9 research outputs found
Development of a novel process to fabricate hierarchical microporous open-cell polymer foam
No full textA new process to fabricate polymeric hierarchical microporous foams was developed and the effects of process parameters on the cell structure, Young’s Modulus, ultimate tensile strength and density of the resulting foams were studied. The process uses a suspo-emulsion in which one phase is volatile blowing agent/particle slurry and the other phase is a heat curable polymer. We found that the initial concentration of each of the components had drastic effects on the stability of the suspo-emulsion and whether or not the suspo-emulsion would phase invert to create polymer particles instead of polymer foam. Also, increasing the amount of blowing agent in a given suspo-emulsion resulted in lower density foam with a larger Young’s modulus and higher ultimate tensile strength. Polydimethylsiloxane (PDMS) was the polymer chosen for the systematic study of the process and epoxy resin was also used to demonstrate the versatility of the process. Since the resulting foam is microporous and open-celled and because PDMS is hydrophobic, the produced foam rejects high surface tension liquids like water, but absorbs low surface tension liquids like motor oil. Thus, foams fabricated from different compositions were evaluated for their ability to absorb oil for their potential application in maritime oil spill cleanup operations.M.S.Includes bibliographical referencesby Michael C. Fechtman
MBE Growth of GaN on NdGaO<sub>3</sub>(101)
No full textAbstractWe report on the growth of GaN on NdGaO3(101) by plasma assisted molecular beam epitaxy (MBE). NdGaO3(101) is an interesting alternative substrate compared to A12O3due to its smaller lattice mismatch of +1.2 % to hexagonal (0001) GaN. Using photoluminescence (PL), X-ray diffraction (XRD), reflection high energy electron diffraction (RHEED) and atomic force microscopy (AFM) the optical and structural properties of the GaN thin films grown on NdGaO3are investigated and compared to those grown on c-plane sapphire. The intended epitaxial relationship of [0001] GaN ║ [101] GaN is hard to realise as confirmed by several tilted or even polycrystalline films. However, the layer quality was found to improve considerably, when the NdGaO3surface showed a (l × 1) instead of other reconstructions.</jats:p
Entwicklung eines Miniatur-Laser-Doppler-Anemometers fuer umgebungsangepasste Geschwindigkeitsmessung Schlussbericht
No full textAvailable from TIB Hannover: F02B1310 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman
High-throughput technology in electrochemistry
No full text104121In order to reach a 55% reduction in greenhouse gas by 2030 and achieve net zero by 2050 hydrogen technologies will play a vital role in the next decades in Europe. In particular, water electrolysis will become a key technology for producing green hydrogen. The first generation of electrolyzers is currently installed in large-scale industrial applications such as refineries or steel factories.
The operational experience gathered there will lbe the basis for further optimization. In addition, large-scale production and material use are in a continuous improvement and quality control process. All of these efforts need strong R&D support with enhanced experimentation and testing technology. At present, classical single fold test technology or short stacks are mostly used for electrochemical R&D on electrolysis or fuel cell applications.
Due to the obvious similarity between el13ctrocatalysis and heterogeneous catalysis, combinatorial methods developed for the latteir can also be applied in electrocatalysis. The objective in this common project was to build on this analogy and to introduce a new tool for combinatorial testing in electrocatalysis. The aim was to address the electrochemical synthesis of renewable feeds, for example, or the conveirsion of these feeds to release stored energy.
Obviously, online analytic tools, applied in heterogeneous catalysis to measure gases or liquids, need to be supplemented by voltammetry and impedance spectroscopy instruments to measure electrochemical properties as well.
Therefore, electrocatalysis requires more advanced digitalization tools as the parameter space expands by numerous new electric parameters. It seems likely that the current tools will no longer suffice and must be upgraded by applying feedback loops or machine learning or both, for example.
In this presentation, we will introduce the high throughput platform for enhanced electrochemical testing to support the ongoing effort of optimizing electrochemical conversion technology. A case study will illustrate the key features of high throughput experimentation in the electrochemical space
