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Seminar Talk: Dr. Rajib Basak

Raman Research Institute, Bangalore, India

24.Sep.2013 11:00
24.Sep.2013 12:00
Sem. room A1-3/Bldg. 04.6

The Effect of Additives on Micelle Forming Triblock Copolymer System - from Jamming Transition to Drug Delivery system


Pluronic F127, a triblock PEO-PPO-PEO copolymer system, exhibits amphiphilic nature at high temperatures. Above a critical concentration and temperature, Pluronic molecules self-aggregate to form spherical micelles in aqueous solution with a hydrophobic PPO core, surrounded by a hydrophilic PEO corona. This micellization process is very sensitive to the presence
of additives and temperature. At high concentrations, F127 micelles close pack to form a jammed solution that shows soft glassy rheology. The addition of an anionic surfactant to this solution results in a decrease in its elasticity and viscosity by several decades. This is due to the formation of anisotropic and sizepolydisperse mixed micelles that change the packing behavior and results in the unjamming of the micellar aggregates [1]. F127 micelles are also used to encapsulate different drugs such as Ibuprofen, Erythromycin and Aspirin. The encapsulation of drugs in these micelles reduces the critical micellization temperature of the dilute micellar solution only if the drug concentration is above a threshold value that depends upon the drug hydrophobicity. The mean hydrodynamic radii and polydispersities of the micelles increase in the presence of drug molecules. Increasing solution pH causes the micelles to rupture and release the drugs into the solution [2].

[1] R. Basak, N. Mukhopadhyay, and R. Bandyopadhyay, Eur. Phys. J. E ,
2011, 34, 103.
[2] R. Basak, R. Bandyopadhyay, Langmuir, 2013, 29 (13), 4350-4356.


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