TY - JOUR A1 - Yin, Huajie A1 - Schönhals, Andreas T1 - Calorimetric glass transition of ultrathin poly(vinyl methyl ether) films JF - Polymer N2 - Specific heat spectroscopy in the frequency range typically from 1 Hz to 1 kHz with a sensitivity of pJ/K was employed to study the glass transition behavior of ultrathin poly(vinyl methyl ether) (PVME) films with thicknesses ranging from 218 nm down to 12 nm. The amplitude and the phase angle of the complex differential voltage as a measure of the complex heat capacity were obtained as a function of temperature at a given frequency simultaneously. Both spectra are used to determine the dynamic glass transition temperature as a function of both the frequency and the film thickness. As main result no thickness dependence of the dynamic glass transition temperature was observed down to a film thickness of 12 nm within the experimental uncertainty of ±2 K. Further the width of the glass transition is independent of the film thickness which indicates that the extent of the cooperativity is essentially smaller than 12 nm. KW - Specific heat spectroscopy KW - Dynamic glass transition KW - Poly(vinyl methyl ether) PY - 2013 DO - https://doi.org/10.1016/j.polymer.2013.02.025 SN - 0032-3861 SN - 1873-2291 VL - 54 IS - 8 SP - 2067 EP - 2070 PB - Springer CY - Berlin AN - OPUS4-28011 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -