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The corrosion inhibition performance of novel synthesized thiosemicarbazide derivative namely, 2-isonicotinoyl-N-phenylhydrazinecarbothioamide (IPC) on the mild steel coupon surface in 1M hydrochloric acid solution is investigated by weight loss measurements. The adsorption parameters of the IPC on the mild steel coupon surface have been evaluated and the surface morphology of the tested mild steel is studied by scanning electron microscope (SEM) technique. The results of this study demonstrate a significant inhibitor (IPC) for mild steel and showed the highest inhibitive efficiency of 96.3% at 5mM as optimum studied inhibitor concentration. The adsorption of IPC molecules on a mild steel coupon surface is obeyed completely by the model of Langmuir adsorption isotherms. SEM has been applied to analyse the layer of IPC molecules which formed on a mild steel coupon surface as a protective layer. The inhibition efficiency (IE) of IPC from weight loss techniques and SEM analysis was harmonic with each other. The Density Functional Theory (DFT) computations have been applied to evaluate the adsorption sites of the IPC molecules and the quantum chemical calculations correlation of IPC molecules with methodological results are discussed. The energy of the highest occupied molecular orbital (EHOMO) shows a significant tendency of the IPC molecules to donate pairs of electrons to the iron atoms on the surface of mild steel. The energy of the lowest unoccupied molecular orbital (ELUMO) for IPS molecules reveals a high tendency to accept electrons from iron atoms on the surface of mild steel.

Two iron complexes of a porphyrin dimer molecule were synthesized and studied at the air-water interface and in Langumir-Blodgett (LB) films. Surface pressure-area isotherm and UV-vis absorption spectroscopic studies revealed an interesting molecular switching behavior between the two iron porphyrin complexes under basic or acidic conditions. Such a reversible structural transition does not only occur in solution phase, but readily takes place in the deposited Langmuir-Blodgett films. Domains with strip or disk-like shapes were formed in the Langmuir films of the metalloporphyrin complexes when barbituric acid was added into the subphase, an indication of supramolecular network formation between the metalloporphyrin dimer and barbituric acid molecules. Magnetic property studies of the Langmuir-Blodgett films of the iron porphyrin complexes by magnetic force microscopy provide further insights into relationships between the magnetic response and molecular structures of the metalloporphyrin LB films.

The 5,10,15,20-tetrakis[3,4-bis(2-ethylhexyloxy)phenyl]-21H,23H-porphinato zinc(II) (ZnEHO) is highly stable and exhibits a colorful absorption spectrum in the visible range. Exposure of a chloroform solution of ZnEHO to amines is shown to induce changes in the characteristic optical spectrum owing to charge transfer between the amine and the delocalized π-electron system within the highly conjugated molecule. Solid state Langmuir Blodgett (LB) films containing only ZnEHO are compared to films containing a mixture of ZnEHO and calix[8]arene. The transparent calix[8]arene does not change the optical response but aids the diffusion of the amine gas into the LB films. Atomic force microscopy (AFM) and scanning near-field optical microscopy (SNOM) images demonstrate the topological and compositional differences between the samples. The response of the LB films of ZnEHO and calix[8]arene to a variety of different amines demonstrates that this is a good material system for use as an amine sensor.

Carbon nanofibers (CNFs) were synthesized by using a safe and less hazardous method, compared to using floating catalysts in chemical vapor deposition (CVD) process. This process used C₂H₂ as carbon source and oil palm kernel shell-based powdered activated carbon (PAC) as cheap solid substrate. Use of nickel (Ni²⁺) impregnated PAC as fixed substrate for the synthesis of CNF is one of the novelties of the research work accomplished by the authors. The PAC–CNFs porous nanocomposite product was used for the sorption of lead ions (Pb²⁺) from synthetic aqueous solution. Kinetics of Pb²⁺ adsorption and isotherms were investigated by varying initial concentration of lead and contact time. PAC–CNFs were found to remove Pb²⁺ better at acidic pH of about 5.5. Langmuir and Freundlich isotherms were applied to the sorption equilibrium data to find the best fitted model. Langmuir isotherm model with R² = 0.965 fitted the adsorption data better than the Freundlich isotherm. The kinetic processes of Pb²⁺ adsorption on CNFs were investigated by applying different kinetic models, namely zero-order, pseudo-first-order and pseudo-second-order. The pseudo-second-order rate equation exhibited the best results with R² = 0.999, q_e = 74.79 (mg/g) and K₂ = 0.029 (min ⋅ g/mg). The novel nanocomposite product seemed to have the potential to remove Pb²⁺ ions from aqueous solution.