Materials Literature
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Abstract Strong multiple complexation of transition metal ions, Cu(II), Zn(II) and Ni(II) with different generations of well‐defined poly(propylene imine) dendrimers as multi(tridentate) ligands has been used to construct nanoscopic assemblies of defined structure and size incorporating a distinct number of metal ions…
This paper reports on the synthesis and morphological characterization of graft block copolymers in which a single polystyrene (PS) arm was grafted at an asymmetric position along a polyisoprene (PI) backbone. These materials represent a model series of asymmetric simple graft (ASG) block copolymer structures. The syn…
Internal strains in cluster-compacted nanocrystalline Pd (crystallite size 10–20 nm) were studied by means of wide-angle x-ray scattering. The strain- and size-induced broadening of the Bragg diffraction peaks was determined by Hall or Warren–Averbach analyses. The Warren–Averbach analysis indicates a spatial confinem…
Solutions of bis(cyclooctadiene)nickel react in the presence of polyvinylpyrrolidone in dichloromethane to give stable colloidal suspensions of nickel with a mean particle size of 20 Å (10 wt % Ni/PVP) and 30 Å (15 wt % Ni/PVP). The PVP-stabilized metal particles in organic suspension adsorb CO in both bridged and lin…
A series of SrTiO/sub 3/ (STO) films have been grown at a wide range of deposition conditions in order to determine the optimal growth parameters to maximize ferroelectric tuning while maintaining the lowest dielectric losses. The deposition pressure of the ambient O/sub 2/ (40 mTorra(bulk) at higher pressures (P(dep)…
Limestone or calcium carbonate (CaCO 3 ) used as a sorbent in the removal of acid gas precursors (SO 2 ) from combustion systems suffers from poor pore structural properties which causes low reactivity and incomplete utilization. The surface area and pore size distribution of CaCO 3, if tailored appropriately, can con…
An experimental miscibility map for 2,3-dimethylbutadiene- stat -4-vinylphenol (DMBVPh) blends with ethylene- stat -vinyl acetate (EVA) is obtained and compared to theoretical calculations. The number of hydrogen-bonded carbonyl groups in these systems is measured by FTIR spectroscopy and some systematic trends are ap…
The preparation and electron paramagnetic resonance (EPR) spectroscopy of a series of fully functionalized poly(propylene imine) dendrimers (DAB- dendr -(NH 2 ) n; n = 2, 4, 8, 16, 32, 64) with 3-carboxy-2,2,5,5-tetramethyl-1-pyrrolidinyloxy radical end groups is described. The pendant nitroxyl end groups exhibit a st…
ParA is an essential P1 plasmid partition protein. It represses transcription of the par genes (parA and parB) and is also required for a second, as yet undefined step in partition. ParA is a ParB-stimulated ATPase that binds to a specific DNA site in the par promoter region. ATP binding and hydrolysis by ParA affect…
A series of conjugated donor−acceptor trienes in which the central double bond is incorporated into an unsaturated isophorone, verbenone, or chromone ring has been synthesized. In each case, the donor group consists of an amine and an aromatic or heterocyclic ring system, and the acceptor is the dicyanomethylidene gro…
Polyelectrolyte multilayers were constructed from a polyviologen and poly(styrene sulfonate) using an alternating polyion solution deposition technique. In situ absorption spectroscopy showed multilayers to be strongly electrochromic. Oxygen reduction at multilayer‐coated conducting glass electrodes was also shown to…
The structure and dynamics of the lanthanide(III) complexes of DTPA-BGLUCA 3 - (DTPA-bis(glucamide)), DTPA-BENGALAA 3 - (DTPA-bis(ethylenegalactamine−amide)), DTPA-BEA 3 - (DTPA-bis(ethanolamide)), and DTPA-BPDA 3 - (DTPA-bis(propanediolamide)) in water have been investigated. These complexes are of relevance as poten…
Phase transformations occurring in materials under high pressures are important for a wide range of problems in materials science and solid-state physics. Most of the results in this area have been obtained using various sophisticated high-pressure cells. We studied solid-state phase transformations and amorphisation…
Uniform upconversion in erbium-doped silicate glasses is investigated as a function of glass composition, concentration, and fabrication method. Comparisons of upconversion coefficients are made among soda lime silicate and aluminosilicate bulk glasses and soda lime silicate waveguides. Comparisons are also made with…
The complexes Ni(C⋮CR)(PPh 3 )(η-C 5 H 5 ) (R = 4-C 6 H 4 NO 2 ( 3 ), 4,4‘-C 6 H 4 C 6 H 4 NO 2 ( 4 ), ( E )-4,4‘-C 6 H 4 CH CHC 6 H 4 NO 2 ( 5 ), ( Z )-4,4‘-C 6 H 4 CH CHC 6 H 4 NO 2 ( 6 ), 4,4‘-C 6 H 4 C⋮CC 6 H 4 NO 2 ( 7 ), 4,4‘-C 6 H 4 N CHC 6 H 4 NO 2 ( 8 )) have been prepared. Electrochemical data for the series…
Abstract Zn(II) L ‐lactate (ZnLac 2 ) was prepared either from ZnO and ethyl L ‐lactate or with slightly higher optical purity from ZnO and L ‐lactide. Using water‐free ZnLac 2 L ‐lactide was polymerized in bulk at 120°C or 150°C. Higher yields and higher molecular weights were found at 150°C. The highest number avera…
A new approach based on the Monte Carlo method of solving molecular crystal structures from full-pattern profile analysis of powder diffraction data is described. The new approach represents a significant advance on previous Monte Carlo methods in that it permits the solution of flexible (i.e. with variable bond lengt…
Abstract The use of preformed poly‐(propylene imine) dendrimers (DAB‐ dendr ‐(NH 2 ) x ) for the rapid and facile construction of high molecular weight carbohydrate‐coated dendrimers (glyco‐dendrimers) is presented. An efficient attachment of spacer‐armed derivatives of D‐galactose and lactose to the primary amino end…
The reasons for the predominant electron-donicity of almost all solid polar surfaces and its implications are discussed in this paper. By contact angle or interfacial tension measurements, the electron-accepting as well as the electron-donating properties of polar liquids can be ascertained, through the interplay betw…
3‘,4‘-Dibutyl-5,5‘‘-diphenyl-2,2‘:5‘,2‘‘-terthiophene (Bu 2 Ph 2 Tth) can be readily converted to the stable cation radical [Bu 2 Ph 2 Tth] + . The hexafluorophosphate salts of the cation radical ([Bu 2 Ph 2 Tth]PF 6 ) are synthesized in millimolar quantities by either chemical or constant current electrochemical oxid…