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Weichelt F.,Leibniz Institute of Surface Modification | Frerich B.,Universitatskllnikum Rostock | Lenz S.,Universitatskllnikum Rostock | Tiede S.,Universitatskllnikum Rostock | And 2 more authors.
Macromolecular Rapid Communications

Porous monolithic materials have been prepared via ring-opening metathesis polymerization from norborn-2-ene and a 7-oxanorborn-2-ene-based cross-linker in the presence of porogenic solvents (i.e., 2-propanol and toluene) and norborn-2-enephosphonate surface-modified CaCO3 nanoparticles, using the 3rd-generation Grubbs-initiator RuCl2(Py) 2(IMeSH2)(CHPh). The experimental setup and the conditions chosen allowed for the manufacturing of polymeric monoliths characterized by a homogeneous distribution of the inorganic nanoparticles throughout the polymeric monolith. Depending on the nanoparticle content, the macropore diameters could be varied in the 30-120 μm regime. Noteworthy, the addition of nanoparticles did not affect the phase separation-triggered formation of the monolithic matrix nor the meso- and microporosity as evidenced by N2-adsorption experiments. (Figure Presented) © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Ernst C.,Leibniz Institute of Surface Modification | Elsner C.,Leibniz Institute of Surface Modification | Prager A.,Leibniz Institute of Surface Modification | Scheibitz B.,Leibniz Institute of Surface Modification | And 2 more authors.
Journal of Applied Polymer Science

Porous polymeric monolithic supports were prepared via electron beam-triggered free radical polymerization using a mixture of ethyl methacrylate and trimethylolpropane triacrylate in 2-propanol, 1-dodecanol and toluene. Bicyclo[2.2.1]hept-5-en-2-ylmethyl acrylate (1) was grafted onto these monolithic supports in a spatially resolved way with the aid of masks using both electron beam- (EB) and UV-triggered free radical polymerization. The thus immobilized norborn-2-ene-containing graft polymers were further treated with the 2nd-generation Grubbs initiator, i.e., RuCl2(PCy 3)(IMesH2)(CHPh) (4) (IMesH2 = 1,3-dimesitylimidazolin-2-ylidene), and then reacted with bicyclo[2.2.1]hept-5- en-2-ylmethyl pyrene-1-carboxylate (2). Alternatively, monoliths completely grafted with poly-1 were surface grafted with 2 in a spatially resolved way in the presence of a latent, UV-triggerable precatalyst, i.e., [Ru(IMesH 2)(CF3COO)(t-BuCN)4 + CF 3COO-] (5). Finally, to demonstrate the utility of this chemistry, a 2nd-generation Grubbs initiator-based approach was used to prepare a trypsin-functionalized monolith-containing chip device that allowed for the online digestion of N-α-benzoyl-L-argininethylester hydrochloride. © 2011 Wiley Periodicals, Inc. Source

Weichelt F.,Leibniz Institute of Surface Modification | Lenz S.,University of Rostock | Tiede S.,University of Rostock | Reinhardt I.,Leibniz Institute of Surface Modification | And 3 more authors.
Beilstein Journal of Organic Chemistry

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. Source

Zimmermann D.D.,University of Stuttgart | Grossholz H.,University of Stuttgart | Wolf S.,University of Stuttgart | Janka O.,University of Stuttgart | And 4 more authors.
Zeitschrift fur Anorganische und Allgemeine Chemie

Two hexagonal series of lanthanoid(III) oxide fluoride selenides with similar structure types can be obtained by the reaction of the components MF3, M2O3, M, and Se in sealed niobium tubes at 850 °C using CsI as fluxing agent. The compounds with the lighter and larger representatives (M = La - Nd) occur with the formula M6O2F8Se3, whereas with the heavier and smaller ones (M = Nd, Sm, Gd - Ho) their composition is M2OF2Se. For both systems single-crystal determinations were used in all cases. The compounds crystallize in the hexagonal crystal system (space group: P63/m) with lattice parameters of a = 1394-1331 pm and c = 403-372 pm (Z = 2 for M6O2F8Se3 and Z = 6 for M2OF2Se). The (M1)3+ cations show different square antiprismatic coordination spheres with or without an extra capping fluoride anion. All (M2)3+ cations exhibit a ninefold coordination environment shaped as tricapped trigonal prism. In both structure types the Se2- anions are sixfold coordinated as trigonal prisms of M3+ cations, being first condensed by edges to generate trimeric units and then via faces to form strands running along [001]. The light anions reside either in threefold triangular or in fourfold tetrahedral cationic coordination. For charge compensation, both structures have to contain a certain amount of oxide besides fluoride anions. Since F- and O2- can not be distinguished by X-ray diffraction, bond-valence calculations were used to address the problem of their adjunction to the available crystallographic sites. © 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim. Source

Anderson E.B.,University of Stuttgart | Kumar P.S.,Leibniz Institute of Surface Modification | Schawaller D.,Institute For Textilchemie Und Chemiefasern | Mavila S.,University of Stuttgart | And 5 more authors.
Macromolecular Chemistry and Physics

Poly(4,4-bis[(3,5-diethoxybenzoyloxy)methyl]-1,6-heptadiyne) is synthesized via cyclopolymerization using modified Grubbs- and Schrock-type initiators. Doping with either I2 or NO+ BF4 - yields a conductive polymer with conductivity up to 1.4 × 10-2 S cm-1. The undoped amorphous conjugated polymer is spun into monofilament and multifilament fibers by a wet-spinning process. Fibers are collected on bobbins with a draw down ratio of 12 resulting in fiber diameters under 60 μm, characterized by scanning electron microscopy. X-ray diffraction data confirms that the amorphous structure of the polymer is preserved; no additional orientation of the polymer chains occurs during fiber spinning. Poly(4,4-bis[(3,5-diethoxybenzoyloxy)methyl]-1,6-heptadiyne) (poly-1) is synthesized via cyclopolymerization and p-doped to yield semiconductive fibers. Furthermore, poly-1 is spun into monofilament or multifilament fibers through a wet-spinning process. The resultant polymer fibers maintain an amorphous structure in X-ray diffraction patterns. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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