Electrostatic Surface Research Articles

Pseudocapacitive deionization of high concentrations of hexavalent chromium using NiFe-layered double hydroxide/polypyrrole asymmetric electrode

The wastewater polluted by high concentrations of aqueous hexavalent chromium (Cr(VI)) has serious adverse effects on ecological environment and human health. As a burgeoning, environmental-friendly, and promising wastewater treatment technology, capacitive deionization (CDI) process for efficient removal of aqueous Cr(VI) needs to be investigated. In this work, pseudocapacitive NiFe-layered double hydroxide/ polypyrrole (NiFe-LDH/PPy, denoted as NiFe/PPy) electrode was synthesized by the in-situ polymerization of PPy on the NiFe-LDH surface. Results of characterizations manifested that NiFe/PPy had the chain spherical structure of PPy. In particular, excellent PPy provides effective reversible capacitance and ion diffusion and improves the conductivity and pseudocapacitance performance of NiFe-LDH. Then, the NiFe/PPy anode and activated carbon (AC) cathode were assembled into the CDI cell for capacitive removal of high concentrations of aqueous Cr(VI). In 20 mL/min of flow velocity, 1.2 V, and 100 mL 100 mg/L of Cr(VI) solution, the Cr(VI) electrosorption capacity and removal ratio attained to 47.95 mg/g and 95.89%, respectively. The electrosorption of Cr(VI) slightly decreased under the common competing anions of Cl−, NO3−, SO42−, HCO3−, and CO32−. Based on Langmuir isotherm model, the maximum theoretical removal capacity of NiFe/PPy for Cr(VI) was 111 mg/g. The electrostatic attraction, reduction, and surface complexation played primary roles in the CDI system of NiFe/PPy//AC asymmetric electrodes. The outstanding electrosorption performance makes this CDI system have a favorable application prospect in the actual wastewater treatment containing high concentrations of Cr(VI).

Ag‐based bimetallic clusters as catalysts for p‐nitrophenol reduction by glycerol: A DFT investigation

AbstractReducing p‐nitrophenol (PNP) to p‐aminophenol is an industrially relevant synthesis. Nevertheless, only a few heterogeneous catalysts have been evaluated for the reduction of PNP by glycerol. Appropriate quantum computational studies can screen potential catalysts for this crucial green reaction. The present research investigates the catalytic activities of Pd@Ag and Ni@Ag core‐shell nanogeometries toward PNP reduction by glycerol through density functional theory (DFT) calculations. The central atom of a geometry‐optimized 13‐atom Ag cluster was replaced by Pd and Ni atoms to create the core‐shell morphologies. The interaction energies of PNP and glycerol with each of the (metal/bimetallic) clusters were evaluated by DFT calculations to find the best PNP and glycerol molecule orientation with the respective bimetallic cluster. Electrostatic potential surface and natural bond orbital analyses were performed to study the charge distribution and transfer between atomic orbitals. The frequencies of vibrational modes in isolated PNP/glycerol structures were compared to those when these molecules were in the presence of the different metal clusters to infer the effect of the interactions. All performed analyses indicated improved catalytic activity toward PNP reduction by glycerol upon Ni‐doping of the Ag13 cluster.

Multiphase Porous Electrode Theory for the Next Generation of SOFC/SOEC Electrodes

The mixed-ionic electronic conduction (MIEC) of gadolinium doped ceria (CGO) under reduced oxygen conditions makes it an excellent fuel electrode material for SOFC/SOEC applications. As part of a composite electrode (Ni/CGO), the nickel phase offers a fast electronic conduction pathway to the current collector and may act as an electrocatalyst at the three-phase boundary. Although the Ni/CGO cermet provides superior electrochemical performance compared with older technologies such as Ni/YSZ, the models used to study MIEC materials do not capture the unique transport and kinetic physics which makes them an excellent choice for the next generation of fuel electrodes. Within the framework of multiphase porous electrode theory, this work provides a novel set of differential-algebraic equations which captures the effects of the activation overpotential on electronic defect concentration, electrostatic surface potential and ionic transport to accurately predict the current-voltage behaviour of the Ni/CGO electrode. Moreover, through concerted electron and proton tunnelling events, we unify the theory of the electrostatic surface potential with proton-coupled electron transfer kinetics.

Panchromatic Light-Capturing Bis-styryl BODIPY-Perylenediimide Donor-Acceptor Constructs: Occurrence of Sequential Energy Transfer Followed by Electron Transfer.

Two wide-band-capturing donor-acceptor conjugates featuring bis-styrylBODIPY and perylenediimide (PDI) have been newly synthesized, and the occurrence of ultrafast excitation transfer from the 1 PDI* to BODIPY, and a subsequent electron transfer from the 1 BODIPY* to PDI have been demonstrated. Optical absorption studies revealed panchromatic light capture but offered no evidence of ground-state interactions between the donor and acceptor entities. Steady-state fluorescence and excitation spectral recordings provided evidence of singlet-singlet energy transfer in these dyads, and quenched fluorescence of bis-styrylBODIPY emission in the dyads suggested additional photo-events. The facile oxidation of bis-styrylBODIPY and facile reduction of PDI, establishing their relative roles of electron donor and acceptor, were borne out by electrochemical studies. The electrostatic potential surfaces of the S1 and S2 states, derived from time-dependent DFT calculations, supported excited charge transfer in these dyads. Spectro-electrochemical studies on one-electron-oxidized and one-electron-reduced dyads and the monomeric precursor compounds were also performed in a thin-layer optical cell under corresponding applied potentials. From this study, both bis-styrylBODIPY⋅+ and PDI⋅- could be spectrally characterizes and were subsequently used in characterizing the electron-transfer products. Finally, pump-probe spectral studies were performed in dichlorobenzene under selective PDI and bis-styrylBODIPY excitation to secure energy and electron-transfer evidence. The measured rate constants for energy transfer, kENT , were in the range of 1011 s-1 , while the electron transfer rate constants, kET , were in the range of 1010 s-1 , thus highlighting their potential use in solar energy harvesting and optoelectronic applications.

Highly efficient adsorption of antibiotic ciprofloxacin hydrochloride from aqueous solution by diatomite-basic zinc chloride composites.

The antibiotic ciprofloxacin (CIP) is used to treat a variety of bacterial infections, yet it poses significant health risks to aquatic environments. While adsorption is a promising technique for CIP removal, current adsorption capacities remain limited. In this study, we introduce a diatomite and basic zinc chloride composite (ZnHC-Dt) prepared using a straightforward deposition method, with the ability to achieve highly efficient ciprofloxacin removal. ZnHC-Dt is characterized using field emission scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), and the Brunauer-Emmett-Teller method (BET). We also assess the zeta potential. The optimized ZnHC-Dt adsorbent, achieved at a mass ratio of 0.45 with ZnHC/(ZnHC+Dt), is adopted with a CIP adsorption capacity of 831.96 mg/g at 25 °C, broad pH adaptability (within 3.0-10.0), rapid adsorption rate (reaching equilibrium in 4 h), and stable performance under Na+ ionic strength. The CIP adsorption process follows pseudo-second-order kinetics and aligns well with the Langmuir adsorption model. The high adsorption capacity of ZnHC-Dt can be attributed to electrostatic attraction, hydrogen bonding, surface complexation, and available adsorption sites. During the desorption process, the CIP removal rate retains 65.33% effectiveness after five cycles. The results suggest that ZnHC-Dt holds significant potential for CIP removal in aqueous solutions.

Equilibrium solubility, solvent effect, equation correlation, and thermodynamic properties of cyclododecanone in twelve organic solvents

The solubility of cyclododecanone (CDON) was determined in twelve solvents containing acetonitrile, acetone, toluene, ethyl acetate, cyclohexane, 1,2-dichloroethane, methanol, ethanol, n-propanol, i-propanol, n-butanol and i-butanol. The temperature range for the remaining solvents used in the experiment was 278.15–313.15 K, except for cyclohexane (283.15–313.15 K). The CDON solubility in solvents measured increased with growing temperature. The CDON solubility varies considerably in different solvents. Among the single solvents selected, CDON was most soluble in 1,2-dichloroethane and least in acetonitrile. The solubility in 1,2-dichloroethane is about 2–3 times higher than in acetonitrile. The carbonyl oxygen of CDON readily combines with alcoholic solvents to form hydrogen bonds. Hansen solubility parameters (HSP) and the physiochemical properties of the solvents explain the solvent effect in diverse solvents. To understand CDON dissolution, the electrostatic potential energy surfaces of CDON and the solute–solvent interactions were analyzed at the molecular level on the basis of density functional theory (DFT). Analysis of solvation effects revealed that variations in the CDON dissolution are influenced by a combination of factors rather than a single one. In addition, the Van't Hoff equation, modified Apelblat equation, Yaws equation, λh equation, Wilson model and Jouyban model were utilized to correlate the experimentally obtained value. The computational data show that the ARD (0.88%) and RMSD (0.24%) of Wilson model are the smallest among the selected equations with the best correlation. The apparent thermodynamic properties of CDON dissolution were further accounted for Van't Hoff equation, and the CDON dissolution was observed to be endothermic and entropy-driven.

Molecular simulations of transport properties of polar hydrofluoroethers: Force field development, fractional Stokes-Einstein and free volume relations

Hydrofluoroethers (HFEs) having simultaneously hydrocarbon (HC) and fluorocarbon (FC) moieties connected through ether oxygen are polar chain molecules with dielectric properties, which makes them a good heat transfer medium, e.g., for cooling of electronics or magnetic devices. In this work, we report, validate, and test high level-ab initio derived force fields and we use partial charges fitted to the electrostatic potential surface (EPS) to reproduce the dipole moments. Computer simulations were performed over a wide range of temperatures and densities to calculate the transport coefficients in the condensed-phase and comparisons were made against available experimental data for five selected molecules; namely HFE-7000, HFE-7100, HFE −7200, HFE −7300, and HFE −7500. Furthermore, structural properties and enthalpy of vaporization were obtained from molecular simulations. Cohen and Turnbull formula for the translational self-diffusion coefficient was tested in the free-volume cast, which itself was correlated against the isothermal compressibility, which can explain the phenomenon of transport properties in liquids, D∝exp-γ/Vf/V∗. The fractional Stokes-Einstein relation was also tested to scale the self-diffusion coefficient vs viscosity in the form of (DT−1) ∝ (1/η)s, with s ranging between ≈ 0.89 and 0.92 for the five molecules in the reduced density range of ρσ3 = 0.56 to 0.75. Finally, the non-equilibrium molecular dynamics (NEMD) simulations of thermal conductivity was found to outperform the equilibrium Green-Kubo approach, but both with comparable accuracy.

Potansiyel JNK1 İnhibe Edici Aktiviteye Sahip 2-((4-(dimetilamino)benziliden)amino)-5-metilfenol’ün Sentezi, Teorik Çalışmaları, Sitotoksisitesi

Cisplatin, doxorubicin, hydroxycamptothecin, leucovorin, vincristine and 5-fluorouracil resistance of cancer cells are associated with the activities of C-Jun N-Terminal Kinase 1 (JNK1). Inhibition of the JNK1 by pharmacological agents could be a beneficial attempt for reversing the chemoresistance of various cancer cells. However, there is no FDA-approved JNK inhibitor for safe use in clinics in today’s clinics. In this study, a Schiff base 2-((4-(dimethylamino)benzylidene)amino)-5-methylphenol, (7S4) has been synthesized and characterized by 1H, 13C-NMR, FT-IR and elemental analysis. The stable geometry of 7S4 has been determined by DFT method with Gaussian09 program (B3LYP/6-311g++(d,p))). The Gibbs Free energies, stable tautomer forms, H-bond, Mulliken charges, dipole moment, natural bond orbital (NBO), HOMO, LUMO and band gap energy (EGAP), molecular electrostatic potential (MEP) and solvent accessibility surface areas (SASA) have been calculated. Drug-likeness, anticancer and JNK1 inhibitory activities of 7S4 have been evaluated. Enol tautomer form of trans 7S4 was characterized as the most stable structure. 7S4 was observed to be a reactive compound in chemical reactions with a low EGAP value. In addition, high and low electron density regions of 7S4 are responsible for the establishment of chemical bonds in biological systems. 7S4 exhibited strong druggability with the agreement on Lipinski, Ghose, Veber, Egan, and Muegge rules. Cytotoxicity tests and molecular docking revealed that 7S4 poses a potential JNK1 inhibitor activity.

Impacts of Ganoderma lucidum (Reishi mushroom) on the properties of electrospun polymeric nanofibers

Three polymeric solutions, PVA, Collagen and Hyaluronic acid (HAc), were prepared and mixed by (55:22.5:22.5) ratios to prepare the net polymeric solution. Also, Ganoderma lucidum (G. lucidum) solution was prepared and added to the neat solution by three ratios (1wt%, 3wt% and 5wt%), which was then pumped by electrospinning technique to create a nanofiber bead. Solutions results showed that G. lucidum caused drag reduction, decreasing the viscosities, facilitating solution flow inside the needle and leading to the formation of fine nanofibers easily. Also, at low G. lucidum ratios, the electrostatic repulsion overcomes the surface tension, which enables fibers to escape from the "Taylor cone" tip and gather on the collector. As well as the electrical conductivity increased due to the ease of movement of HAc ions due to viscosity reduction. FTIR results proved no losses of any component of the net blend, and there is no chemical reaction among them. Results of the obtained nanofiber showed that, with the G. lucidum addition, there is an increment in fiber diameter, number of beads, the goodness of orientation and surface roughness. G. lucidum also reduced the wettability, the crystallinity and the enthalpy consumed during the thermal transition. Keywords: Ganoderma lucidum, FESEM, Directionality Histogram, Electrospinning, Wettability

Synthesis of 1-(4-Bromobenzoyl)-1,3-dicyclohexylurea and Its Arylation via Readily Available Palladium Catalyst-Their Electronic, Spectroscopic, and Nonlinear Optical Studies via a Computational Approach.

In this study, we reported the synthesis of 1-(4-bromobenzoyl)-1,3-dicyclohexylurea by the reaction of DCC (N,N'-dicyclohexylcarbodiimide) with 4-bromobenzoic acid. Subsequently, we further synthesized a new series of 1-(4-arylbenzoyl)-1,3-dicyclohexylurea (5a-g) derivatives using a Suzuki cross-coupling reaction between 1-(4-bromobenzoyl)-1,3-dicyclohexylurea (3) and various aryl/heteroaryl boronic acids (4). Thus, density functional theory (DFT) calculations have been performed to examine the electronic structure of the synthesized compounds (3, 5a-g) and to calculate their spectroscopic data. Moreover, optimized geometries and thermodynamic properties, such as frontier molecular orbitals (HOMO, LUMO), molecular electrostatic potential surfaces, and reactivity descriptors, were also calculated at the PBE0-D3BJ/def2-TZVP/SMD1,4-dioxane level of theory to validate the structures of the synthesized compounds.

Ligand and Substituent Effect on Regium-π Bonding in Cu and Ag π-Conjugated Complexes: A Density Functional Study.

Density functional theory investigation of regium (Rg)-π bonding using the RgL-X model system, where Rg = Cu and Ag; L = CN, NO2, and OH; X = π-conjugated system (benzene, cyanobenzene, benzoic acid, pyridine, 2-methoxy aniline, 1,4-dimethoxy benzene, and cyclophane), has been performed. Conclusive evidence of the Rg-π bond has been provided by analysis of molecular electrostatic potential surfaces, Rg-π bond length, interaction energy (ΔE), second-order perturbation energy (E2), charge transfer (Δq), quantum theory of atom in molecules, and noncovalent interaction plots for 42 structural arrangements with varying ligands and the substituted aromatic ring. The Rg-π bond length in the optimized model systems varies from 2.03 to 2.12 Å in Cu complexes (1-21) and from 2.26 to 2.38 Å in Ag complexes (22-42) at the PBE0-D3 functional. While the ligand (L) attached to the Rg metal has a bargaining effect on the strength of the Rg-π bond (in the order of -OH > -CN = -NO2), the π-conjugated systems have a diminutive effect. Two X-ray crystal structures (CUCSOI and AHIDQU) having the Rg-π bond, accessed from Cambridge Crystallographic Data Centre (CCDC), are discussed here to signify the influence of Rg-π bonding on the crystal structure.

Polypeptide N-acetylgalactosaminyltransferase (GalNAc-T) isozyme surface charge governs charge substrate preferences to modulate mucin type O-glycosylation.

A large family of polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts) initiate mucin type O-glycosylation transferring α-GalNAc from a UDP-GalNAc donor to the hydroxyl groups of Ser and Thr residues of peptides and proteins, thereby defining sites of O-glycosylation. Mutations and differential expression of several GalNAc-Ts are associated with many disease states including cancers. The mechanisms by which these isozymes choose their targets and their roles in disease are not fully understood. We previously showed that the GalNAc-Ts possess common and unique specificities for acceptor type, peptide sequence and prior neighboring, and/or remote substrate GalNAc glycosylation. In the present study, the role of flanking charged residues was investigated using a library of charged peptide substrates containing the central -YAVTPGP- acceptor sequence. Eleven human and one bird GalNAc-T were initially characterized revealing a range of preferences for net positive, net negative, or unique combinations of flanking N- and/or C-terminal charge, correlating to each isozyme's different electrostatic surface potential. It was further found that isoforms with high sequence identity (>70%) within a subfamily can possess vastly different charge specificities. Enzyme kinetics, activities obtained at elevated ionic strength, and molecular dynamics simulations confirm that the GalNAc-Ts differently recognize substrate charge outside the common +/-3 residue binding site. These electrostatic interactions impact how charged peptide substrates bind/orient on the transferase surface, thus modulating their activities. In summary, we show the GalNAc-Ts utilize more extended surfaces than initially thought for binding substrates based on electrostatic, and likely other hydrophobic/hydrophilic interactions, furthering our understanding of how these transferases select their target.

Synthesis of conch-like layered carbon nanosheets by ball-milling assisted ultrasonic exfoliation for highly selective removal of Cd(II) from multiple water matrices

Development of carbonaceous materials from biomass have attracted tremendous research interest because of their intriguing physicochemical properties and promising applications. However, endowing them with precisely controlled morphologies remains a formidable challenge. Herein, oxygen-functionalized biomass-derived carbon-nanosheets (CNSs) framework was synthesized using ball-milling ultrasonic exfoliation for their application to remove cadmium Cd(II) from water matrices. The obtained CNSs showed remarkably higher surface area (368.9 m2/g), thickness-range (∼6–8 nm) and pore size (10.58 nm) than pristine carbon (PC) (10.126 m2/g, 1–2 µm and 2.13 nm, respectively). CNSs demonstrated higher adsorption capacity (545.76 mg g−1), superior reusability (removal efficiency maintained >91 % after 10 cycles) and excellent selectivity (Kd = 4.7 × 106 mL g−1). The adsorption isotherm and kinetics data were better fitted by Langmuir and pseudo-second order models. High adsorption selectivity of CNSs led to 97.7 % Cd(II) adsorption in presence of Cu(II), Zn(II), Pb(II) and Ni(II) ions. The strong efficiency of CNSs was also evident in complex water matrices including tap water, groundwater (Cd(II) removal of >99 %) and river water (98.97 %). The experimental analyses indicate that electrostatic attraction and surface complexation as the prominent adsorption mechanisms. Overall, this work illustrates an applicable strategy to develop carbon-nanosheets and their successful application to remove toxic metals from water matrices.

Studying the influence of surface properties on the cell attachment and anti-fouling capacity of Ag/SiO2 superhydrophobic coatings for building materials

Anti-fouling coatings are a common solution for the protection of porous building materials from the effects of microbial colonization over their functionality and durability. Usually, this is achieved through the incorporation of biocides or the passive control by reducing bioreceptivity. Superhydrophobic surfaces are considered a promising strategy due to their reported capacity for reducing cell adhesion, but their affinity to non-polar substances may decrease their effectiveness under the right circumstances (e.g. organic contamination, cell walls with hydrophobic domains). The combination of these surfaces with active biocides may compensate these drawbacks, however, a close contact with the microorganisms is necessary to promote their effect.This work studies the factors that determine the anti-fouling capacity of a coating, tested on porous building materials, that combines superhydrophobic surface with a nanostructured Ag/SiO2 biocide agent. Special attention is paid to understanding to which extent the cell-surface interactions modulate the initial cell attachment to the surface and the biocidal effect. To this end, the electrostatic forces and surface energy balance were considered using different reference bacteria and a yeast. The results indicate that the hydrophobic character of the surface favors the cell attachment and the biocide agent may be unable to fully compensate this effect for all microorganisms. In addition, changes in micro and nano roughness seem to play an equally significant role. Overall, this study aims to provide a theoretical and experimental insight to assist in the future design of anti-fouling coatings tailored to the organisms responsible of fouling processes.

Health risks posed by environmental benzophenone-type ultraviolet filters (BP-UVFs): An investigation into the binding of BP-UVFs to trypsin and their adverse effects

Benzophenone-type ultraviolet filters (BP-UVFs) are ubiquitous in the environment, and people frequently ingest them via food chain and drinking water. However, there is no clear information about whether BP-UVFs are detrimental to human health. Herein, experiments using multi-spectroscopy revealed typical BP-UVFs, i.e., benzophenone (BP), 2-hydroxybenzophenone (2-OHBP), 4-hydroxybenzophenone (4-OHBP), 2,2′-dihydroxybenzophenone (2,2′-OHBP), 2,4-dihydroxybenzophenone (2,4-OHBP), 4,4′-dihydroxybenzophenone (4,4′-OHBP), 2,4,4′-trihydroxybenzophenone (2,4,4′-OHBP), 2,2′,4,4′-tetraphydroxybenzophenone (2,2′,4,4′-OHBP), 2-hydroxy-4-methoxybenzophenone (2-OH-4-MeOBP) and 2,2′-dihydroxy-4-methoxybenzophenone (2,2′-OH-4-MeOBP), could bind to the active site of trypsin with different binding constants (2.69 × 104–1.07 × 106 L/mol), cause structural abnormalities and inhibit the enzymatic activity in varying degrees, indicating that the BP-UVFs ingestion poses a risk to human health. In contrast to previous research, this study systematically analysed the binding mechanism using an innovative combination of molecular docking and advanced quantum chemistry calculations, including molecular dynamics simulations, energy calculations, etc. The results revealed that most amino acids that make up trypsin have a greater positive electrostatic surface potential (ESP). Therefore, the greater the area and distribution of negative ESP in a particular BP-UVFs, the more easily it will bind to trypsin. This provides new insight into the binding of pollutants to proteins. This study suggests a need for better monitoring and control of environmental BP-UVFs.

Novel antiferroelectric materials with resorcinol-based symmetrical fluorinated bent-core mesogens

The synthesis of several symmetrical bent-core compounds with two or four fluorine atoms as substituents on the calamitic units is reported. The influence of fluorine substitution concerning its effect upon the mesophase structure and switching behavior was investigated. The synthesized compounds are built from resorcinol as central core and contain seven phenyl rings linked by ester, imine and azo units with terminal decyloxy/dodecyloxy chains. The mesophases were characterized by polarizing optical microscopy, differential scanning calorimetry, electro-optical investigations and X-ray diffraction (XRD) studies. The photochemical characterisation of bent-core azobenzene compounds confirmed the structure of E isomer. The temperature range of mesophases increases upon the introduction of fluorine substituents, as compared with the corresponding unsubstituted compound. All the compounds exhibit antiferroelectric properties. Depending on the number of the F substituents, racemic SmCSPA mixtures and SmCAPA homochiral structures were identified. High values of spontaneous polarization up to 900 nC/cm2 were recorded. DFT studies were used to calculate the minimum energy molecular structures, the dipole moments and the electrostatic potential surfaces of the compounds.

First detection and genome analysis of simple nosed bat polyomaviruses in Central Europe.

Polyomaviruses (PyVs) are known to infect a diverse range of vertebrate host species. We report the discovery of PyVs in vesper bats (family Vespertilionidae) from sampling in Central Europe. Seven partial VP1 sequences from different PyVs were detected in samples originating from six distinct vesper bat species. Using a methodology based on conserved segments within the major capsid virus protein 1 (VP1) among known PyVs, the complete genomes of two different novel bat PyVs were determined. The genetic distances of the large T antigen coding sequences from these PyVs compared to previously-described bat PyVs exceeded 15% meriting classification as representatives of two novel PyV species: Alphapolyomavirus epserotinus and Alphapolyomavirus myodaubentonii. Phylogenetic analysis revealed that both belong to the genus Alphapolyomavirus and clustered together with high confidence in clades including other bat alphapolyomaviruses reported from China, South America and Africa. In silico protein modeling of the VP1 subunits and capsid pentamers, and electrostatic surface potential comparison of the pentamers showed significant differences between the reference template (murine polyomavirus) and the novel bat PyVs. An electrostatic potential difference pattern between the two bat VP1 pentamers was also revealed. Disaccharide molecular docking studies showed that the reference template and both bat PyVs possess the typical shallow sialic acid-binding site located between two VP1 subunits, with relevant oligosaccharide-binding affinities. The characterisation of these novel bat PyVs and the reported properties of their capsid proteins will potentially contribute in the elucidation of the conditions creating the host-pathogen restrictions associated with these viruses.

Electrostatic Surface Modes Under Exchange–Correlation Effects in Semi-Bounded Quantum Plasma

Electrostatic Surface Modes Under Exchange–Correlation Effects in Semi-Bounded Quantum Plasma

Insights into synthesis, structural, energetic, vibrational, anticancer activity and molecular characteristics of 2-((2-aminopyridin-3-yl)methylene)-N-phenylhydrazinecarbothioamide as evaluated using spectroscopic and DFT investigations

Synthesis of 2-((2-aminopyridin-3-yl)methylene)-N-phenylhydrazinecarbothioamide (APHB) was attempted. Elemental analysis and NMR spectra were used to ascertain its formation. Torsional potential energy scans, for all the rotating bonds were made to get approximate initial values of dihedral angles. FT-IR, FT Raman, and UV–Vis spectra were measured for APHB. Their anticancer activity was determined experimentally, for human carcinoma cell lines pertaining to liver, Colorectal, and lung. Barrier heights, around six rotating bonds in APHB were computed. Optimized structure parameters, general valence force field, harmonic vibrational fundamentals, potential energy distribution, infrared and Raman intensities, frontier molecular orbital (FMO) parameters, NLO behaviour, NBO characteristics and molecular electrostatic surface potential (MESP) were determined using DFT/B3LYP/6-311++G(d,p) level of theory. TD-DFT was used to compute absorption maxima (λmax) of electronic transitions for the molecule in DMSO‑d6 solvent. Frontier molecular orbitals were used to understand origin of UV–Vis spectrum and chemical reactivity of the molecule. Good agreement was found between measured and computed structure parameters, IR, Raman and UV–Vis spectra. The rms error between experimental and theoretical vibrational frequencies was 9.5 cm−1, for APHB. All vibrational fundamentals were assigned unambiguously. The computations demonstrated that the molecule was good for NLO applications, which was substantiated by NBO analysis. Existence of bifurcated intramolecular hydrogen bond was predicted for APHB.

DFT Study on Na-Ion Conducting Solid Biopolymer Electrolyte-Based on Agar-Agar and NaPF6 for Sodium-Ion Batteries

This research article is focused on the structural, electronic, thermal, and vibrational properties of solid biopolymer electrolytes based on Agar-Agar and sodium hexafluorophosphate (NaPF6) salt. Herein, the density functional theory (DFT) technique is used to investigate these properties. The structural analysis provides information about the interactions between Agar-Agar and NaPF6 and hence interaction energy is analysed. Thermodynamic parameters such as Gibbs’ free energy (G), enthalpy (H), entropy (S), and specific heat (Cv) etc. are studied by frequency analysis at normal temperature pressure (NTP) of titled electrolytes. The chemical descriptors of the electrolytes have been studied using the molecular orbital theory (MOT). Molecular electrostatic potential surface (MEPS) demonstrates the three-dimensional molecular charge distribution and illustrates the electron-rich and deficit regions over the whole electrolyte system. Mulliken population analysis (MPA) gives the identification of intramolecular hydrogen bonding. The theoretical infrared (IR) study confirms the formation of the complex system between Agar-Agar and NaPF6 salt. The overall DFT studies of sodium ion-based biopolymer electrolytes have better possibilities for safe sodium-ion batteries.