<?xml version="1.0" encoding="utf-8"?>
<export-example>
  <doc>
    <id>2041</id>
    <completedYear/>
    <publishedYear>2003</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>S1139</pageFirst>
    <pageLast>S1148</pageLast>
    <pageNumber/>
    <edition/>
    <issue>11</issue>
    <volume>15</volume>
    <type>article</type>
    <publisherName>IOP Publ. Ltd.</publisherName>
    <publisherPlace>Bristol</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Molecular dynamics of polymers in random nanometer confinements investigated by relaxational scattering techniques</title>
    <abstract language="eng">Dielectric spectroscopy and temperature-modulated differential scanning calorimetry are employed to study the molecular dynamics of oligomeric poly(propylene glycol) (PPG) melts of different molecular weights confined to nanoporous glasses (pore sizes 2.5, 5.0, 7.5 and 20 nm). Moreover, the results obtained for the polymers are compared with those for the corresponding monomer. The experimental results are discussed in the framework of the interplay of confinement and adsorption effects. For large pore sizes (&gt; 5 nm) a speeding up of the molecular dynamics is observed (the confinement effect), whereas for small pore sizes (&lt; 5 nm) a slowing down of the segmental fluctuations is found (the adsorption effect). In addition, a minimal length scale for the glass transition of 1.6 nm is estimated for PPG confined in nanoporous glasses. This supports the idea that the molecular motions responsible for the glassy dynamics must be describable by a characteristic length scale.
Polarized Raman scattering investigations are carried out to investigate the conformations of the macromolecules inside the pores. These experiments show that the confined polymer chains are locally stretched. This effect increases with decreasing pore size.</abstract>
    <parentTitle language="eng">Journal of physics / Condensed matter</parentTitle>
    <identifier type="old">1947</identifier>
    <identifier type="doi">10.1088/0953-8984/15/11/334</identifier>
    <identifier type="issn">0953-8984</identifier>
    <identifier type="issn">1361-648X</identifier>
    <enrichment key="eventName">3rd Workshop on Non-Equilibrium Phenomena in Supercooled Fluids, Glasses and Amorphous Materials</enrichment>
    <enrichment key="eventPlace">Pisa, Italy</enrichment>
    <enrichment key="eventStart">2003-09-22</enrichment>
    <enrichment key="eventEnd">2003-09-27</enrichment>
    <enrichment key="date_peer_review">05.03.2003</enrichment>
    <author>Andreas Schönhals</author>
    <author>Harald Goering</author>
    <author>Klaus-Werner Brzezinka</author>
    <author>C. Schick</author>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Weder Datei noch physisches Exemplar vorhanden ("No Access")</collection>
  </doc>
</export-example>
