Cinnamic acid (CA) is known to lose its definite function by forming into radicals that able to penetrate into the skin and lead to health issues. Incorporating CA into zinc/aluminum-layered double hydroxides (Zn/Al-LDH) able to reduce photodegradation and eliminate close contact between skin and CA. Co-precipitation or direct method used by using zinc nitrate hexahydrate and aluminium nitrate nonahydrate as starting precursors with addition of various concentration of CA. The pH were kept constant at 7 ± 0.5. Fourier Transform Infrared-Attenuated Total Reflectance (FTIR-ATR) shows the presence of nanocomposites peak 3381 cm–1 for OH group, 1641 cm–1 for C=O group, 1543 cm–1 for C=C group and 1206 cm–1 for C–O group and disappearance of N–O peak at 1352 cm–1 indicates that cinnamic acid were intercalated in between the layered structures. Powder X-Ray Diffraction (PXRD) analysis for Zn/Al-LDH show the basal spacing of 9.0 Ǻ indicates the presence of nitrate and increases to 18.0 Ǻ in basal spacing in 0.4M Zn/Al-LDH-CA. CHNS analysis stated that 40 % of cinnamic acid were being found and intercalated in between the interlayer region of the Zn/Al-LDH with higher thermal stability. Field Emission Scanning Electron Microscope (FESEM) images of 0.4 M Zn/Al-LDH-CA shows that the nanocomposites are in more compact, flaky non porous, large agglomerates with smooth the surfaces of the intercalated compound. Controlled release was successful with 80 % release in phosphite anion and 70 % release carbonate anion. The cinnamic acid was successfully inserted between the interlayer regions of Zn/Al-LDH with slow release formulation.

Density functional theory (DFT) and molecular dynamics (MD) simulations were employed to investigate the inhibition mechanism of cationic quaternary ammonium surfactant corrosion inhibitors (CIs) with varying chain lengths in 1.0 M HCl and 500 ppm acetic acid on Fe (110) surfaces. DFT calculations demonstrated that all surfactant CI molecules possess favorable inhibition properties, with the cationic quaternary ammonium groups (N⁺) and alpha carbon serving as electron-donating reactive centers, characterized by a low band-gap energy of 1.26 eV. MD simulations highlighted C12, with a 12-alkyl chain length, as the most promising CI molecule, exhibiting high adsorption and binding energies, a low diffusion coefficient, and a random distribution at low concentrations, thereby facilitating optimal adsorption onto the Fe (110) metal surface. The insights gained from computational modeling regarding the influence of alkyl chain length on inhibition efficiency, coupled with the comprehensive theoretical understanding of cationic quaternary ammonium surfactant CI molecules in acidic corrosion systems, can serve as a foundation for the future development of innovative surfactant CI molecules incorporating ammonium-based functional groups.

This study explored the possibility of Schiff-base ligand compound, 2-acetylpyridine 4-ethyl-3-thiosemicarbazone (LH) and its organotin(IV) complex (BuSn(L)Cl2) as a corrosion inhibitor for mild steel in 1M hydrochloric acid (HCl) medium. The chemical structures of the synthesised compounds were confirmed by performing elemental analysis, FT-IR, UV-Vis, NMR spectroscopy, and X-ray crystallography diffraction study. The structure showed the LH served as a tridentate (N, N’, S) donor to tin through its pyridyl, azomethine nitrogen, and thiolate sulphur. The corrosion inhibition characteristics of the free Schiff-base ligand and its organotin complex were studied by the standard weight loss method. They showed inhibition activity through adsorption, and this phenomenon was found to obey Langmuir adsorption isotherm. The inhibition efficiency of both compounds was found to increase as their concentration was increased from 1 to 3mM, but the efficiency achieved with the tin complex was greater, being 98.98% at 3mM concentration.