Experimental, Density Functional Theory, and Dynamic Molecular Studies of Imidazopyridine Derivatives as Corrosion Inhibitors for Mild Steel in Hydrochloric Acid

Removal of crystal violet dye using a three-dimensional network of date pits powder/sodium alginate hydrogel beads: Experimental optimization and DFT calculation

Biodegradable and very low-cost adsorbent beads were prepared from date pits powder (DP) and sodium alginate (SA). DP to SA ratios was varied (1/2, 1/4 and 1/6) and used to eliminate Crystal violet (CV) a cationic dye. Adsorbents were characterized by FTIR, SEM-EDS, UV-vis DR, TGA and the point of zero charge (pHPZC). The optimal composite beads SA@6DP show high adsorption capacities of 83.565 mg/g toward CV than SA@2DP and SA@4DP. The kinetics investigation showed that the adsorption is well described by the pseudo-second-order kinetic (R2 = 0.998). The thermodynamics and isotherms studies exhibit that the adsorption phenomenon for SA@6DP adsorbent is endothermic and significantly fitted with the Redlich-Peterson model. The experimental adsorption tests were optimized by the Box-Behnken design (BBD) which led to conclude the maximal CV removal efficiency achieved by SA@6DP was 99.873 % using [CV] = 50 mg/L, adsorbent mass = 20 mg and 48 h of contact time. The theoretical calculation proved that the CV molecules favor the mode of attack due to their electrophilic character and can accept the SA@6DP adsorbent electrons more easily to form an anti-bonding orbital. SA@6DP hydrogel beads are therefore an exceptional bio-adsorbent that offers excellent adsorption performance.

Synthesis, Characterization, Antibacterial, Antifungal and Anticorrosion Activities of 1,2,4-Triazolo[1,5-a]quinazolinone

The synthesis of 5,6,7,8-tetrahydro-[1,2,4]triazolo[5,1-b]quinazolin-9(4H)-one (THTQ), a potentially biologically active compound, was pursued, and its structure was determined through a sequence of spectral analysis, including ¹H-NMR, ¹³C-NMR, IR, and HRMS. Four bacterial and four fungal strains were evaluated for their susceptibility to the antibacterial and antifungal properties of the THTQ compound using the well diffusion method. The impact of THTQ on the corrosion of mild steel in a 1 M HCl solution was evaluated using various methods such as weight loss, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) analysis. The study revealed that the effectiveness of THTQ as an inhibitor increased with the concentration but decreased with temperature. The PDP analysis suggested that THTQ acted as a mixed-type inhibitor, whereas the EIS data showed that it created a protective layer on the steel surface. This protective layer occurs due to the adsorption behavior of THTQ following Langmuir's adsorption isotherm. The inhibition potential of THTQ is also predicted theoretically using DFT at B3LYP and Monte Carlo simulation.