FTIR Absorption Research Articles

Improving the interface compatibility and mechanical performances of the cementitious composites by low-cost alkyl ketene dimer modified fibers

Natural fibers-reinforced cement composites have recently attracted more interest due to the trend in the development of sustainable construction materials. However, the poor fiber–matrix interface compatibility, which is caused by the swelling-shrinking behavior of hydrophilic natural fiber, negatively affects the mechanical properties of the composites thereby hindering their practical application. In order to promote interfacial compatibility, a new fiber surface treatment is needed. A low-cost alkyl ketene dimer (AKD) is adopted in this work, aiming at replacing the relatively expensive silane agents. This study focuses on fiber surface treatment and the resulting effects on the interface compatibility and mechanical performances of the composites. The effect of the fiber modification was characterized by FTIR and water absorption test; The interfacial compatibility of the composites was evaluated by the compatibility index calculation and SEM observation; A series of strength properties of the composites were carried out considering the influence of interface compatibility on mechanical performance. Results show a clear improvement in both interface compatibility and mechanical properties of the composites when AKD-modified fibers are used as reinforcement. The compressive and flexural strength are effectively increased up to 53 MPa and 8 MPa, respectively. Moreover, the approach of the low-cost AKD modification could further be applied to any natural fibers in cementitious composites, allowing cost-effectiveness in practical applications.

A study on solubility of bismuth cations in nickel cobalt ferrite nanoparticles and their influence on dielectric and magnetic properties

In this work, a low temperature (∼600 °C) solution combustion technique is employed for the synthesis of Ni0.5Co0.5BixFe2-xO4 (NCBFO, where x = 0.0, 0.05, 0.1, 0.15, & 0.2) nanoparticles with crystallite size variation of 17–22 nm. The X-ray diffraction (XRD) technique is used to confirm the formation of cubic spinel phase of Bi3+ doped (for x ≤ 0.05 samples) nickel–cobalt ferrite (NCFO) nanoparticles. The increase in bismuth substitution (x > 0.05) results in the formation of the Bi2O3 along with the NCFO structure, which results in the reduction of binding energy and is confirmed by the XRD and X-ray photoelectron spectroscopy (XPS) techniques. From the Raman spectra, the change in the intensities of the peaks is observed due to the variation of Bi3+ in NCFO matrix. Due to increasing cation concentration and electronegativity, the FTIR absorption band shifts toward the lower wave numbers. Dielectric measurements were carried out to examine the charge transport behavior and electric conduction mechanism. The FESEM images shows the non-magnetic bismuth atoms are diffused into the NCFO nanoparticles. From the vibrating sample magnetometer (VSM) analysis, it is observed that saturation magnetization, remanent magnetization, coercivity and squareness ratio are found to be maximum for x = 0.15 NCBFO sample. The high coercivity (Hc = 916.8 Oe) for the x = 0.15 sample indicates the hard ferromagnetic behaviour of the samples.

Active Site Descriptors from 95Mo NMR Signatures of Silica-Supported Mo-Based Olefin Metathesis Catalysts.

The olefin metathesis activity of silica-supported molybdenum oxides depends strongly on metal loading and preparation conditions, indicating that the nature and/or amounts of the active sites vary across compositionally similar catalysts. This is illustrated by comparing Mo-based (pre)catalysts prepared by impregnation (2.5-15.6 wt % Mo) and a model material (2.3 wt % Mo) synthesized via surface organometallic chemistry (SOMC). Analyses of FTIR, UV-vis, and Mo K-edge X-ray absorption spectra show that these (pre)catalysts are composed predominantly of similar isolated Mo dioxo sites. However, they exhibit different reaction properties in both liquid and gas-phase olefin metathesis with the SOMC-derived catalyst outperforming a classical catalyst of a similar Mo loading by ×1.5-2.0. Notably, solid-state 95Mo NMR analyses leveraging state-of-the-art high-field (28.2 T) measurement conditions resolve four distinct surface Mo dioxo sites with distributions that depend on the (pre)catalyst preparation methods. The intensity of a specific deshielded 95Mo NMR signal, which is most prominent in the SOMC-derived catalyst, is linked to reducibility and catalytic activity. First-principles calculations show that 95Mo NMR parameters directly manifest the local strain and coordination environment: acute (SiO-Mo(O)2-OSi) angles and low coordination numbers at Mo lead to highly deshielded 95Mo chemical shifts and small quadrupolar coupling constants, respectively. Natural chemical shift analyses relate the 95Mo NMR signature of strained species to low LUMO energies, which is consistent with their high reducibility and corresponding reactivity. The 95Mo chemical shifts of supported Mo dioxo sites are thus linked to their specific electronic structures, providing a powerful descriptor for their propensity toward reduction and formation of active sites.

Flavonoids, phenolics, and tannins loaded polycaprolactone nanofibers (NF) for wound dressing applications

Triphala is one of the commonly used ayurvedic formulations for gastrointestinal disorders. In Ayurveda, Triphala water has been used to wash wounds as an antimicrobial agent for wound healing. In this study, the wound healing property of Triphala was further enhanced by mixing equal proportions of medicinal plants like Acacia catechu, Glycyrrhiza glabra Azadirachta indica, and Coscinium fenestratum. The polyherbal extract was prepared from the new polyherbal formulation using a methanol-chloroform solvent mixture and analysed for its quality and quantity of phytochemicals. Then, the polyherbal extract at 1%, 3%, and 5% concentration was mixed with 10% polycaprolactone (PCL) polymer and converted into poly-herbal extract-loaded nanofibers using an electrospinning technique. The prepared nanofibers were characterized by FTIR, XRD, FESEM, contact angle, and water absorption. Further, the biological properties like antimicrobial activity and biocompatibility were also analysed. Finally, the in-vivo wound healing efficiency was studied using an animal model. The FTIR analysis reveals the presence of unique phytochemicals of plant extracts. Further, the FESEM confirms the presence of the drug on the surface of nanofibers. From the XRD, the reduction in crystallinity was observed due to herbal drug incorporation. Further, contact angle, water absorption also proved the absorbing ability of polyherbal-loaded nanofibers. The polycaprolactone-polyherbal (PCL-PHF) formulation of 3% and 5% loaded nanofibers shows faster wound healing compared to the control and standard. In addition, the polyherbal drug-loaded polycaprolactone shows faster granulation tissue formation and collagen synthesis compared to the standard group. The antioxidant property of the patch protects the wound from lipid peroxides and myeloperoxidase. Overall, the antimicrobial, antioxidant, and anti-inflammatory property of polyherbal extract aids in faster wound healing. This finding suggests that the polyherbal drug-loaded polycaprolactone nanofibrous mats could be used as an effective candidate for the treatment of open wounds.

Design and Implementation of Montmorillonite Clay-Based Catalyst for Carbon Nanotube Synthesizing

In this study, a catalyst based on Montmorillonite clay was implemented for carbon nanotubes (CNTs) synthesizing. The kaolinite clay was used as a supporting material for iron-cobalt bimetallic catalytic nanoparticles. The CNTs have been synthesized by using atmospheric chemical vapor deposition (APCVD). To assess the quality of preparation both the catalyst and CNTs have been characterized by different techniques. The chemical bonding and interactions were verified by FT-IR. The general overview of microstructure was examined using SEM, while, the detailed structure and morphology were examined by HR-TEM, in addition to thermal analysis (DTA); surface area (BET); X-ray fluorescence (XRF), Raman spectroscopy, and XRD analysis. The results revealed that; Fe2O3 and Co3O4 NPs were uniformly assembled on the clay nanoplatelets. The specific BET surface area of the clay and catalyst was determined to be 46.12 and 57.06 m2/g respectively. Also, from XRD, the peaks at 26° and 42.7° confirm the presence of CNTs. The FTIR absorption bands, D, G, and G\ bands from the Raman spectrum confirm the hexagonal structure of the CNTs. The obtained results prove the high quality of CNTs preparation.

Chitosan-based multifunctional films reinforced with cerium oxide nanoparticles for food packaging applications

The current study discusses the use of nanoceria as a multifunctional filler in food packaging biopolymer films for the first time. Nanoceria was synthesized using co-precipitation method. Chitosan-based food packaging films incorporated with 1 wt% and 2 wt% nanoceria were prepared and characterized. The FTIR absorption spectra confirms the presence of hydrogen bonding between nanoceria and chitosan structure. The nanocomposite films displayed strong UV-A and UV-B blocking properties besides being mechanically strong, thermally stable and possessing high moisture barrier properties. Further, due to the switching of oxidation states by cerium between Ce3+ and Ce4+, nanoceria shows high photocatalytic activity. This results in strong antimicrobial activity against E. coli and L. monocytogenes, especially under visible light. Further, the nanocomposite films displayed ∼1.25 times and ∼2.3 times higher ABTS and DPPH free radical scavenging potential, respectively, compared to pristine chitosan films, which indicate their high antioxidant potential. Moreover, the films depicted good biocompatibility towards L929 cells indicating their safety for food contact applications. With all these properties, the nanoceria-added chitosan films display strong potential for use in active food packaging, especially for high fat food products such as nuts and meats.

An optimization of synthesis technique for Na-X zeolite from coal-fly ash using Taguchi experimental design

Na-X Zeolite was made from Class-F coal fly ash from a thermal power plant in the Indian state of Gujarat. The objective of this study is to maximize Na-X zeolite crystallization by using alkaline fusion hydrothermal treatment. The authors have also optimized the process variables using the L9 orthogonal Taguchi method. The operating parameters investigated are fusion temperature, fusion time, liquid/solid (L/S) ratio, and alkaline solution concentration. The XRF analysis of coal fly ash reveals that quartz (SiO2), mullite (Al2O3.SiO4), and a small fraction of hematite and magnetite are the major minerals. The highly crystalline zeolite (ZT-5) was synthesized in a 0.3 M NaOH solution at a fusion temperature of 550 °C for 12 h. with a 1.3 L/S ratio. Contrary to the CFA graph, the zeolite (ZT-5) XRD pattern displays prominent peaks between 20 and 40°. The SEM images illustrate the transition from a smooth spherical texture to a highly crystalline lattice structure in the morphology of zeolite. A sharp stretch around 440 and 460 cm−1 and weak bend around 660 and 694 cm−1 show the relative O-T-O deformation and the change in shape of the Al-O-H bonds, as measured by FT-IR absorption.

Zinc oxide nanoparticles adsorb emerging pollutants (glyphosate pesticide) from aqueous solutions

The present study captures the precipitation synthesis of zinc nanoparticles and modification with alumina and oleic acid. The crystalline size evaluated from the XRD profile of the zinc oxide nanoparticles was 18.05nm but was reduced to 14.20 and 14.50nm upon modification with oleic acid and alumina. The XRD spectra also showed evidence of the amorphous nature of zinc oxide nanoparticles and subsequent enhancement upon modification. A porous appearance was observed in the SEM instrumentation but seems to be enhanced by modification. The FTIR absorption spectra of the nanoparticles showed a peak associated with ZnO vibration around 449cm, but the enhanced intensity was observed due to modification. The prepared ZnO-NPs and the modified samples were good materials for the adsorption removal of glyphosate from water, recording efficiencies above 94% at neutral pH and showing a possible incremental trend with an enhanced period of contact and adsorbent dosage. The adsorbents showed maximum capacity that ranged from 82.85 to 82. 97mg/g. The adsorption models of Freundlich, Temkin, Dubinin-Radushkevich and BET showed excellent fitness. Results from computational results complemented experimental data and were used to identify the sites for adsorption and characteristics of molecular descriptors for the systems.

78 Application of End-of-Shift Respirable Crystalline Silica Monitoring to Construction

Abstract Pilot project was conducted to determine the effect of common construction dusts as interferences in a new portable end-of-shift (EoS), direct-on-filter (DoF) sampling and analysis method for respirable crystalline silica (RCS), in this case quartz. The sampling and analysis system was developed by NIOSH (USA) for mineral dusts containing quartz in the mining environment. Construction dusts were prepared from plaster, drywall, cement and brick by grinding bulk materials to dust, aerosolizing the dust, and collecting the respirable fraction with high flow-rate respirable cyclones. Laboratory samples were generated by loading filters with different levels of Min-u-Sil 5 α-quartz, and different levels of the interfering dusts, singly and in combination. Samples were analyzed by the EoS-DoF FTIR procedure and some samples were sent for confirmatory XRD analysis. Good correlations were found between nominal quartz loading (0 µg, 25 µg, 50 µg, and 100 µg) adjusted for quartz in the interfering dust and FTIR absorbance alone and in the presence of all interfering dusts. In the important range of adjusted nominal quartz values (25-110 µg) the slopes of the correlations are similar. The presence of cement leads to lower quartz values and brick leads to higher values, but overall, 92% of the quartz contents predicted from the averaged calibration data agreed within 50% of the adjusted nominal loadings. This result is encouraging given the high levels of interfering dusts. Samples loaded with smaller amounts of all four dusts in combination gave even better results, with all nine results within 25% of the adjusted nominal loadings.

Hydrophobicity and FTIR absorbance spectroscopy of Polydimethylsiloxane (PDMS) films treated with aqueous gold nanoparticles (AuNP) solution

Polydimethylsiloxane (PDMS) thin films were treated with aqueous solutions of gold nanoparticles. Samples treated for 24, 48, and 72 h, including untreated PDMS film, were subjected to hydrophobicity test and FTIR absorbance spectroscopy. Hydrophobicity test involved measuring the contact angle of water droplets placed on top of the sample films. Contact angles were measured using Image J software. Treated samples showed significant hydrophobicity changes shown by the increasing value of measured contact angle from 71.3° for the untreated sample to 104.0° for the sample treated for 72 h. FTIR absorbance spectra of the treated sample showed peaks at 3374 cm−1, 3295 cm−1, 2096 cm−1 and 2031 cm−1 with the peak intensity values increasing with corresponding samples of increasing hours of treatment. With the presence of gold nanoparticles on the PDMS film confirmed, the gold nanoparticles may now be functionalized for biosensing and biotesting applications of liquid samples.

Synthesis and Characterization of Schiff Base Ligands and Their Palladium(II) Complexes

Abstract: This paper is concerned with the preparation and characterization of Schiff base ligands derived from the condensation of salicylaldehyde with three different diamines, namely, ethylenediamine, o-phenylenediamine, and trans-1,2-diaminocyclohexane. The Schiff base ligands were characterized by elemental analysis, melting point, FTIR, UV-Vis, 1H-NMR and 13C-NMR. The Schiff base ligands are reacted with palladium(II) ion via direct reaction or using a template method. Identical complexes were obtained from the two methods with the same percentage yields. The formulas obtained for the complexes are PdC16H16N2O2Cl2, [PdL1]Cl2; PdC16H16N2O2Br2, [PdL1]Br2; PdC16H16N2O2.(BF4)2, [PdL1](BF4)2; PdC20H16N2O2Cl2, [PdL2Cl]Cl; PdC20H16N2O2Br2, [PdL2]Br2; PdC20H15N2O2.BF4, [PdL2]BF4; PdC20H22N2O2Cl2, [PdL3]Cl2; PdC20H22N2O2Br2, [PdL3]Br2; PdC20H20N2O2.2H2O, [PdL3].2H2O. The isolated compounds were characterized based on their melting points, elemental analyses, conductivity measurements, nuclear magnetic resonance, FTIR and electronic absorption spectra.

Guanine adsorption on gold electrodes studied by in situ surface-enhanced infrared reflection absorption spectroscopy

The adsorption of guanine on single-crystal and thin-film gold electrodes has been explored by combination of cyclic voltammetry and ATR-SEIRA ‘in situ’ spectroscopy at two pD values (8 and 11.6) employing D2O as a solvent. The experimental conditions are selected to study the adsorption / desorption of the two forms of guanine involved in the second acid-base equilibria and its tautomeric forms.The ATR-SEIRA spectra of adsorbed guanine were compared to the absorption FT-IR spectra in solution and interpreted in light of DFT calculations of the different acid-base and tautomeric forms with different solvation states of the CO group. Furthermore, the preponderance of each tautomeric form and the possible changes in orientation with the electric field have been determined by analyzing the two-dimensional correlation spectrum (2D COS) as well as the influence of the potential on the integrated intensities of the spectral signals in the 1800–1400 cm−1 region. It has been found that at pD 8 the adsorbed keto-amino tautomer of neutral guanine predominates in solution and in adsorbed state, and adsorbed guanine slightly rotate its molecular plane with the potential. At pD 11.6 the keto-amino tautomer of anionic guanine is the unique form detectable in the solution, while in adsorbed state the keto-imino tautomeric form is also present with its preponderance increasing with the electrode potential.

Application of Bio-Inspired Gold Nanoparticles as Advanced Nanomaterial in Halt Nociceptive Pathway and Hepatotoxicity via Triggering Antioxidation System

This study aimed to investigate the pharmacological efficacy of gold nanoparticles (GNs) synthesized using a green route, employing the rhizome extract of Euphorbia wallichii (REEW) as a bioreductant and surface stabilizing agent. The GNs were characterized by a series of complementary analytical techniques including SEM-EDX, XRD, DLS, and IR spectroscopy. The reducing ability of REEW and synthesis of GNs were confirmed using UV–visible absorption spectroscopy, and the presence of spherical GNs with an fcc geometry was further confirmed through SEM and XRD analyses. The role of REEW’s extract as a stabilizing agent towards GNs was verified through FTIR and electronic absorption spectral measurement. The GC-MS analysis showed the presence of 41 different phytochemicals in REEW (chloromethyl 2-chloroundecanoate; cortisone; benzo[h]quinolone; piperidine, 2,4-dimethyl- 3,6,7-trimethoxyphenanthroindolizidine; 4-methyl-; 2-[2-quinolylmethyleneamino]ethanol, etc.), with RT values ranging from 3.10 to 27.22 min. The REEW-functionalized GNs exhibited promising antioxidant efficacy against H2O2 and *OH used as probe molecules. DPPH scavenging test showed significant EC50 values of 19.47 µg/mL, 13.53 µg/mL, and 10.57 µg/mL at 30, 60, and 90 min of incubation, respectively. Thermal nociceptive mice significantly acquired analgesia in a dose-dependent manner. Moreover, pre-treatment with REEW-GNs significantly restored serum ALT, AST, ALT, T.P, and Bilirubin levels in PCM-intoxicated mice. The antidiabetic activity in alloxan-induced diabetic rabbits fell in orders of metformin > GNs 300 mg/kg b.w > GNs 200 mg/kg b.w > GNs 100 mg/kg b.w > saline at 0.1 h of drug administration. To sum up, REEW functionalized GNs have tremendous potential for curing degenerative/metabolic diseases caused as a result of oxidative stresses.

Novel Metal Coordination Complexes Based on 4-Aminophenol: Spectroscopic Analysis and Antibacterial Test

The aims of this research are to synthesize and determine the formula, characteristics, and complex structure of Cu(II) and Co(II) with 4-aminophenol and to investigate their antibacterial activity. The complexes were synthesized by refluxing a solution of CuSO4·5H2O and CoSO4·7H2O, respectively, with 4-aminophenol in methanol for 1 h. The products were characterized using UV-Vis spectroscopy, atomic absorption spectroscopy, thermal analysis, conductivity, FTIR, and magnetic moment. The formation of the complex was indicated by shifting of maximum wavelength of the metal solution toward shorter, i.e., 817 to 421 nm for Cu(II) and 566 to 450 nm for Co(II). From the characterization, the proposed formulas of the complexes are [Cu(4-aminophenol)4]SO4 and [Co(4-aminophenol)4(H2O)2]SO4·5H2O forming square planar and octahedral geometry, respectively. Both complexes are paramagnetic with negligible antibacterial activity against Staphylococcus aureus, Staphylococcus epidermis, Escherichia coli, and Pseudomonas aeruginosa.

Greater efficiency of polyherbal drug encapsulated biosynthesized chitosan nano-biopolymer on diabetes and its complications

Diabetes is a highly complex disease that has an adverse impact on the lives of individuals, and the current medicines used to manage diabetes have obvious side effects. Medicinal plants, on the other hand, may serve as an alternate source of anti-diabetic drugs. A polyherbal combination has a higher and more extensive therapeutic potential than a single herb. Yet, due to deterioration during the absorption process, the usage of this drug still yields inadequate results. Encapsulation of polyherbal drug with chitosan nanoparticles is one of the key ways to solve this problem due to its biocombatibilty, slow and targeted drug delivery characteristics. In the present study, the chitosan was derived from prawn shell and the chitosan nanoparticles had been prepared by ionic-gelation method. The anti-diabetic polyherbal drug (Andrographis paniculata, Andrographis alata, Adhatoda zeylanica, Gymnema sylvestre, Syzygium cumini, and Justicia glabra) was encapsulated with a bio-derived chitosan biopolymer. The drug loading efficiency was about 85 %. The chemical and physical properties of the chitosan and drug-loaded chitosan nanoparticles had been analyzed by FT-IR absorption, XRD, SEM, TEM and EDAX analysis. The antidiabetic efficiency, hepatoprotective activity and antihyperlipedimic activity of the chitosan nanoparticles, polyherbal drug and polyherbal drug encapsulated with chitosan nanoparticles were assessed in a group of rats. The polyherbal drug reduced the serum glucose level from 306.4 mg/dL to 134.47 mg/dL, while the polyherbal drug encapsulated with chitosan nanoparticles reduced to 127.017 mg/dL. This was very close to the serum glucose level of non-diabetic rat (124.65 mg/dL). Further, it considerably increased the insulin level close to that of non-diabetic rat. Thus, the polyherbal drug encapsulated with chitosan nanoparticles showed superior efficiency in antidiabetic and also diabetic complications.

Synthesis of composites from hydroxypropyl cellulose:iron (III) oxide nanoparticles

In the present work, hydroxypropyl cellulose and hematite (α-Fe2O3) nanoparticles (HPC:Fe2O3NPs) composites in various ratios (20:0.5, 20:1, 20:1.5, and 20:2 wt:wt) were synthesised. X-ray diffraction (XRD), scanning electron microscopy (SEM), FTIR spectroscopy, and thermal analysis (DSC, and TGA) were used to examine the structural configuration and thermal properties of the produced composites. The IR crystallinity indices (TCI, LOI, and HBI) were also computed. XRD patterns reveal a mixture of amorphous HPC polymer components and Fe2O3NPs which identifies the relationship between the characteristics of the structure. Distributions and dispersions of Fe2O3NPs on the surface of HPC are apparent in SEM. FTIR absorbance spectra reveal that as the quantity of Fe2O3NPs increased alterations in the intensity, area, and band width were found indicating a change in the molecular configuration of HPC. Variations in the shape, size, and shifts in melting temperature to higher temperatures were found by DSC and TGA when the amount of Fe2O3NPs is increased which could be due to interactions between HPC and Fe2O3NPs. The antibacterial activity of the nanocomposites was tested against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria. The composites have good antibacterial activity, confirmed a high potential of antibacterial activity. The findings demonstrated that HPC:Fe2O3NPs composites lead to technological applications in a variety of medical applications.

Novel Vegetable Tanning Techniques by Notholithocarpus densiflorus Extract and Fatliquoring with Indigenous Bovine Fat

The major technical challenge of vegetable tanning is to improve the higher wear-comfort, leather strength and water resistance efficiency in daily necessities of leather products, aiming as an alternative to chrome tanning. The demonstration has been made by indigenous bovine fat and Tanoak tree (Notholithocarpus densiflorus) bark-wood extract for usage in the tanning process as a new kind of stuffing tanning technique for the first time. The tannin content maximum efficiency was found at 34.25% for the bark and 28.5% for the wood sample. The presence of tanning content was characterized by using UV-visible absorption spectroscopy, FTIR spectroscopy and HPLC techniques. The characterization data revealed mainly catechol presence in the bark and pyrogallol presence in the wood. The stuffing techniques tanned leather showed a shrinkage temperature of 95±2 °C. Other physical properties such as tensile strength, tear strength, grain cracking load, and flexing endurance were comparable to conventional chrome-tanned leather. The cross-sectional morphology and thermal degradation of the tanned leathers were characterized by FE-SEM and TGA techniques which revealed a fat-coated compact structure of the leather fibres and decomposition at mainly 100 °C to 300 °C respectively. The average contact angle of a water droplet on bark-tanned leather was greater than 100° and wood-tanned 88° at the solid-liquid interface respectively, which indicated the low wettability of leather as a water resistance leather. These new kinds of stuffing techniques of vegetable tanning processes will help to replace the chromium tanning, sustainable tanning approach and save the environment.

Structural, optical and radiation shielding parameters of sodium aluminium borate glasses modified with chromium oxide

Samples of nominal composition xCr2O3. (60-x)B2O3.5Al2O3.35Na2O: x = 0 (Cr0), 0.1 (Cr0.1), 0.2 (Cr0.2), 0.4 (Cr0.4), 0.6 (Cr0.6), 0.8 (Cr0.8), and 1 (Cr1) mol% were prepared via the traditional melt quenching route. Structural FTIR absorption spectra of the prepared glasses reveal distinct absorption bands which are characteristic of both triangular BO3 and tetrahedral BO4 groups within their varying wavenumber vibrational sites. The dopant chromium ions are observed to have no distinct variations on the FTIR spectra because of low dopant percent. Optical absorption characterization indicates that the undoped glass shows only UV absorption which is related to originating from unavoidable trace ferric ions present as impurities in the used chemicals. The Cr2O3-doped glasses reveal additional UV absorption at about 370-385 nm correlated with the hexavalent state of chromium, producing this distinct charge transfer band. Additionally, two visible bands are identified at about 420-400 nm and 580-640 nm originating from trivalent chromium ions with distorted octahedral coordination. Optical parameters including band gap, refractive index, molar refraction, and reflection losses were calculated together with optical dielectric properties, electronic and molar polarizability. In terms of radiation shielding capacity, increasing Cr2O3 mol% of the sample encoded Cr1 that possessed the highest mass (μm) and linear (μ) attenuation coefficients, but the lowest half value layer (HVL) at low and high incident photon energy, results showed that Cr1 can be used in optical and radiation shielding safety.

Co-Application of Silver Nanoparticles and Symbiotic Fungus Piriformospora indica Improves Secondary Metabolite Production in Black Rice

In the current research, unique Nano-Embedded Fungus (NEF), made by the synergic association of silver nanoparticles (AgNPs) and endophytic fungus (Piriformospora indica), is studied, and the impact of NEF on black rice secondary metabolites is reported. AgNPs were synthesized by chemical reduction process using the temperature-dependent method and characterized for morphological and structural features through UV visible absorption spectroscopy, zeta potential, XRD, SEM-EDX, and FTIR spectroscopy. The NEF, prepared by optimizing the AgNPs concentration (300 ppm) in agar and broth media, showed better fungal biomass, colony diameter, spore count, and spore size than the control P. indica. Treatment with AgNPs, P. indica, and NEF resulted in growth enhancement in black rice. NEF and AgNPs stimulated the production of secondary metabolites in its leaves. The concentrations of chlorophyll, carotenoids, flavonoids, and terpenoids were increased in plants inoculated with P. indica and AgNPs. The findings of the study highlight the synergistic effect of AgNPs and the fungal symbionts in augmenting the secondary metabolites in leaves of black rice.

Inhibition of Polymicrobial Biofilms of Candida albicans-Staphylococcus aureus/Streptococcus mutans by Fucoidan-Gold Nanoparticles.

The polymicrobial proliferation and development of complex biofilm morphologies by bacterial and fungal pathogens in the host are some of the key factors contributing to the failure of antimicrobial treatments. The polymicrobial interaction of Candida albicans and some bacterial species has been extensively studied in both in vitro and in vivo model systems. Alternative strategies for disrupting polymicrobial interaction and biofilm formation are constantly needed. Among several alternative strategies, the use of nanoparticles synthesized using a natural product in the treatment of microbial infection has been considered a promising approach. The current study aimed to synthesize gold nanoparticles (AuNPs) using a natural product, fucoidan, and to test their efficacy against mono and duo combinations of fungal (Candida albicans) and bacterial (Staphylococcus aureus/Streptococcus mutans) biofilms. Several methods were used to characterize and study Fu-AuNPs, including UV-vis absorption spectroscopy, FTIR, FE-TEM, EDS, DLS, zeta potential, and XRD. The concentration-dependent inhibition of early-stage biofilms and the eradication of mature biofilms of single species of C. albicans, S. aureus, and S. mutans have been observed. Early biofilms of a dual-species combination of C. albicans and S. aureus/S. mutans were also suppressed at an increasing concentration of Fu-AuNPs. Furthermore, Fu-AuNPs significantly eradicated the established mature biofilm of mixed species. The treatment method proposed in this study, which involves the use of marine-bioinspired nanoparticles, is a promising and biocompatible agent for preventing the growth of polymicrobial biofilms of bacterial and fungal pathogens.