title: Formation of a polypseudorotaxane via self-assembly of γ-cyclodextrin with poly(N-isopropylacrylamide).
abstract: A polypseudorotaxane (PPR) comprising γ-cyclodextrin (γ-CD) as host molecules and poly(N-isopropylacrylamide) (PNIPAM) as a guest polymer is prepared via self-assembly in aqueous solution. Due to the bulky pendant isopropylamide group, PNIPAM exhibits size-selectivity toward self-assembly with α-, β-, and γ-CDs. It can fit into the cavity of γ-CD to give rise to a PPR, but cannot pass through α-CD and β-CD under the same conditions. The ratio of the number of γ-CD molecules to entrapped NIPAM repeat units is kept at 1:2.2 or 1:2.4, determined by (1) H NMR spectroscopy and TGA analysis, respectively, indicating that there are more than 2 but less than 3 NIPAM repeat units included by one γ-CD molecule. This finding opens new avenues to PPR-based supramolecular polymers to be used as solid, stimuli-responsive materials.
authors.affiliation: School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, PR China.
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.forename: Shuo
authors.initials: S
authors.lastname: Li
authors.forename: Lin
authors.initials: L
authors.lastname: Ye
authors.forename: Ai-Ying
authors.initials: AY
authors.lastname: Zhang
authors.forename: Zeng-Guo
authors.initials: ZG
authors.lastname: Feng
mesh_terms: D000178:Acrylamides / Q000737:chemistry*; D000180:Acrylic Resins; D015394:Molecular Structure; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D043862:Rotaxanes / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry; D047408:gamma-Cyclodextrins / Q000737:chemistry*
chemical_list: D000178:Acrylamides; D000180:Acrylic Resins; D011108:Polymers; D043862:Rotaxanes; D047392:beta-Cyclodextrins; D047408:gamma-Cyclodextrins; C052970:poly-N-isopropylacrylamide; C023792:gamma-cyclodextrin