Intensity Of Vibrational Bands Research Articles

Growth of dendritic CuS nanostructures for photoacoustic image guided Chemo-Photothermal therapy

Herein, we report a unique method for design and development of carboxyl enriched dendritic CuS nanostructures (CuS NSs) for photoacoustic image guided chemo-photothermal therapy. The dendritic network was grown on the surface of CuS nanoparticles via layer-by-layer assembly of amino acid. XRD and TEM studies established the formation of crystalline well-spherical nanosized hexagonal covellite (CuS) phase. The successful growth of dendritic structure was apparent from the rise in surface charge, hydrodynamic diameter and characteristic vibrational band intensity of peptide bonds. The developed different generations of dendritic CuS NSs (D0-CuS NSs, D1-CuS NSs, D2-CuS NSs and D3-CuS NSs) displayed wide-ranging absorption band in near infrared (NIR) zone and exhibited good photothermal heating efficacy upon irradiation of 980 nm laser light. From in to vitro cellular studies, it has been found that the NIR irradiation effectively enhanced the photothermal toxicity of D3-CuS NSs towards cancer cells. Moreover, these negatively charged water-dispersible D3-CuS NSs were conjugated with positively charged anticancer drug, doxorubicin hydrochloride (DOX) through electrostatic interaction. The DOX loaded D3-CuS NSs (DOX@D3-CuS NSs) revealed pH dependent drug release behaviour and their considerable uptake in breast cancer cells (MCF-7). Further, DOX@D3-CuS NSs exhibited a much higher toxicity towards cancer cells upon NIR light over individual counterparts suggesting their strong ability for chemo-photothermal therapy. Moreover, these biocompatible CuS NSs have shown excellent concentration dependent photoacoustic properties at pulse laser excitation (850 nm) and thus, they can be found potential application in chemo-photothermal therapy.

Infrared Reflection-Absorption Spectroscopy (IRRAS) applied to oxides: Ceria as a case study

Infrared Reflection-Absorption Spectroscopy (IRRAS), a pivotal tool in the study of the surface chemistry of metals, has recently also gained substantial impact for oxide surfaces, despite the inherent challenges originating from their dielectric properties. This review focuses on the application of IRRAS to ceria (CeO2), a metal oxide for which a significant amount of experimental data exists. We elaborate on the differences in optical properties between metals and metal oxides, which result in lower intensity of adsorbate vibrational bands by approximately two orders of magnitude and polarization-dependent shifts of vibrational frequencies. We examine how the surface selection rule, governing IR spectroscopy of adsorbates on metals, contrasts sharply with the behavior of dielectrics where both positive and negative vibrational bands can occur, and how IRRAS can capture vibrations with transition dipole moments oriented parallel to the surface—a capability not feasible on metallic surfaces. Finally, this paper explores the broader implications of these findings for enhancing our understanding of molecule interactions on oxide surfaces, and for using IR spectroscopy for operando studies under technologically relevant conditions.

The pH effects on thermal amyloid fibrillation kinetics of hen egg‐white lysozyme using new normalization factor for Raman spectroscopy

AbstractAmyloid fibrillation kinetics of proteins associated with neurodegenerative diseases has been extensively studied using Raman spectroscopy. The normalization factor for the spectra is crucial for obtaining correct kinetics of Raman indicators, especially vibrational band intensities. Here, we compared the concentration dependences between the absorption at 280 nm in UV–vis spectroscopy and the phenylalanine (Phe) Raman band intensity at 1003 cm−1 in amyloid fibrillation kinetics of lysozyme. The former exhibits better performance as normalization factor. Using this new normalization factor, the effect of pH value on the transformation of hen egg‐white lysozyme (HEWL) tertiary and secondary structures was studied subsequently. With increasing acidity, the unfolding of tertiary structures and the transformation of secondary structures are significantly accelerated. Notably, the populations of various secondary structures in the final state remain in the pH < 2.0 solutions, indicating that the branching ratios of “on‐pathway” to amyloid fibrils and “off‐pathway” to gel‐like aggregates are independent on the pH value in the range of 1.1–1.9.

Ru(II)‐Nitrophenylhydrazine/Chlorophenylhydrazine Complexes: Nanoarchitectonics, Biological Evaluation and In silico Study

AbstractRu(II)‐arene compounds are being investigated as anticancer agents due to the biocompatibility of ruthenium and their structural diversity. Two newly synthesized Ru(II) complexes, [RuCl(η6‐p‐cymene)(3‐DNPH)] (chlorido(η6‐p‐cymene)(3‐nitrophenylhydrazine‐k2N,N′)ruthenium(II)) (1) and [RuCl(η6‐p‐cymene)(3‐CNPH)] (chlorido(3‐chlorophenylhydrazine‐k2N,N′)(η6‐p‐cymene)ruthenium(II)) (2), are experimentally (IR, NMR) and theoretically (B3LYP/6‐31+G(d,p)(H,C,N,Cl)/LanL2DZ(Ru)) characterized. Experimental and theoretical values of 1H and 13C chemical shifts and position of the most intense vibrational bands showed high correlation coefficients and low mean absolute errors, proving the predicted structure and applicability of the selected level of theory. Cell viability studies performed on MDA‐MB‐468, BT‐474, and PC3 cells using MTT and CV assay indicated the activity of the second complex similar to the activity of cisplatin towards BT‐474 breast cancer cells. The spectrofluorimetric measurements of Bovine Serum Albumin showed the binding process‘s spontaneity of complexes and protein, with a binding energy of around −30 kJ mol−1. Detailed molecular docking analysis allowed the elucidation of the binding mechanism through specific intermolecular interactions. Both compounds showed a higher affinity towards BSA than naproxen and cisplatin. Molecular docking simulations proved the spontaneity of the complexes binding to DNA. Based on these promising results, further biological examinations of these compounds are advised.

13CH4/12CH4 sensing using Raman spectroscopy

The paper presents a technique for measuring the concentration of 13CH4 in natural methane using Raman spectroscopy. The peak positions and the relative scattering cross-sections of the Q-branches for the most intense vibrational bands of 13CH4 are determined. Features of the 13CH4/12CH4 ratio measurement methods using Q-branches of the ν1 and ν3 bands were considered. It was shown that the 13CH4/12CH4 ratio can be determined by simulation of the ν3 bands of these molecules without the use of experimental spectra. In our experiments the measurement error of δ13C value was 10 ‰ using the 100-s exposure spectrum at a gas pressure close to 1 atm recorded on the developed Raman spectrometer. In addition, the Raman spectra of alkanes (up to n-hexane) in the range of 2850–3050 cm−1 at a resolution of 0.4 cm−1 are presented, and their integrated intensities in the ranges of the characteristic bands of 13CH4 and 12CH4 are provided. The data obtained make it possible to expand the capabilities of Raman gas analyzers in the mud gas logging industry.

Neutron sensing at spallation neutron sources by SERS

Neutron detectors are paramount in many applications from medical science to homeland security and aerospace. A miniaturized solid-state device based on a nanostructured-gold thin film grown by pulsed laser ablation under deposition-controlled conditions and functionalized with a monolayer of 4-mercaptophenyboronic acid (4-MPBA) was fabricated as a neutron dose detector. The device is tested with slow neutron detection in the thermal and epithermal energy range at ISIS spallation neutron source (UK). After the neutron irradiation, 4-MPBA is converted into thiophenol (TP), and the chemical modification is monitored by the intensity of related vibrational bands at 1586 cm−1 (4-MPBA) and 1574 cm−1 (TP). The latter are used as a vibrational signature of the absorbed dose by surface-enhanced Raman spectroscopy (SERS). The conversion of 4-MPBA to TP is due to the loss of the boron-containing group after the absorption of a slow neutron by 10B isotope. The I1574/I1586 ratio is used to estimate the ratio of 10B nuclei absorption reactions due to the thermal and epithermal contributions and it is proposed for the development of neutron dosimetry for nuclear medicine, aerospace, and security applications.

Influence of γ–radiation input dose and post-radiation high temperature shear grinding on polypropylene functional group composition

The effect of γ-irradiation in vacuum and air followed by HTSG of polypropylene (PP) is studied using both infrared (IR) spectroscopy and computational chemistry at the correlated G3(MP2)B3 molecular orbital theory level. γ-irradiation of PP in vacuum was found to primarily induce unsaturation and hydroxyl formation from residual system water whereas γ-irradiation of PP in air oxidizes the polymer and degrades the backbone in a thin layer due to oxygen permeability limitations as supported by the computational thermodynamics results. HTSG of the irradiated PP produced smaller particles than un-irradiated PP. HTSG of the irradiated PP led to a decrease in the IR band intensity from degradation due to a nominal homogenization of the pellet. HTSG of air irradiated PP led to a reduction in IR vibrational band intensity from oxidation due to thermal degradation. High-temperature shear grinding of γ-irradiated PP produces variable chemical and physical composition depending on irradiation input dose and environmental conditions. The combination of γ-irradiation and HTSG may be of benefit in recycling polypropylene.

TD-DFT calculation, equilibrium and kinetic adsorption study of removal of rose bengal dye by poly vinyl alcohol as a synthetic polymer adsorbent hybrid blend

Spectrophotometric study of the efficacy of the synthetic polymer such as polyvinyl alcohol in the removal of the dye Rose Bengal (RO) was examined. Different contact times, starting dye concentrations, adsorbent doses, dye solution temperatures, and pH values were tested. Density functional theory (DFT) with functional B3LYP and Hartree-Fock (HF) were used to investigate the optimal geometries, vibrational wavenumbers, vibrational band intensities, and atomic charges of 9VC. The researchers contrasted theoretical predictions for the basic vibrational modes with actual measurements. Using the functional B3LYP of DFT, we analyzed the hybrid organic dye (PVA+RO)HB such as the shape of geometry, electronic configuration, the capacity of polarizability, and second-order hyperpolarizability. The time-dependent density functional theory (TD- DFT), linked to a variety of hybrid functionals, was used in order to conduct research on the electronic absorption spectrum. Good agreement was found between the correlation coefficient values obtained from the Langmuir and Freundlich isotherm models, which were used to characterize the adsorption equilibrium. Pseudo-first-order kinetics was the best fit for the data on RO adsorption onto PVA. The values of enthalpy change and free energy change are negative and these confirm that our study concluded the exothermic and adsorption mechanism was spontaneous, respectively. The adsorption capacity was found to increase with increasing temperature. So, the kinetic parameters were evaluated from the temperature dependence of the adsorption capacity using the method of least squares.

Exploring the structure–property relationship of ethylenediammonium hydrogen phosphite: Insights from XRD, vibrational, DFT, and biological evaluation

The interaction between the molecules of phosphonic acid (H2P(H)O3) and ethylenediamine (NH2CH2CH2NH2) reacts in an aqueous solution and results in the formation of salt molecules with two NH∙∙∙O hydrogen bonds. The calculated stabilization energy of the 1:1 salt molecule, which represents the strength of the two NH∙∙∙O hydrogen bonds, is 8.063 kcal/mol (33.735 kJ/mol). The title compound crystallizes in the centrosymmetric space group Pbca of the orthorhombic system with eight molecules per unit cell. The three-dimensional supramolecular network is formed by hydrogen bonds between every hydrogen atom in both of the NH3+ groups of the ethylenediammonium cation. Hirshfeld surfaces and two-dimensional fingerprint plots were used to analyze the interactions of ethylenediammonium cations and hydrogen phosphite anions forming a three-dimensional supramolecular structure. Practically, two types of interactions, i.e. NH∙∙∙O and H∙∙∙H, are observed for both building units, ethylenediammonium cation and the hydrogen phosphite anion, which cover 100 % of the HS surface of each unit. Density functional theory (DFT) computations of normal mode force constants and structure optimizations were employed to evaluate the molecular structure, fundamental vibrational frequencies, and vibrational band intensities. The utilization of potential energy distribution (PED) allowed for the determination of comprehensive vibrational assignments for the wave numbers. The interactions involving the charge transfers of the supramolecular unit are explained by the computed HOMO and LUMO energy gap of 5.193 eV. To prove that the EDHP has stabilized, NBO analysis has been done. NBO studies establish that strong intra and intermolecular stabilization exists between the ethylenediammonium cation and the hydrogen phosphite anion. Furthermore, to investigate the synthetic chemical EDHP as a possible drug candidate, molecular docking studies and drug-likeness evaluation have been carried out. The best binding energy of the obtained cluster is −3.85 kcal/mol. The rmsd value is found to be 1.950 (≤2 Å) which is fairly good and confirms the best superimposed docked pose. Thus Molecular docking studies reveal that EDHP molecule has a substantial binding affinity for the SARS-CoV-2 protein and can serve as a promising drug candidate. The bioavailability score of 0.55 from pharmacokinetics study suggests that EDHP may have moderate bioavailability.

Molecular structure, electronic properties, spectroscopic, quantum computational studies of 1-(4-hydroxy-3-methoxyphenyl)ethanone-effective anticancer medicine

The molecular structure of 1-(4-hydroxy-3-methoxyphenyl) ethenone has been optimized, and its various parameters were ascertained, using Density Functional Theory. The molecule’s Fourier Transform-Infra Red and Raman spectra are recorded and examined. By comparing the computational and experimental results, molecular structure, bond length, and vibrational band intensity were all interpreted. The Integral Equation Formalism polarizable continuum model’s depictions of electronic and Frontier Molecular Orbital solvent interaction investigations are sported to perceive the charge transfer among the atoms of the molecule in eco-green solvents such as water, acetone, and ethanol. The reactivity sites can be studied by locating and charting the electron density on the surface. The compound’s hardness, softness, electrophilicity, and ionization potential were all analyzed. The pharmacological effects and intra-molecular hyper conjugative interactions are liable for its molecular stability, as shown by Natural Bond Orbital research. Topological studies, including Electron Localized Function, Localized Orbital Locator, and Reduced density gradient analysis, were performed to locate the compound’s bonding area and Vander Waals interactions. Urea was used as a reference compound to examine the substance’s non-linear optical characteristics. Total Density of States has investigated the role of molecular orbitals. Drug-likeness, a Ramachandran plot, and molecular docking were also performed to further analyze 1-(4-hydroxy-3-methoxyphenyl) ethanone’s biological activity. The docking results lend credence to the idea that the title compound could function as a powerful cancer treatment.

Effect of accelerated weathering on pyrolysis kinetics and ignition characteristics of typical thermal insulation materials

Thermal insulation materials are widely installed on external walls because of their excellent properties. However, thermal insulation materials are often exposed to air and sunlight as external facades fall off, which can lead to weathering and potential fire risk. Especially, weathering may cause changes in pyrolysis and combustion characteristics of thermal insulation materials, which is of great significance for understanding fire. To simulate real exposure conditions, typical thermal insulation materials (expanded polystyrene) were weathered by accelerated weathering for 25, 45, 90, 135 and 180 days. Pyrolysis characteristics of unweathered and weathered materials were researched by thermogravimetric analysis, Fourier transform infrared (FTIR) spectrometric technique and cone calorimeter experiments. The kinetic parameters were estimated and optimized using Coats-Redfern and Shuffled Complex Evolution methods. Subsequently, the correlation between weathering time and kinetic parameters was obtained. The functional groups were detected by FTIR. Finally, the ignition time was measured. The results showed that the color of materials changed and the chalking appeared as accelerated weathering increased. Activation energy decreased from 324.44 kJ/mol to 91.04 kJ/mol, and pre-exponential factors reduced from 52.31 lns−1 to 10.72 lns−1. The intensity of vibration bands was strengthened. Ignition time was shortened by 119 s, indicating that weathered EPS is more easily ignited.

Synthesis of nickel oxide nanoparticles from Enicostemma littorale plant extract and investigation of their photocatalytic and antimicrobial properties

Nickel oxide nanoparticles (NiOxi‐NPs) with a spherical shape have been developed using a green aqueous extract of the Enicostemma littorale plant, and their efficacy on various photochemical and biological applications like antibacterial and anticancer has been studied. The intense vibrational bands in the Fourier transformer infrared spectroscopy (FT‐IR) spectrum correspond to Ni‐O, C=O, and O‐H, confirming the formation of NiOxi‐NP. Also, two intense peaks at 2θ = 36.42° (111) and 42.87° (200) in the X‐ray diffraction (XRD) spectrum confirm the NiOxi‐NP crystal lattice as face center cubic (FCC). To determine the light‐absorbing behavior and shape of the newly produced NiOxi‐NP, UV‐visible, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) investigations were performed. NiOxi‐NP has a maximal distinctive UV‐visible absorption wavelength in the 306‐nm region. The nickel oxide nanoparticles are formed in spherical form and dispersed in the 33‐ to 46‐nm size range, according to the SEM and TEM investigations. According to the 3‐(4,5‐dimethyl thiazolyl‐2)‐2,5‐diphenyltetrazolium bromide (MTT) assay, the Michigan Cancer Foundation‐7 (MCF‐7) breast tumor cancer cell line is extremely responsive to the green NiOxi‐NPs' exceptional lethal effectiveness. The IC50 value for MCF‐7 cell lines is 12.87 μg/mL. When tested against bacteria such as Bacillus subtilis, Staphylococcus, and Escherichia coli stains, the aforementioned particles demonstrate greater activity on the three bacteria. The photocatalytic activity of the greenery NiOxi‐NP over the dye rhodamine B (RBD) was finished in 16 min when the solution concentration was 0.025 mg/L. The green synthesis of NiOxi‐NP nanoparticles can behave as a better UV‐visible screener between 290 and 450 nm, a better antimicrobial agent, a better RBD degradation agent, and a better low‐dose anticancer agent.

Thermal Decomposition of 2- and 4-Iodobenzyl Iodide Yields Fulvenallene and Ethynylcyclopentadienes: A Joint Threshold Photoelectron and Matrix Isolation Spectroscopic Study.

The thermal decomposition of 2- and 4-iodobenzyl iodide at high temperatures was investigated by mass-selective threshold photoelectron spectroscopy (ms-TPES) in the gas phase, as well as by matrix isolation infrared spectroscopy in cryogenic matrices. Scission of the benzylic C-I bond in the precursors at 850 K affords 2- and 4-iodobenzyl radicals (ortho- and para-IC6H4CH2•), respectively, in high yields. The adiabatic ionization energies of ortho-IC6H4CH2• to the X̃+(1A') and ã+(3A') cation states were determined to be 7.31 ± 0.01 and 8.78 ± 0.01 eV, whereas those of para-IC6H4CH2• were measured to be 7.17 ± 0.01 eV for X̃+(1A1) and 8.98 ± 0.01 eV for ã+(3A1). Vibrational frequencies of the ring breathing mode were measured to be 560 ± 80 and 240 ± 80 cm-1 for the X̃+(1A') and ã+(3A') cation states of ortho-IC6H4CH2•, respectively. At higher temperatures, subsequent aryl C-I cleavage takes place to form α,2- and α,4-didehydrotoluene diradicals, which rapidly undergo ring contraction to a stable product, fulvenallene. Nevertheless, the most intense vibrational bands of the elusive α,2- and α,4-didehydrotoluene diradicals were observed in the Ar matrices. In addition, high-energy and astrochemically relevant C7H6 isomers 1-, 2-, and 5-ethynylcyclopentadiene are observed at even higher pyrolysis temperatures along with fulvenallene. Complementary quantum chemical computations on the C7H6 potential energy surface predict a feasible reaction cascade at high temperatures from the diradicals to fulvenallene, supporting the experimental observations in both the gas phase and cryogenic matrices.

Kinetics and TD-DFT calculations of base-catalyzed oxidation of acriflavine hydrochloride: Removal of dyes colors from wastewater

The oxidation kinetics of acriflavine hydrochloride (AFH) to nitro-acriflavine (N-AFH) by KMnO4 as oxidizing agent in sodium hydroxide medium at a constant ionic strength of 0.5 moldm−3 was studied using spectrophotometric methods. It was found that the reaction went through two distinct steps that could be monitored. In the first stage, coordination species including transient blue pentavalent manganese and/or green hexavalent manganese species may be made quite quickly followed by the decomposition of intermediates in the second slow stage to produce soluble Mn (IV) and the nitroacriflavine as resulting products of oxidation. It has been investigated how several variables such as pH, ionic strength, permanganate ion concentration, and AFH substrate concentration affect oxidation rates. The experimental results demonstrated a first-order dependence in [MnO4−] and fractional first-order kinetics in each of [AFH] and alkali concentration under pseudo-first-order reaction conditions of [MnO4−] >>10 [AFH]. Sodium hydroxide concentrations accelerated the oxidation reaction, and as the alkali concentration rose, so the type of catalyzed is base-catalyzed. Evidence for the creation of a 1:1 intermediate complex was discovered using spectrophotometry and kinetics. In accordance with the kinetic findings, an efficient oxidation process that is compatible with the kinetic data obtained in terms of the activation parameters evaluated was analyzed, proposed, and debated. There are several techniques used to study the nanostructure thin films (AFH)TF and (N- AFH)TF, with using FT-IR, kinetic, isotherms of liquid-phase adsorption, and optical characteristics. A low deposition rate and a chamber pressure of 5 × 105 mbar are used in the PVD method to create (AFH)TF and (N-AFH)TF thin coatings with a 95 nanometer thickness. The isolated molecules (AFH)Iso and (N-AFH)Iso were additionally optimized using time-dependent density functional theory (TD-DFT) using TD-DFTD/Mol3 and Cambridge Serial Total Energy Bundle (TD-FDT/CASTEP). The optimized geometries, vibrational wavenumbers, intensity of vibrational bands, and various atomic charges of 9VC have all been investigated using DFT-B3LYP system using a 6-31G (d,p) basis set.

Synthesis, crystal structure, static and dynamic properties, molecular structure, reactive sites, wavefunction and molecular docking of 1-(3-((4-(diethylamino)-2-hydroxybenzylidene)amino)phenyl)ethan-1-one

The Schiff base compound1-(3-((4-(diethylamino)-2-hydroxybenzylidene)amino)phenyl)ethan-1-one (34D2HA) has been synthesized and characterized by FT-IR, XRD techniques. The title compound was optimized. From the calculated perspective, the title compound's Natural bond orbital, Molecular Electrostatic Potential, Electron Localization Function, Localized-Orbital Locator, Frontier Molecular Orbital, Mulliken charges and Fukui function properties were also examined. The vibrational analysis of 34D2HA were investigated by means of computational calculations. The intensity of vibrational bands and the fundamental frequencies were evaluated by the standard B3LYP method on the basis set of 6–311G(d,p) combination with diffusion function + + are done by density functional theory (DFT). In addition to PED, VEDA was utilized to predict vibrational assignment. The absorptions were analyzed theoretically using UV–Vis spectra with different solvents. The experimental and computed bond parameters exhibit a strong agreement. The infrared frequency calculations lead overall agreement with observed spectral patterns. Beside, ADME studies have been carried out and this compound satisfies with Lipinski's rule of five. The results of protein- ligand docking using the Auto Dock method with various proteins suggest that the molecule has pharmaceutical properties against receptors.

Surface-enhanced Raman spectroscopy enables confirmatory detection of dyes on hair submerged in hypolimnion water for up to twelve weeks.

Difficulties in the localization of bodies of homicidal or drowning victims in natural water result in their submergence for weeks if not months. Water insects and microbes drastically change the body's appearance, which significantly changes the determination of a victim's identity. DNA analysis is commonly used for identifying the decedent; however, this PCR-based approach is time-consuming and destructive of the evidence. Considering that nearly half of the people in the world dye their hair with a variety of permanent and semi-permanent dyes, one can expect that confirmatory identification of dyes on the body's hair can be used to shed light on the victim's identity. A growing body of evidence suggests that surface-enhanced Raman spectroscopy (SERS) can be used to detect and identify hair dyes. In this study, we investigated the extent to which SERS could be used to detect black and blue, permanent and semi-permanent dyes on hair submerged in hypolimnion water for up to twelve weeks. We found that SERS enabled 100% accurate identification of analyzed dyes on hair submerged in hypolimnion water for up to 8 weeks, whereas, on average, 87% accurate identification of the hair dyes could be achieved on hair exposed for 10 weeks and 50% for hair exposed 12 weeks in hypolimnion water. We also found that the aqueous environment caused progressive fading of some dyes, whereas other dyes showed substantial spectral transformations after prolonged submergence. Finally, we found that changes in the intensity of vibrational bands of dyes could be used to predict the duration of submergence of colored hair in hypolimnion water.

Spectroscopic, kinetics and molecular structure investigations of acriflavine hydrochloride dye onto thiobarbituric acid nanoblend TD-DFT calculations: Removal of dyes from wastewater applications

The goal of this study is to use an ultraviolet–visible spectroscopic method at maximum absorption λmax = 450 nm to explore the elimination of poisonous acriflavine hydrochloride (ACF) utilizing antibacterial thiobarbituric acid (TBA) as an adsorbent. We looked at the effects of a number of variables, including [dye], adsorbent quantity, time, and temperature on the adsorption process. At 450 nm, thiobarbituric acid had a maximum percentage removal of ACF is 62 % at 20 °C and the adsorbent dose increased from 0.01 to 0.1 g/10 ml, so, the percentage removal efficiency of acriflavine dye increases steadily but the adsorption capacity of acriflavine dye suddenly decreases. The nanoblend (ACF + TBA)NB thin film is studied using various methods, including FT-IR, kientic, isotherms of liquid-phase adsorption and SEM methods. In FT-IR spectra the changes appears in the absorption peak suggested that the ACF molecules were interacting with the functional groups of the bio-sorbent. Again, the surface of TBA morphology and textural characteristics was carried out using SEM technique. TBA absorbed a substantial amount of ACF and developed an ACF material covering their surface. The physicochemical interactions between TBA and adsorbate molecules change the microstructure of TBA somewhat. (TBA)TF and (ACF + TBA)NB thin films with a thickness of 200 ± 5 nm are manufactured by PVD technique at a low deposition rate with basic pressure of the chamber was 5 × 10−5 mbar. Time dependent Density Functional theory (TD-DFT) was also utilised tooptimizeisolated molecule nanoblend (ACF + TBA)NB/Iso employing TD-DFTD/Mol3 and Cambridge Serial Total Energy Bundle (TD-FDT/CASTEP). Using the DFT-B3LYP method with a 6-31G(d,p) basis, the optimised geometries, vibrational wavenumbers, intensity of vibrational bands, and numerous atomic charges of 9VC have been studied. The adsorption equilibrium were evaluated using Langmuir and Freundlich isotherms, and a suitable reaction mechanism was proposed and argued. From the experimental results obtained, the temperature rises from 293 to 323 oK, and the dye's capacity of adsorption and percentage of removal decrease with rising temperature. The exothermic nature of the adsorption of ACF on TBA is demonstrated by the obtained value of ΔH° as −15.3809 kJ mol−1. The assumed ΔG° value (−13.672 kJmol−1) establishes the spontaneous type of the adsorption model. Additionally, the value of ΔS° (−5.83 J mol K−1) provides information about TBA's lack of affinity for ACF.

Experimental and simulated TD-DFT study of malachite green dye and tetrahydroquinoxaline hybrid blend: Its application removal from wastewater

2-Carbethoxy-3-oxo-1,2,3,4-tetrahydroquinoxaline (CTQ) was synthesized using a condensation reaction between o-phenylenediamine and diethylbromomalonate under regulated conditions. CTQ compound was used as a powerful adsorbent in the elimination of harmful malachite green (MG) dye from wastewater using the spectrophotometer technique. By applying Hartree-Fock (HF) and density functional theory (DFT-B3LYP) with 6-31G(d,p) as the basis, the optimized geometries, vibrational wavenumbers, intensities of vibrational bands, and various atomic charges of 9VC have been investigated. The basic vibrational modes measured experimentally are analyzed and compared to theoretical predictions. Density functional theory (DFT) was used to examine the geometry, electronic structure, polarizability, and hyperpolarizability of the hybrid blend organic dye (CTQ+MG)HB, which contains π-conjugated tetrahydroquinoxaline unit with an electron donor-acceptor moiety, and time-dependent DFT (TD-DFT) with several hybrid functionals were used to examine the electronic absorption spectrum. Various factors affecting the removal of this toxic dye like adsorbent dose, contact time, initial dye concentration, and dye solution temperature were examined. To show the equilibrium of the adsorption, Freundlich and Langmuir isotherm models were utilized. Freundlich and Langmuir's equations' correlation coefficient values were found to be in perfect agreement. The transfer of MG to quinoxaline is regulated by a pseudo-second-order procedure. The adsorption approach was a spontaneous and exothermic type. A suitable reaction mechanism has also been described and explored in this study along with an analysis of the thermodynamic parameters.

Raman spectroscopy detects chemical differences between potato tubers produced under normal and heat stress growing conditions.

Potato is the most consumed vegetable worldwide. Potato tubers contain water, starch, proteins, minerals, and vitamins. The amounts of these chemicals depend on the cultivar and growing location. When potatoes are exposed to high temperatures during the growing period, tuber yield and quality are detrimentally affected; however, there is limited knowledge about the influence of high temperatures on tuber chemical composition. With temperatures rising around the globe, the reaction of potato cultivars to high temperatures is increasingly important, and heat-induced changes, including changes in the chemical composition of tubers, should be considered. The Texas A&M University Potato Breeding Program has been selecting potato clones under high-temperature conditions for many years. Several released cultivars are considered heat-tolerant based on high marketable yields and low internal and external tuber defects. In this study, we used Raman spectroscopy (RS), an analytical tool, to determine whether heat stress causes changes in the chemical composition of tubers of ten potato cultivars. RS is a non-invasive method that requires less time and labor than conventional chemical analysis. We found drastic changes in the intensities of vibrational bands that originate from carbohydrates in the spectra acquired from tubers of heat-stressed plants compared to tubers produced by potato plants grown under normal conditions. These results demonstrate that RS could be used as a replacement or complement to conventional chemical analysis to inspect the effect of heat stress on tuber chemical composition.

Facile Formulation of New Innovative Eco-Friendly Hybrid Protective Coating for Mild Steel in Acidic Media

This research deals with the formulation, characterization, and evaluation of new anticorrosive protective coatings. The study objective is to protect mild carbon steel in acidic media by adherent nonporous polymeric coatings formulated from polystyrene and shrimp shells. Solid wastes of shrimp shells are dried into a fine powder and sonicated in toluene. The obtained suspension is refluxed with polystyrene. The hot-melt coatings are applied to the metal surface by the hot dipping technique. The shrimp shells improve the performance of polystyrene. These eco-friendly, low-cost anticorrosive coatings are formulated from solid waste (SW) of shrimp shells and polystyrene (PS) with no aiding additives. Intense vibrational bands in the infrared spectra and the high thermal stability of the coating samples confirm the compatibility of the coating constituents. The results of the evaluation of coating performance by electrochemical impedance spectroscopy and potentiodynamic polarization techniques show that the coating is protective for mild steel in the aggressive acidic media of 1.0 M HCl. The coating protects the metal surface without affecting the corrosion mechanism. Polarization curves show that the coating film retards both the anodic metal dissolution reaction and the cathodic hydrogen evolution reaction, acting as mixed-type inhibitors. The percent protection (%P) increases with the increasing weight percent (wt.%) of PS and the SW of shrimp shells. A %P up to 99% is achieved for the coating composition of 2.0 g/L PS + 0.02 g/L SW. The %P obtained by impedance and polarization measurements are in good agreement. The prepared multi-functional polymeric coating forms an adherent nonporous coating film on the metal surface. Impedance plots show that the coating samples are insulating dielectric coatings that electrically insulate the metal surface from the aggressive acidic media. The coating protects the metal surface by the adsorption mechanism. Shrimp shells fill the pores and increase the stiffness of the polymeric coating film of polystyrene. The obtained results in this study will be useful for all industrial sectors and academic research in the field of corrosion control of metals and alloys.