Unusual temperature dependence of the positron lifetime in a polymer of intrinsic microporosity

被引：28

作者：

de Miranda, Rodrigo Lima

Kruse, Jan

Raetzke, Klaus

Faupel, Franz

Fritsch, Detlev

Abetz, Volker

Budd, Peter M.

Selbie, James D.

McKeown, Neil B.

Ghanem, Bader S.

机构：

[1] Univ Kiel, Tech Fak, Lehrstuhl Mat Verbunde, D-24143 Kiel, Germany

[2] GKSS Forschungszentrum Geesthacht GmbH, Max Planck Inst Polymerforsch, D-21502 Geesthacht, Germany

[3] Univ Manchester, Sch Chem, Manchester M13 9PL, Lancs, England

[4] Cardiff Univ, Sch Chem, Cardiff CF10 3AT, Wales

来源：

PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS | 2007年 / 1卷 / 05期

关键词：

D O I：

10.1002/pssr.200701116

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The performance of polymeric membranes for gas separation is mainly determined by the free volume. Polymers of intrinsic microporosity are interesting due to the high abundance of accessible free volume. We performed measurements of the temperature dependence of the positron lifetime, generally accepted for investigation of free volume, in two polymers of intrinsic microporosity (PIM-1 and PIM-7) in the range from 143 to 523 K. The mean value of the free volume calculated from the ortho-positronium lifetime is in the range of typical values for high free volume polymers. However, the temperature dependence of the local free volume is non-monotonous in contrast to the macroscopic thermal expansion. The explanation is linked to the spirocenters in the polymer. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

引用

页码：190 / 192

页数：3

共 20 条

[1] Gas separation membranes from polymers of intrinsic microporosity [J].