Physical Chemistry Research
Volume:10 Issue: 4, Autumn 2022

Zinc Aluminum Lithium borate (ZALB) glasses of different compositions doped with Cu2+ ions have been prepared using conventional melt quenching technique. X-Ray diffraction Electron paramagnetic resonance and Fourier transform infrared studies have been carried out for ZALB glasses. The XRD pattern of ZALB glass confirms the amorphous structure of the glass matrix. From EPR spectra in Cu2+ doped zinc aluminium lithium borate glass system, 〖 g〗_∥>g_⊥, showing the position of the Cu2+ ion in the glasses with tetragonally elongated octahedral (D4h) site. FTIR spectra showed that the increment of copper oxide caused the breaking of B-O-B bonds and by creating new and more bonds. FTIR findings likewise confirmed both the EPR and the findings of optical absorption, which suggested the major role of copper oxide in the formation of cross-linking bands.

In the present study, experimental and thermodynamic aspects of solid-liquid equilibrium were evaluated for ten ternary fatty acid mixtures formed by capric, undecylenic, pentadecylic, margaric, and stearic acids as potential phase change materials (PCMs). The latent heat and melting temperature of the ternary fatty acids mixtures were determined by data from differential scanning calorimetry (DSC). Furthermore, the coefficients of the non-random equation of two liquids (NRTL) thermodynamic model were calculated using quasi-binary mixing law to correlate the liquidus line of solid-liquid equilibrium for understudying ternary mixtures. The comparison between the results of the proposed thermodynamic model with the experimental data represents the average absolute deviations less than 1%, which validates the correlated thermodynamic model. The melting temperature of ternary mixtures of fatty acids studied in this study was in the range of 281-315 K with melting enthalpies of 26.09 and 45.74 kJ.mol-1, which indicated that these mixtures have good potential to utilize as low-temperature thermal energy storage.

The spherical iron oxide (α Fe2O3) nanoparticles was prepared using facile, low-cost and environmental friendly one step thermal decomposition of Fe(NO3)3∙3H2O at the presence of malic acid (mass ration 1:1) at 600°C for 3 h. The product was characterized by Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and transmission electron microscope (TEM). The FT-IR and XRD results predict the formation of single phase of rhombohedral α Fe2O3 nanoparticles. TEM image illustrated the α Fe2O3 nanoparticles were spherical shapes. VSM result show that the as-prepared α Fe2O3 nanoparticles is a ferromagnetic material with Ms of 1.96 emu/g. The photocatalytic activity of α Fe2O3 nanoparticles investigated by photodegradation of methyl orange (MO) and methyl blue (MB) in aqueous solution under visible light irradiation. The effect of pH solution, sorbent dose, contact time (0 – 120 min) and initial concentration of dyes (30, 50 and 70 mg/L) was studied. At the end of process, the catalyst could be separation and recovered using an external magnetic field. The results indicated that the α Fe2O3 nanoparticles could be used as an efficient photocatalyst for other dyes from aqueous solution and also beneficial to large-scale production.

Nasunin is the main phenol-based constituent of eggplant peels, be famed for its multiple advantages and antioxidant activity. α-lactalbumin (α-lac) is a milk protein with a great nutritional worthiness due to its necessary amino acids. Mechanism of interaction of α-lac with nasunin were investigated by in silico and spectroscopy studies. The results of the fluorescence quenching experiments demonstrated a reduction in the fluorescence parts by cause of bonding approach with fluorescing residues. The particle size of α-lac and nasunin complex is considerably more than the native protein. Far ultraviolet circular dichroism outcomes indicated that the second construction of the protein was rearranged in attending nasunin. Molecular docking pointed out that hydrogen binding has a significant influence on the constitution of nasunin-α-lac complex. The results suggested that α-lac could be a perfect carrier to nasunin loading for additional uses in nutrition field.

The Electro-Fenton technique was used to investigate the discoloration of carmoisine red azo dye solution. Carbon graphite (cathode) and platinum (anode) electrodes were used to achieve the optimal discoloration efficiency. We examined the effect of Fe2+ concentration and current density. The results showed that with 200 mA/cm2 of electrolysis current and 0.2 mM of Fe2+ at pH = 3; 93% discoloration efficiency was achieved in 60 minutes. IR, LC-MS-MS, and Ion Chromatography studies were used to evaluate the degradation process of carmoisine red. Intermediates of aromatic compounds have been identified. A possible carmoisine red degradation pathway was proposed and discussed.

Equilibrium, kinetic and thermodynamic study of the adsorption capacity of activated carbon prepared from empty palm fruit bunch was done using samples of electroplating process waste stream and waste vegetable oil with the focus being on copper, iron and zinc heavy metal ions contained in the samples. Activation was chemically done using sulphuric acid at 3M concentration with furnace temperature and time being 450 oC and 3 h respectively. The equilibrium adsorption data were analysed using the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich adsorption isotherms. Linear regression was used for comparing the best fit of the isotherms. The best fit to the adsorption data of the investigated heavy metal ions in both samples was found to be the Langmuir isotherm. The kinetics of the adsorption process was evaluated with the pseudo-second order kinetic model providing the best description of the adsorption kinetics in both samples. Thermodynamic parameters (ΔG0, ΔH0, ΔS0) were also calculated which together with other theoretical basis proved the adsorption mechanism in both samples to be physical. Results showed that adsorption was exothermic and spontaneous in both samples with ΔH0 for samples A and B calculated to be -1.14 x 10-2 KJ/mol and -1.68 x 10-3 KJ/mol respectively.

Recently, a new series of N-benzyl-3,6-dimethylbenzo[d]-isoxazol-5-amine derivatives and its prostate anti-cancer activity were produced and evaluated, respectively. Its compounds were perceived to have a strong inhibitory effect on the bromodomain of the related Tripartite motif-containing protein 24 (TRIM24). The 3D-QSAR study was applied utilizing the methods of Comparative Molecular Field Analysis (CoMFA) and Comparative Molecular Similarity Indices Analysis (CoMSIA). This gave result to the cross-validation coefficient (Q2) values of 0.850 and 0.92, the determination coefficient (R2) values of 0.998 and 0.987, respectively. The predictive capacity of these models is based on a test set of seven molecules that generated acceptable values of coefficient of determination (R2 test) of 0.793 and 0.804, corresponding respectively to CoMFA and CoMSIA., respectively. The study used molecular docking analysis to validate 3D-QSAR methods and to explain the binding site interactions and energy between the TRIM24 bromodomain receptor and the most active ligands. Based on the results of the previous model, it was allowed for us to predict new and active compounds and its pharmacokinetic properties were verified using drug-likeness and ADMET prediction. Finally, to affirm the dynamic stability and behavior of the molecules, the most appropriate docked candidate molecules were simulated by molecular dynamics

Iron oxide (Fe3O4) nanoparticles (NPs) are the most important group of magnetic nanoparticles. This study modifies iron oxide (Fe3O4) magnetic nanoparticles (MNPs) by polyethylene glycol (PEG) and polyvinyl alcohol (PVA) coating co-precipitation method. MNPs were characterized by XRD, FTIR, TEM, DLS, and VSM analyses to study their structure, morphology, and magnetic properties. The results showed the superior properties of PEG and PVA-coated Fe3O4 compared to the pristine sample. It is illustrated that modified Fe3O4 MNPs improved magnetic saturation. The particle size of PEG-coated Fe3O4 nanoparticles was estimated at 11 nm with magnetic saturation of 60.98 emu/g and coercivity of 8.26G.

This study intends to synthesize Schiff bases derived from chitosan and aromatic aldehyde to investigate their photo-stability. The surface morphology and chemical structure of modified polymer were characterized using different techniques such as infrared spectroscopy (FTIR), scanning electron microscope (SEM), microscopic images, atomic force microscopy (AFM), and energy dispersive X-Ray (EDX) mapping. The thermal stability of synthesized materials was determined using thermogravimetric analysis (TGA). The modification in the chemical structure and morphology of new Schiff bases were verified using FT-IR, NMR, AFM, and SEM, whereas the thermal properties were investigated by TGA. Thus it was demonstrated that the thermal stability of chitosan has improved after the modification with the corresponding aldehyde. The decomposition temperature (Td) of pure chitosan is about 220 °C while it is between 250-256 °C for modified Schiff bases. Two approaches were applied to investigate the physical photo-stability of modified chitosan the weight loss percentage, and monitoring of the functional group by FTIR. The weight loss percentages of blank films are much higher than modified chitosan polymeric films. This is because the photo-degradation of blank chitosan is faster when irradiated by UV light. The main reason is attached aldehydes groups are aromatic moieties that absorb light in the UV region and convert it to harmless heat. Compound 3 showed the best results this might be because of the existence of the phenol group which is known as an excellent free radical scavenger. Chitosan modification with aromatic aldehydes would have an accelerating effect on thermal decomposition and they are photo-stabilizers, we used many techniques to prove that like FESEM, AFM, weight loss, EDX, TGA.

Molecular interaction in organic solvents and water causes a significant change in physicochemical properties of organic solvent (OS)- water systems, which may also affect the stability of such systems. Although optimized models of OS-water systems have been shown to have strong hydrogen bond formation, some changes may occur in bond distances and angles following a molecular interaction between solvents and H2O or H3O + ions. Organic solvents, such as aldehyde, ketone, carboxylic acid, amine, aniline, amide, etc., might have different interaction modes with water molecules, but the proton donor-acceptor nature of such systems greatly impacts their free energy, enthalpy, zero-point energy, and other thermodynamic parameters. The analysis of enthalpy changes (∆Hº) for all OS-water systems showed negative values, which reflects their exothermic behavior; however, the Gibbs free energy change (∆Gº) shows the feasibility of the formation of all types of OS-water systems. The hydrophobic or hydrophilic nature of such systems not only controls the stability of donoracceptor complexes but also defines their acidic or basic nature. In all cases, optimized models provide some detailed information about the changes in the geometry of OS-water mixtures. Furthermore, the physicochemical properties of OS-H3O + and OS-H2O systems have been found to follow a similar trend. In this study, the standard free energy change (∆Gº), enthalpy change (∆Hº), zero-point energy change (∆ZPE), the effect of protonation, electron charge density, and other parameters of OS-H2O and OS-H3O + systems were evaluated by quantum mechanical calculations.

Sodium dodecyl sulfate (SDS) solution is considered a cell membrane mimicking solution. In this study, the effect of the amyloid-beta peptide on the structure and diffusion coefficient of SDS was investigated by molecular dynamics simulation. To control the accuracy of the calculations, a micelle containing 60 molecules of SDS was simulated. The radius of gyration and the moment of inertia of the micelle were calculated and compared with the experimental and simulation results. The results obtained were in good agreement with the experimental and simulation results. The simulations in the presence of amyloid-beta were performed at two concentrations of SDS, below and above the critical micelle concentration. The results showed that as the concentration of SDS increased, the diffusion coefficient of peptide and sodium ion increased while the diffusion coefficient of water and SDS decreased. The calculation of the moments of inertia in different directions showed that the micelles deviated from the ellipsoidal shape at sub-critical micelle concentrations of SDS.

Recently, green synthesis of nanoparticles using plant has attracted much attention due to the environmental and economic benefits. The present work demonstrates an eco-friendly and low-cost method to study the antibacterial activity of the silver nanoparticles [AgNPs] biosynthesized from phenolic compounds of plant extracts (Raphanus sativus and Curcuma longa). Using GCMS and 1H NMR spectroscopy analyses, the presence of phenolic compounds and alcohol groups of long-chain were detected. Polyphenol compound such as catechol and phenolic derivative such as curcumin were capped with silver nanoparticles and proved by SEM analysis. However, the antibacterial potential of these green synthesized phytochemical capped AgNPs was further explained in in vivo studies. Albino mouse was induced with multidrug-resistant E.coli and was treated with Ciprofloxacin as a conventional drug for the standard groups and with synthesized catechol-curcumin capped silver nanoparticles for the test groups. Histopathology of albino mice kidney and bladder was performed after dosing the mice with specific concentrations of the nanoparticles for 3, 7, and 14 days. Photomicrographs of the kidney and bladder histology revealed cell regeneration, normal renal cortex, and glomerular tufts in the mice exposed to the nanoparticles.