Progress in Color, Colorants and Coatings
Volume:17 Issue: 2, Spring 2024

Corrosion of mild steel in acidic environments presents a significant challenge across diverse industries. This pioneering research explores the novel potential of expired BCAA (Leucine, Isoleucine, and Valine) as a dynamic corrosion inhibitor for mild steel immersed in HCl solution. Through meticulous weight loss techniques, we quantified the corrosion rates of mild steel, both with and without the intervention of BCAA. Complementing our experimental approach, Density Functional Theory (DFT) calculations illuminated the intricate molecular interactions between BCAA and the metal surface. Furthermore, a comprehensive study of the adsorption isotherm unraveled the adsorption behavior of BCAA molecules on the mild steel surface. Remarkably, the inhibition efficiency of BCAA soared to an impressive 92.2 % at a concentration of 500 mM, a temperature of 303 K, and an immersion time of 5 hours. However, with the temperature increase to 333 K, a notable reduction in inhibition efficiency was observed. Intriguingly, the adsorption isotherm analysis showcased BCAA's adherence to the Langmuir adsorption isotherm, revealing additional insights into its inhibitory prowess. These groundbreaking findings highlight the untapped potential of expired BCAA as a corrosion inhibitor, offering valuable insights into its inhibition efficiency, temperature dependence, and adsorption behavior.

Poly(vinyl chloride) (PVC) finds wide-ranging applications, including protective clothing, pipes, gloves, and tubing. Recent studies have prioritized the enhancement of PVC's performance to meet specific criteria. This study delves into the impact of incorporating metal oxide nanoparticles into PVC films to bolster their UV light protection and chemical stability. Five modified PVC films, each laden with distinct metal oxide nanoparticles, were prepared and juxtaposed against the unaltered PVC film. These films endured 300 hours of UV light exposure and underwent assessment through gel content analysis, scanning electron microscopy (SEM), and UV-Vis spectroscopy. The outcomes divulged that the modified PVC films, especially those embedding Cr2O3 nanoparticles, exhibited diminished UV light absorbance and minimal gel content after an overnight immersion in tetrahydrofuran solvent. This attests to an elevated UV protection level and heightened chemical stability when compared to the plain PVC film. Our findings underscore the potential of metal oxide nanoparticle modification in amplifying the attributes of PVC films for demanding applications.

Photovoltaic systems, for example, dye-sensitized solar cells (DSSCs), are one of the useful tools for producing renewable and green energy. To develop DSSCs technology, it is necessary to overcome obstacles such as the need for expensive compounds. Organic dyes system containing responsible group for using in dye-sensitized solar cells and effective anchoring group for improving interaction between dye (photosensitizers) and nanolayer were designed and prepared. A series of DSSCs were designed and manufactured based on organic dyes as photosensitizers. The π-electrons in the HOMO orbitals of the dyes are delocalized only in dyes 1 and 2. A new MoS2/GO hybrid or composite was also employed instead of platinum. The DSSCs were prepared using MoS2/GO hybrid or composite and compared with that containing platinum. Under same conditions, the DSSCs with MoS2/GO composite illustrated better efficiency than MoS2/GO hybrid. The proposed dyes used as photosensitizer in a dye solar cell structure in the presence of Na-doped TiO2 and their photovoltaic properties investigated. The highest PCE in the presence of GO/MoS2 nanocomposite as opposite electrode and TiO2 and Na-doped TiO2 is 5.14 and 5.48, respectively, and corresponds to dye 8. The improved performance of Na doped TiO2 based DSSC could be attributed to the enhancement in optical properties of the sample by decreasing the intrinsic defects.

The ability of doxycycline to prevent corrosion of mild steel in 0.5 M sulphuric acid was investigated by using weight loss measurements, polarization resistance, Tafel polarization, and EIS (Electrochemical Impedance Spectroscopy). Doxycycline was a powerful inhibitor for mild steel corrosion, with an effectiveness of 99.2 % at 4.5×10-4 M. The thermodynamic parameters were computed and discussed to evaluate the process of inhibition. The drug fits the Langmuir isotherm. Potentiodynamic polarization studies indicate that it acts as a mixed-type inhibitor. The Electrochemical impedance spectroscopy reveals that raising the concentration of doxycycline amplifies the charge transfer resistance while dropping the double-layer capacitance. Surface morphology investigations were done with atomic force microscopy (AFM) on metal surfaces.

The direct laser melting of plasma sprayed bond coat has the possibility of improving the surface topography and can be done with Yb:YAG laser. In the current paper, laser melting of plasma sprayed coatings of 50 wt. % standard Amdry 963 (Ni24.5Cr6Al0.4Y) and 50 wt. % standard Amdry 9621 (Ni22Cr10AlY) was carried out by using 600 W continuous wave Yb:YAG laser. Notably, the obtained melted tracks were investigated from the upper surface plan view and transverse section. The topography, microstructure, phases, hardness, and compositions of the plasma sprayed coatings and laser-remelted tracks were characterized by scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), roughness, and microhardness. By controlling the dependent laser variables  (power density and interaction time), a different effect can be obtained for the plasma sprayed bond coating (NiCrAlY). Typically, the results obtained show that at low specific energies, four different distinct zones were observed. These specific energies were not sufficient to produce a uniform melting. The MCrAlY coatings remelted with high specific energies were characterized by completely uniform melting and cellular/dendritic microstructures. The melted coatings have high roughness reduction (1.2 μm) and low hardness (275 HV0.5) in comparison with plasma-sprayed coatings (10.5 μm) and (315 HV0.5) respectively.

This paper discusses the effects of UV light exposure on Citrus paradisi (grapefruit) peel in terms of naringin and TINUVIN 622 (a commercial stabilizer) compounds. This study aimed to develop a plant extract with the necessary properties to protect polystyrene from sunlight. Polystyrene films containing a low concentration of naringin were prepared, and TINUVIN 622, a commercial UV light stabilizer, irradiated the polystyrene sheets for 300 hours. Following irradiation, the study examined the infrared spectrum of polystyrene, weight loss, molecular weight reduction, and changes in surface morphology. Naringin and TINUVIN 622 significantly reduced the photodegradation of polystyrene films, acting as photostabilizers when compared to blank films.

Digital printing is affected by several parameters therefore, Process changes aimed at improving printer engine performance must take into consideration not only the process variables, but also the melt rheological variables. The thermo-mechanical properties of Konica Minolta BizHub C350 toners (in four colors) have been investigated with TGA, DSC and rheometer, as well as the physical and optical properties that have been evaluated using optical microscope, laser scattering particle size analyzer and spectrophotometer. The thermo-rheological evolution of the electrophotographic printing toners in the fusing stage of the image development has been investigated thoroughly. It was found that by increasing the temperature, the toner particles undergo initial surface fusing at around 70 °C which is followed by reduction in viscosity. However, the melting of the particles takes place at 155-172 °C which is resulted in completely merged particles. The melting temperature of the fur colors are occurred at a specific order that matches the standard printing sequence of four-color printing.

Corrosion presents a formidable challenge to the durability of metallic materials, especially in aggressive environments. This study delves into the corrosion inhibition capabilities of Methyl 3H-2,3,5-triazole-1-formate when applied to mild steel immersed in a 1 M HCl solution. Weight loss techniques meticulously scrutinize the inhibitor's efficacy across concentrations (0.1, 0.2, 0.3, 0.4, 0.5, and 1 mM). Immersion durations (1, 5, 10, 24, and 48 hours), all conducted at a constant temperature of 303 K. Furthermore, we explore the influence of temperature fluctuations (ranging from 303 to 333 K) on varying inhibitor concentrations (0.1-1 mM) through a 5-hour immersion period. To delve deeper into the molecular interactions underpinning the inhibitor's effects, we employ Density Functional Theory (DFT) calculations, harnessing the Gaussian 09 software package. Leveraging the B3LYP method, which fuses exchange and correlation functionals alongside a 6-31G++(d,p) basis set, our investigation yields critical insights. Complementary to this analysis, we determine pivotal molecular descriptors, encompassing electronegativity (χ), hardness (η), softness (σ), and transferred electrons fractional number (ΔN). Our experimental findings underscore the inhibitor's prowess, showcasing an impressive inhibition efficiency of 93.8 % at the optimized concentration of 5 mM and an immersion duration of 5 hours at 303 K. Also, we discern that the adsorption behavior of the inhibitor on the mild steel surface aligns with the Langmuir adsorption isotherm, shedding light on its interaction mechanisms. These comprehensive findings hold profound implications for advancing corrosion protection strategies and optimizing inhibitor applications across diverse industrial settings.