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Block Copolymer Self-Assembly q
Nagarajan, R.; Ganesh,
K. Block Copolymer Self-Assembly in Selective Solvents: Spherical Micelles With Segregated Cores. Journal
of Chemical Physics 90, 5843-5856 (1989). q
Nagarajan, R.; Ganesh,
K. Block Copolymer Self-Assembly in Selective Solvents: Theory of
Solubilization in Spherical Micelles. Macromolecules
22, 4312-4325 (1989). q
Nagarajan, R.; Ganesh,
K. Solubilization in Spherical Block Copolymer Micelles: Scaling Analysis Based
on Star Model. Journal
of Chemical Physics 98, 7440-7450 (1993). q
Nagarajan, R. Solubilization of
Hydrophobic Substances by Block Copolymer Micelles in Aqueous Solutions. In
SOLVENTS AND SELF-ORGANIZATION OF POLYMERS, NATO Advanced Study Institute
Series E. Vol. 327, Webber, S.E.; Munk, P.; Tuzar, Z. (Eds.), Kluwer
Academic Publishers, Dordrecht, The Netherlands
(1996) p.121-165. q
Nagarajan, R.; Ganesh,
K. A Comparison of Solubilization of Hydrocarbons in Diblock
and Triblock Copolymer Micelles. Journal
of Colloid and Interface Science 184, 489-499 (1996). q
Nagarajan, R. Solubilization of
Hydrocarbons and Resulting Aggregate Shape Transitions in Aqueous Solutions
of Pluronic (PEO-PPO-PEO) Block Copolymers. Colloids
and Surfaces B. Biointerfaces 16, 55-72
(1999). q
Nagarajan, R. Solubilization of
"Guest" Molecules into Polymeric Aggregates. Polymers
for Advanced Technologies 12, 23-43 (2001). Related Graduate
Student Thesis Ø
Kailasam, Ganesh (Ph.D. 91) "Molecular
Self Assembly of Block Copolymers”
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Solubilization of Benzene in Diblock
PEO-PPO Copolymer Micelles Formed In Aqueous Solution |
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NO SOLUBILIZATE |
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Schematic representation of a spherical micelle containing the solubilizate. The red lines denote solvent-incompatible PPO block, while the blue lines refer to the solvent-compatible PEO block. The solvent water molecules are not shown in the figure. The solubilizate benzene molecules are shown to be present within the core region only as a solution with the PPO blocks. |
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The contour plot displays the
distribution of size (aggregation number of block copolymer molecules in a
spherical micelle) and composition (volume fraction of the solubilizate
benzene in the micelle core). The
point enclosed by the closed curves corresponds to the most populous
micelles, that is, those aggregates whose concentration in the solution is
the largest. The three contour lines surrounding this point are the loci of
micellar sizes and compositions, corresponding to which the micellar
concentrations are respectively 1, 2, and 3 orders of magnitude
smaller compared to the concentration of the most populous micelles. In other
words, the contours enclose the size and compositions of 90, 99 and 99.9
percent of aggregates, respectively, suggesting that both size and
composition dispersions are very narrow. |
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Solubilizate-Induced
Aggregate Structural Transitions of Pluronic
PEO-PPO-PEO Block Copolymers |
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Equilibrium aggregate morphologies generated
by various Pluronic block copolymers in the absence of any solubilizate and
in the presence of hexane, cyclohexane, toluene and benzene as the solubilizates. The equilibrium structures are those that
are predicted to occur in the limit of saturation solubilization of the
hydrocarbons. The horizontal lines denote lamellar aggregates, the honeycomb
represents cylindrical aggregates and the shaded areas refer to spherical
aggregates. For example, P104 which forms
spherical micelles will transform into cylinders and eventually to lamellar
aggregates when benzene is solubilized. |
