Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 3, 2018
Previous Article Next Article

Anomalies in the low frequency vibrational density of states for a polymer with intrinsic microporosity – the Boson peak of PIM-1

Author affiliations

Abstract

Polymers with intrinsic microporosity are promising candidates for the active separation layer in gas separation membranes. Here, the vibrational density of states (VDOS) for PIM-1, the prototypical polymer with intrinsic microporosity, is investigated by means of inelastic neutron scattering. The results are compared to data measured for a more conventional high-performance polyimide used in gas separation membranes (Matrimid). The measured data show the characteristic low frequency excess contribution to VDOS above the Debye sound wave level, generally known as the Boson peak in glass-forming materials. In comparison to the Boson peak of Matrimid, that of PIM-1 is shifted to lower frequencies. This shift is discussed considering the microporous, sponge-like structure of PIM-1 as providing a higher compressibility at the molecular scale than for conventional polymers. For an annealed PIM-1 sample, the Boson peak shifts to higher frequencies in comparison to the un-annealed sample. These changes in the VDOS of the annealed PIM-1 sample are related to changes in the microporous structure as confirmed by X-ray scattering.

Graphical abstract: Anomalies in the low frequency vibrational density of states for a polymer with intrinsic microporosity – the Boson peak of PIM-1

Back to tab navigation

Supplementary files

Article information


Submitted
20 Oct 2017
Accepted
13 Dec 2017
First published
13 Dec 2017

Phys. Chem. Chem. Phys., 2018,20, 1355-1363
Article type
Paper

Anomalies in the low frequency vibrational density of states for a polymer with intrinsic microporosity – the Boson peak of PIM-1

R. Zorn, H. Yin, W. Lohstroh, W. Harrison, P. M. Budd, B. R. Pauw, M. Böhning and A. Schönhals, Phys. Chem. Chem. Phys., 2018, 20, 1355
DOI: 10.1039/C7CP07141H

Social activity

Search articles by author

Spotlight

Advertisements