Materials Literature
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Abstract Tin and lead nanoparticles and metal sponges were prepared by reducing Me 2 Si(N t Bu) 2 Sn ( 7 ) and Me 2 Si(N t Bu) 2 Pb ( 9 ) with [H 2 AlO t Bu] ( 3 ), [HAl(O t Bu) 2 ] ( 13 ), [H 2 AlOSiMe 2 t Bu] ( 8 ), and [(Me 2 t BuSiO) 2 AlH] ( 15 ). Together with dihydrogen and the metals in their elemental state t…
Abstract The action of alkali treatment in both aqueous and alcoholic media is investigated to attain silk‐like polyester fabric. The use of alkoxide solutions is more effective on polyester fabric. Rapid loss in weight up to 15–20% occurs at ambient conditions. Immersion and padding techniques are applied. The effect…
Using a Femtosecond Transient Thermoreflectance (FTT) technique, we studied the thermomechanical properties of two Si∕SiGe superlattices. A theoretical model is presented which agrees well with the experimental results and allows us to determine the cross-plan thermal conductivity of the superlattices at room temperat…
The wavevector-dependent shear viscosity, eta(k), is evaluated for a range of temperatures in a supercooled binary Lennard-Jones liquid. The mode coupling theory of Keyes and Oppenheim (Phys. Rev. A 1973, 8, 937) expresses the self-diffusion constant, D, in terms of eta(k). Replacing eta(k) with the usual viscosity, e…
Abstract A series of nanocomposite hydrogels were prepared from acrylic acid (AA), N ‐isopropylacrylamide (NIPAAm), and intercalated hydrotalcite (IHT) by photopolymerization. The influence of the intercalating content of 2‐acrylamido‐2‐methyl propane sulfonic acid (AMPS) in HT on the swelling and mechanical propertie…
Abstract A new class of optically active poly(amide–imide–urethane)s (PAIUs) was synthesized via a two‐step diisocyanate route under microwave irradiation. In these reactions, 4,4′‐methylene‐bis(4‐phenylisocyanate) was reacted with bis( p ‐amido benzoic acid)‐ N ‐trimellitylimido‐ L ‐leucine and poly(ethylene glycol d…
Abstract Step heating melt polycondensation was adopted in the preparation of polyamides based on 1,16‐octadecane diacid and α,ω(CH 2 ) 2 n diamines ( n = 1–6). The structure was confirmed by various spectroscopic techniques (IR, Raman, 1 H‐NMR, and 13 C‐NMR). High molecular masses were obtained only in the presence…
We found that the optically isotropic (I(M)) mesophase observed recently below the nematic phase of the bent-core liquid crystal 4-chlororesorcinol bis[4-(4-n-dodecyloxybenzoyloxy)benzoate] shows ferroelectric-type switching. Polarizing microscopic, electric current, dielectric, and dynamic light scattering studies le…
Quantum tunneling of magnetization (QTM) in an $\mathrm{Fe}$-substituted single molecular magnet ${\mathrm{Mn}}_{11}\mathrm{Fe}$ has been studied by ac susceptibility measurements in ${\mathrm{Mn}}_{11}\mathrm{Fe}∕{\mathrm{Mn}}_{12}$ mixed crystal. Although the blocking temperature of the ${\mathrm{Mn}}_{11}\mathrm{Fe…
Abstract High‐conversion (HC) copolymers of aniline and o‐methoxyaniline (o‐anizidine) were synthesized for the first time by chemical oxidative copolymerization by using various polymerization techniques (simultaneous or consecutive introduction of comonomers into the polymerizing system). Low‐conversion (LC) copolym…
Abstract Environmental and enzymatic degradations were investigated on a series of copolycarbonates consisting of equimolar amounts of 1,4 : 3,6‐dianhydrohexitols (1,4 : 3,6‐dianhydro‐ D ‐glucitol (1a) and 1,4 : 3,6‐dianhydro‐ D ‐mannitol (1b)) and alkylene diols (1,4‐butanediol, 1,6‐hexanediol, 1,8‐octanediol, and 1,…
Fundamental understanding of protein crystal nucleation facilitates crystallization of biological macromolecules for structure determination and control of crystal size distribution. In the studies presented here, nucleation kinetics of hen egg-white lysozyme crystals were measured at solution conditions that exhibite…
Abstract The nonisothermal crystallization half-time (t0.5), defined as the time taken for a polymer film to reach half of its equilibrium crystallinity, was estimated from Raman spectroscopic measurements of crystallinity during blown film extrusion of a linear low-density polyethylene (LLDPE) and an isotactic polypr…
The direct formation of iron phosphate nanoparticles on hydroxyl-terminated SiO(2)/Si substrates with a narrow size distribution (average diameter = 2.2 nm) is achieved by a simple room temperature spontaneous reaction of ferric chloride and phosphoric acid. Single-walled carbon nanotubes (SWNTs) are grown in high yie…
Abstract The in situ Fourier transform infrared spectroscopic study of isotactic polypropylene showed that structural changes are induced at liquid nitrogen temperature, and start to show up in the FTIR spectra with heating from −196 to +200 °C. This structural change leads to the detection of an abnormal behavior in…
Infrared (IR) chemiluminescence studies of CO2 formed during steady-state CO + NO reaction over Pd(110) and Pd(111) surfaces were carried out. Kinetics of the CO + NO reaction were studied over Pd(110) using a molecular-beam reaction system in the pressure range of 10-2-10-1 Torr. The activity of the CO + NO reaction…
The unusual suspects: By using a series of ruthenium clusters of the type [{Ru3O(μ-CH3COO)6(CO)L′}(μ-L){Ru3O(μ-CH3COO)6(CO)L′′}] (see picture) it has been possible to identify the existence of charge-transfer isomers and establish them as identifiable chemical entities that exist in dynamic equilibrium.
A series of new asymmetric bent main-chain liquid crystalline (LC) polyesters (BPE-C n ) were synthesized through the condensation polymerization of A−B type asymmetric α,ω-carboxylic acid−hydroxyl-terminated monomers containing different even numbers of methylene spacers (BPCA-C n -P m OH, where n = 6, 8, and 10). Di…
Reconstitution into planar lipid bilayers of a poly-3-hydroxybutyrate/calcium/polyphosphate (PHB/Ca(2+)/polyP) complex from Escherichia coli membranes yields cationic-selective, 100 pS channels (Das, S., Lengweiler, U.D., Seebach, D. and Reusch, R.N. (1997) Proof for a non-proteinaceous calcium-selective channel in Es…
Abstract The present study examined poly(ethylene terephthalate) (PET) and a series of statistical and blocky copolymers in which up to 30% of the terephthalate was replaced with isophthalate by copolymerization and melt blending, respectively. Some level of transesterification during processing of melt blends resulte…