title: Self-assembled supramolecular gels of reverse poloxamers and cyclodextrins.
abstract: A series of supramolecular aggregates were prepared using a poly(propylene oxide)-poly(ethylene oxide)-poly(propylene oxide) (PPO-PEO-PPO) block copolymer and β- or α-cyclodextrins (CD). The combination of β-CD and the copolymer yields inclusion complexes (IC) with polypseudorotaxane structures. These are formed by complexation of the PPO blocks with β-CD molecules producing a powder precipitate with a certain crystallinity degree that can be evaluated by X-ray diffraction (XRD). In contrast, when combining α-CD with the block copolymer, the observed effect is an increase in the viscosity of the mixtures yielding fluid gels. Two cooperative effects come into play: the complexation of PEO blocks with α-CD and the hydrophobic interactions between PPO blocks in aqueous media. These two combined interactions lead to the formation of a macromolecular network. The resulting fluid gels were characterized using different techniques such as differential scanning calorimetry (DSC), viscometry, and XRD measurements.
authors: Departamento de Química y Edafología, Facultad de Ciencias, Universidad de Navarra, 31080 Pamplona, Navarra, Spain.
authors: Eneko
authors: E
authors: Larrañeta
authors: José Ramón
authors: JR
authors: Isasi
mesh_terms: D005782:Gels; D011092:Polyethylene Glycols / Q000737:chemistry*; D011409:Propylene Glycols / Q000737:chemistry*; D044366:Transition Temperature; D047391:alpha-Cyclodextrins / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D005782:Gels; D011409:Propylene Glycols; D047391:alpha-Cyclodextrins; D047392:beta-Cyclodextrins; C560788:poly(propylene oxide)-block-poly(ethylene oxide)-block-poly(propylene oxide); D011092:Polyethylene Glycols