Related Experiment Video
Updated: Jun 22, 2026
Cooling Rate Dependent Ellipsometry Measurements to Determine the Dynamics of Thin Glassy Films
Published on: January 26, 2016
Thermal conductivity of amorphous polystyrene in supercritical carbon dioxide studied by reverse nonequilibrium
Elena A Algaer1, Mohammad Alaghemandi, Michael C Böhm
1Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, Petersenstrasse 20, D-64287 Darmstadt, Germany. e.algaer@theo.chemie.tu-darmstadt.de
Abstract:
The thermal conductivity of amorphous atactic polystyrene (PS) swollen in supercritical carbon dioxide (sc CO(2)) has been investigated over wide temperature, pressure, and concentration ranges. Nonequilibrium molecular dynamics simulations with a full atomistic force field have been used to calculate the thermal conductivity of neat PS and sc CO(2) as well as of the binary system at different compositions. An analytical interpolation formula for the thermal conductivity of the binary mixture on the basis of PS and CO(2) data has been obtained. Particular attention has been paid to the implications of the quasi-degeneracy and finite-size effects in the simulated polymer system. It has been found that, in addition to the degrees of freedom per volume, the orientation of the carbon-carbon bonds in the backbone relative to the direction of the temperature gradient is important for the heat transport in PS.
Related Concept Videos
01:08Molecular Weight of Step-Growth Polymers
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
01:21Polymer Classification: Crystallinity
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
01:16Specific Heat
For example, increasing the temperature of one gram of water by 1°C requires one calorie of heat energy and can be written as 1 cal/g-°C, or 4186 J/kg/K.
01:24Thermodynamics: Activity Coefficient
The activity coefficient is a measure of the deviation from ideal behavior. When the ionic strength of the solution is minimal, the activity coefficient of an ionic species is close to unity, making...
01:16Thermal Sigmatropic Reactions: Overview
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in 1,5-hexadiene, referred to as...