Assessment of complexing properties and mechanisms involved in covalently-bonded carbon-supported hyperbranched polyethyleneimines towards metal ions environmental technical interest.

Strong, dissolved, copper-complexing ligands are known to control copper speciation and bioavailability in most marine waters. We are testing the hypothesis that metal-responsive production of such ligands occurs in the Elizabeth River estuary, and that picoplankton and bacterioplankton produce the ligands. Recent studies utilizing cultures of marine picoplankton (Synechococcus) and bacteriopla...

Abstract

In the preparation of nanostructured materials, it is important to optimize synthesis parameters in order to obtain the desired material. This work investigates the role of complexing agents, oxalic acid and tartaric acid, in the production of MgO nanocrystals. Results from simultaneous thermogravimetric analysis (STA) show that the two different synthesis routes yield precursors with different...

In order to control the deposition of Zn-related films by chemical bath deposition, effects Zn-complexing agent are analyzed. ZnS were produced technique employing sodium citrate, ethanolamine and Triethanolamine as complexing agents. The conditions for (ZnO) thin obtained through a thermodynamic analysis, using distribution diagrams molar fraction Zn complexes. From species Zn-ethanolamine, Zn...

Although in a recent study (1) the susceptibility of diphtheria antitoxin to the denaturing action of urea was apparently established, the question of the fundamental nature of the reaction remains essentially unsolved. Since the action of urea probably involves a partial unfolding of the polypeptide chains of proteins, the lability of antibody in urea suggests that the antibody structure resid...

The preparation of O-hexofuranosides was accomplished from unprotected 1-thioimidoyl furanosides as donors. The present methodology was first used for the synthesis of octyl galactofuranoside and further extended to D-galactofuranose-containing disaccharides. Within this study, we emphasized the need for additional complexing cations to maintain the furanose ring in its initial size. After expe...

Electrophilic aromatic sulfonation of benzene with sulfur trioxide is studied with ab initio molecular dynamics simulations in gas phase, and in explicit noncomplexing (CCl3F) and complexing (CH3NO2) solvent models. We investigate different possible reaction pathways, the number of SO3 molecules participating in the reaction, and the influence of the solvent. Our simulations confirm the existen...

(II) is spectrophotometrically determined with 4-(2-pyridylazo)resorcinol (PAR) 1–4 in the presence of EDTA. This color reaction can never be carried out by a batch method because the stability constant of copper(II)-EDTA (log K = 18.8) is larger than that of copper(II)-PAR (log K = 14.8). 1 Therefore, PAR is used as an indicator in the EDTA titration of copper(II). We found that a color reacti...