TY - JOUR A1 - Gili, A. A1 - Bischoff, B. A1 - Simon, U. A1 - Schmidt, Franziska A1 - Kober, D. A1 - Görke, O. A1 - Bekheet, M. A1 - Gurlo, A. T1 - Ceria-based dual-phase membranes for high-temperature Carbon dioxide separation: Effect of iron doping and pore generation with MgO template N2 - Dual-phase membranes for high-temperature carbon dioxide Separation have emerged as promising technology to mitigate anthropogenic greenhouse gases emissions, especially as a pre- and post-combustion separation technique in coal burning power plants. To implement These membranes industrially, the carbon dioxide permeability must be improved. In this study, Ce_(0.8) Sm_(0.2) O_(2-d) (SDC) and Ce_(0.8)Sm_(0.19)Fe_(0.01)O_(2-d) (FSDC) ceramic powders were used to form the skeleton in dual-Phase membranes. The use of MgO as an environmentally friendly pore generator allows control over the membrane porosity and microstructure in order to compare the effect of the membrane’s ceramic phase. The ceramic powders and the resulting membranes were characterized using ICP-OES, HSM, gravimetric analysis, SEM/EDX, and XRD, and the carbon dioxide flux density was quantified using a high-temperature membrane permeation setup. The carbon dioxide permeability slightly increases with the addition of iron in the FSDC membranes compared to the SDC membranes mainly due to the reported scavenging effect of iron with the siliceous impurities, with an additional potential contribution of an increased crystallite size due to viscous flow sintering. The increased permeability of the FSDC system and the proper microstructure control by MgO can be further extended to optimize carbon dioxide permeability in this membrane system. KW - Samarium doped ceria KW - SDC KW - FSDC KW - CO2 separation membranes KW - Scavenging effect of iron KW - Permeability PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-488612 DO - https://doi.org/10.3390/membranes9090108 SN - 2077-0375 VL - 9 IS - 9 SP - 108, 1 EP - 15 PB - MDPI AN - OPUS4-48861 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Palantöken, Sinam A1 - Bethke, K. A1 - Zivanovic, V. A1 - Kneipp, Janina A1 - Rademann, Klaus A1 - Kalinka, Gerhard T1 - Cellulose hydrogels physically crosslinked by glycine: Synthesis, characterization, thermal and mechanical properties N2 - Biopolymers are very efficient for significant applications ranging from tissue engineering, biological devices to water purification. There is a tremendous potential value of cellulose because of ist being the most abundant biopolymer on earth, swellability, and functional groups to be modified. A novel, highly efficient route for the fabrication of mechanically stable and natural hydrogels is described in which cellulose and glycine are dissolved in an alkaline solution of NaOH and neutralized in an acidic solution. The dissolving temperature and the glycine amount are essential parameters for the self-assembly of cellulose chains and for Tuning the morphology and the aggregate structures of the resulting hydrogels. Glycine plays the role of a physical crosslinker based on the Information obtained from FTIR and Raman spectra. Among the prepared set of hydrogels, CL5Gly30 hydrogels have the highest capacity to absorb water. The prepared CL5Gly30 gels can absorb up to seven times their dry weight due to its porous 3-D network structure. CL5Gly10 hydrogel exhibits 80% deformation under 21 N force executed. The method developed in this article can contribute to the application of heavy metal adsorption in aqueous solutions for water purification and waste management. KW - Biopolymer KW - Cellulose KW - Hydrogel KW - Natural KW - Synthesis PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-486845 DO - https://doi.org/10.1002/APP.48380 SN - 1097-4628 SN - 0021-8995 VL - 136 SP - 48380, 1 EP - 11 PB - Wiley CY - USA AN - OPUS4-48684 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wang, X. A1 - Schmidt, Franziska A1 - Gurlo, A. T1 - Fabrication of polymer-derived ceramics with hierarchical porosities by freeze casting assisted by thiol-ene click chemistry and HF etching N2 - The freeze casting technique assisted with cryo thiol-ene photopolymerization is successfully employed for the fabrication of macroporous polymer-derived silicon oxycarbide with highly aligned porosity. It is demonstrated that the free radical initiated thiol-ene click reaction effectively cross-linked the vinyl-containing liquid polysiloxanes into infusible thermosets even at low temperatures. Furthermore, mixed solution- and suspension-based freeze casting is employed by adding silica nanopowders. SiOC/SiO2 foams with almost perfect cylindrical shapes are obtained, demonstrating that the presence of nano-SiO2 does not restrict the complete photoinduced cross-linking. The post-pyrolysis HF acid treatments of produced SiOC monoliths yields hierarchical porosities, with SiOC/SiO2 nanocomposites after etching demonstrating the highest specific surface area of 494 m2/g and pore sizes across the macro-, meso- and micropores ranges. The newly developed approach gives a versatile solution for the fabrication of bulk polymer-derived ceramics with controlled porosity. KW - Freeze casting KW - Preceramic polymer KW - Hierarchical porosities KW - Thiol-ene click chemistry KW - Frozen state photopolymerization PY - 2019 DO - https://doi.org/10.1016/j.jeurceramsoc.2019.09.038 SN - 0955-2219 VL - 40 IS - 2 SP - 315 EP - 323 PB - Elsevier AN - OPUS4-49172 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zocca, Andrea A1 - Lüchtenborg, Jörg A1 - Mühler, T. A1 - Wilbig, Janka A1 - Mohr, Gunther A1 - Villatte, T. A1 - Léonard, Fabien A1 - Nolze, Gert A1 - Sparenberg, M. A1 - Melcher, J. A1 - Hilgenberg, Kai A1 - Günster, Jens T1 - Enabling the 3D Printing of Metal Components in μ-Gravity N2 - As humanity contemplates manned missions to Mars, strategies need to be developed for the design and operation of hospitable environments to safely work in space for years. The supply of spare parts for repair and replacement of lost equipment will be one key need, but in-space manufacturing remains the only option for a timely supply. With high flexibility in design and the ability to manufacture ready-to-use components directly from a computeraided model, additive manufacturing (AM) technologies appear extremely attractive. For the manufacturing of metal parts, laser-beam melting is the most widely used AM process. However, the handling of metal powders in the absence of gravity is one prerequisite for its successful application in space. A gas flow throughout the powder bed is successfully applied to compensate for missing gravitational forces in microgravity experiments. This so-called gas-flow-assisted powder deposition is based on a porous Building platform acting as a filter for the fixation of metal particles in a gas flow driven by a pressure difference maintained by a vacuum pump. KW - Additive manufacturing KW - µ-gravity KW - Laser beam melting KW - Parabolic flight KW - 3D printing PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-492190 DO - https://doi.org/10.1002/admt.201900506 SP - 1900506 PB - WILEY-VCH Verlag GmbH AN - OPUS4-49219 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -