On the formation of inclusion complexes at the solid/liquid interface of anchored temperature-responsive PNIPAAM diblock copolymers with γ-cyclodextrin
- Autori: Lazzara, G.;Campbell, R.A.; Bayati, S.; Zhu, K.; Nyström, B.; Nylander, T.; Schillén, K.
- Anno di pubblicazione: 2017
- Tipologia: Articolo in rivista (Articolo in rivista)
- Parole Chiave: Acrylic monomers; Amides; Block copolymers; Cyclodextrins; Reflection; Reflectometers; Viscoelasticity, Inclusion complex; Poly (n isopropylacrylamide); Reflectometry; Solid/liquid interfaces; Thermo-responsive, Hydrogels, copolymer; gamma cyclodextrin; poly(n isopropylacrylamide); polyrotaxane; unclassified drug, Article; atom transfer radical polymerization; complex formation; ellipsometry; liquid; neutron reflectometry; polymerization; priority journal; quartz crystal microbalance; reflectometry; solid; solid liquid interface; supramolecular chemistry; synthesis; Cyclodextrin; Inclusion complex; Poly(N-isopropylacrylamide); Reflectometry; Solid/liquid interface; Thermoresponsive block copolymer
- OA Link: http://hdl.handle.net/10447/297515
Abstract
The thermal responsive behavior of adsorbed layers of diblock copolymers of poly(N-isopropylacrylamide) (PNIPAAM) and poly((3-acrylamidopropyl)trimethylammonium chloride) (PAMPTMA(+)) with γ-cyclodextrin (γ-CD) at the solid/liquid interface has been investigated using three in situ techniques: null ellipsometry, quartz–crystal microbalance with dissipation monitoring, and neutron reflectometry. The measurements provided information about the adsorbed amounts, the layer thickness, hydration and viscoelastic properties, and the interfacial structure and composition. The copolymers adsorb to silica with the cationic PAMPTMA(+) blocks sitting as anchors in a flat conformation and the PNIPAAM chains extending into the solution. The copolymer system alone exhibits reversible collapse above the lower critical solution temperature of PNIPAAM. The addition of γ-CD to pre-adsorbed copolymer layers results in a highly extended conformation as well as some loss of copolymer from the surface, which we discuss in terms of the formation of surface-invoked lateral steric repulsion of formed inclusion complexes. © 2017, The Author(s).