Sökning: "mesopores"

Visar resultat 1 - 5 av 19 avhandlingar innehållade ordet mesopores.

  1. 1. Free Volume and Mesopores in Polymer Nanocomposites

    Författare :Petra Winberg; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemical technology and engineering; Kompositmaterial; Composite materials; Macromolecular chemistry; permeability ; membrane ; positron annihilation ; fumed silica ; clay ; mesopores ; polymer nanocomposites ; free volume ; Kemiteknik och kemisk teknologi; Makromolekylär kemi;

    Sammanfattning : The free volume in polymers is coupled to several important physical properties, such as density, viscosity and gas diffusivity. The physical properties of polymers close to a solid surface have been shown to be significantly perturbed as compared to their bulk state. LÄS MER

  3. 2. Studies of inorganic crystal structures and gas adsorption process in mesoporous crystals : New approach through analysis of electron charge distribution by synchrotron powder X-ray diffraction

    Författare :Norihiro Muroyama; Osamu Terasaki; Clément Sanchez; Stockholms universitet; []
    Nyckelord :XRD; Mesoporous; Gas adsorption; Laves Phase; MEM; strukturkemi; Structural Chemistry;

    Sammanfattning : Using synchrotron powder XRD experiments, I studied (i) structures of silica mesoporous MCM-41 and MCM-48 crystals, (ii) gas adsorption processes of Ar and N2 in the mesopores of the mesoporous crystals, and (iii) bonding features of CaAl2-xZnx crystals through the analysis of electron charge density distributions. In the case of mesoporous crystals, the following two different approaches were taken depending on the number of observed X-ray reflections1. LÄS MER

  4. 3. A structural study into the boundary surface and associated curvature of three-dimensional mesoporous silica crystals

    Författare :Keiichi Miyasaka; Osamu Terasaki; Reinhard Nesper; Stockholms universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; mesoporous crystal; electron crystallography; electrostatic potential map; equi-potential surface; curvature; multiplly-twinned particle; Chemistry; Kemi; Structural Chemistry; strukturkemi;

    Sammanfattning : Since their first discovery in the early 1990s, mesoporous crystals (MCs) have fascinated researchers in various fields because of their interesting structures and their potential uses. Electron crystallography (EC) gives the direct three-dimensional (3D) realization of a crystal as a reconstructed electrostatic potential map (EPM). LÄS MER

  5. 4. Structured MFI film catalysts and adsorbents

    Författare :Olov Öhrman; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical Technology; Kemisk teknologi;

    Sammanfattning : A method originally developed at the division of Chemical Technology, Luleå University of Technology was tailored for the preparation of well-defined ZSM-5 films and zoned MFI films on supports suitable for catalysis and adsorption applications. Films were grown on monoliths, ceramic foams, alumina beads, soda glass beads and quartz glass. LÄS MER

  7. 5. Formation mechanism of anionic-surfactant-templated mesoporous silica (AMS)

    Författare :Chuanbo Gao; Osamu Terasaki; Anders Palmqvist; Stockholms universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; mesoporous silica; anionic surfactant; formation mechanism; structural control; Chemistry; Kemi; Structural Chemistry; strukturkemi;

    Sammanfattning : This dissertation is focused on synthesis, characterization and formation mechanism of anionic-surfactant-templated mesoporous silica (AMS). Structural control mechanisms of AMS are investigated. LÄS MER