• Chambers Rooney posted an update 1 week, 2 days ago

    Surfaces containing APTES were found to be more hydrophobic. Fuel cells with PDMS performed better when compared to those with APTES. Fuel cells with 5wt.% APTES with a current density of 321.31 mA/cm 2 and power density of 0.191 W/cm 2 , and 10wt.% PDMS with a current density of 344.52 mA/cm 2 and power density of 0.205 W/cm 2 were the best performing fuel cells at 0.6V.This study introduces a new production method to use as a porous silicon-based proton exchange membrane for μDMFCs. In this respect, EIS, fuel crossover test, and fuel cell performance test at the μDMFC sample cell are performed at room temperature on a porous silicon-based membrane that was produced for passive mode μDMFC as a proton exchange membrane. The reason for performing the fuel crossover test is to ensure the silicon opened pores along the silicon wafer and to examine the fuel permeability of the membrane. The fuel crossover test shows that the fuel cell provides energy for about 60 min with a 50 mL fuel. EIS reveals proton permeability of proton exchange membrane. The calculated value of the conductivity of the membrane is 0.0016 S/cm. OCV of the system is 0.4V, whereas values (with highest power density is 0.1 mW/cm²and with the highest current density is 0.39 mA/cm²) are low. However, porous silicon is not a natural proton conductor. read more Hence, these values can be increased by different ways such as porous silicon functionalized, or serial connection of fuel cells. On the other hand, the value of OCV is consistent with the previous studies. In sum, this study presents a simple, cost-effective, and short time-consuming method for the production of porous silicon as proton-conducting membrane behavior.Schiff base derivatives with anthracene- and pyrene-based units, A1-A6 and P1-P6 were synthesized (89%-99% yields). Schiff base derivatives were designed to possess an heterocyclic moiety on one side to enhance the coordination ability towards metals. To investigate the biological assay of the newly synthesized compounds, their DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, metal chelating, reducing power, antibacterial and DNA binding activities were tested. A6 (63.1%) showed the maximum free radical scavenging activity among all. However, compound P3 at concentration of 200 μg/mL possessed the highest metal chelating (45.8%) activity and power of reduction. In addition, P3 and A6 showed antibacterial activity against all bacteria tested and both compounds were very well bound to CT-DNA. Density functional theory method with B3LYP/6-311++G(d,p) basis set was performed to get information about the structural and electronic properties of the present compounds. In addition, the metal coordination properties of the dimers of the parent Schiff bases were investigated through interactions with Zn2+.The objective of this study is to synthesize ZnO and Mg doped ZnO (Zn1-xMgxO) nanoparticles via the sol-gel method, and characterize their structures and to investigate their biological properties such as antibacterial activity and hemolytic potential.Nanoparticles (NPs) were synthesized by the sol-gel method using zinc acetate dihydrate (Zn(CH3COO)2.2H2O) and magnesium acetate tetrahydrate (Mg(CH3COO)2.4H2O) as precursors. Methanol and monoethanolamine were used as solvent and sol stabilizer, respectively. Structural and morphological characterizations of Zn1-xMgxO nanoparticles were studied by using XRD and SEM-EDX, respectively. Photocatalytic activities of ZnO and selected Mg-doped ZnO (Zn1-xMgxO) nanoparticles were investigated by degradation of methylene blue (MeB). Results indicated that Mg doping (both 10% and 30%) to the ZnO nanoparticles enhanced the photocatalytic activity and a little amount of Zn0.90 Mg0.10 O photocatalyst (1.0 mg/mL) degraded MeB with 99% efficiency after 24 h of irradiation under ambient visible light. Antibacterial activity of nanoparticles versus Escherichia coli ( E. coli ) was determined by the standard plate count method. Hemolytic activities of the NPs were studied by hemolysis tests using human erythrocytes. XRD data proved that the average particle size of nanoparticles was around 30 nm. Moreover, the XRD results indicatedthat the patterns of Mg doped ZnO nanoparticles related to ZnO hexagonal wurtzite structure had no secondary phase for x ≤ 0.2 concentration. For 0 ≤ x ≤ 0.02, NPs showed a concentration dependent antibacterial activity against E. coli . While Zn0.90Mg0.10 O totally inhibited the growth of E. coli , upper and lower dopant concentrations did not show antibacterial activity.Since benzo [ b ] thiophene scaffold is one of the privileged structures in drug discovery as this core exhibitsactivities for different biological problems, in this study bis (benzo[ b ]thiophene-2-yl) alkyl methanimine derivatives (1-9) were synthesized by reacting benzo[ b ]thiophene-2-carbaldehyde with diamines. All newly compounds were characterized by IR, 1H NMR and 13C NMR spectroscopic methods. Synthesized compounds were investigated using binary QSARbased models on therapeutic activity prediction of synthesized compounds and they showed high predicted activities in following diseases bacterial, angina, allergy, depression and obesity. Thus, they were then tested for their antimicrobial and antileishmanial activities as a result of this theoretical study. Compound 1(N, N’- (propane-1,3-diyl) bis (1-(benzo [ b ] thiophene-2-yl)) methanimine) was found the most active compound in both diseases. Thus, its molecular docking studies were also carried out.A fluorogenic probe based on a coumarin-derivative for Cu2+ sensing in CH3CN/H2O media (v/v, 95/5, 5.0 μM) was developed and applied in real samples. 3-(4-chlorophenyl)-6,7-dihydroxy-coumarin (MCPC) probe was obtained by synthetic methodologies and identified by spectral techniques. The probe MCPC showed remarkable changes with a “turn-off” fluorogenic sensing approach for the monitoring of Cu2+ at 456 nm under an excitation wavelength of 366 nm. The response time of the probe MCPC was founded as only 1 min. The detection limit of the probe MCPC was recorded to be 1.47 nM. The binding constant and possible stoichiometric ratio (11) values were determined by Benesi-Hildebrand and Job’s plot systems, respectively. The mechanism of the probe MCPC with Cu2+ was further confirmed by ESI-MS and FT-IR analyses, as well as supported by theoretical calculations. Furthermore, the probe MCPC was successfully employed for the practical applications to sense Cu2+ in different herbal and black tea samples. The proposed sensing method was also verified by ICP-OES method.