Synthesis and electrochemical investigation of <Emphasis Type="Italic">beta</Emphasis>-substituted thiophene-based donor–acceptor copolymers with 3,4-ethylenedioxythiophene (EDOT)

The present work reports the synthesis of four electron-acceptor beta-substituted thiophenes that were studied as monomers for electrochemical polymerization with 3,4-ethylenedioxythiophene (EDOT), an electron-donating monomer, aiming the combination of electron-acceptor and donor monomer thiophene to a simpler and convenient build up of novel donor–acceptor copolymeric materials via electrochemical polymerization. Four novel copolymers poly(EDOT-co-3-thiophene phenylacetate), (PEDOT-co-PPhTAc-2a), poly(EDOT-co-3-thiophene(4-nitrophenyl)acetate) (PEDOT-co-PPhTAc-2b), poly(EDOT-co-3-thiophenephenylcarboxylate) (PEDOT-co-PPhTCb), and poly(EDOT-co-3-(phenoxymethyl)thiophene) (PEDOT-co-PPhOMT) were electrochemically polymerized. The monomers were characterized by spectrometric techniques (FTIR, ¹H NMR, and ¹³C NMR), and the copolymers were identified by electrochemical analyses and FT-IR. Although the corresponding homopolymers could not be obtained, in the presence of EDOT, the copolymers were formed in a quasi-reversible electrochemical kinetics. The infrared spectra of the copolymers as well the electrochemical profile corroborates their obtaining. The mass variation during the electrosynthesis was analyzed using a quartz crystal microbalance. The film’s morphologies were investigated by SEM. Interestingly, the combination of electron-rich monomer thiophene (EDOT) and these electron-deficient carboxy-substituted thiophenes might be a convenient building block couple to increase the performance control of physic-chemical properties of mixed polythiophenes with innovative applications and they also showed a possible applicability as charge storage device.     

Electrical study of cathodic activation and relaxation of La0,80Sr0,20MnO3

The effect of cathodic activation of sprayed La_0.8Sr_0.2MnO₃ (LSM) films has been studied by electrochemical spectroscopy impedance (EIS). LSM powder was prepared by a citrate route and X-ray diffraction analyses show a complete LSM crystallization without La₂O₃ or La(OH)₃ as side products. Porosity and grain size estimated from scanning electronic microscopy gave values of 33% and 100 nm, respectively. EIS measurement was performed on a Pt/yttria-stabilized zirconia/LSM cell before and after a cathodic current load (300 mA/cm²) on LSM electrode. The relaxation process, which is time-dependent, has been investigated. A drastic decrease of the electrode resistance was noticed just after applying the cathodic current, but after 9 h at optimized valence configuration in air at 850 °C, the recorded polarization resistance gradually enhanced until it almost reached the initial value. The resulting diagrams have been fitted using a Gerischer associated with a resistor and constant phase elements. This simple method has permitted us to observe that only the electrode interfaces are modified by a cathodic activation and the microstructure remains nearly constant.     

Electrochemical recycling of cell phone Li-ion batteries: application as corrosion protector of AISI 430 stainless steel in artificial seawater

This article aims to present a new alternative to waste management of spent Li-ion batteries from cell phones. In this sense, the proposed is recycling the cobalt from Li-ion cathode by electrodeposition and apply it as corrosion protector of AISI 430 stainless steel. Thus, two greatest environmental problems can be solved, producing a low-cost and high-corrosion-resistant stainless steel. The cobalt electrodeposition bath came from acid dissolution of spent Li-ion cathode with chemical formula LiCoO₂. The charge efficiency for cobalt electrodeposition in ?1.0 V and pH = 3 reaches 95 %. A protective layer of Co₃O₄ was successfully obtained by treatment of AISI 430 stainless steel with cobalt electrodeposited at 800 °C for 200 h in air atmosphere. The corrosion current of AISI 430 stainless steel in artificial seawater was reduced from 30 to 0.76 μA cm^?2. The treatment proposed produces a AISI 430 stainless steel with double of corrosion resistance and half of cost if compared with AISI 304 stainless steel.     

Influence of cathode functional layer composition on electrochemical performance of solid oxide fuel cells

Journal of Solid State Electrochemistry - In this work, anode-supported solid oxide fuel cells (SOFC) were tested with a yttria-stabilized zirconia (YSZ) (8&nbsp;mol%...     

Folate-Targeted Curcumin-Loaded Niosomes for Site-Specific Delivery in Breast Cancer Treatment: In Silico and In Vitro Study

As the most common cancer in women, efforts have been made to develop novel nanomedicine-based therapeutics for breast cancer. In the present study, the in silico curcumin (Cur) properties were investigated, and we found some important drawbacks of Cur. To enhance cancer therapeutics of Cur, three different nonionic surfactants (span 20, 60, and 80) were used to prepare various Cur-loaded niosomes (Nio-Cur). Then, fabricated Nio-Cur were decorated with folic acid (FA) and polyethylene glycol (PEG) for breast cancer suppression. For PEG-FA@Nio-Cur, the gene expression levels of Bax and p53 were higher compared to free drug and Nio-Cur. With PEG-FA-decorated Nio-Cur, levels of Bcl2 were lower than the free drug and Nio-Cur. When MCF7 and 4T1 cell uptake tests of PEG-FA@Nio-Cur and Nio-Cur were investigated, the results showed that the PEG-FA-modified niosomes exhibited the most preponderant endocytosis. In vitro experiments demonstrate that PEG-FA@Nio-Cur is a promising strategy for the delivery of Cur in breast cancer therapy. Breast cancer cells absorbed the prepared nanoformulations and exhibited sustained drug release characteristics.     

Electrochemical Sulphenylation/Cyclization of Quinones: A Rapid,Green, and Efficient Access to Cytotoxic Compounds

Undivided electrochemical cells enable economical preparation of sulphur-containing naphthoquinones through electrochemical sulphenylation of quinoidal compounds. The environmentally friendly and efficient protocol eliminates the use of chemical oxidants and facilitates the synthesis of the desired molecules. This approach offers an efficient and versatile method to synthesize quinones that exhibit cytotoxicity against cancer cell lines.