TY - JOUR
T1 - Free Volume in Poly(ether imide) Membranes Measured by Positron Annihilation Lifetime Spectroscopy and Doppler Broadening of Annihilation Radiation
AU - Madzarevic, Zeljka P.
AU - Schut, Henk
AU - Čížek, Jakub
AU - Dingemans, Theo J.
PY - 2018
Y1 - 2018
N2 - In order to characterize the free volume of a homologous series all-aromatic poly(ether imide) (PEI) membranes, two positron annihilation techniques were utilized: positron annihilation lifetime spectroscopy (PALS) and Doppler broadening (DB) of annihilation radiation. First, DB, which is a fast and convenient method, indicated differences in free volume of all PEIs investigated, whereas PALS experiments gave more quantitative information, with respect to the size and distribution of the voids. DB results show that S, W pairs for this PEI-series tend to group according to their dianhydride moiety, meaning that, in this series, dianhydrides govern the differences in the S parameter, indicating more free volume with increasing S value. The semicrystalline PEI samples exhibit the lowest S parameter, while the amorphous samples based on 3,3′,4,4′-oxydiphthalic dianhydride (ODPA) all lie on the higher S side of the S-W plot. With the 1,4-bis(4-aminophenoxy)benzene (P1)-based PEI (ODPA-P1) standing out with the highest S parameter. The same could be confirmed and quantified by PALS, where ODPA-P1 is the only membrane in this series with its free volume described by both smaller and larger free-volume elements. The larger voids in ODPA-P1 can be characterized as having a radius (R) of 3.3 Å, which is 5 times larger than the lowest measured free-volume content in this series observed for 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) and 1,3-bis(4-aminophenoxy)benzene (M1)-based PEI (BPDA-M1), which has voids with a radius of R ≈ 0.7 Å. When comparing results obtained by DB and PALS, a very good correlation is observed between the S parameter (determined by DB) and the free-volume content (quantified by PALS).
AB - In order to characterize the free volume of a homologous series all-aromatic poly(ether imide) (PEI) membranes, two positron annihilation techniques were utilized: positron annihilation lifetime spectroscopy (PALS) and Doppler broadening (DB) of annihilation radiation. First, DB, which is a fast and convenient method, indicated differences in free volume of all PEIs investigated, whereas PALS experiments gave more quantitative information, with respect to the size and distribution of the voids. DB results show that S, W pairs for this PEI-series tend to group according to their dianhydride moiety, meaning that, in this series, dianhydrides govern the differences in the S parameter, indicating more free volume with increasing S value. The semicrystalline PEI samples exhibit the lowest S parameter, while the amorphous samples based on 3,3′,4,4′-oxydiphthalic dianhydride (ODPA) all lie on the higher S side of the S-W plot. With the 1,4-bis(4-aminophenoxy)benzene (P1)-based PEI (ODPA-P1) standing out with the highest S parameter. The same could be confirmed and quantified by PALS, where ODPA-P1 is the only membrane in this series with its free volume described by both smaller and larger free-volume elements. The larger voids in ODPA-P1 can be characterized as having a radius (R) of 3.3 Å, which is 5 times larger than the lowest measured free-volume content in this series observed for 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) and 1,3-bis(4-aminophenoxy)benzene (M1)-based PEI (BPDA-M1), which has voids with a radius of R ≈ 0.7 Å. When comparing results obtained by DB and PALS, a very good correlation is observed between the S parameter (determined by DB) and the free-volume content (quantified by PALS).
UR - http://www.scopus.com/inward/record.url?scp=85058278921&partnerID=8YFLogxK
U2 - 10.1021/acs.macromol.8b01723
DO - 10.1021/acs.macromol.8b01723
M3 - Article
AN - SCOPUS:85058278921
SN - 0024-9297
VL - 51
SP - 9925
EP - 9932
JO - Macromolecules
JF - Macromolecules
IS - 23
ER -