TY - JOUR A1 - Aliyah, K. A1 - Prehal, C. A1 - Diercks, J. S. A1 - Diklić, N. A1 - Xu, L. A1 - Ünsal, S. A1 - Appel, C. A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob A1 - Guizar-Sicairos, M. A1 - Herranz, J. A1 - Gubler, L. A1 - Büchi, F. N. A1 - Eller, J. T1 - Quantification of PEFC Catalyst Layer Saturation via In Silico, Ex Situ, and In Situ Small-Angle X-ray Scattering JF - ACS Applied Materials & Interfaces N2 - The complex nature of liquid water saturation of polymer electrolyte fuel cell (PEFC) catalyst layers (CLs) greatly affects the device performance. To investigate this problem, we present a method to quantify the presence of liquid water in a PEFC CL using small-angle X-ray scattering (SAXS). This method leverages the differences in electron densities between the solid catalyst matrix and the liquid water filled pores of the CL under both dry and wet conditions. This approach is validated using ex situ wetting experiments, which aid the study of the transient saturation of a CL in a flow cell configuration in situ. The azimuthally integrated scattering data are fitted using 3D morphology models of the CL under dry conditions. Different wetting scenarios are realized in silico, and the corresponding SAXS data are numerically simulated by a direct 3D Fourier transformation. The simulated SAXS profiles of the different wetting scenarios are used to interpret the measured SAXS data which allows the derivation of the most probable wetting mechanism within a flow cell electrode. KW - Polymer electrolyte fuel cell KW - Water management KW - Catalyst layer KW - Representative morphology modeling KW - Small-angle X-ray scattering KW - MOUSE KW - SAXS PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-575973 DO - https://doi.org/10.1021/acsami.3c00420 SN - 1944-8244 VL - 15 IS - 22 SP - 26538 EP - 26553 PB - ACS Publications AN - OPUS4-57597 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dal Molin, E. S. A1 - Henning, L. M. A1 - Müller, J. T. A1 - Smales, Glen Jacob A1 - Pauw, Brian Richard A1 - Bekheet, M. F. A1 - Gurlo, A. A1 - Simon, U. T1 - Robocasting of ordered mesoporous silica‐based monoliths: Rheological, textural, and mechanical characterization JF - Nano Select N2 - Hierarchically porous, high‐surface‐area silica materials are excellent candidates for multiple applications like catalysis and environmental remediation. Shaping these materials with additive manufacturing (AM) techniques, like robocasting, could enable their use with the benefit of on‐demand, customized shaping and maximizing performance. Herein, ordered mesoporous silica COK‐12 slurries were robocasted into monoliths, containing different ratios of uncalcined COK‐12 and sodium bentonite (0–25 wt.%). The rheology of the mixed slurries is characterized by lower flow indexes (0.69 vs. 0.32) and higher yield stresses (96 vs. 259 Pa) compared to pure COK‐12 ones. Monoliths were printed in woodpile structures and calcined at 600°C. Micro‐CT measurements showed a linear shrinkage of 25% after calcination. Mechanical characterization showed increased uniaxial strength (0.20 ± 0.07 to 1.0 ± 0.3 MPa) with increasing binder/solids ratio from 13 to 25%. The amorphous, mesoporous structure of COK‐12 was retained. The structures exhibited open porosities of 52 ± 4% and showed higher specific mesopore volumes, and increased average mesopore size (6 vs. 8 nm) compared to COK‐12. Small‐angle x‐ray scattering analysis revealed an increased lattice parameter (10.3 vs. 11.0 nm) and reduced wall thickness (3.1 nm vs. 4.1 nm) of the COK‐12 in the monoliths. These properties indicate suitability for their application as porous supports and adsorbents. KW - Industrial and Manufacturing Engineering KW - Additive manufacturing KW - OMS KW - Porous materials KW - Robocasting KW - X-ray scattering KW - MOUSE PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-582503 DO - https://doi.org/10.1002/nano.202300109 VL - 4 IS - 11-12 SP - 615 EP - 631 PB - Wiley-VCH GmbH AN - OPUS4-58250 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Foroutan, F. A1 - Kyffin, B. A. A1 - Nikolaou, A. A1 - Merino-Gutierrez, J. A1 - Abrahams, I. A1 - Kanwal, N. A1 - Knowles, J. C. A1 - Smith, A. J. A1 - Smales, Glen Jacob A1 - Carta, D. T1 - Highly porous phosphate-based glasses for controlled delivery of antibacterial Cu ions prepared via sol–gel chemistry JF - RSC Advances N2 - Mesoporous glasses are a promising class of bioresorbable biomaterials characterized by high surface area and extended porosity in the range of 2 to 50 nm. These peculiar properties make them ideal materials for the controlled release of therapeutic ions and molecules. Whilst mesoporous silicate-based glasses (MSG) have been widely investigated, much less work has been done on mesoporous phosphate-based glasses (MPG). In the present study, MPG in the P2O5–CaO–Na2O system, undoped and doped with 1, 3, and 5 mol% of Cu ions were synthesized via a combination of the sol–gel method and supramolecular templating. The non-ionic triblock copolymer Pluronic P123 was used as a templating agent. The porous structure was studied via a combination of Scanning Electron Microscopy (SEM), Small-Angle X-ray Scattering (SAXS), and N2 adsorption–desorption analysis at 77 K. The structure of the phosphate network was investigated via solid state 31P Magic Angle Spinning Nuclear Magnetic Resonance (31P MAS-NMR) and Fourier Transform Infrared (FTIR) spectroscopy. Degradation studies, performed in water via Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), showed that phosphates, Ca2+, Na+ and Cu ions are released in a controlled manner over a 7 days period. The controlled release of Cu, proportional to the copper loading, imbues antibacterial properties to MPG. A significant statistical reduction of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacterial viability was observed over a 3 days period. E. coli appeared to be more resistant than S. aureus to the antibacterial effect of copper. This study shows that copper doped MPG have great potential as bioresorbable materials for controlled delivery of antibacterial ions. KW - Bioresorbable Biomaterials KW - Mesoporous phosphate-based glasses KW - Synthesis KW - Degradation studies KW - X-ray scattering KW - MOUSE KW - Antibacterial properties KW - Aantimicrobial PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-578101 DO - https://doi.org/10.1039/D3RA02958A VL - 13 IS - 29 SP - 19662 EP - 19673 PB - Royal Society of Chemistry AN - OPUS4-57810 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Henning, L. M. A1 - Smales, Glen Jacob A1 - Colmenares, M. G. A1 - Bekheet, M. F. A1 - Simon, U. A1 - Gurlo, A. T1 - Synthesis and properties of COK-12 large-pore mesocellularsilica foam JF - Nano Select N2 - Large, ink-bottle-shaped pores in mesocellular foams (MCFs) are desired for various applications requiring enhanced mass transfer or the immobilization of larger compounds. Hence, the cylindrical pores of COK-12, an ordered mesoporous silica structurally comparable to SBA-15 but synthesized at room-temperature at quasi-neutral pH, are chemically swollen into ink-bottle pores. Therefore, p-xylene is used as a more sustainable swelling agent compared to popular alternatives. Its high boiling point allows for an additional thermal aging step to amplify the mesostructure enlargement without needing additional chemicals. For COK-12, the MCFs obtained at room temperature reach an unprecedented plateau for the modal mesopore cell and window diameter of 19.9 and 5.5 nm, respectively, with an underlying broad pore size distribution and distorted hexagonal lattice up to 14.5 nm, involving hexagonal and spherical structures. The combined chemical and thermal swelling resulted in the selective enlargement of the window diameter to more than 200% and a slightly increased cell diameter, pore size distribution, and hexagonal lattice distortion in comparison to the room temperature synthesis. Such materials are thought to be promising alternatives to SBA-15-based MCFs, often utilizing toxic catalysts during synthesis. The presented results pave the way for enhanced adsorptive, catalytic, and drug delivery performances for COK-12-based materials. KW - SAXS KW - MOUSE KW - Mesocellular foam KW - Mesoporous silica PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569590 DO - https://doi.org/10.1002/nano.202200223 SP - 1 EP - 11 AN - OPUS4-56959 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob A1 - Anker, A. S. A1 - Annadurai, V. A1 - Balazs, D. M. A1 - Bienert, Ralf A1 - Bouwman, W. G. A1 - Breßler, Ingo A1 - Breternitz, J. A1 - Brok, E. S. A1 - Bryant, G. A1 - Clulow, A. J. A1 - Crater, E. R. A1 - De Geuser, F. A1 - Del Giudice, A. A1 - Deumer, J. A1 - Disch, S. A1 - Dutt, S. A1 - Frank, K. A1 - Fratini, E. A1 - Garcia, P. R. A. F. A1 - Gilbert, E. P. A1 - Hahn, Marc Benjamin A1 - Hallett, J. A1 - Hohenschutz, M. A1 - Hollamby, M. A1 - Huband, S. A1 - Ilavsky, J. A1 - Jochum, J. K. A1 - Juelsholt, M. A1 - Mansel, B. W. A1 - Penttilä, P. A1 - Pittkowski, R. K. A1 - Portale, G. A1 - Pozzo, L. D. A1 - Rochels, L. A1 - Rosalie, Julian M. A1 - Saloga, Patrick E. J. A1 - Seibt, S. A1 - Smith, A. J. A1 - Smith, G. N. A1 - Spiering, G. A. A1 - Stawski, Tomasz M. A1 - Taché, O. A1 - Thünemann, Andreas A1 - Toth, K. A1 - Whitten, A. E. A1 - Wuttke, J. T1 - The human factor: results of a small-angle scattering data analysis round robin JF - Journal of Applied Crystallography N2 - A round-robin study has been carried out to estimate the impact of the human element in small-angle scattering data analysis. Four corrected datasets were provided to participants ready for analysis. All datasets were measured on samples containing spherical scatterers, with two datasets in dilute dispersions and two from powders. Most of the 46 participants correctly identified the number of populations in the dilute dispersions, with half of the population mean entries within 1.5% and half of the population width entries within 40%. Due to the added complexity of the structure factor, far fewer people submitted answers on the powder datasets. For those that did, half of the entries for the means and widths were within 44 and 86%, respectively. This round-robin experiment highlights several causes for the discrepancies, for which solutions are proposed. KW - Round Robin KW - Data analysis KW - Small-angle scattering KW - Nanomaterials KW - Interlaboratory comparability KW - Nanostructure quantification KW - Methodology KW - MOUSE PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-587091 DO - https://doi.org/10.1107/S1600576723008324 VL - 56 IS - 6 SP - 1618 EP - 1629 PB - International Union of Crystallography (IUCr) AN - OPUS4-58709 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -