Surfactant-dye interactions are very important in chemical and dyeing processes. The dyes interact strongly with surfactant and show new spectrophotometric properties, so the UV-vis absorption spectrophotometric method has been used to study this process and extract some thermodynamic parameters. In this work, the association equilibrium between ionic dyes and ionic surfactant were studied by a...

Thin-film opals comprising three layers of 440 nm diameter SiO2 spheres were assembled on Pt electrodes and modified with amino groups on the silica surface. Diffusion of anionic, cationic, and neutral redox species through the opals was studied by cyclic voltammetry. The chemically modified opal membranes demonstrate high molecular throughput and, at low pH, selectively block transport of a ca...

A review is presented on the use of charged cyclodextrins (CDs) as chiral selectors in capillary electrophoresis (CE) for the separation of analytes in pharmaceutical analysis. An overview is given of theoretical models that have been developed for a better prediction of the enantiomeric resolution and for a better understanding of the separation mechanism. Several types of charged CDs have bee...

Colloids and polymeric systems constitute building blocks of choice for designing and controlling material properties. One major parameter is therefore the aggregation state of the polymer/particles complexes and its control to achieve desired properties. In this presentation, two examples will be given to illustrate this principle. The first example relates to paper surface hydrophobation, oft...

Human group IIA phospholipase A(2) (hGIIA) is secreted from a number of cells during inflammation and is known to interact strongly with anionic membranes and to exhibit potent Gram-positive bactericidal activity. This protein contains 23 cationic residues, which are scattered over its entire surface, resulting in a high pI of 9.39. To understand the molecular basis for the selective binding of...

The BO neutral, cationic, and anionic molecular species have been painstakingly studied through multireference configuration interaction and single reference coupled cluster methods employing basis sets of quintuple cardinality. Potential energy curves have been constructed for 38 (BO), 37 (BO(+)), and 12 (BO(-)) states and the usual molecular parameters have been extracted most of which are in...

Chitosan resins modified with amino acids, such as glycine, valine, leucine, and serine, were synthesized for investigating the adsorption behavior of cationic and anionic species, and showed good abilities for the adsorption of trace elements in aquatic media as follows: glycine for lanthanoids at pH 7, leucine for molybdenum at pH 1-5, serine for uranium at pH 2-7, and amino acids for bismuth...

We report the synthesis and X-ray crystal structures of three acyclic CB[n]-type molecular containers (2a, 2h, 2f) that differ in the charge on their solubilizing groups (SO3(−), OH, NH3(+)). The X-ray crystal structures of compounds 2h and 2f reveal a self-folding of the ArOCH2CH2X wall into the cavity driven by π–π interactions, H-bonds and ion–dipole interactions. The need to reverse this se...

The present study addresses the direct flotation route for the concentration of a zinc silicate ore. Flotation of hemimorphite faces some challenges due to the similarity of hemimorphite and quartz surface properties. XRD, and XRF analyses, optical mineralogy and SEM with X-ray mapping were performed for characterization. The results showed that the quartz, hemimorphite, calcite and dolomite ar...