Articles
Publication Date: 2023
Sensors and Actuators B: Chemical (0925-4005)379
A reversible multichannel chemosensor IPBTO [E)-5-(4-(1H-imidazo[4,5-b]phenazin-2-yl) benzylidene)-2-thioxothiazolidin-4-one] was fabricated as a D-pi-A system and used for the detection of cyanide ion (CN-) in aqueous solutions. This chemosensor exhibited a switch-off fluorescence response at 566 nm for CN- in the presence of other tested anions. The detection limit of IPBTO toward CN- was 0.7 mu M with the association constant being 2.0 x 106 M-1. The reversibility and reusability aspects of this chemosensor were investigated for five consecutive runs, and good results were obtained. In addition, IPBTO as a bioimaging agent with good cell viability was deployed for the detection of CN- in MDA-MB-231 cells. Excellent potential for sensing CN- was also realized for this chemosensor in food and environmental samples. Besides, IPBTO was self-assembled on the gold electrode surface (Au-IPBTO SAM) and used for accumulation and detection of CN- in aqueous media. This modified electrode was characterized by ATR surface analysis, and the electrochemical behavior of the electrode was studied utilizing cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Our results have conclusively revealed that this electrochemical sensor could be successfully used to detect CN-.
Publication Date: 2021
Separation and Purification Technology (13835866)275
An extraction-electrooxidation (E-EODS) system is introduced for the removal of dibenzothiophene (DBT) from model fuel (DBT in n-hexane). The process is run in an electrochemical cell as a batch reactor, where, the model fuel is in contact with an appropriate immiscible polar solvent composed of acetonitrile and water (MeCN-water, 90:10% v/v) that serves as both the extraction solvent and electrochemical medium. The electrochemical oxidation of DBT, which is extracted into the MeCN-water phase, enhances the continuous removal of DBT from the model fuel phase. The effects of the composition of the extraction solvent, applied potential and the process time on DBT removal efficiency are assessed. The results indicate that with the selection of the MeCN-water, 90:10 v/v in a 1:1 ratio respect to the model fuel, this extraction method yields about 100% extraction efficiency within 5 h, at 25 °C at 2.9 V and atmospheric pressure as determined by HPLC technique. Cyclic voltammetry (CV), Fourier transform infrared (FT-IR) spectroscopy, and gas chromatography-mass spectrometry (GC–MS) techniques are applied to identify the electrochemical oxidation products of DBT. The electrochemical oxidation-derived extraction process through this method is innovative and feasible for deep desulfurization of liquid fossil fuels. © 2021
Publication Date: 2021
Polymers for Advanced Technologies (10427147)32(10)pp. 4014-4028
In this research, waterborne polyurethane (WPU) nanocomposites incorporated with MgAl-NO3LDH layered double hydroxide (LDH) and phytic acid intercalated LDH (PA-LDH) nanostructures were prepared as novel environmental-friendly corrosion protective coatings. Fourier-transform infrared spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis, field emission scanning electron microscope (SEM), and high-resolution transmission electron microscopy analysis confirmed the prosperous preparation of LDHs nanosheets. Moreover, structural, thermal, thermo-mechanical, and morphological investigations of prepared WPU/LDHs films were also evaluated. The SEM images exhibited that the intercalation of LDH nanosheets with PA could drastically overcome the agglomeration problem of unmodified LDH within the polyurethane matrix. Based on XRD results, WPU/LDHs films showed a lower micro-phase separation degree and crystallinity compared to pure WPU film. According to wettability analysis, WPU/PA-LDH film demonstrated the highest hydrophobicity among samples due to its lowest phase-separation degree, which causes the castor oil and poly(tetramethylene ether) glycol segments to migrate toward the surface of film from the bulk. Furthermore, the potentiodynamic polarization scanning and electrochemical impedance spectroscopy analysis revealed that the WPU/PA-LDH sample containing 1.0 wt% of PA-LDH has a superlative anti-corrosion performance for SS 304 steel with an inhibition efficiency of 99.9%. This superior anti-corrosive property benefited from the barrier property and chloride absorption capability of well-dispersed PA-LDH nanosheets, deposition of PA on the steel substrate, and improved hydrophobicity of the WPU/PA-LDH coating. © 2021 John Wiley & Sons Ltd.
