Jürgen Morell

Synthesis and characterization of highly ordered bifunctional aromatic periodic mesoporous organosilicas with different pore sizes

The first syntheses of highly ordered bifunctional periodic mesoporous organosilicas (PMOs) containing different amounts of aromatic thiophene and benzene bridging groups are reported. Employing the triblock copolymer Pluronic P123 as well as the oligomeric Brij 76 surfactant under acidic conditions as supramolecular structure-directing agents, the syntheses of two series of bifunctional aromatic PMO materials with pore sizes in the range of 4.8–5.4 and 3.3 nm, respectively, have been realized. Independent of the molar ratios of the organosilanes in the initial reaction mixtures, highly ordered PMO materials with 2D hexagonal mesostructures have been obtained in all cases. After a one-off calibration based on 29Si MAS NMR measurements, the quantification of the organic functional groups has been carried out for the first time, in case of PMO materials, using Raman spectroscopic methods.

Combining nitrogen, argon, and water adsorption for advanced characterization of ordered mesoporous carbons (CMKs) and periodic mesoporous organosilicas (PMOs).

Ordered mesoporous CMK carbons and periodic mesoporous organosilica (PMO) materials have been characterized by combining nitrogen (77.4 K) and argon (87.3 K) adsorption with recently developed quenched solid density functional theory (QSDFT). Systematic, high-resolution water adsorption experiments have been performed in the temperature range from 298 to 318 K in order to ascertain the effect of surface chemistry (using periodic mesoporous organosilicas (PMOs) of given pore size) and pore size/pore geometry (using CMK-3, CMK-8 carbons) on the adsorption, pore filling, condensation and hysteresis behavior. These data reveal how the interplay between confined geometry effects and the strength of the adsorption forces influence the adsorption, wetting, and phase behavior of pore fluids. Further, our results indicate that water adsorption is quite sensitive to both small changes in pore structure and surface chemistry, showing the potential of water adsorption as a powerful complementary tool for the characterization of nanoporous solids.

Synthesis and Characterization of Chiral Benzylic Ether-Bridged Periodic Mesoporous Organosilicas

The first synthesis of a chiral periodic mesoporous organosilica (PMO) carrying benzylic ether bridging groups is reported. By hydrolysis and condensation of the new designed chiral organosilica precursor 1,4-bis(triethoxysilyl)-2-(1-methoxyethyl)benzene (BTEMEB) in the presence of the non-ionic oligomeric surfactant Brij 76 as supramolecular structure-directing agent under acidic conditions, an ordered mesoporous chiral benzylic ether-bridged hybrid material with a high specific surface area was obtained. The chiral PMO precursor was synthesized in a four-step reaction from 1,4-dibromobenzene as the starting compound. The evidence for the presence of the chiral units in the organosilica precursor as well as inside the PMO material is provided by optical activity measurements.

Towards peptide formation inside the channels of a new divinylaniline-bridged periodic mesoporous organosilica

The first synthesis of a new highly ordered divinylaniline-bridged periodic mesoporous organosilica (PMO) with crystal-like pore walls and further chemical modification of the amino groups on the inner surface of the product by a peptide formation reaction with a chiral amino acid are reported.