This theoretical study investigates the adsorption of eco-friendly tannins on cellulose surfaces as a means to develop sustainable wood adhesives with reduced formaldehyde emissions. Conceptual density functional theory calculations reveal the global and local chemical reactivity parameters governing the interaction between tannins and wood substrates. Monte Carlo simulations explore the configuration space of substrate adsorbate, while molecular dynamics simulations elucidate the binding strength and stability of tannins. The results demonstrate that tannins adsorb parallel to the cellulose surface, driven by donor-acceptor interactions. The adsorption energy calculations reveal spontaneous adsorption, with prodelphinidin exhibiting the strongest adsorption energy. This research provides valuable insights into the adsorption behavior of tannins and contributes to the development of eco-friendly wood adhesives that mitigate formaldehyde emissions.

Knowledge of pesticide adsorption characteristics is essential to predict their behavior in soil. The adsorption equilibrium isotherms of two insecticides chlorantraniliprole (CAP) and dinotefuran (DNF) on two common Egyptian soil types, clay loam and sandy loam were studied and modeled. To predict the adsorption isotherms and to determine the adsorption parameters, ten isotherm models: Langmuir (five linear forms), Freundlich, Temkin, Dubinin-Radushkevich, Elovick, Fowler-Guggenheim, Kiselev, Jovanoic, Harkins-Jura, and Halsey were applied on experimental data. The results revealed that the adsorption isotherm models fitted the data in the order of Halsey > Freundlich > Jovanoic > Langmuir isotherme. The models of Harkins-Jura, Elovich, Temkin, and Fowler-Guggenheim are not applicable to predict the adsorption isotherms of the tested insecticides. In order to determine the best-fit isotherm, the correlation coefficient (R2), comparing the experimental (exp) and calculated (cal) adsorption data, and a normalized standard deviation (Δg%) were used to evaluate the data. Therefore, the isotherm models Halsey and Freundlich could be used to predict the adsorption characteristics of CAP and DNF in the common Egyptian soil types, clay loam and sandy loam. Consequently, the mathematical models Halsey, Freundlich, and Jovanoic can describe the fate of CAP and DNF and can be used to control Egyptian soil contamination.

This investigation demonstrates the successful synthesis of well-crystallized pristine and Ag-doped BiFeO3 microspheres using flash auto combustion technology. The effects of Ag doping on the morphology and microstructural characteristics were thoroughly examined through SEM, EDS, and powder X-ray diffraction (XRD) studies. Gas sensing experiments were performed to evaluate the response of the synthesized materials to NO gas. The results revealed a remarkable enhancement in the gas sensing capabilities of 5% wt Ag-doped BiFeO3 compared to pure BiFeO3. Specifically, the gas response towards NO was found to be 2.4 times higher for Ag-doped BiFeO3. This significant improvement can be attributed to the presence of Ag atoms within the lattice structure, which not only increased the density of holes in the material but also created additional gas molecule adsorption sites. Furthermore, the Ag dopant exhibited a catalytic effect, contributing to the excellent gas sensor performance of the material. These findings hold great promise for the development of highly sensitive and efficient gas sensors, particularly in applications where the detection of low concentrations of NO is crucial. The utilization of flash auto combustion technology in the synthesis process offers a viable route for scalable production of advanced gas sensing materials with enhanced performance.

Heavy metals contamination of water is a serious and complex environmental problem due to rapid industrialization, bioaccumulation and non-degradability. Therefore, the reuse of agricultural waste in the process of purifying water from pollutants is an attractive and promising method. Almost inexpensive materials are used to purify water, thus achieving the desired economic and environmental goal. In this study banana peel (BP) was used before and after modification by 0.1M sulphuric acid (H2SO4) to enhance the removal of Zinc Zn(II), Lead Pb(II) and Nickel Ni(II). The effect of various parameters was studied Such as pH, contact time, adsorbent dosage and initial metal ion concentration at 5 ppm. All these parameters were studied in batch experiments for a comparative study. The removal percentage was found to be 84% Zn (II),78%Pb (II) and 72% Ni (II) before modification and 92% Zn (II) , 94% Pb (II) and 96% Ni (II) after modification at initial concentration of 5 ppm. The data obtained from sorption isotherms were described with Langmuir and Freundlich isotherm models but were found to be well fitted for the Langmuir model. The correlation coefficient values R2 for Langmuir were at the range (0.996-0.999) while that for Freundlich were at the range (0.912-0.972). The rate of adsorption follows Pseudo-second-order kinetics. This work proved the high banana peels efficiency as an adsorbent agent for heavy metals removal from aqueous solutions.

A series of isoxazole derivatives, 3-aryl-5-[5-(4-nitrophenyl)-2-furyl]-2,3-dihydroisoxazoles (5a-j) were synthesized by cyclocondensation reaction between 1-aryl-3-[5-(4-nitrophenyl)-2-furyl]prop-2-en-1-ones (4a-j) and hydroxylamine hydrochloride in presence of sodium acetate in glacial acetic acid at reflux temperature. Formerly, compounds (4a-j) were synthesized by the condensation of 5-(4-nitrophenyl) furan-2-carbaldehyde (3) with various aromatic ketones by using alkali as catalyst. The structures of the synthesized various isoxazole have been characterized by using elemental analysis, Infrared,¹H-NMR spectroscopy and further supported by Mass spectroscopy. All the products have been screened for their in-vitro biological assay like antibacterial activity towards Gram-positive and Gram-negative bacterial strains and antifungal activity towards Aspergillus niger at a concentration of 40 µg/ml. It was exposed that the compounds 5a, 5c, 5e, 5f, and 5i showed inspiring antibacterial and antifungal activity compared to the used reference standard.

The corrosion inhibition power of an eco-friendly green inhibitor Ixora coccinea extract (ICE) for mild steel in 1 M HCl and 0.5 M H2SO₄ was analysed using physicochemical and electrochemical techniques. 1–5 v/v% ICE was prepared and added into the corrosive acidic media for different analyses. Weight loss measurements conducted for a period of 24hrs for mild steel immersion revealed 89.38% and 77.96% inhibition capacity of ICE in 1 M HCl and 0.5 M H2SO₄ medium respectively. Electrochemical impedance parameters show that as concentration is increased, efficiency increases and double layer capacitance decreases. Potentiodynamic polarization techniques are also in good agreement with impedance studies and exhibit the mixed type inhibition character of ICE. Electrochemical noise spectrum also strongly supports the anti-corrosive property of ICE and the magnitude of noise signal decreases concerning the increase in ICE concentration. Ixorene, which is one of the major constituents of Ixora coccinea leaves was also studied for its corrosion inhibition nature by quantum mechanical calculations and was found to match with all other results. Adsorption studies of ICE are in accordance with Langmuir isotherm. Surface morphological studies confirm the formation of a protective barrier on mild steel surface in both media, i.e., 1 M HCl and 0.5 M H2SO₄.

This study was focused to investigate the adsorptive behavior of activated carbon prepared from wheat straw treated with acid and base for the removal of 2, 4-dichlorophenoxy acetic acid (2,4-D). The morphology of the adsorbent was characterized using infrared spectroscopy and scanning electron microscopy. Compared with acid activated wheat straw, base activated wheat straw has provided lower ash content, moisture and volatile matter. However, it has higher iodine number than acid activated wheat straw. The removal of 2,4-D from aqueous solution was investigated at various physicochemical parameters such as pH (2–10), contact time (5–60 min), temperature (20-80 oC), amount of adsorbent (0.1-1.4 g) and initial concentration of 2,4-D (1.0-25 mg/L). The removal efficiency of 2,4-D in aqueous solution was found to be 92.02%. The equilibrium data were analyzed using Langmuir and Freundlich isotherm and the Langmuir model better describes that the active adsorption sites were homogeneously distributed on the surface of the adsorbent. Therefore, the activated carbon prepared from wheat straw treated with base can be used as efficient and cost-effective method to remove 2,4-D from aqueous solution.

Two heterocyclic oximes (E)-N-hydroxy-1-(pyridin-2-yl)methanimine (Hp2ylm) and (E)-N-hydroxy-1-(pyridin-3-yl)methanimine (Hp3ylm) were synthesized from pyridine-2-carbaldehyde and pyridine-3-carbaldehyde, respectively. These oximes were characterized by various spectroscopic tools like UV, IR, MASS and NMR. The inhibition capacity of these oximes against copper corrosion in 0.1 M HNO3 was determined by polarization and impedance spectroscopic studies (EIS). At all concentrations, Hp3ylm exhibited higher inhibition efficiency than Hp2ylm. Attempt was made to illustrate the mechanism of corrosion inhibition by these oximes with the help of adsorption isotherm, scanning electron microscopic (SEM) and quantum chemical studies.

The adsorption behavior of a potential polynuclear Schiff base, (s)-2-(anthracen-9(10H)-ylideneamino)-3-phenyl propanoic acid (A9Y3PPA) on carbon steel (CS) in 1M hydrochloric acid solution has been investigated using weight loss measurements, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization studies. The surface morphology of the carbon steel specimens in the presence and absence of the inhibitor was evaluated by AFM analysis. The corrosion inhibition efficiencies of parent amine and parent ketone on carbon steel in 1M HCl solution have also been investigated using weight loss studies. The adsorption of A9Y3PPA obeys Langmuir adsorption isotherm. Thermodynamic parameters (Kads, ∆G0ads) were calculated using the adsorption isotherm. Activation parameters of the corrosion process (Ea, ∆H* and ∆S*) were also calculated from the corrosion rates obtained from temperature studies. Tafel plot analysis revealed that A9Y3PPA acts as a mixed type inhibitor. A probable inhibition mechanism was also proposed.

In the current work, beach sand (BS) and beach sand coated with polyaniline (BS/Pani) were used as an efficient green adsorbent for dye removal from aqueous solutions. Methylene blue (MB) was chosen as a test probe for the evaluation of the selected adsorbents for dye removal efficiency. The adsorption experiments were carried out in batch system and the effect of some important empirical parameters affecting adsorption processes were then investigated. The experimental data were also analyzed by Langmuir and Freundlich adsorption models. Based on the correlation coefficient values obtained (R2), it was found that equilibrium data for both adsorbents fitted well with both models. Adsorption data were also examined by pseudo-first-order and pseudo-second-order models and their respective rate constants were estimated. It was found that sorption of MB dye onto BS/Pani is fitted very well with pseudo-second-order kinetic model. Using the equilibrium concentration constants obtained at different temperatures, important thermodynamic parameters of the sorption process were calculated. It was found that the chemically modified beach sand is an effective and low cost adsorbent for dye removal from aqueous solutions.