Search for dissertations about: "porous silica materials, thesis"

Showing result 1 - 5 of 45 swedish dissertations containing the words porous silica materials, thesis.

2. 1. Nanostructured Catalysts and Electrode Materials for PEM Fuel Cells

   Author : Kjell Wikander; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; PEMFC; mesoporous; alkylthiol; alkylamine; carbon; microemulsion; Fuel cell; surfactants; nanoparticles; electron microscopy; Pt; nanocasting; silica; cathode; phase transfer method; oxygen reduction;

   Abstract : The Polymer Electrolyte Membrane Fuel Cell (PEMFC) is a promising energy converting technology for powering automotives and electrical equipment using hydrogen gas as fuel and producing water as the only exhaust. The active carbon-supported platinum catalyst present in the electrodes limits the maximum power generation in state-of-the-art PEMFCs due to platinum’s poor activity for the oxygen reduction reaction (ORR) taking place at the cathode. READ MORE

4. 2. Microstructure and liquid mass transport control in nanocomposite materials

   Author : Christoffer Abrahamsson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; magnetic alignment; permeability; colloidal gels; microgels; bond water; clay; flow; microstructure; nanocomposites; poly N-isopropylacrylamide ; porous materials; liquid mass transport; diffusion; diffusion NMR; particle aggregation; phase behavior; silica;

   Abstract : Some of the biggest problems currently facing the world are closely tied to unsolved technological challenges in the material sciences. Many materials have a porous microstructure that controls their overall properties. READ MORE

5. 3. Synthesis and modification of potential CO2 adsorbents : Amine modified silica and calcium carbonates

   Author : Baroz Aziz; Niklas Hedin; Lennart Bergström; Helmut Cölfen; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Amine-modified silica; carbon capture; Fractional factorial design; IR spectroscopy; calcium carbonate; Materials Chemistry; materialkemi;

   Abstract : The prospect of rapid changes to the climate due to global warming is subject of public concern. The need to reduce the emissions of atmospheric green house gases and in particular carbon dioxide is greater than ever. Extensive research is performed to find new solutions and new materials, which tackles this problem in economically benign way. READ MORE

6. 4. Characterization of some natural and synthetic materials with silicate structures

   Author : Edwin Escalera; Farid Akhtar; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Konstruktionsmaterial; Engineering Materials; Materialteknik; Engineering Materials;

   Abstract : The present thesis deals with characterization of silicate structures with a determined morphology and structure such as ordered mesoporous silica and layered silicates. Mesoporous silica groups are amorphous solids exhibiting highly ordered pore structures with narrow pore size distributions and large surface areas. READ MORE

7. 5. Characterization and preparation of lightweight silica based ceramics for building applications

   Author : Edwin Escalera; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materialteknik; Engineering Materials;

   Abstract : Bolivia is a country with considerable quantities of non-metallic resources. Some important deposits of these resources are located in the high and cold Altiplano as well as in the tropical areas. These deposits are not being exploited industrially but both areas have production of some ceramics in a handmade and empiric way. READ MORE