Rheological and mechanical properties of hydroxypropyl methylcellulose-based hydrogels and cryogels controlled by AOT and SDS micelles.

SDS micelles bound to the HPMC chains building "bead necklaces", increasing considerably the storage modulus G' values of the hydrogels and the compressive modulus E values of the corresponding cryogels. The dangling SDS micelles promoted multiple junction points among the HPMC chains. AOT micelles and HPMC chains did not form "bead necklaces". Although AOT increased the G' values of the hydrogels, the resulting cryogels were softer than pure HPMC cryogels. The AOT micelles are probably embedded between HPMC chains. The AOT short double chains rendered softness and low friction to the cryogel cell walls. Therefore, this work demonstrated that the structure of the surfactant tail can tune the rheological behavior of HPMC hydrogels and hence the microstructure of the resulting cryogels.