Conductometric study of the complex system polyelectrolyte/surfactant in aqueous solution

In this work, the interaction between the anionic surfactant sodium dodecyl sulfate (SDS) and the polyelectrolyte complex hydrolyzed polyacrylamide/poly(4-vinylpyridine) (AD37–P4VP) in aqueous solution was investigated by conductometric measurements. Three main series with SDS concentrations of 0.01, 0.25 and 1 % and in a wide range of P4VP and AD37 concentrations, from 0.1 × 10^?4 to 4 × 10^?4 g/ml, and from 10^?4 to 10^?3 g/ml, respectively, were studied. The polyelectrolyte complex interacts strongly with the SDS surfactant. These interactions are of electrostatic and hydrophobic types. Thus, the effect of salt on the critical micelle concentration of SDS, and the neutralization degree on behavior conductivity of the mixture, were quantified.     

Prediction of structural and thermodynamic properties of three products: 1-bromobenzene, tetrachlorethylene and 4-hydroxy-chromen-2-one using numerical methods

Our work concerns interaction spherical study of three toxic products, bromobenzene, tetrachloroethylene, and 4-hydroxy-chromene-2-one; using the Leap Frog algorithm, we calculated new values of cut-off of the box through Lennard-Jones potential parameters. This model was adapted to allow the determination of the characteristics for the SP₁, SP₂ and SP₃ state points and was applied to study the properties for the three products by molecular dynamics. This method provides an advantage to confirm the structure–activity relationship for these compounds. We calculated the thermodynamic and structural properties for both canonical NVT and isothermal–isobaric NPT ensembles of these products. Numerical system results have been compared with both experimental data and recent investigation theoretical. Our simulation model isobaric–isothermal system gives accurate results, and comparing with the canonical system, this model agrees very well with the experimental data. We aim to demonstrate that the classical approach with a low statistical uncertainty for liquid toxic leads to data in very good agreement with experiment or other types of calculations. We obtained a good prediction of the thermodynamic properties. We hope that this model with a lower threshold to 2.5σ could be an effective starting material for studying the properties of complex systems.     

Enhancement of Congo red dye removal efficiency using Mg-Fe-layered double hydroxide

Research on Chemical Intermediates - In this study, Mg-Fe(II)-Al-layered double hydroxide with different molar ratios Fe/Al (Mg0.80-Fe0.14-Al0.06-LDHs and Mg0.80-Fe0.20-Al0.00-LDHs) was prepared...     

The synthesis of N-acyl-2-hydroxymethyl aziridines of biological interest

A practical synthesis of the title compounds from protected amino acylazides is described. All the compounds might be considered as a novel class of dipeptide isostere precursors; they all induce lymphocyte proliferation and protein production as observed from preliminary biological tests.     

Interaction between poly(4-vinylpyridine-graft-bromodecane) and textile blue basic dye by spectrophotometric study

The interactions between poly(4-vinylpyridine-graft-bromodecane) (P4VPBrD) and textile blue basic (TBB) dye in aqueous solution were investigated by a spectrophotometric method at room temperature, considering that the electrostatic force is the main binding force and that the color change during the combination is due to the transformation of dye species of acidic form into bound basic form as well as the bathochromic and hypsochromic effects of conjugation. The formation of an isosbestic point in the absorption spectra of textile blue basic dye species of acidic form was explained based on a new consideration about the solution equilibrium. An application based on the interaction of P4VPBrD with the basic coloring agent is presented. Tests were carried out to estimate the retention rate of the dye by P4VPBrD.