(553g) Self-Assembly and Phase Behavior of Hyperbranched Copolymers | AIChE

(553g) Self-Assembly and Phase Behavior of Hyperbranched Copolymers


Chapman, W. - Presenter, Rice University
Zhang, Y., Rice University
Xi, S., Rice University
We study the phase behavior of associating dendrimers in explicit solvents using
classical density functional theory. The existence of association enables uptake of solvent inside the dendrimer even for unfavorable Lennard Jones interaction between
solvent and dendrimer. Depending on the distributions of associating sites, the den-
drimer conformation can be either dense-core or dense-shell. The conformation of the
associating dendrimer is greatly affected by temperature. Due to the interplay between
association interaction and Lennard Jones attractions, we find lower critical solution
temperature (LCST) behavior of dendrimer conformation and study how it changes as
the dendrimer size or solvent size changes. The dendrimer in our study displays no
LCST behavior at low generations and it has a maximum LCST at G4. Moreover, in-
creasing the solvent chain length decreases the LCST. For solvents with self-association,
the competition between solvent-solvent association and solvent-dendrimer association
also tends to reduce the LCST. Qualitatively consistent with experiments, our results
provide insight into the molecular mechanism of LCST behavior of associating den-