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- ItemChromo-and fluorophoric water-soluble polymers and silica particles by nucleophilic substitution reaction of poly(vinyl amine)(Frankfurt, M : Beilstein-Institut zur Förderung der Chemischen Wissenschaften, 2010) Hofmann, K.; Kahle, I.; Simon, F.; Spange, S.Novel chromophoric and fluorescent carbonitrile-functionalized poly(vinyl amine) (PVAm) and PVAm/silica particles were synthesized by means of nucleophilic aromatic substitution of 8-oxo-8H-acenaphtho[1,2-b]pyrrol-9- carbonitrile (1) with PVAm in water. The water solubility of 1 has been mediated by 2,6-O-β-dimethylcyclodextrin or by pre-adsorption onto silica particles. Furthermore, 1 was converted with isopropylamine into the model compound 1-M. All new compounds were characterized by NMR, FTIR, UV-vis and fluorescence spectroscopy. The solvent-dependent UV-vis absorption and fluorescence emission band positions of the model compound and the carbonitrile-functionalized PVAm were studied and interpreted using the empirical Kamlet-Taft olvent parameters π* (dipolarity/polarizability), α (hydrogen-bond donating capacity) and β (hydrogen-accepting ability) in terms of the linear solvation energy relationship (LSER). The solvent-independent regression coefficients a, b and s were determined using multiple linear correlation analysis. It is shown, that the chains of the polymer have a significant influence on the solvatochromic behavior of 1-P. The structure of the carbonitrile 1-Si bound to polymer-modified silica particles was studied by means of X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) measurements. Fluorescent silica particles were obtained as shown by fluorescence spectroscopy with a diffuse reflectance technique. © 2010 Hofmann et al; licensee Beilstein-Institut.
- ItemROMP-Derived cyclooctene-based monolithic polymeric materials reinforced with inorganic nanoparticles for applications in tissue engineering(Frankfurt, M : Beilstein-Institut zur Förderung der Chemischen Wissenschaften, 2010) Weichelt, F.; Lenz, S.; Tiede, S.; Reinhardt, I.; Frerich, B.; Buchmeiser, M.R.Porous monolithic inorganic/polymeric hybrid materials have been prepared via ring-opening metathesis copolymerization starting from a highly polar monomer, i.e., ciw-5-cyclooctene-trans-1,2-diol and a 7-oxanorborn-2-ene-derived cross-linker in the presence of porogenic solvents and two types of inorganic nanoparticles (i.e., CaCO3 and calcium hydroxyapatite, respectively) using the third-generation Grubbs initiator RuCl2(Py) 2(IMesH2)(CHPh). The physico-chemical properties of the monolithic materials, such as pore size distribution and microhardness were studied with regard to the nanoparticle type and content. Moreover, the reinforced monoliths were tested for the possible use as scaffold materials in tissue engineering, by carrying out cell cultivation experiments with human adipose tissue-derived stromal cells. © 2010 Weichelt et al; licensee Beilstein-Institut.