Self-assembled supramolecular gels of reverse poloxamers and cyclodextrins.

Eneko Larrañeta, José Ramón Isasi

Departamento de Química y Edafología, Facultad de Ciencias, Universidad de Navarra, 31080 Pamplona, Navarra, Spain.

Langmuir : the ACS journal of surfaces and colloids 2012 Aug 28

filter terms:

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.

Citation

Eneko Larrañeta, José Ramón Isasi. Self-assembled supramolecular gels of reverse poloxamers and cyclodextrins. Langmuir : the ACS journal of surfaces and colloids. 2012 Aug 28;28(34):12457-62