A recent model for unentangled polymer chains in confinement [M. Dolgushev and M. Krutyeva, Macromol. Theory Simul. 21, 565 (2012)] is scrutinized by small-angle neutron scattering (SANS) with respect to its static prediction, the single-chain structure factor. We find a remarkable agreement although the model simplifies the effect of the confinement to a harmonic potential. The effective confinement size from fits of SANS data with the model agrees well with the actual pore size. Starting from this result we discuss the possibility of an experiment on the dynamic structure factor predicted by the model. It turns out that such an experiment would need a large ratio polymer dimension/pore size which is difficult but not impossible to achieve.

The decrease of the lattice size of periodic mesoporous organosilicas (PMOs) is one important goal in obtaining a microporous material for storage or adsorption of small molecules. To determine the influence of different synthesis parameters in the lattice size, here we performed in situ small-angle X-ray diffraction studies and show that a variation of the surfactant's headgroup size is not directly followed by the lattice parameter of the resulting structure. We show that in the surfactant series of penta-, hexa-, hepta-, octa-, nona-, and decaethylene glycol monododecyl ether (C12(EO)n, n = 5, 6, 7, 8, 9, 10) the lattice size decreases between n = 5 and n = 8 and then increases, while the ordering of the materials is always cubic (space group Fd3m). This size effect is due to the ethylene oxide (EO) chain conformation that changes as the number of EO groups increases. Short ethylene oxide chains tend to have a so-called "zigzag" conformation while an increase of the chain length leads to a "Mäander" (coiling) conformation. Although this phenomenon is most commonly observed for chains consisting of more than 10 ethylene oxide units, we found a minimum PMO lattice size for 8 EO units and intermediate values for 6 and 7 EO units. The increase of the lattice parameter for more than 9 EO units is attributed to the increasing number of "Mäander" configurated EO units.

Phenylene-bridged periodic mesoporous organosilica (PMO) materials with hexaethylene glycol mono hexadecylether (C16(EO)6) as structure directing agent (SDA) in acidic solution were synthesised and the reaction was studied in different conditions, including in situ small angle X-ray scattering at room temperature and at 60 °C. The in situ SAXS investigations at 60 °C show the formation of a 2D hexagonal mesostructure after 3 hours reaction time. In contrast to these results the same reaction performed in the laboratory produced a powder that, after drying at room temperature, shows a large number of diffraction peaks, allowing identifying a lamellar structure, possibly in coexistence of a micellar cubic structure (space group Pm3n). Aposteriori removal of the surfactant from the powder synthesised in the laboratory led to the collapse of the lamellar structure.

We present results on new periodic mesoporous organosilicas synthesized with 1,4-bis(triethoxysilyl)benzene (BTEB), 1,2-bis(trimethoxysilyl)ethane (BTME) and bis[3-(trimethoxysilyl)propyl]amine (BTMPA). The materials show high inner surfaces up to 830 m 2 /g and pore diameters in the range of 2.7 to 3.7 nm depending on the structure directing agent used. In case of BTEB as precursor and triblock copolymer Pluronic P123 as structure directing agent exceptional thick pore walls were obtained (7.2 nm). Characterization was carried out by P-XRD, nitrogen physisorption analysis, thermoanalytical methods and IR spectroscopy.

Fuel Cell operation at high temperature (e.g. 120 degrees C) and low relative humidity (e.g. 50%) remains challenging due to creep (in the case of Nafion) and membrane dehydration. We approached this problem by filling PES 70, a sulfonated poly(ether sulfone) with a T-g of 235 +/- 5 degrees C and a theoretical IEC of 1.68 mmol g(-1), with 5-20% silica nano particles of 7 nm diameter and 390 +/- 40 m(2) g(-1) surface area. While simple stirring of particles and polymer solutions led to hazy, strongly anisotropic (air/glass side) and sometimes irregular shaped membranes, good membranes were obtained by ball milling. SEM analysis showed reduced anisotropy and TEM analysis proved that the nanoparticles are well embedded in the polymer matrix. The separation length between the ion-rich domains was determined by SAXS to be 2.8, 2.9 and 3.0 nm for PES 70, PES 70-S05 and Nafion (R) NRE 212, respectively. Tensile strength and Young's modulus increase with the amount of silica. Ex-situ in-plane proton conductivity showed a maximum for PES 70-S05 (2 mS cm(-1)). In the fuel cell (H-2/air, 120 degrees C, <50%), it showed a current density of 173 mA cm(-2) at 0.7 V, which is 3.4 times higher than for PES 70. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

We synthesize and characterize alkylthiohydroquinones (ATHs) in order to investigate their interactions with lipid model membranes, POPE and POPC. We observe the formation of structures with different morphologies, or curvature of the lipid bilayer, depending on pH and increasing temperature. We attribute their formation to changes in the balance charge/polarity induced by the ATHs. Mixtures of ATHs with POPE at pH 4 form two cubic phases, P4(3)32 and Im3m, that reach a maximum lattice size at 40 °C while under basic conditions these phases only expand upon heating from room temperature. The cubic phases coexist with lamellar or hexagonal phases and are associated with inhomogeneous distribution of the ATH molecules over the lipid matrix. The zwitterionic POPC does not form cubic phases but instead shows lamellar structures with no clear influence of the 2,6-BATH.

In situ small-angle X-ray diffraction (SAXD) investigations are carried out in order to obtain an insight into the formation process of 2D hexagonal ordered phenylene- and thiophene-bridged periodic mesoporous organosilicas (PMOs) synthesized with Brij 76 (polyethylene (10) stearylether). The reaction solution is investigated by pumping it through a capillary placed in a synchrotron radiation beam. Data collection is stopped when the growing particle size lead to an irregular flow of the solution. The resulting data is compared with powder X-ray diffraction of the samples synthesized in the laboratory. The 2D hexagonal ordered PMO products synthesized with Brij 76 are formed via a metastable three-dimensional hexagonal ordered transition state. Here, we describe the formation process of the PMO materials regarding the properties of the structure-directing agent.

The formation of phenylene-bridged periodic mesoporous organosilicas (PMOs) in the presence of three diblock copolymers differing in hydrophobic hydrocarbon chain lengths was investigated. Hexaethylene glycol octadecylether (C18(EO)6), hexaethylene glycol hexadecylether (C16(EO)6), and hexaethylene glycol dodecylether (C12(EO)6) were chosen in order to obtain insight on the influence of the hydrocarbon chain length on the mesostructure. 1,4-Bis(triethoxysilyl)benzene (BTEB) was used as organosilica precursor under mild acidic conditions. The reactions were followed by in situ small-angle X-ray diffraction (SAXD) on-time in a capillary flow setup. It was found that during the reaction the formation of different structures was observed, which is ascribed to the hydrolysis and condensation of the organosilica precursor. In all cases, different structures evolve with time and phase transitions are observed during the measurements independent of the hydrocarbon chain length.

After the completion of the experimental flow-through setup at the soft condensed matter beamline A2 first reactions were investigated. The formation of a phenylene-bridged mesoporous organosilica material was followed on time with this setup. A mixture containing the surfactant hexaethylene glycol monohexadecylether (C16(EO)6 or hexaethylene glycol mono dodecylether (C12(EO)6) in slight acidic solution (pH = 1) was prepared and the reaction was started by the addition of the organosilica precursor 1,4-bis(triethoxysilyl)benzene (BTEB). The different steps of the reaction from the two-phase (organic/inorganic) system, the hydrolysis and condensation to a solid material were documented by SAXS patterns collected every three minutes with two minutes exposure time. The influence of the hydrocarbon chain lengths on the resulting structure can clearly be concluded from the experiments. Figure 1 shows selected frames from the SAXS measurement of the solution containing C16(EO)6 as structure-directing agent.

Alternative Adsorbentien: Sphärische Partikel aus phenylenverbrücktem periodisch-mesoporösem Organosilica (sph-PMO) wurden erstmalig in der Hochleistungsflüssigkeitschromatographie eingesetzt. Drei verschiedene Testmischungen mit bis zu vier Komponenten unterschiedlicher Polarität konnten mit dem neuen Säulenmaterial getrennt werden.

Alternative adsorbents: Spherical particles of a phenylene-bridged periodic mesoporous organosilica material (see picture) are applied in HPLC for the first time. Three test mixtures of up to four components with different polarities can be separated with the new column material. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2006/z504568_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

We have incorporated microspheres, 50 μm to 80 μm in diameter, of periodic mesoporous organosilica (inner surfaces up to 1000 m2/g and pore sizes in the nanometre range) with two types of organic functionalities (benzene and ethane bridges, respectively) inside microstructured channels (each 200 μm wide and 100 μm deep) and, exemplarily, monitored by Raman microscopy that the temperature characteristics of the adsorption-desorption equilibria of benzene and ethanol vary significantly with the type of organic functionality of the microspheres and the pore morphology. The integration of this class of nanostructured material into devices by means of microchannels is a promising novel approach to, among others, substance separation in analytics, micro process engineering, and micro chemistry.

Monodispersed spherical periodic mesoporous organosilicas (sph-PMOs) with high specific surface area and narrow pore size distributions were synthesised in a modified Stober-reaction using long-chai tetraalkylammonium surfactants under alkaline conditions and 1,2-bis(trimethoxysilyl)ethane (BTME) an 1,4-bis(triethoxysilyl)benzene (BTEB) as bridged organosilica precursor. The synthesis leads to particle with an average size of 0.5 mu n. The sph-PMOs were characterised by powder X-ray diffraction (P-XRD) Nitrogen physisorption, Raman spectroscopy SEM and TEM.

The synthesis of a mesoscopically ordered biphenylene-bridged organosilica with crystal-like pore walls was studied by time-resolved in situ SAXS/XRD. The formation of periodic order both on the mesoscopic scale and within the pore walls is found to occur simultaneously and in a highly cooperative process.

Monodisperse spherical periodic mesoporous organosilicas (sph-PMOs) with high specific surface areas and narrow pore size distributions were synthesised in a modified Stoeber-reaction using long-chain tetraalkylammonium surfactants under alkaline conditions and 1,2-bis(trimethoxysilyl)ethane (BTME) as a bridged organosilica precursor. Variation of the surfactant chain length leads to pore diameters between 2.5 and 3.2 nm. The synthesis yields particles with an average size between 0.4 and 0.5 μm. The sph-PMOs were characterised by powder X-ray diffraction (P-XRD), nitrogen physisorption, IR spectroscopy, Raman spectroscopy, SEM and TEM.

Zeitschrift für anorganische und allgemeine ChemieVolume 630, Issue 11 p. 1715-1715 Poster Periodic Mesoporous Organosilicas (PMOs): A New Class of Porous Inorganic-organic Hybrid Materials Maximilian Cornelius, Maximilian Cornelius Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Gießen, GermanySearch for more papers by this authorJürgen Morell, Jürgen Morell Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Gießen, GermanySearch for more papers by this authorVivian Rebbin, Vivian Rebbin Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Gießen, GermanySearch for more papers by this authorMichael Fröba, Corresponding Author Michael Fröba Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Gießen, GermanyInstitut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Gießen, GermanySearch for more papers by this author Maximilian Cornelius, Maximilian Cornelius Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Gießen, GermanySearch for more papers by this authorJürgen Morell, Jürgen Morell Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Gießen, GermanySearch for more papers by this authorVivian Rebbin, Vivian Rebbin Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Gießen, GermanySearch for more papers by this authorMichael Fröba, Corresponding Author Michael Fröba Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Gießen, GermanyInstitut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Gießen, GermanySearch for more papers by this author First published: 31 August 2004 https://doi.org/10.1002/zaac.200470048AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume630, Issue11September 2004Pages 1715-1715 RelatedInformation

Zeitschrift für anorganische und allgemeine ChemieVolume 630, Issue 11 p. 1755-1755 Poster Spherical Periodic Mesoporous Organosilicas (sph-PMOs) in a Wide Particle Size Range Vivian Rebbin, Vivian Rebbin Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Giessen, GermanySearch for more papers by this authorMichaela Jakubowski, Michaela Jakubowski Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Giessen, GermanySearch for more papers by this authorSteffen Pötz, Steffen Pötz Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Giessen, GermanySearch for more papers by this authorMichael Fröba, Corresponding Author Michael Fröba Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Giessen, GermanyInstitut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Giessen, GermanySearch for more papers by this author Vivian Rebbin, Vivian Rebbin Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Giessen, GermanySearch for more papers by this authorMichaela Jakubowski, Michaela Jakubowski Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Giessen, GermanySearch for more papers by this authorSteffen Pötz, Steffen Pötz Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Giessen, GermanySearch for more papers by this authorMichael Fröba, Corresponding Author Michael Fröba Institut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Giessen, GermanyInstitut für Anorganische und Analytische Chemie, Justus-Liebig Universität, Heinrich-Buff-Ring 58, D-35392 Giessen, GermanySearch for more papers by this author First published: 31 August 2004 https://doi.org/10.1002/zaac.200470123AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume630, Issue11September 2004Pages 1755-1755 RelatedInformation