TY - THES A1 - Cui, Jing T1 - Preparation of medical grade, amorphous polymer systems with adjustable stiffness and development of self- surfficiently moving model scaffolds based on shape-memory polymer composites Y1 - 2010 CY - Potsdam ER - TY - THES A1 - Chanana, Munish T1 - Synthesis of stimuli-responsive and switchable inorganic nanoparticles for biomedical applications Y1 - 2010 CY - Potsdam ER - TY - JOUR A1 - Wessig, Pablo A1 - Matthes, Annika A1 - Schilde, Uwe T1 - Crystal structure of 3,4-diacetyl-15,21-dioxatetracyclo- [23.4.0.02,7.06,11]nonacosa-1(29),2,4,6,8,10,25,27- octaene- 14,22-dioneùwater (1:2), C31H32O6 · 2H2O Y1 - 2010 UR - ftp://ftp.oldenbourg.de/pub/download/frei/ncs/225-4/1267-3146.pdf SN - 1433-7266 ER - TY - JOUR A1 - Schmidt, Bernd A1 - Werner, Frank A1 - Kelling, Alexandra A1 - Schilde, Uwe T1 - The reaction of 3,4-dihydro-2H-pyran with oxalyl chloride : formation and crystal structure analysis of an unexpected bicyclic product N2 - 3,4-Dihydro-2-H-pyran and oxalyl chloride react, depending on the conditions, to keto esters, a pyran-3- carboxylic acid or derivatives thereof, or to an hitherto unknown bicyclic acetal containing a vinyl chloride moiety. The structure of the latter product has been unambiguously elucidated by single-crystal X-ray structure analysis. A mechanism for its formation is proposed. Y1 - 2010 UR - 1960 = dx.doi.org/10.1002/jhet.456 SN - 0022-152X ER - TY - JOUR A1 - Kuke, S. A1 - Marmodee, Bettina A1 - Eidner, Sascha A1 - Schilde, Uwe A1 - Kumke, Michael Uwe T1 - Intramolecular deactivation processes in complexes of salicylic acid or glycolic acid with Eu(III) N2 - The complexation of Eu(III) by 2-hydroxy benzoic acid (2HB) or glycolic acid (GL) was investigated using steady- state and time-resolved laser spectroscopy. Experiments were carried out in H2O as well as in D2O in the temperature range of View the MathML source. The Eu(III) luminescence spectra and luminescence decay times were evaluated with respect to the temperature dependence of (i) the luminescence decay time ;, (ii) the energy of the View the MathML source transition, (iii) the width of the View the MathML source transition, and (iv) the asymmetry ratio calculated from the luminescence intensities of the View the MathML source and View the MathML source transition, respectively. The differences in ligand-related luminescence quenching are discussed. Based on the temperature dependence of the luminescence decay times an activation energy for the ligand-specific non-radiative deactivation in Eu(III)-2HB or Eu(III)-GL complexes was determined. It is stressed that ligand-specific quenching processes (other than OH quenching induced by water molecules) need to be determined and considered in detail, in order to extract speciation- relevant information from luminescence data (e.g., estimation of the number of water molecules nH2O in the first coordination sphere of Eu(III)). In case of 2HB, conclusions drawn from the evaluation of the Eu(III) luminescence are compared with results of a X-ray structure analysis. Y1 - 2010 UR - http://www.sciencedirect.com/science/article/pii/S1386142510000144 SN - 0584-8539 ER - TY - JOUR A1 - Starke, Ines A1 - Kammer, Stefan A1 - Holdt, Hans-Jürgen A1 - Kleinpeter, Erich T1 - Stability of disubstituted copper complexes in the gas phase analyzed by electrospray ionization mass spectrometry N2 - A series of nitrogen ligand (L)/copper complexes of the type [(CuL)-L-I](+), [(CuL)-L-II(X)](+) and [(CuL2)-L- I](+) (X = Cl-, BF4-, acac(-), CH3COO- and SO3CF3-) was studied in the gas phase by electrospray ionization mass spectrometry. The following ligands (L) were employed: 1,12-diazaperylene (dap), 1,1'-bisiso-quinoline (bis), 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen), 2,11-disubstituted 1,12-diazaperylenes (dap), 3,3'- disubstituted 1,1'-bisisoquinoline (bis), 5,8-dimethoxy-substituted diazaperylene (meodap), 6,6'-dimethoxy- substituted bisisoquinoline (meobis) and 2,9-dimethyl-1,10-phenanthroline (dmphen). Collision-induced decomposition measurements were applied to evaluate the relative stabilities of the different copper complexes. The influence of the spatial arrangement of the ligands, of the type of substituents and of the counter ion of the copper salts employed for the complexation was examined. Correlations were found between the binding constants of the [ML2](+) complexes in solution and the relative stabilities of the analogous complexes in the gas phase. Furthermore, complexation with the ligands 2,11-dialkylated 1,12-diazaperylenes [alkyl = ethyl (dedap) and isopropyl (dipdap)] was studied in the solvents CH3OH and CH3CN. Y1 - 2010 UR - http://www3.interscience.wiley.com/cgi-bin/jhome/4849 U6 - https://doi.org/10.1002/Rcm.4519 SN - 0951-4198 ER - TY - JOUR A1 - Harms, Stephan A1 - Raetzke, Klaus A1 - Faupel, Franz A1 - Egger, Werner A1 - Ravello, Lori Boyd de A1 - Laschewsky, André A1 - Wang, Weinan A1 - Müller-Buschbaum, Peter T1 - Free volume and swelling in thin films of poly(n-isopropylacrylamide) end-capped with n-butyltrithiocarbonate N2 - The free volume in thin films of poly(N-isopropylacrylamid) end-capped with n-butyltrio-carbonate (nbc-PNIPAM) is probed with positron annihilation lifetime spectroscopy (PALS). The PALS measurements are performed as function of energy to obtain depth profiles of the free volume of nbc-PNIPAM films. The range of nbc-PNIPAM films with thicknesses from 40 to 200 nm is focused. With decreasing film thickness the free volume increases in good agreement with an increase in the maximum swelling capability of the nbc-PNIPAM films. Thus in thin hydrogel films the sorption and swelling behavior is governed by free volume. Y1 - 2010 UR - http://www3.interscience.wiley.com/cgi-bin/jhome/10003270 U6 - https://doi.org/10.1002/marc.201000067 SN - 1022-1336 ER - TY - JOUR A1 - Haase, Martin F. A1 - Grigoriev, Dmitry A1 - Moehwald, Helmuth A1 - Tiersch, Brigitte A1 - Shchukin, Dmitry G. T1 - Encapsulation of amphoteric substances in a pH-sensitive pickering emulsion N2 - Oil-in-water (o/w) Pickering emulsions stabilized with silica nanoparticles were prepared. Droplets of diethyl phthalate (oil phase) act as reservoirs for 8-hydroxyquinoline (8-HQ), which is used as (a) the hydrophobizing agent for the silica particles and (b) an encapsulated corrosion inhibitor for application in active feedback coatings. The hydrophobization of silica nanoparticles with 8-HQ is determined by the amount of this agent adsorbed on the nanoparticle surface. The latter is governed by the 8-HQ concentration in the aqueous phase, which in turn depends on the degree of protonation and fir ally on the pH. We observe three ranges of 8-HQ adsorption value with respect to nanoparticle hydophobization: (I) insufficient, (2) sufficient, and (3) excessive adsorption by the formation of an 8-HQ bilayer, where only case 2 leads to the necessary nanoparticle hydrophobization. Hence emulsions stable in a narrow pH window between pH 5.5 and 4.4 follow. Here functional molecules are sufficiently charged to compensate for the charges on silica nanoparticles to make them interfacially active and thus able to stabilize an emulsion but they are still to a large extent uncharged and thereby remain in the oil phase. The emulsification is reversible upon changing the pH to a value beyond the stability region. Y1 - 2010 UR - http://pubs.acs.org/journal/jpccck U6 - https://doi.org/10.1021/Jp104052s SN - 1932-7447 ER - TY - JOUR A1 - Glatzel, Stefan A1 - Badi, Nezha A1 - Paech, Michael A1 - Laschewsky, André A1 - Lutz, Jean-Francois T1 - Well-defined synthetic polymers with a protein-like gelation behavior in water N2 - Homopolymers of N-acryloyl glycinamide were prepared by reversible addition-fragmentation chain transfer polymerization in water. The formed macromolecules exhibit strong polymer-polymer interactions in aqueous milieu and therefore form thermoreversible physical hydrogels in pure water, physiological buffer or cell medium. Y1 - 2010 UR - http://xlink.rsc.org/jumptojournal.cfm?journal_code=CC U6 - https://doi.org/10.1039/C0cc00038h SN - 1359-7345 ER - TY - JOUR A1 - Fudickar, Werner A1 - Linker, Torsten T1 - Novel anthracene materials for applications in lithography and reversible photoswitching by light and air N2 - Herein we demonstrate how the photoreaction between anthracenes and singlet oxygen (O-1(2)) is employed for applications either as photoswitch or as photoresist. Thin Films of the diaryl-alkyl anthracene 1 and the analogous oligomeric species 2 were it-radiated under photomasks to generate pattern structures composed of 1/1-O-2 and 2/2-O-2. Kelvin probe force microscopy (KPFM) provided a powerful and nondestructive method to image the pattern information. The following studies based on AFM, KPFM and contact angle measurements unfold that the two species 1 and 2 underwent different progressions after the imaging step. Degrading is observed for the monomeric compound 1 and the pattern eventually becomes recognizable in topography. In the oxidized state (1-O-2) the monomeric species remains physically stable. In consequence, the unreacted portion is removable and the remaining oxygenated form 1-O-2 is sufficiently stable to protect in underlying substrate (e.g., silver) from etching. Thus, the system 1/1-O-2 operates as photoresist. Oil the other hand, both states of the oligomier 2 remain stable. The Film is stable up to temperatures > 120 degrees C required to erase the pattern within acceptable time by cycloreversion. Anthracene 2 therefore acts as erasable and rewritable photochromic switch. The different behavior between 1 and 2 is explained by phase transitions which cause crystallization and finally ablation. Such transitions affect only the monomeric system 1/1-O-2 and not the oligomeric system 2/2-O-2. In conclusion, we designed two very similar materials based on diarylanthracenes, which can act either as a photoresist or as a rewritable photochrornic switch. Y1 - 2010 UR - http://pubs.acs.org/journal/langd5 U6 - https://doi.org/10.1021/La904299n SN - 0743-7463 ER -