| Popis: |
Corrosion is one of the serious problems countered in different industries as it dramatically causes strong impacting on the infrastructures. As an attempt for sorting out such problem, this approach investigated an innovative strategy for synthesis of corrosion inhibitor for steel surfaces based on composite of polystyrene and zinc nanoparticles (ZnNPs@polystyrene composite). The successive immobilization of ZnNPs (size average of 4-50 nm) within polystyrene matrix (Mwt of 372.587 g/ mole and degree of polymerization equals 3582 repeat unit/ molecule) for clustering of the desirable ZnNPs@polystyrene composite (surface area of 33.62 m2/g, average pore diameter of 9 nm) was approved via several instrumental analyses of FT-IR, XRD, SEM, HRSEM, EDX, TEM and BET with estimation of total pore volume and average pore diameter for the prepared composite. Thermal stability of the prepared composite was affirmed via TGA analysis. Corrosion percentage via weight loss percent in three media of water, H2SO4 and diesel fuel was estimated to reach maximally to 25 % in case of H2SO4, while, corrosion inhibition efficiency (CIE) percentage estimated according to weight loss to reach 94.27, 88.18 and 85.05 % after 10 days of soaking the steel samples coated with the synthesized ZnNPs@polystyrene composite (800 ppm) at 25 ℃, while, elevation of temperature up to 45 ℃, resulted in non-significant effect on the estimated CIE to be diminished to 91.8, 85.2 and 81.1% after soaking in water, diesel fuel and sulfuric acid as corrosion media, respectively. CIE was estimated to be near 30% in case of coating steel samples with polystyrene polymer, to be significantly increased to near 80 % and formidably jumped to near 100% by coating with ZnNPs@polystyrene composite, with weight percent of 30 & 50% of ZnNPs, respectively. In addition to, Zeta potential was also detected to be - 9.67 in case of untreated steel samples, while, it became - 4.98 after coating of sample with ZnNPs@polystyrene composite. Eventually, from Arrhenius plots, activation energies and thermodynamic parameters of rate constant, enthalpy (ΔH) and entropy (ΔS) confirmed that the interaction is more taking place between the corrosion species and ZnNPs@polystyrene composite as corrosion inhibitor rather than with steel surface. Postulation of the reaction mechanism for the anticorrosive action of the synthesized ZnNPs@polystyrene composite was presented according to the illustrated instrumental analyses. |
