Sökning: "siloxanes"

Hittade 4 avhandlingar innehållade ordet siloxanes.

  1. 1. Partitioning and persistence of volatile methylsiloxanes in aquatic environments

    Författare :Dimitrios Panagopoulos; Matthew MacLeod; Annika Jahnke; Amelie Kierkegaard; Whelan Mick; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; siloxanes; organic carbon; sediment; partitioning; persistence; Applied Environmental Science; tillämpad miljövetenskap;

    Sammanfattning : The presence of volatile methylsiloxanes (VMS) in the environment has raised concerns among environmental chemists and regulators about their persistence and the risks they may pose to the environment. This thesis explores the partitioning and persistence of VMS in aquatic environments. LÄS MER

  3. 2. Methods for the preparation of capillary columns for gas chromatography

    Författare :Thomas Wännman; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis is dedicated to column technology, and describes methods for the preparation of efficient, well deactivated and durable capillary columns for gas chromatography.Problems associated with column preparation are discussed in conjunction with a brief literature survey of the most important contributions to column technology since the concept of capillary gas chromatography was first introduced by M. LÄS MER

  4. 3. Loss and recovery of hydrophobicity of polydimethylsiloxane after exposure to electrical discharges

    Författare :Henrik Hillborg; KTH; []
    Nyckelord :silicone rubber; polydimethysiloxane; dydrophobicity; corona; air-plasma; oxygen-plasma; surface characterisation;

    Sammanfattning : Silicone rubber based on polydimethylsiloxane is used ashigh voltage outdoor insulation, due to its ability to preservethe hydrophobic surface properties during service and evenregain hydrophobicity after exposure to electrical discharges.The underlying processes for the hydrophobic recovery arediffusion of low molar mass siloxanes from the bulk to thesurface and reorientation by conformational changes ofmolecules in the surface region. LÄS MER

  5. 4. Crosslinking of Polymers. Molecular Structure and Properties of Sol and Network

    Författare :Helena Andersson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; PDMS; long chain branchin; entanglement; crosslinking; contamination; network; bimodal; Silicone; polyethylene;

    Sammanfattning : Crosslinking is a well-known procedure for improving a variety of features of polymers, particularly the dimension stability at elevated temperatures. Crosslinking implies the formation of a network, the gel, but there is always a certain portion of the material, the sol, that remains non-crosslinked within the network. LÄS MER