Institut für Chemie und Bioanalytik

Dauerhafte URI für die Sammlung

https://irf.fhnw.ch/handle/11654/24

Listen

Neueste Veröffentlichungen

Gerade angezeigt 1 - 5 von 226
  • Vorschaubild
    Publikation
    Using membrane-supported liquid–liquid extraction for the measurement of extraction kinetics
    (Swiss Chemical Society, 2011) Riedl, Wolfgang; Mollet, Daniel; Grundler, Gerhard [in: CHIMIA]
    Membrane-supported liquid–liquid extraction uses artificial membranes for the generation of a phase interface between the two liquid phases involved in extraction. Additional equipment for the generation of droplets as well as phase separation afterwards is no longer necessary. Since the membranes used for this special type of extraction are quite well described concerning thickness, porosity, tortuosity and material it is possible to generate information about the diffusion coefficient of the component to be extracted within the preferred solvent from extraction trails easily. This article describes an experimental set-up for both the proof of principle of membrane-supported liquid–liquid extraction and, using a dedicated computer-aided data treatment, how to calculate the overall mass transfer coefficient as well as the diffusion coefficient for a given system within moderate testing duration.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild
    Publikation
    Energy-related chemical research at the universities of applied sciences
    (Swiss Chemical Society, 2013) Riedl, Wolfgang; Fischer, Fabian; Marti, Roger; Brühwiler, Dominik [in: CHIMIA]
    An overview of current activities in the field of energy-related chemical research at the Swiss Universities of Applied Sciences is presented.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild
    Publikation
    Sustainable Chemistry at the Universities of Applied Sciences
    (Swiss Chemical Society, 2012) Sanglard, Pauline; Rogano, Frank; Naef, Olivier; Riedl, Wolfgang; Crelier, Simon; Fischer, Fabian; Morganti, Franziska; Hinderling, Christian [in: CHIMIA]
    An overview of activities in the field of sustainable or 'green' chemistry at the Universities of Applied Sciences in Switzerland is presented.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    Limestone nanoparticles as nanopore templates in polymer membranes. Narrow pore size distribution and use as self-wetting dialysis membranes
    (Royal Society of Chemistry, 2014) Kellenberger, Christoph R.; Pfleiderer, Florian C.; Raso, Renzo; Burri, Cornelia H.; Schumacher, Christoph M.; Grass, Robert N.; Stark, Wendelin J. [in: RSC Advances]
    Limestone nanoparticles can be used as nanopore templates to prepare porous polymeric films. Their application as membranes is so far strongly limited by the fact that these films are highly hydrophobic. In this study, a simple method is reported to directly produce self-wetting membranes by the template removal method. Triethyl citrate modified polyethersulfone and cellulose acetate membranes were produced using dissolvable limestone nanoparticles as pore templates. The nanoporous polymer films were used as dialysis membranes and characterized by means of buffer exchange rate, molecular weight cut-off, protein adsorption, pore size distribution and water contact angle. The herein prepared membranes were further benchmarked against commercially available dialysis membranes with comparable average pore size. They showed narrow pore size distributions, fast dialysis rates at low protein adsorption and molecular weight cut-off of around 12 kDa. Interestingly, the triethyl citrate modified polyethersulfone membranes displayed only moderate change in pore size distribution as a result of the plasticizer additive compared to pure polyethersulfone membranes. This is a matter of substantial interest considering the fact that additive modifications of membranes produced by the predominant phase inversion process typically show alterations in morphology that lead to undesired changes in membrane performance. Furthermore, dextran recovery analysis proved to meet the specific requirements for dialysis membrane characterization and benchmarking.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    Template-particle stabilized bicontinuous emulsion yielding controlled assembly of hierarchical high-flux filtration membranes
    (American Chemical Society, 2015) Hess, Samuel C.; Kohll, A. Xavier; Raso, Renzo; Schumacher, Christoph M.; Grass, Robert N.; Stark, Wendelin J. [in: ACS Applied Materials & Interfaces]
    A novel solvent-evaporation-based process that exploits template-particle stabilized bicontinuous emulsions for the formation of previously unreached membrane morphologies is reported in this article. Porous membranes have a wide range of applications spanning from water filtration, pharmaceutical purification, and battery separators to scaffolds for tissue engineering. Different situations require different membrane morphologies including various pore sizes and pore gradients. However, most of the previously reported membrane preparation procedures are restricted to specific morphologies and morphology alterations require an extensive optimization process. The tertiary system presented in this article, which consists of a poly(ether sulfone)/dimethylacetamide (PES/DMAc) solution, glycerol, and ZnO-nanoparticles, allows simple and exact tuning of pore diameters ranging from sub-20 nm, up to 100 nm. At the same time, the pore size gradient is controlled from 0 up to 840%/μm yielding extreme asymmetry. In addition to structural analysis, water flux rates of over 5600 L m–2 h–1 are measured for membranes retaining 45 nm silica beads.
    01A - Beitrag in wissenschaftlicher Zeitschrift