2+ ions to Ca0 nanoparticles. The characteristic FTIR peak seen at 767 cm-1 corresponded to Ca-O bond stretching and, thus, confirmed the biosynthesis of the CaONPs, while the scanning-electron micrographs revealed near-CaO aggregates with an average diameter of 84.87 ± 2.0 nm. The antibacterial and anti-biofilm analysis of the CaONPs showed inhibition of bacteria in the following order: P. aeruginosa (28 ± 1.0) > S. aureus (23 ± 0.3) > K. pneumoniae (18 ± 0.9) > P. vulgaris (13 ± 1.6) > E. coli (11 ± 0.5) mm. The CaONPs were shown to considerably inhibit biofilm formation, providing strong evidence for their major antibacterial activity. It is concluded that this straightforward environmentally friendly method is capable of synthesizing stable and effective CaONPs. The therapeutic value of CaONPs is indicated by their potential as a antibacterial and antibiofilm agents in future medications.

Moisture and fungal degradation in fibrous plaster

Fibrous plaster degradation has been a key concern over recent years, with ceiling failures occurring suddenly in historic buildings, including the Apollo theatre in 2013. This rigorous investigation explores fibrous plaster degradation through subjecting 290 specimens to a range of moisture and fungal-related treatment conditions over periods of up to two years and analysis using mechanical flexural tests, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Deoxyribonucleic Acid (DNA) sequencing. Using FTIR peak ratios from spectra of hessian fibres and mechanical tests in conjunction, an original methodology for identifying mechanisms and severity of fibrous plaster degradation through moisture and fungal exposure was developed. Results showed defined clusters for differing moisture and fungal treatments when two peak ratios are plotted together and compared with mechanical data. Fungal exposure over two years, water submersion and wetting and drying were particularly detrimental conditions for fibrous plaster. Fungal exposure resulted in degradation of cellulose bonds in hessian fibres, with defined clusters on the extreme left of peak ratio plots correlating with a pronounced reduction in fibrous plaster mean flexural strength of 51%. Fungal species Penicillium and Chaetomium were identified on test samples. Moisture affected plaster matrices significantly with wetting/drying and water submersion treatments resulting in a 71% reduction in mean flexural strength for unreinforced plaster, reducing to 26% with hessian-reinforced fibrous plaster. Many buildings containing fibrous plaster are listed and removal of material is often minimised - the high impact of this research stems from the ability to rapidly assess the mechanical integrity of a very small quantity of harvested historic hessian fibres using FTIR. Identifying the location of weakened fibres in a ceiling is highly important for effective restoration and conservation.

Comparison of photocatalytic and antibacterial activities of allotropes of graphene doped Sm2O3 nanocomposites: Optical, thermal, and structural studies

AbstractThis study mainly focuses on the synthesis of two allotropes of graphene, graphene oxide (GO) and reduced graphene oxide (rGO), by the modified Hummers' method and chemical reduction method, respectively. Sm2O3/GO and Sm2O3/rGO nanocomposites were further synthesized in the presence of the cationic surfactant CTAB via the sol–gel method followed by the reflux method. Synthesized nanocomposites were subjected to characterization by Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), and UV–Visible spectroscopy to explore structural, thermal, optical, and photocatalytic properties. Characteristic FTIR peaks were observed in nanocomposites, and the bond length of the Sm‐O bond was calculated. The Coats‐Redfern method was employed to calculate the kinetics and thermodynamic parameters. Hexagonal crystallite shapes of Sm2O3/GO and Sm2O3/rGO nanocomposites with 11.8 and 13.13 nm crystallite sizes and 3.9 and 2.5 eV optical band gaps were observed. The photocatalytic efficiency of Sm2O3/GO and Sm2O3/rGO nanocomposites was assessed against the degradation of methylene blue in the presence of sunlight, and its degradation was confirmed through FTIR. The antimicrobial activities were also performed against the bacterial strains Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus.

The biosynthesis of nickel oxide nanoparticles using watermelon rind extract and their biophysical effects on the germination of Vigna radiata seeds at various concentrations

Unique and bio-inspired synthesis of nickel oxide nanoparticles by using an innocuous and ecofriendly waste material that is watermelon rind. In the reaction, watermelon rind recycled and used its extract as a solvent which act as a reductant for a synthesis of nickel oxide nanoparticle. The synthesized NiO NPs were analyzed by using X-ray Diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and UV-Vis spectroscopy. FTIR peak at 745 cm-1 and 671 cm-1 indicated that the formation of Ni-O bond. A prominent peak of UV-Vis spectra at 283 nm and band gap, calculated with the help of UV data, was ~3.3 eV. The obtained PXRD pattern and JCPDS data suggested the formation of nickel oxide nanoparticle and the average crystallite size calculated by Scherrer’s equation in between 30 to 150 nm. The average grain size of NiO NPs perceived from TEM images was 46.55 nm and polygonal barrel shape particles. Since, a simple, straightforward, pollutant-free, and economical technique for the synthesis of nickel oxide nanoparticles. However, the above synthesized nickel oxide nanoparticles have been explored for biophysical parameter vis. radicle length, plumule length and germination percentage on a Vigna radiata (moong) seed by the treatment of some concentration i.e. 25 ppm, 50 ppm, 100 ppm and 200 ppm in germination processes. At a low concentration of 25 ppm, a beneficial improvement in the germination process of Vigna radiata seed was observed.

Facile Characterization of Titanium Dioxide Nano- particles Prepared via Hydrothermal Method with in-situ Surface Modification

Aim: The present study is focused on the synthesis and characterization of titanium dioxide nanoparticles prepared via the hydrothermal method prepared via in-situ surface modification. 
 Purpose of the study: The proposed research is based on the requirement of alternate antimicrobial therapies. The global misuse and overuse of antibiotics have given rise to the antibiotic resistance crisis. The emergence of multi-drug resistant bacteria has failed the conventional treatment methods involving antibiotics. To meet the need for efficient alternate strategies, metal oxide nanoparticles such as titanium dioxide are explored since it's known for their preventing and treating infections.
 Method: Titanium dioxide nanoparticles were successfully synthesized via hydrothermal and Surface modification of nanoparticles in dehydrated ethanol at room temperature. The obtained nanoparticles are characterized by utilizing Scanning Electron Microscope, Transmission Electron Microscope, Energy Dispersive X-ray Spectroscopy, Zeta Potential Analysis, Thermogravimetric analysis, and Fourier transform Infrared spectroscopy. 
 Results: According to scanning electron microscopy and transmission electron microscopy, the morphological analysis of the synthesized titanium dioxide was spherical shaped and had an average size of 5-20nm and a size distribution of 14-20nm. The Energy Dispersive X-ray spectroscopy analysis depicted the percentage of elements in TiO2 as Ti (47.10%) and O2 (52.90%). The zeta potential for titanium dioxide was reported as -13.39, and the negative value indicated superior physical stability of nanoparticles in a suspension. The Fourier Transform Infrared spectroscopy peak at 1417.68 indicated the O-Ti-O bond in anatase morphology. While Thermogravimetric analysis showed three main stages of mass loss, there was no mass loss after 503°C, which started oxide formation.
 Conclusion: It was concluded from the present study that the synthesis of titanium dioxide is an economical process and yields excellent nanoparticles via the hydrothermal method. Characterization of the nanomaterial allowed us to determine the thermal stability, morphology, and purity of titanium dioxide nanoparticles.  

Applying spectrochemical analyses on venous disease patients treated by N-Butyl Cyanoacrylate Ablation Surgery.

The venous disease of the legs is a common disease among adults that may lead to a deterioration in the structure and concentration of biomolecules. N-Butyl Cyanoacrylate Ablation Surgery (NBCA) or cyanoacrylate embolization (CAE) technique to adhesive the saphenous vein is an alternative method for the treatment of venous disease. We aimed to show what kind of changes occurs after CAE surgery using FTIR spectroscopy combined chemometrics. We compared before and after surgery blood sera of patients to find whether a correlation between spectral data and laboratory indexes. We studied the blood sera of those who suffered from varicose veins and treated them by CAE technique. In order to examine the molecular profiles in blood sera who underwent the CAE technique of the great saphenous vein for the treatment we used Fourier Transform InfraRed spectroscopy (FTIR) spectroscopy of blood samples of patients before and after surgery as a fast diagnostic technique. To obtain information about the spectra variation among the types of samples Principal component analysis (PCA) was performed for fingerprint, amide II with amide I regions. To find normality among variations Partial Least Square P-P plot of residual was performed. Absorbance values were statistically significant only in amide II, amide I, and OH vibrations. In the blood collected before surgery, higher peaks area of α-helix and β-harmonica were noticed. However, in both groups of samples, a higher amount of β-harmonica was visible. Pearson correlation analysis showed that the value of white blood cells (WBC) correlate with absorbance at 2858 cm-1 wavenumber. Moreover, a correlation between neutrophil (NEU) and OH vibrations, and between hematocrit (HCT) and 1082 cm-1, were found. Furthermore, a high correlation Platelets (PLT) and FTIR peak at 1165 cm-1, was noticed. This methodology suggests with PCA analysis CAE caused structural and quantitative chemical changes in blood samples of patients.

Retrogradation in radiation-synthesized cassava starch/acrylic acid super water absorbent and its effect on gel stability

The effects of long-term storage and retrogradation on the stability of the gel properties of radiation-synthesized super water absorbents (SWA) made from cassava starch and acrylic acid were explored in this study. Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM) analyses were used to explore the retrogradation phenomenon. TEM and scanning area electron diffraction (SAED) images revealed the presence of starch nanocrystallites and increase of crystalline state in SWA matrix after 24 months storage. FT-IR peak ratios and enthalpy changes in DSC analysis also confirmed retrogradation of aged SWA samples. However, no sharp peak was observed in XRD diffractograms which is mainly due to the nanostarches present in the SWA. The most critical property affected by starch retrogradation in SWA is the degree of swelling. The degree of swelling of SWA was greatly reduced from 148 to 30 g/g while the gel fraction remained stable after 24 mos. The aged SWA samples with low degree of swelling due to retrogradation returned to their high and stable soil water content after 15 d in unsterile pure garden soil. Despite being exposed to high energy gamma radiation of starch with acrylic acid to form SWA, wherein possible oxidation and chemical modification of starch may take place, retrogradation can still occur. Lowering the storage temperature evidently suppressed the effect of starch retrogradation in SWA. Suppression of starch retrogradation in the optimized SWA is crucial to prolong its marketable life.

Lead Oxide Nanodots Synthesized by Solvothermal and Microwave Assisted Method and its Comparative Characterization

This study is focused on synthesis of lead oxide (PbO) nanodots (quantum dots) via two methods viz. microwave-assisted (B) and solvothermal method (A). The results of microwave-assisted method are slightly different in comparison to the solvothermal method. Several techniques, such as Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and selective area electron diffraction (SAED) were used for characterizing PbO nanodots synthesized by both methods. The FTIR peak at 687 cm-1 indicated the formation of the Pb-O-Pb bond. The band gap, calculated with the help of UV data, was ~5.5 eV. The obtained PXRD pattern and miller indices suggested the formation of β-PbO and α-PbO nanoparticles with orthorhombic and tetragonal geometries. The crystallinity of PbO nanodots methods by A and B methods was 96% and 99%, respectively. The average crystallite size (for both samples synthesized by methods A and B) calculated by Debye-Scherrer’s equation was 42 and 38 nm, respectively. Sample A mostly contains α-type lead oxide nanodots, while sample B mainly contains mostly β-type lead oxide nanodots. The average size of nanodots observed from TEM images for samples A and B was 3.7 and 2.7 nm, respectively.

Comparative study of structural and magnetic properties of Ni and La substituted calcium hexaferrite

Ni and La substituted M-type Ca hexaferrite of composition CaNi1Fe11O19 and CaLa1Fe11O19 were synthesized by sol-gel auto combustion method using metal nitrates as oxidants and citric acid as reducing agent. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray analysis (EDAX), and vibrating sample magnetometry (VSM). XRD study revealed that both samples had lattice parameters a and c within the range of M-type hexaferrite. The SEM micrographs displayed grains having irregular shapes and sizes in the nanometer range. FTIR peaks confirmed the structure of M-type hexaferrite. EDAX spectra showed the homogeneous distribution of ions in both samples. In CaNi1Fe11O19, we found saturation magnetization (Ms) of 12.18 emu/g and coercivity (Hc) of 193.2 Oe. On the other hand, in CaLa1Fe11O19, we found Ms of 0.55 emu/g and Hc of 404.4 Oe. Saturation magnetization and coercivity values obtained for La substituted M-type Ca hexaferrite are suitable for low-density magnetic recording devices.

Understanding the evolution of cellulose fibers during enzyme treatment

Enzyme treatment is a potential strategy for producing cellulose fibrils but its evolution of the mesoscopic and microcosmic structures is not fully understood. In this work, the effect of the properties and microstructures of cellulose bleached hardwood kraft pulp (BHKP) subjected to different enzyme treatment times (0−10 h) on further fibrillation was explored by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results showed that the enzyme treatment did not change the crystal structure of cellulose but destroyed the intermolecular and intramolecular hydrogen bonds, leading to the increase of the crystal index and size. A thorough investigation on the relation between treatment and evolution of inter-/intra-molecular H-bonds in cellulose including content and cleave sequence of H-bonds was conducted by FTIR peak fitting, second derivative analysis and generalized two-dimensional correlation spectroscopy (2DCOS). Compared to intramolecular H-bonds, the intermolecular H-bonds was first broken with a significant decrease in content. In addition, enzyme treatment could promote the peeling of fibrils, and various properties such as yield, water retention value, aspect ratio, and degree of polymerization, etc. were gradually reduced over time relative to the original material, these discoveries provide a theoretical support to a more effective treatment method for the commercial production of cellulose fibrils.

Crystallographic, Functional Group and Microstructural Properties of Oil Palm Biochar Reinforced Hybrid Polystyrene Composite Doped with Aluminium

ABSTRACT Polymer composites have recently received a considerable amount of scientific and technological interest, because their properties can be properly controlled, choosing the adequate doped particles, their size and concentrations, and the synthesis conditions. The aim of this study was to determine the crystallographic, functional group and microstructural analysis of oil palm biochar-reinforced hybrid polystyrene composite doped with aluminium. The composites were characterised by X-ray Diffractometry (XRD), Fourier Transform Infra-Red Spectroscopy (FTIR) and Scanning Electron Microscope (SEM). The composite was prepared by hand-layup technique at room temperature (25 ± 2°C) and cured for 7 days. The study revealed that the addition of aluminium as dopant induced sharp peaks at 38°, 40° and 68°, which are suggestive of crystalline properties of the hybrid composite. The changing/shifting FTIR peaks and the disappearance and reappearance of different peaks with change in aluminium doping were due to chemical interactions between the biochar filler and the aluminium dopant. The analysis suggested that the composites are likely to be susceptible to moisture due to the presence of strong and broad polar – OH groups from the spectra. Microstructural analysis showed that the interfacial adhesion of the composite increased as the aluminium composition increased.

Impact of Macrodiols on the Morphological Behavior of H12MDI/HDO-Based Polyurethane Elastomer.

In this study, we evaluated the morphological behavior of polyurethane elastomers (PUEs) by modifying the soft segment chain length. This was achieved by increasing the soft segment molecular weight (Mn = 400–4000 gmol−1). In this regard, polycaprolactone diol (PCL) was selected as the soft segment, and 4,4′-cyclohexamethylene diisocyanate (H12MDI) and 1,6-hexanediol (HDO) were chosen as the hard segments. The films were prepared by curing polymer on Teflon surfaces. Fourier transform infrared spectroscopy (FTIR) was utilized for functional group identification in the prepared elastomers. FTIR peaks indicated the disappearance of −NCO and −OH groups and the formation of urethane (NHCOO) groups. The morphological behavior of the synthesized polymer samples was also elucidated using scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. The AFM and SEM results indicated that the extent of microphase separation was enhanced by an increase in the molecular weight of PCL. The phase separation and degree of crystallinity of the soft and hard segments were described using X-ray diffraction (XRD). It was observed that the degree of crystallinity of the synthesized polymers increased with an increase in the soft segment’s chain length. To evaluate hydrophilicity/hydrophobicity, the contact angle was measured. A gradual increase in the contact angle with distilled water and diiodomethane (38.6°–54.9°) test liquids was observed. Moreover, the decrease in surface energy (46.95–24.45 mN/m) was also found to be inconsistent by increasing the molecular weight of polyols.

Biosynthesis of silver nanoparticles using Haloferax sp. NRS1: image analysis, characterization, in vitro thrombolysis and cytotoxicity

Haloferax sp strain NRS1 (MT967913) was isolated from a solar saltern on the southern coast of the Red Sea, Jeddah, Saudi Arabia. The present study was designed for estimate the potential capacity of the Haloferax sp strain NRS1 to synthesize (silver nanoparticles) AgNPs. Biological activities such as thrombolysis and cytotoxicity of biosynthesized AgNPs were evaluated. The characterization of silver nanoparticles biosynthesized by Haloferax sp (Hfx-AgNPs) was analyzed using UV–vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The dark brown color of the Hfx-AgNPs colloidal showed maximum absorbance at 458 nm. TEM image analysis revealed that the shape of the Hfx-AgNPs was spherical and a size range was 5.77- 73.14 nm. The XRD spectra showed a crystallographic plane of silver nanoparticles, with a crystalline size of 29.28 nm. The prominent FTIR peaks obtained at 3281, 1644 and 1250 cm− 1 identified the Functional groups involved in the reduction of silver ion reduction to AgNPs. Zeta potential results revealed a negative surface charge and stability of Hfx-AgNPs. Colloidal solution of Hfx-AgNPs with concentrations ranging from 3.125 to 100 μg/mL was used to determine its hemolytic activity. Less than 12.5 μg/mL of tested agent showed no hemolysis with high significant decrease compared with positive control, which confirms that Hfx-AgNPs are considered non-hemolytic (non-toxic) agents according to the ISO/TR 7405-1984(f) protocol. Thrombolysis activity of Hfx-AgNPs was observed in a concentration-dependent manner. Further, Hfx-AgNPs may be considered a promising lead compound for the pharmacological industry.

Impact of rare-earth ions on the physical properties of hexaferrites Ba0.5Sr0.5RE0.6Fe11.4O19, (RE = La, Yb, Sm, Gd, Er, Eu, and Dy)

Rare-earth ions RE3+ doped Sr/Ba-hexaferrite nanoparticles were prepared via the sol-gel auto-combustion method. The effect of replacing Fe3+ by RE3+ ions on the structural and morphological properties have been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The functional groups were detected by Fourier Transform infrared spectroscopy (FTIR). Hysteresis loops were formed by applying a magnetic field of ± 20 kOe, using vibrating sample magnetometer (VSM). The electric and dielectric parameters; conductivity (σ), dielectric constant (ε′), dielectric loss (ε"), tangent loss (tan δ) were obtained using LCR Meter at frequencies up to 5 MHz and temperature up to 620 K. The XRD analysis showed a pure M-type hexagonal phase with a space group P63/mmc. The Bragg's angle 2θ has been shifted toward lower values by RE3+ addition. Sedimentation of RE3+ ions on the grain boundaries makes barriers for the grain growth, where the size of nanoparticles varies in the range (35.22−51.9 nm). The characteristic FTIR peaks of hexaferrites are obtained between 430 and 595 cm−1. The hexagonal shape shown in the (SEM) images reflects the quality of preparation and uniform distribution of RE3+ ions. (EDX) results showed that there is no significant difference between the theoretical and experimental data for the weight percent of each element. The hysteresis loops give rise to the ferromagnetic nature of the materials at 300 K. Substitution of RE3+ ions with different properties changes the hopping rate of electrons between cations of the same element, which affect the dielectric parameters.