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Premnitz, Germany

Rose M.,TU Dresden | Klein N.,TU Dresden | Senkovska I.,TU Dresden | Schrage C.,TU Dresden | And 5 more authors.
Journal of Materials Chemistry | Year: 2011

Cyclotrimerization of bifunctional acetyl compounds is used to obtain highly porous organic frameworks. Syntheses in solution induced by silicon tetrachloride result in highly disperse powders while syntheses in molten 4-toluene sulfonic acid result in polymeric monoliths with a hierarchical pore structure containing micro- and macropores allowing for direct impregnation of textiles with a porous polymer. The materials show specific BET surface areas up to 895 m2 g-1 and large pore volume (1.99 cm3 g-1) combined with a highly hydrophobic character. The amorphous materials are thermally stable below 300 °C in air and show no decomposition effects in aqueous environment. These outstanding properties in combination with the opportunity to generate shapes of any kind desired for an application render the materials as highly promising for application in air filtration systems and individual protection, as well as gas storage and separation. Source


With P.,University of Leipzig | Heinrich A.,University of Leipzig | Lutecki M.,University of Leipzig | Fichtner S.,Adsor Technology Gmbh | And 2 more authors.
Chemical Engineering and Technology | Year: 2010

Highly porous zirconia with defined particle morphology can be prepared by impregnation of spherical activated carbon as an exotemplate with a zirconia nanoparticle sol. The resulting zirconia spheres show a particle size distribution between 0.2 and 0.4 mm and exhibit high specific surface areas and specific pore volumes up to 104 m2g-1 and 0.56 cm3g-1, respectively. Addition of a triblockcopolymer (TBC) as an endotemplate during the synthesis leads to the formation of an additional pore system. The corresponding spherical zirconia products possess a hierarchically structured pore system with a bimodal pore size distribution with maxima at ca. 3 and 20 nm. The relative fraction of pores originating from the endotemplate can be varied by changing the endotemplate content in the zirconia nanoparticle sol. The presence of the TBC also has an influence on the specific surface area and the specific pore volume. Using the ratio of TBC to zirconium of nTBC/nZr = 0.027, a material can be prepared that exhibits a specific surface area and a specific pore volume of 161 m2g-1 and 0.62 cm3g-1, respectively. These values are more than twice as high as for zirconia prepared by a conventional precipitation method (68 m2g-1 and 0.11 cm3g-1, respectively). Highly porous zirconia with defined particle morphology can be prepared by impregnation of spherical activated carbon as an exotemplate with a zirconia nanoparticle sol. Addition of a triblockcopolymer (TBC) as an endotemplate during the synthesis leads to the formation of an additional pore system. The presence of the TBC also has an influence on the specific surface area and the specific pore volume. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Rose M.,TU Dresden | Klein N.,TU Dresden | Bohlmann W.,University of Leipzig | Bohringer B.,Blucher GmbH | And 2 more authors.
Soft Matter | Year: 2010

We present new highly microporous element organic frameworks synthesized by the Pd catalyzed Suzuki coupling reaction. They show specific surface areas of up to 1380 m2 g-1 with a strong hydrophobic character. Thus, they are interesting for the adsorption of non-polar substances. By variation of the organic linkers, the modular concept of the materials in analogy to the metal-organic frameworks is demonstrated. The polymeric materials have thermal stability up to 573 K and show no decomposition in aqueous environment, allowing excellent handling and processing. They are accessible by a basic synthetic approach, and by their chemical and thermal stabilities they may provide adequate properties for applications in many fields, especially in adsorptive separation processes and storage of non-polar gases. © 2010 The Royal Society of Chemistry. Source


Bastos-Neto M.,University of Leipzig | Bastos-Neto M.,Federal University of Ceara | Patzschke C.,University of Leipzig | Lange M.,University of Leipzig | And 9 more authors.
Energy and Environmental Science | Year: 2012

As a basis for the evaluation of hydrogen storage by physisorption, adsorption isotherms of H2 were experimentally determined for several porous materials at 77 K and 298 K at pressures up to 15 MPa. Activated carbons and MOFs were studied as the most promising materials for this purpose. A noble focus was given on how to determine whether a material is feasible for hydrogen storage or not, dealing with an assessment method and the pitfalls and problems of determining the viability. For a quantitative evaluation of the feasibility of sorptive hydrogen storage in a general analysis, it is suggested to compare the stored amount in a theoretical tank filled with adsorbents to the amount of hydrogen stored in the same tank without adsorbents. According to our results, an "ideal" sorbent for hydrogen storage at 77 K is calculated to exhibit a specific surface area of >2580 m2 g-1 and a micropore volume of >1.58 cm3 g-1. This journal is © The Royal Society of Chemistry 2012. Source


Bohringer B.,Blucher GmbH | Guerra Gonzalez O.,Blucher GmbH | Eckle I.,Blucher GmbH | Muller M.,Blucher GmbH | And 3 more authors.
Chemie-Ingenieur-Technik | Year: 2011

Polymer-based spherical activated carbon (PBSAC), produced by means of carbonization and subsequent activation of a polymeric precursor in a batch process represent adsorbents with adjustable pore size distribution and adsorption characteristics. This flexibility results from batch operation and from the possibility to combine different activation media, therefore controlling the mechanisms of pore generation. The geometry and the mechanical properties of PBSAC allow for structuring of filter media e.g., for adsorbent enlargement or fixation. Other intrinsic product properties such as roundness, high crush strength and high abrasion resistance of PBSAC offer advantages in various adsorption applications. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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