Physical Chemistry Research
Volume:9 Issue: 2, Spring 2021

The removal efficiency of Sulfamethazine as a representative antibiotic (SMT) on a new and eco-friendly activated carbon provided from watermelon seeds species as adsorbent has been studied in simple systems. Some experimental parameters, namely the pH, the amount of adsorbent and the contact time are studied. The results showed that the weak chemical bond (π-π EDA interaction) dominated the sorption of SMT to watermelon seeds. The present adsorbent played an important role in the sorption of SMT, leading to a higher sorption capacity onto watermelon seeds (90.78 mg/g). The solvent effect is been studied to show that the electron-donor-acceptor (EDA) interaction is the main adsorption mechanism of SMT antibiotic and that adsorption capacity increases with the increase of dipole moment of solvents. A kinetic study showed that the removal efficiency process followed the pseudo-second-order model and the Langmuir isotherm was the best model to fit and describe the phenomenon in the single system.

In this study, tie-line points and solubility data were experimentally measured for the ternary mixture (water + lactic acid + diethyl ether) at T = 293.2 K and atmospheric pressure. UNIFAC calculations predicted that lactic acid and diethyl ether do not form an azeotrope. The mass fractions of organic and aqueous layers were determined by acid-base and the Karl Fisher titrations. Cloud point method verified that the LLE behavior of the studied system is Type-1. The reliability of the tie-line points was demonstrated by the Othmer–Tobias and Hand plots. Thermodynamic correlation of tie-line data was done by NRTL model and the obtained binary interaction parameters were tested after validation. The experimental and correlated data had very good accordance (rmsd = 0.88 %). Extraction quality of diethyl ether was investigated using the calculation of distribution coefficients and separation factors over the immiscibility area. Separation factors decreased from 1.93 to 1.13 when aqueous mass fraction of lactic acid increased from 0.070 to 0.305. However, distribution coefficient increased from 0.07 to 0.12 in the same region. The study shows that the extraction of lactic acid is possible in all investigated feeds at 293.2 K.

The (3,5-diphenyl-4,5-dihydro-1H-pyrazol-1-yl)(phenyl)methanone (DPPPM) were synthesized by using rapid and recyclable reaction media polyethylene glycol-400 (PEG-400) and catalytic amount of acetic acid. This method gives remarkable advantages such as simple workup and a greener method by avoiding hazardous and toxic solvents. The computational calculations for title compound have been carried out by using DFT method with B3LYP hybrid functional and 6-311++G (d, p) basis set. The structural parameters like bond lengths, bond angle, and dihedral angles were obtained from the optimized molecular geometry and discussed. This structural analysis shows, the DPPPM molecule has non-planar structure and possess C1 point group symmetry. The infrared vibrational spectral bands assignments were made by correlating experimental findings with the computed data and results shows good agreement. The electronic spectral properties were explored using the time-dependent density functional theory (TD-DFT) in the gas phase and two different polarity solvents. This obtained theoretical UV-Visible absorption results are in acceptable concurrence with the UV-Visible absorption experimental results. The solvent effect on wavelength of absorption also been reported. The frontier molecular orbital, MESP and global chemical reactivity parameters for the title molecule in the gas phase were reported and discussed. Theses result shows molecule possesses good strength and stability.

Water chemical pollution originates from a wide range of toxic derivatives, especially heavy metals and dyes. Its destructive effects on humans and the ecosystem have been considered as a serious environmental disaster. Therefore, there is a need to develop technologies to remove toxic pollutants from the environment. Adsorption is one of the most common methods of removing contaminants from wastewater among all the proposed methods. Adsorption is an optional method for industrial sewage treatment and a useful instrument for environmental protection. In recent years, numerous studies have been conducted to achieve low-cost, efficient, and environmentally friendly adsorbents. Among the low-cost adsorbents, the application of agricultural waste, as bio-adsorbent, is the most widely used for removing heavy metals and dyes. The advantages of using these compounds are low cost, good efficiency, minimal energy, simple maintenance and high adsorption capacity. This study deals with the risks, effects, and resources of manufacturers of heavy metal and dyes in addition to examination of agricultural wastes as low-cost adsorbents. Moreover, equilibrium, kinetic, and thermodynamic behaviors of the process of adsorption of heavy metal ions and dyes, using Langmuir and Freundlich adsorption isotherms, and Pseudo first and second-order kinetic models, and thermodynamic parameters were studied.

Since photocatalysts play a vital role in solar cell performance, and solar cells are also an effective source of green energy. In this paper,a facile and affordable protocol for designing an effective photoanode based on the quantum dot was introduced. multi-layered quantum dots containing CdS and different layers of n-type of PbS (2, 4, 6cycles)has been used to improve photoanodes sensitivity through the successive ionic layer adsorption and reaction(SILAR)with a coat of TiO2 nanoparticles on ITO substrates.CuS was used as a counter electrode for all cells. The film's behavior was examined in the dark and under simulated sunlight (200 mW cm-2) with electrochemical techniques (chronoamperometry(CA), chronopotentiometry(CE), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry(LSV)). The morphology of prepared films was investigated by scanning electron microscopy(SEM) and energy dispersive X-Ray spectroscopy (EDS). The results for the TiO2/4CdS/4PbS film revealed that developing multi-layered cells could improve the quantum dot sensitivity and the performance of the cell in case of reaching the optical layer.The TiO2/4CdS/4PbS electrode improved the sensitivity of the cell remarkably and the maximum difference between light and darkness was observed in the 1.5 V potential, in which the constant 1.5 V potential current lead to the 18 µA/cm2 difference in chronoamperometry.

The main purpose of this study was to find a simple reaction condition for reproducible synthesis of water-soluble superparamagnetic iron oxide nanoparticles (SPIONs) through the co-precipitation method. For this purpose, the effect of alkali solution, working atmosphere and final reaction temperature on type, size and magnetic properties of synthesized particles were examined. The results reveal that from two different tested alkali precipitants including ammonia and 1M NaOH, samples synthesized using ammonia demonstrate proper magnetic properties, while the latter agent leads to production of nonmagnetic brown suspensions in all reaction conditions. UV-Vis and XRD showed the typical magnetite pattern for samples synthesized using ammonia as the alkali precipitant. In addition, the results show that higher reaction temperatures lead to the production of smaller size black particles with lower oxidation level, better crystallization, and higher saturation magnetization. The optimal results were obtained when the ammonia was used as an alkali precipitant and the reaction temperature was set to 80 ̊C under N2 atmosphere. Furthermore, particles which were made under the air condition at 80 ̊C using 25% ammonia, showed satisfactory dimensional and magnetic properties. The simple reaction condition used in this study could be applicable for large scale synthesis of stable SPIONs.

As a known non-ionic, -denaturing detergent and emulsifier, Triton™ X-100 is often used in various biochemical studies including in the isolation of membrane-protein complexes for solubilizing membrane proteins, in the process of periplasmic protein extraction as a component of the lysis buffer, in both indirect immunofluorescence staining and flow cytometry as a permeabilization reagent, etc. It has been shown that the diluted solution of Triton™ X-100 with the optimal pH range of 6.0-8.0 has a significant absorption of UV light. In the present project, we show that the absorption spectrum of Triton™ X-100, when dissolved in 1X phosphate-buffered saline, is similar to that of α-synuclein, as a representative of those proteins lack tryptophan but contain tyrosine as their main UV absorber. These results show that whenever the use of Triton™ X-100 for extracting membrane and periplasmic proteins is inevitable, scavenging it before the characterization of the proteins by UV-Vis spectroscopy, especially the determination of their concentration using Beer-Lambert Law, would be necessary.

The present research aimed to evaluate the effects of synthesis parameters on morphology and photocatalytic activity of TiO2 nanotube aligned arrays (TNAs) via a low cost anodization process. The impact of electrolyte composition, anodization time, as well as applied voltage on morphological and architecture properties of TNAs including; length, inner diameter, and wall thickness were accurately investigated. We further studied effect of heat treatment on crystalline and phase transformation of the samples at different annealing temperatures. Photocatalytic properties of the fabricated samples were studied for degradation of p-nitrophenol under UV light irradiation. Physical/chemical characteristics of the photo-anodes were observed using several techniques including field emission scanning electron microscopy (FE-SEM) , Energy Dispersive X-Ray Spectroscopy (EDX) and XRD . Moreover, the maximum photocatalytic performance for p-nitrophenol degradation was obtained as about 80%.

This research examined the photocatalytic degradation of oily pollutant, BiVO4 with efficient photocatalytic activities synthesized via hydrothermal method with its surface modified by (3- aminopropyl) triethoxysilane (APTES). The structural, morphological, and optical properties of the as synthesized samples were evaluated by X-ray powder diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), contact angle (CA), Thermo Gravimetric Analysis )TGA(, Fourier-transform infrared spectroscopy (FT-IR), UV-vis diffuse reflectance spectroscopy (DRS), and Analysis Brunauer–Emmett–Teller (BET). The photocatalytic efficiency of the prepared samples was evaluated by Kerosine degradation. The experiments were designed by the Box-Behnken method. Finally, the software is the best point for achieving the highest percentage of degradation of oily pollutant under optimal conditions with pollutant concentration of 436.32 (ppm), time of 2.62 (h), catalyst mass of 0.77 (g), and H2O2 concentration of 0.42 (M).

The molecular dynamics (MD) method was used to study short time relaxation processes in the dimethylimidazolium chloride-methanol system at T = 400K. We demonstrate that the establishment of thermodynamic equilibrium in the dmim+/Cl-- methanol system is associated with both short-time relaxation processes (β-relaxation) and at relatively long-time relaxation processes. The processes of β-relaxation at t

In this research, the ZnO-MgFe2O4/ZnAl-LDH, ZnO-MgFe2O4/MgAl-LDH, ZnO-MgFe2O4, ZnAl-LDH, and MgAl-LDH were prepared and characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and FT-IR spectrometer analysis. The samples were synthesized by the co-precipitation method. The efficiency of the samples was investigated for the Congo red dye removal from the aqueous solution. According to the results, a similar efficiency for the LDHs samples and ZnO-MgFe2O4/LDHs composites was observed. The experimental data for the ZnO-MgFe2O4/ZnAl-LDH and ZnO-MgFe2O4/MgAl-LDH composites were analyzed by adsorption isotherm (Langmuir and Freundlich) and kinetic models (pseudo-first-order, pseudo-second-order, and intra-particle diffusion). The results showed more than >90% of the Congo red dye was removed from the solution after 90 min contact time. The experimental results showed the adsorption process fitted well with the Langmuir isotherm model and pseudo-second-order kinetic model. For the ZnO-MgFe2O4/ZnAl-LDH and ZnO-MgFe2O4/MgAl-LDH samples, the RL value close to zero (0.024 and 0.037) was obtained. This result indicates that the adsorption of the CR dye molecules on the surface of the samples is an almost irreversible process. The low RL value indicates that the interactions between Congo red dye molecules and LDH composites might be relatively strong.

Herein, A facile and green approach was employed to fabricate iron-copper nanocomposites (ICNCs) using peanut vine extracts, and the ICNCs were used for the removal of pefloxacin (PFX) and enrofloxacin (ENR) from aqueous solution. Following this, ICNCs were comprehensively characterized by BET, XPS, SEM, FT-IR and EDS. The equilibrium adsorption data of PFX and ENR on ICNCs were well described by Langmuir and Sips isotherm models, and thermodynamics parameters revealed the spontaneous and endothermic nature of PFX and ENR adsorption processes. Kinetic data were best fitted by pseudo-second-order model. Hydrogen bonding, π-π and n-π electron-donor-acceptor interaction, complexation and electrostatic interaction were the main forces in adsorption processes of ICNCs. The maximum monolayer adsorption capacities of ICNCs for PFX and ENR were 240.70 and 195.97 mg/g at 298 K, respectively, indicating that ICNCs is a promising adsorbent for PFX or ENR removal in wastewater treatment.