Sökning: "cation exchange"

Visar resultat 1 - 5 av 49 avhandlingar innehållade orden cation exchange.

  1. 1. Cation adsorption properties of substituted kraft fibres : an experimental and thermodynamic modelling study

    Författare :Ola Sundman; Lars-Olof Öhman; Per Persson; Janne Laine; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Kraft fibres; Donnan equilibria; ion exchange; acid base properties; potentiometric titrations; thermodynamic modelling; NPEs; GaAl12 7 ; EXAFS; Chemistry; Kemi;

    Sammanfattning : Acid/base and metal ion adsorption properties have been investigated for a range of chemically modified bleached Kraft fibre materials (pulps). The studies were performed via potentiometric titrations, Flame Atomic Absorbtion (and Emission) Spectroscopy, Inductively Coupled Plasma Optical Emission Spectroscopy and Extended X-ray Absorbtion Fine Structure measurements. LÄS MER

  3. 2. Diffusion of Radionuclides in Bentonite Clay : Laboratory and in sity Studies

    Författare :Mats Jansson; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bentonite; montmorillonite; cation; anion; diffusion; sorption; cobalt; caesium; strontium; iodide; pertechnetate; surface diffusion; in situ; Chemistry; Kemi;

    Sammanfattning : This thesis deals with the diffusion of ions in compactedbentonite clay. Laboratory experiments were performed toexamine in detail different processes that affect thediffusion. To demonstrate that the results obtained from thelaboratory investigations are valid under in situ conditions,two different kinds of in situ experiments were performed. LÄS MER

  4. 3. Multiscale Modeling of Molecular Sieving in LTA-type Zeolites : From the Quantum Level to the Macroscopic

    Författare :Amber Mace; Laaksonen Aatto; Tina Düren; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; CO2 separation; carbon capture; kinetic sieving; Zeolite A; Zeolite NaKA; cation exchange; temporal coarse graining; Kinetic Monte Carlo; Molecular Dynamics; AIMD; DFT; fysikalisk kemi; Physical Chemistry;

    Sammanfattning : LTA-type zeolites with narrow window apertures coinciding with the approximate size of small gaseous molecules such as CO2 and N2 are interesting candidates for adsorbents with swing adsorption technologies due to their molecular sieving capabilities and otherwise attractive properties. These sieving capabilities are dependent on the energy barriers of diffusion between the zeolite pores, which can be fine-tuned by altering the framework composition. LÄS MER

  5. 4. Origin and mobility of major and key trace elements (Cs, YREEs) in fracture groundwater in the upper 1.2 kilometres of coastal granitoids : Implications for future repositories of spent nuclear fuel

    Författare :Frédéric A. Mathurin; Mats E. Åström; Marcus Laaksoharju; Birgitta Kalinowski; Niklaus Waber; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fracture groundwater; groundwater mixing; seawater intrusion; water-rock interactions; cation exchange; Cesium; Rare Earth Elements; colloidal speciation; humic substances; dual porosity; inverse modelling; Äspö HRL; Laxemar; Forsmark; eaux de fractures; mélange d eaux; intrusion d eau de mer; interactions eau-roche; échanges cationiques; Césium; Elements Terres Rares; spéciation colloïdale; substances humiques; double porosité; modélisation inverse; Äspö HRL; Laxemar; Forsmark; sprickvatten; grundvatten mixing; havsvattenintrusion; vatten-berg interaction; katjonbyte; cesium; sällsynta jordartsmetaller; kollidal speciation; humusämnen; dual porositet; invers modellering; Äspölaboratoriet; Äspötunneln; Laxemar; Forsmark; Miljövetenskap; Environmental Science;

    Sammanfattning : This thesis focuses on the chemical and isotopic features of groundwater residing in the upper 1.2 km of sparsely fractured crystalline bedrock of the Baltic Shield. LÄS MER

  7. 5. Exploring N-alicyclic quaternary ammonium functional polymers as hydroxide exchange membranes

    Författare :Joel Olsson; Centrum för analys och syntes; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrolyte membrane; Anion exchange membranes; Anion exchange membrane fuel cells; Structure-property relationship; Quaternary ammonium cations; Alkaline stability; Synthesis; Characterization;

    Sammanfattning : As the global power generation is shifted toward renewable and intermittent sources, the importance of fuel cells and other energy storage and conversion devices is continually increasing. However, many of these technologies are still under development and further research is necessary before they can be implemented. LÄS MER