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991.
Friedrich B 《The journal of physical chemistry. A》2011,115(25):6739-6741
992.
Catalin Croitoru Silvia Patachia Attila Porzsolt Christian Friedrich 《Cellulose (London, England)》2011,18(6):1469-1479
In this paper, the influence of three alkylimidazolium-based ionic liquids with the same cation (1-ethyl-3-methylimidazolium)
and different anions (chloride, tetrafluoroborate and hexafluorophosphate) on the structure and properties of cellulose, have
been studied by using Fourier transform infrared spectroscopy measurements, fluorescence microscopy imaging, viscometric and
methylene blue sorption tests. Cellulose treated with ionic liquids showed better stability to UV light, as demonstrated by
the lower variations of the polymerization degree, carboxyl groups content, moisture index, crystallinity index, lateral order
index and allomorph index, with the increase of the UV exposure period, by comparing to non-treated cellulose. The results
show that the tested ionic liquids could be effective as “green” plasticizers and UV stabilizers for cellulose-based materials. 相似文献
993.
Raphael J. Gübeli Martin Ehrbar Martin Fussenegger Christian Friedrich Wilfried Weber 《Macromolecular rapid communications》2012,33(15):1280-1285
Interactive materials being responsive to a biocompatible stimulus represent a promising approach for future therapeutic applications. In this study, we present a novel biohybrid material synthesized from biocompatible components being stimulus‐responsive to the pharmaceutically approved small‐molecule novobiocin. The hydrogel design is based on the gyrase B (GyrB) protein, which is covalently grafted to multi‐arm polyethylene glycol (PEG) using a Michael‐type addition reaction. Upon addition of the GyrB‐dimerizing substance coumermycin, stable hydrogels form which can be dissolved in a dose‐adjustable manner by the antibiotic novobiocin. The switchable properties of this PEG‐based hydrogel are favorable for future applications in tissue engineering and as externally controlled drug depot. 相似文献
994.
The intermolecular compatibility of 107–108 independent pair configurations of linear chains (chain length 64 ≤ N ≤ 8192) with and without intramolecular interaction on various lattices is checked and the intermolecular excluded volume u evaluated. From the (average) number of possible i‐tuples of overlaps in the pair configurations the parameters Ck of the perturbation theory are calculated. Differences between the various lattice types at finite N vanish completely for N → ∞. While the theoretical values of C1 and C2 were recovered within very narrow limits for chains without intramolecular interaction, markedly higher figures apply to self‐avoiding walks. The excluded volume u itself and higher Ck parameters are called upon to test several classical and renormalized perturbation theories.
995.
Athermal chains of various stiffness embedded in several types of lattices were analyzed with respect to their pair distribution function G(R). Extrapolation to infinite chain‐length on a reduced distance scale made all the G(R) data coincide within extremely narrow limits, thus suggesting the existence of a universal pair distribution function for polymers in good solvents in the long‐chain limit. The ratio –ln(G(R))/Z(R) with Z(R) being the reduced distribution of overlaps is also universal in type and varies only little with distance R. Further, a likewise universal function could be established that allows the construction of Z(R) from the Flory–Krigbaum expression taking into account not only the deviations from Gaussian behavior but also the effect of intramolecular repulsion present in athermal chains.
996.
997.
Alaa Fahmy Renate Mix Andreas Sch?nhals J?rg Friedrich 《Plasma Chemistry and Plasma Processing》2012,32(4):767-780
Polystyrene (PS) spin coated thin films were modified by O2 and Ar plasma as well as by UV irradiation treatments. The modified PS samples were compared with plasma polymerized and commercial polystyrene. The effects of plasma (O2 and Ar) and UV irradiation treatments on the surface and the bulk properties of the polymer layers were discussed. The surface properties were evaluated by X-ray Photoelectron Spectroscopy and Contact angle measurements and the bulk properties were investigated by FTIR and dielectric relaxation spectroscopy. As a result only one second treatment time was sufficient to modify the surface. However, this study was also dedicated to understand the effect of plasma and plasma irradiation on the deposited layers of plasma polymers. The dielectric measurements showed that the plasma deposited films were not thermally stable and underwent an undesired post-plasma chemical oxidation. 相似文献
998.
Weinhardt L Benkert A Meyer F Blum M Wilks RG Yang W Bär M Reinert F Heske C 《The Journal of chemical physics》2012,136(14):144311
The electronic structure of gas-phase H(2)O and D(2)O molecules has been investigated using resonant inelastic soft x-ray scattering (RIXS). We observe spectator shifts for all valence orbitals when exciting into the lowest three absorption resonances. Strong changes of the relative valence orbital emission intensities are found when exciting into the different absorption resonances, which can be related to the angular anisotropy of the RIXS process. Furthermore, excitation into the 4a(1) resonance leads to nuclear dynamics on the time scale of the RIXS process; we find evidence for vibrational coupling and molecular dissociation in both, the spectator and the participant emission. 相似文献
999.
Kluge O Friedrich D Wagner G Krautscheid H 《Dalton transactions (Cambridge, England : 2003)》2012,41(28):8635-8642
The complex [((i)Pr(3)PCu)(2)(Me(2)Ga)(2)(SCH(2)CH(2)S)(2)] (4) was synthesized from trimethylgallium, [((i)Pr(3)PCu)(4)(SCH(2)CH(2)S)(2)] (1) and ethanedithiol by elimination of methane. The related monomethyl compound [((i)Pr(3)PCu)(2)(MeGaSPh)(2)(SCH(2)CH(2)S)(2)] (5) has been prepared from [((i)Pr(3)PCuSPh)(3)] (2) and [(MeGaSCH(2)CH(2)S)(2)] (3) by a ligand exchange reaction in tetrahydrofuran solution. The molecular structures of 1 and 3-5 were determined by single crystal X-ray diffraction. Thermolysis of 4 and 5 results in the formation of the ternary semiconductor CuGaS(2), gallite. The residue of 5 was characterized using X-ray powder diffraction, energy dispersive X-ray spectroscopy and transmission electron microscopy. The CuGaS(2) crystals obtained are mainly hexagonal plates of around 200 to 300 nm diameter and 10 to 30 nm thickness, exhibiting an unusual metastable hexagonal crystal structure, related to wurtzite. Partially, the usual tetragonal chalcopyrite structure or its disordered cubic zinc-blende analogue is realized by stacking faults, resulting in an overall similarity to the zinc-blende-wurtzite polytypism in ZnS and related compounds. 相似文献
1000.