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Aggregation Behavior of Poly( N ‐isopropylacrylamide) Semitelechelics with a Perfluoroalkyl Segment in Water a
Author(s) -
Li Zheng,
Kyeremateng Samuel Oppong,
Fuchise Keita,
Kakuchi Ryohei,
Sakai Ryosuke,
Kakuchi Toyoji,
Kressler Jörg
Publication year - 2009
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200900334
Subject(s) - lower critical solution temperature , poly(n isopropylacrylamide) , micelle , polymer chemistry , dynamic light scattering , chemistry , copolymer , materials science , aqueous solution , polymer , nanotechnology , nanoparticle , organic chemistry
Two hydrophobically modified PNIPAM semitelechelics P x F 9 were prepared by “clicking” PNIPAM containing an azide endgroup (P x N 3 ) with nonadecafluoro‐1‐decyl hex‐5‐ynoate (F 9 ). Micelles of P x F 9 in water with a core of F 9 ‐segments and a PNIPAM corona were detected by dynamic light scattering and by 1 H and 19 F NMR spectroscopy below the LCST. Just below the LCST, the PNIPAM chains start to collapse onto the F 9 core followed by aggregation of several collapsed micelles to large particles in the range of ≈110 nm. The F 9 segments shifted the LCST to lower temperatures when comparing P x N 3 with P x F 9 . The existence of micelles in P x F 9 solutions also improved the reversibility of the LCST behavior as measured by DSC.