The preparation and property studies of transparent resins containing rare earth terbium(III) complex

The binary and ternary rare-earth terbium(m) complexes were introduced into the styrene/alpha -methylacrylic acid copolymerization system, and some optical resins that possess a high transparency in visible light region were obtained. The study of the optical property showed that they have good luminescent properties such as a high luminous intensity and a long luminous lifetime, In addition, we investigated the relationship among the transparency, the luminescent property of the copolymer, and the content of the components in the polymeric system. The results indicated that the optical resins can provide a relatively stable environment for composite rare earth complexes, which is good to exhibit the luminescent properties of rare earth complexes. At the same time, the rare earth complexes can offer the transparent resin a novel function.

H/D exchange reaction of cyclopropane derivatives in the ion system of CD3OD

The fragmentation properties of the product ions [M + 1](+), [M + 2](+) and [M + 3](+) formed by ion-molecule reaction of four cyclopropane derivatives with the ion system of CD3OD were investigated by using collision-induced dissocation technique. The experiment results indicated that the product ions were produced via the H/D exchange reaction between reactants and reactive reagent ions of CD3OD. There are two exchangable hydrogen atoms on the ring of compounds 1 and 2, and only one for compound 3 and 4.

Influence of cation concentration on 7,7,8,8-tetracyanoquinodimethane in polyelectrolyte by using in-situ microscopic Fourier transform infrared spectroelectrochemistry

The ion pair between the dianion of 7,7,8, 8-tetracyanoquinodimethane(TCNQ) and Li+ were investigated by in - situ microscopic Fourier transform infrared( FTIR) spectroelectrochemical technique. The effect of ion pair increases with increasing the concentration of cation. We observed a new band at 2130 cm(-1).

Probe beam deflection study on electrochemically controlled release of 5-fluorouracil

In this paper, the polypyrrole (PPy) film modified electrodes are used as an electroreleasing reservoir. The electrochemically controlled release of 5-fluorouracil (5-FU) from a PPy film modified electrode to aqueous electrolytes is studied by the in situ probe beam deflection (PBD) method combined with cyclic voltammetry (CV) and chronoamperometry (CA). The PBD results reveal that the release of 5-FU from PPy film depends on the electrochemical redox process of the PPy film electrode. The released amount is controlled by the reduction potential and is proportional to the thickness of the film. The exchange of 5-FU anions with Cl- on an open circuit is slow on the time scale of minutes, but the release of 5-FU anions can proceed quickly at -0.6 V (vs Ag/AgCl). The amount of released 5-FU decreases with the time that the PPy film is soaked in aqueous solution. (C) 1998 Elsevier Science Ltd. All rights reserved.

Structure of [C8H7](+) and intramolecular proton transfer reactions in 3-phenyl-1-butyn-3-ol by MS/MS technique

The electron impact mass spectrum (EIMS) of 3-phenyl-1-butyn-3-ol was reported in this paper. Collision-induced dissociation (CID) was used to study the gas phase ion structure of [C8H7](+) formed by the fragmentation of ionized 3-phenyl-1-butyn-3-ol, and that it has the same structure as m/z 103 ions generated by cinnamic acid and alpha-methylstyrene. Deuterium labelling, metastable ion (MI) and CID experimental results indicate the formation of m/z 103 ion resulting from molecular ion of 3-phenyl-1-butyn-3-ol, which is a stepwise procedure via twice proton transfers, rather than concerted process during the successive elimination of methyl radical and neutral carbon monoxide accompanying hydrogen transfer. Moreover, in order to rationalized these fragmentation processes, the bimolecular proton bound complex between benzyne and acetylene intermediate has been proposed.

Morphologies and mechanical properties of epoxy resins toughened by hydroxyl-terminated butadiene-acrylonitrile copolymer

The morphologies and mechanical properties of epoxy resins toughened by hydroxyl-terminated butadiene-acrylonitrile copolymer (HTBN) and cured with hexahydrophthalic anhydride were studied, The results show that the level of HTBN in epoxy resin, content of acrylonitrile in HTBN and curing temperature influence the morphology and then influence the mechanical properties of cured epoxy resin.

Electrochemical Study of the Self-exchange between Viologen-thiol Self assembled Monolayers and Alkanethiol Gold Electrodes

The preparation and cyclic voltammetric behaviors of self assembled monolayers (SAMs) containing electroactive viologen group have been investigated. Treatment of this viologen SAM with solutions of alkanethiols remits in replacing the electroactive third, shifting negatively its formal potentials and decreasing its heterogeneous elixtron transfer constants along with the immersion time. The aim of the work is to understand the exchange regularity of the mixed SANK on gold electrode surface.

Comb polymer electrolytes - Ionic conductivity and cation-polymer interaction

Three comb polymers(CP) with oligo-oxyethylene side chains of the type -O(CH2CH2O)(n)CH3 were prepared from methyl vinyl ether/maleic anhydride alternating copolymer. Homogeneous amorphous polymer electrolytes were made from CP and LiCF3SO3 or LiClO4 by solvent-casting method, and their conductivities were measured as a function of temperature and salt concentration. The conductivity which displayed non-Arrhenius behaviour was analyzed using the Vogel-Tammann-Fulcher equation. The conductivity maximum appears at lower salt concentration when CP has longer side chains. XPS was used to study the cation-polymer interaction.

The transfer of chloride ion across an anion exchange membrane

The transfer of chloride ions into a low resistance anion exchange membrane (AEM) was investigated by cyclic voltammetry (CV) and electrochemical impedance spectra. In all cases, concentration polarization of Cl- ions is exterior to the membrane. It controls the flux and produces the limiting currents: either steady state or transient (peak type) current. In CV experiments, when the size of the holes in the membrane was much smaller than the distance between membrane holes, the Cl- anion transfer showed steady state voltammetric behavior. Each hole in the membrane can be regarded as a microelectrode and the membrane was equivalent to a microelectrode array in this condition. When the hole in the membrane was large or the distance between membrane holes was small, the CV curve of the Cl- anion transfer across the membrane showed a peak shape, which was attributed to linear diffusion. In AC impedance measurement, the impedance spectrum of the membrane system was composed of two semicircles at low DC bias, corresponding to the bulk characteristics of the membrane and the kinetic process of ion transfer, respectively. The bulk membrane resistance increases with increasing DC bias and only one semicircle was observed at higher DC bias. The parameters related to kinetic and membrane properties were discussed.

A study of the dependence of ferrocene diffusion on electrolyte concentration and size in a polymer medium using non-steady-state chronoamperometry

This article describes a quantitative study of the diffusion rate of ferrocene(Fc) dissolved in ploy(ethylene glycol)(PEG) medium containing MClO(4)(M = Li+, Na+, Bu(4)N(+), Hx(4)N(+)). The apparent diffusion coefficient D-app and the active concentration c(a) of Fc were simultaneously measured by using non-steady-state chronoamperometry. The D-app and c(a) of Fc have been estimated in PEG containing different concentrations and sizes of supporting electrolyte, and the dependence of D-app on ferrocene concentrations has been observed. The values of D-app decrease with increasing concentrations of Fc, increasing concentrations of LiClO4 or the ratio (O:Li) and also with 4 decreasing cation radius of the electrolyte. The temperature dependencies conform to a simple free volume model. The concentration and size of the counterion dependencies of the diffusion rate are similar to the behavior of their dependencies of ionic conductivity in polyelectrolyte.

Probe beam deflection study of the ion exchange between Prussian blue film or indium hexacyanoferrate film and electrolyte solutions

Probe beam deflection(PBD) technique together with electrochemical techniques such as cyclic voltammetry was used to study the ion exchange in prussian blue(PB) film and its analogue indium hexacyanoferrate (InHCF) chemically modified electrodes, The ion exchange mechanism of PB was verified as following: K2Fe2+FeI(CN)(6)(-e--K+)reversible arrow(+e-+K+)KFe(3+)Fe(I)(CN)(6)(-xe--xK+)reversible arrow(+xe-+xK+) [Fe3+FeI(CN)(6)](x)[KFe3+FeI(CN)(6)](1-x) where on reduction in contact with an acidic KCl electrolyte, H+ enter PB film before K+. Both the cations and anions participate concurrently in the redox process of InHCF, meanwhile K+ ion plays a major role in the whole charge transfer process of this film with increasing radii of anions.

A novel in-situ spectroelectrochemical technique with probe beam deflection: For study of the ion exchange between films on electrode surface and solutions

A novel in-situ spectroelectrochemical technique, the combination of probe beam deflection (PBD) with cyclic voltammetry (CV), was used to study the ion exchange process of prussian blue(PB) modified film electrode in contact with various electrolyte solutions. The ion exchange mechanism was verified as following: (K2Fe2+FeII)(CN)(6) -e(-)-k(+)reversible arrow +e(-)+k(+) (KFe3+FeII)(CN)(6) -ke(-)-xk(+)reversible arrow +xe(-)+kk(+) [(Fe3+FeIII)(CN)(6)](x)[(KFe3+FeII)(CN)(6)](1-x) where on reduction PB film in contact with an acidic KCl electrolyte, it was confirmed that protons enter into the PB film before K+ cations.

A STUDY OF TETRAMETHYLAMMONIUM CATION ACROSS THE WATER-NITROBENZENE INTERFACE BY NEOPOLAROGRAPHY

The transfer behavior of tetramethylammonium cation (TMA~+) across the water/ nitrobenzene interface has been investigated by neopolarography including semiintegral (m), semidifferential (e), 1.5th order differential (e′) and 2.5 th order differential (e″) methods. The predicted dependences of peak height, peak potential and peak width on concentration and scan rate, etc have been discussed theoretically. The neopolarographic theory on the transfer of ions across the interface has been confirmed ...