Influence of Solvents on the Oxidation Kinetics of Aldehydic Group Compounds by Diethylammonium Chloro-chromate

The redox studies of some compounds containing aldehydic functional groups by diethyl ammonium chloro-chromate (DEACC) in dimethyl sulfoxide leading a product forming to acid of correspondimg order. Reactions are found to be in unit order with oxidant while a fractional order (less than unity) was found w.r.t. reductants. The redox reactions are influenced with acid, the acid dependence is governed by this equation: kobs = a + b[H+].. When isomeric form of aldehyde, that is Me-CDO is oxidised with the same oxidant it was observed a considerable K.I.E. (Deuterium effect; kH/kD = 05.69 at 298 K). The reaction of Acetaldehyde was done in various non aqueous medium, soluble or miscible in DMSO. The effect of solvent is studied fitting our data in the solvent model of Taft's and Swain's applied for this purpose.. Rate constants are correlating very well with already reported Taft’s values of *; further the reaction constants are negative in nature. Suitable mechanism involving are proposed with transfer of hydride ion..

Features of Electrophoretic Formation of Local Heat Sources Based on Nanosized Powder Al

In this study, the features of electrophoretic deposition (EPD) method to form nano-Al based energetic layers were investigated. The influence of solvents and additive components on the EPD process was analyzed, and the optimal composition of the suspension for the best deposition of layers based on nanoscale Al particles was acquired. The obtained layers can be used as an initiator of secondary reactions for on-chip energetic systems and a local heat source for joining surfaces by reactive bonding.

Influence of Solvents on the Antioxidant Properties of the Birch Outer Bark Extract in Cosmetic Emulsions

The goal of this study was to evaluate the influence of birch outer bark (BOB) extraction solvents on the antioxidant properties of the obtained dry extracts, which were added in cosmetic product emulsions. Extracts obtained in ethanol, 2-propanol, 1-butanol and ethyl acetate as well as one purified in ethanol by means of recrystallization were used as antioxidant additives, in 30 and 60 mg·g-1 concentrations, to cosmetic water-in-oil type emulsions. It was found that raw extracts had a considerably higher antioxidant stability than purified ones, because the raw extracts showed a higher phenolic compound content. The highest stability was detected in the cosmetic sample, which had a raw BOB extract obtained in 2-propanol. At the additive concentration of 60 mg·g-1, the protection factor was 20.6 times higher than in the case of a blank sample. Among other solvents used, 2-propanol showed the best solubility for BOB extract phenolic compounds, the content of which reached 3.58 wt% from the oven dry extract. It could be concluded that raw BOB extracts act as an excellent antioxidant additive in cosmetic emulsions.

Influence of Solvents on Properties of ZnS Thin Films Synthesized by Chemical Spray Pyrolysis Technique

In this paper, the influence of solvents on the structural, optical, surface and electrical properties of spray-deposited ZnS thin films has been studied. Different precursor mixtures were prepared from ethylene glycol, deionized water and alcohol solvents and sprayed on heated glasses via a simple and cost-effective technique known as spray pyrolysis. XRD patterns confirmed cubic and tetragonal phases of synthesized ZnS material. The optical analysis of the synthesized ZnS films showed that films prepared using ethylene glycol solvent have the highest transmittance and the best bandgap (3.61 eV). Surface morphology showed the absence of voids and pinholes in the Scanning Electron Micrograph of ZnS film prepared from ethylene glycol and electrical studies showed that ZnS films prepared using the same solvent have the lowest resistivity. Keywords: ZnS, Thin film, Spray pyrolysis, Bandgap, Morphology.

Spectral Characteristics and Molecular Structure of (E)-1-(4-Chlorophenyl)-3-(4-(dimethylamino)phenyl)prop-2-en-1-one (DAP)

In this work, a laser dye of (E)-1-(4-chlorophenyl)-3-(4-(dimethylamino)phenyl)prop-2-en-1-one (DAP) was synthesized and examined as a new laser medium. The compound DAP’s photophysical properties were investigated under the influence of solvents, concentrations, and pump power excitations. The absorption spectra showed a single band, and the shape of the spectra remained the same, regardless of the optical density. The fluorescence spectra showed a band around 538 nm; its intensity was inversely proportional to the concentration. DAP exhibits dual amplified spontaneous emission (ASE) bands at 545 and 565 nm under suitable pump power laser excitation and concentration. The results revealed that the ASE band at 565 nm is affected by solvents polarity, concentrations and pump power energies. This band could be attributed to the combination of two excited molecules and the solvent between them (superexciplex). Moreover, the molecular structure, the energy bandgap, and the total energy of DAP was calculated using density functional theory.