TY - JOUR
T1 - The structural transitions of π-complexes of poly(styrene-b-butadiene-b-styrene) block copolymers with silver salts and their relation to facilitated olefin transport
AU - Kim, Jong Hak
AU - Lee, Dong Hoon
AU - Won, Jongok
AU - Jinnai, Hiroshi
AU - Kang, Yong Soo
N1 - Funding Information:
The authors acknowledge the SAXS experiments carried out at the Pohang Accelerator Laboratory (PAL) in Korea. HJ is grateful to NEDO for support of this study through a Japanese National Project “Nano Structure Polymer Project” by the Ministry of Economy, Trade and Industry. HJ also thanks Mrs. H. Nishioka, U. Matsuwaki for their help in TEM observations.
PY - 2006/9/15
Y1 - 2006/9/15
N2 - π-Complexes consisting of silver salts such as AgBF4 and AgCF3SO3 dissolved in poly(styrene-b-butadiene-b-styrene) (SBS) block copolymers have been prepared for use as facilitated olefin transport membranes. Facilitated olefin transport is not observable up to the silver mole fraction of 0.14, a threshold concentration, above which it increases almost linearly with the silver salt concentration. FT-IR spectra of these complexes show that silver ions selectively coordinate with the C{double bond, long}C bonds of PB blocks up to the silver mole fraction of 0.14, and that the coordinative interaction of the silver ion with aliphatic C{double bond, long}C is stronger than that with aromatic C{double bond, long}C. Interestingly, the bicontinuous morphology of the neat SBS block copolymer prepared from THF solution persists in the SBS complex with the salt concentrations less than 0.14. At high silver salt concentrations, the PS domains are additionally coordinated by silver ions and thus the morphology transition occurs from bicontinuous to lamellar. The threshold silver concentration of 0.14 for the facilitated olefin transport is nearly coincident with the composition at which the silver ions start coordinating with the aromatic C{double bond, long}C bonds of the PS blocks, suggesting their important role in determining overall transport properties. Therefore, we have shown that the transport properties of the SBS complex membranes are significantly affected by the coordinative interaction of the block copolymers with the silver ions and their membrane morphology.
AB - π-Complexes consisting of silver salts such as AgBF4 and AgCF3SO3 dissolved in poly(styrene-b-butadiene-b-styrene) (SBS) block copolymers have been prepared for use as facilitated olefin transport membranes. Facilitated olefin transport is not observable up to the silver mole fraction of 0.14, a threshold concentration, above which it increases almost linearly with the silver salt concentration. FT-IR spectra of these complexes show that silver ions selectively coordinate with the C{double bond, long}C bonds of PB blocks up to the silver mole fraction of 0.14, and that the coordinative interaction of the silver ion with aliphatic C{double bond, long}C is stronger than that with aromatic C{double bond, long}C. Interestingly, the bicontinuous morphology of the neat SBS block copolymer prepared from THF solution persists in the SBS complex with the salt concentrations less than 0.14. At high silver salt concentrations, the PS domains are additionally coordinated by silver ions and thus the morphology transition occurs from bicontinuous to lamellar. The threshold silver concentration of 0.14 for the facilitated olefin transport is nearly coincident with the composition at which the silver ions start coordinating with the aromatic C{double bond, long}C bonds of the PS blocks, suggesting their important role in determining overall transport properties. Therefore, we have shown that the transport properties of the SBS complex membranes are significantly affected by the coordinative interaction of the block copolymers with the silver ions and their membrane morphology.
KW - Block copolymer
KW - Facilitated transport
KW - Membrane
KW - Olefin
KW - Silver
UR - http://www.scopus.com/inward/record.url?scp=33746718105&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33746718105&partnerID=8YFLogxK
U2 - 10.1016/j.memsci.2006.04.002
DO - 10.1016/j.memsci.2006.04.002
M3 - Article
AN - SCOPUS:33746718105
VL - 281
SP - 369
EP - 376
JO - Jornal of Membrane Science
JF - Jornal of Membrane Science
SN - 0376-7388
IS - 1-2
ER -