A New pH and Thermo-Responsive Chiral Hydrogel for Stimulated

Jul 13, 2007 - A facile preparation of pH-temperature dual stimuli-responsive supramolecular hydrogel and its controllable drug release. Mi Zhou , Kai...
2 downloads 20 Views 427KB Size
9294

J. Phys. Chem. B 2007, 111, 9294-9300

A New pH and Thermo-Responsive Chiral Hydrogel for Stimulated Release B. Vijai Shankar and Archita Patnaik* Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India ReceiVed: April 29, 2007

Chirality of the amphiphile to promote gelation in the given solvent medium is narrated in a new catanionic surfactant mixture from a twin-chiral, twin-tailed surfactant derived from tartaric acid and cetyltrimethylammonium bromide (CTAB). The surfactant bis(decyloxy) succinic acid (BDSA), a chiral Gemini-type surfactant with a rigid spacer, in association with CTAB formed pH and temperature responsive vesicles and hydrogels. Molecular chirality gave rise to supertwisted fibrillar hydrogels at a BDSA:CTAB molar ratio of 1:2 and in 31% water content. The hydrogels from enantiomeric BDSA were reversibly pH and irreversibly temperature responsive at pH