Progress in Color, Colorants and Coatings
Volume:12 Issue: 1, Winter 2019

Harvesting the energy from the sun through the bulk heterojunction (BHJ) solar cells need materials with specific electronic characteristics. However, any promising material if cast improperly in cells will end into low or even null power conversion efficiency (PCE). Cell casting optimization is a time/material consumable step in any photovoltaic manufacturing practice. In this study, we showed that how the artificial intelligence (AI) could help to find optimum values of device preparation variables. For this purpose, an in-house code will catch the input variables (donor: acceptor ratio, spin casting rate, annealing temperature); learn the trends by the hybrid artificial neural network (ANN), genetic algorithm (GA) and optimize the output results simultaneously. The results showed that ANN/GA is capable to learn the trends of relatively small size dataset without over-fitting. This study highlights that how implementing the suggested AI model can help to learn more information and find the optimum recipe from less number of experiments with the highest precision.  

In this paper, the effect of penicillin G benzathine (PGB) drug as a green corrosion inhibitor on mild steel in 1.0 M hydrochloric acid solution has been investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The inhibition efficiency (IE) was found to increase with increasing inhibitor concentration. Potentiodynamic polarization measurements indicated that PGB is a mixed type inhibitor. The results of potentiodynamic polarization and EIS measurements demonstrated that the adsorption of PGB on mild steel in 1.0 M HCl follows Langmuir isotherm. The calculated values of free energy indicated that both physical and chemical adsorption take place. The IE values obtained from EIS measurements show a reasonable agreement with those obtained from potentiodynamic polarization method.

This article applies the standard deviation of partial signal (SDPS) plots of electrochemical noise (EN) current signals originating from corrosion events on the symmetrical and asymmetrical electrodes made of uncoated and polypyrrole (PPy)-coated mild steel alloy in 4000 ppm NaCl+1000 ppm NaNO2 solution. Signal recording was performed after 30, 60, 90 min and 24 h from immersion time. Two types of symmetrical electrodes were made from uncoated (Bare-Bare) and PPy coated (PPy-PPy) mild steel electrodes. The asymmetrical electrodes (PPy-Bare) prepared from a difference in the coating between two working electrodes which are otherwise identical. The time records and the corresponding SDPS plots obtained from the three types of systems show an increase in the amplitude and the time width of EN current transients with movement from Bare-Bare to PPy-PPy. Therefore, the corrosion severity increases with movement from Bare-Bare to PPy-PPy. Over time from 30 min to 24 hours‚ the PPy coating in the Bare-PPy configuration is early insulated compared to the PPy-PPy. It seems that the symmetrical configuration (Bare-PPy) is the suitable system for evaluating the corrosion protection of PPy coatings by EN technique.

In this paper, we designed and synthesized free-metal dyes based on indoline. The proposed dyes were synthesized from phenothiazine as the starting material by standard reactions. The chemical structure of the synthesized dye was confirmed using FT-IR, 1HNMR and DSC techniques. Spectrophotometric measurements of the organic dyes in acetonitrile and on a TiO2 substrate were carried out in order to assess the changes in the dye. Maximum absorption wavelength for organic dye in solution is 453 nm and on TiO2 film is 467 nm. Finally, the proposed dyes were used as sensitizer in a dye solar cell structure and their photovoltaic properties were investigated. The Conversion efficiency for the synthesized dye is 0.92%.

The objective of this work is investigation of the adsorption and decomposition of Reactive Blue 19 from industrial wastewaters using laccase enzyme immobilized on activated carbon powder and fiber as adsorbent. Time, pH, temperature, stirring rate, the amount of the adsorbent, dye initial concentration, solution flow rate in the column and column height were studied as key operating parameters to determine the optimal adsorption conditions. The results indicated 80.70% of the adsorption for reactive blue 19 by immobilized laccase enzyme on adsorbent. In addition, kinetic parameters of the enzyme (Vmax and Km), optimal temperature effect, optimal pH and thermal stability of the free and stabilized laccase were studied and the results showed 66.66% of laccase enzyme immobilization yield on the adsorbent. The study of adsorption isotherms (Langmuir, Freundlich and Temkin) showed that the process follows a Langmuir model with a correlation coefficient (R2: 0.9389). Dye removal efficiency and characterization of the intermediate products of removal process were investigated using UV-Vis, TOC and LC/MS methods. Kinetic and thermodynamic models were studied based on the obtained results, the adsorption process follows a pseudo second order kinetic model. Determination of Gibbs free energy, ∆G, enthalpy, ∆H and entropy, ∆S, showed that the reaction is a spontaneous, exothermic process.

In this study, nanoparticle zinc ferrites with different particle sizes were synthesized via sol-gel method using ferric nitrate and zinc nitrate. The obtained gel was dried and calcined at three different temperatures (i.e. 500, 600 and 800 °C) for 2 h. Adequate amounts of the as-synthesized nanoparticle samples were then added to the mixture of polyester resin and formaldehyde resin. The obtained mixtures were applied on the surface of mild steel specimens, and then the corrosion behavior of the coated mild steel was studied by electrochemical impedance spectroscopy and salt spray. In addition, mechanical and thermal properties of the coating were evaluated using dynamic mechanical thermal analysis. The crystalline and chemical structures of the coatings were investigated using X–ray diffraction analysis and infrared spectroscopy, respectively. The results showed that not only the incorporation of nanoparticle zinc ferrites in the coating has no negative effects on curing, but also increased corrosion protective performance and mechanical properties of the coatings.