The optimal structure-conductivity relation in epoxy-phthalocyanine nanocomposites.

Phthalcon-11 (aquocyanophthalocyaninatocobalt (III)) forms semiconducting nanocrystals that can be dispersed in epoxy coatings to obtain a semiconducting material with a low percolation threshold. We investigated the structure-conductivity relation in this composite and the deviation from its optimal realization by combining two techniques. The real parts of the electrical conductivity of a Phthalcon-11/epoxy coating and of Phthalcon-11 powder were measured by dielectric spectroscopy as a function of frequency and temperature.

Separation and characterization of functional poly(n-butyl acrylate) by critical liquid chromatography.

The separation of functional poly(n-butyl acrylate) (PnBA) polymers based on the number of end-groups under critical liquid chromatography (LC) conditions has been studied using a bare-silica column. The (near-) critical solvent compositions for non-, mono-, and difunctional (telechelic) carboxyl-PnBAs were determined in normal-phase LC, using mixtures of acetonitrile, acetic (or formic) acid, and dichloromethane of varying composition. Some formic or acetic acid had to be added to the mobile phase to elute PnBA polymers with carboxyl end-groups.

Mass spectrometric characterization of functional poly(methyl methacrylate) in combination with critical liquid chromatography.

State-of-the-art techniques for the mass spectrometric characterization of synthetic polymers have been applied to functional poly(methyl methacrylate), synthesized by reversible addition-fragmentation chain-transfer (RAFT) polymerization. The polymers were first separated effectively according to functionality by liquid chromatography (LC) at the critical conditions (i.e.

Surface modification of oxidic nanoparticles using 3-methacryloxypropyltrimethoxysilane.

Tin oxide, antimony-doped tin oxide (ATO), and silica nanosized particles in aqueous dispersion were reacted with various amounts of 3-methacryloxypropyltrimethoxysilane (MPS). The kinetics were followed by 29Si NMR and the products were analyzed by FTIR and 29Si NMR. The kinetic experiments on ATO and silica revealed that the hydrolysis is the rate-determining step in these reactions.