Self-assembly of a semi-fluorinated diblock copolymer in a selective solvent

Dilru R. Ratnaweera, Umesh M. Shrestha, Naresh Osti, Chung Mien Kuo, Stephen Clarson, Ken Littrell, Dvora Perahia

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

The self-assembly of a highly incompatible siloxane containing semi-fluorinated diblock copolymer, polytrifluoro propyl methylsiloxane-b- polystyrene (SiF-PS), in toluene, a selective solvent for polystyrene, was studied using Small Angle Neutron Scattering. Incompatibility is often enhanced by inserting fluorinated segments into one of the blocks and as a result not only the interchain interactions are changed but also the rigidity of the blocks. Herein the incorporation of siloxane into the backbone of a semi-fluorinated block maintains its flexibility and allows separation of the effects of direct interactions due to fluorine atoms from those of rigidity. Measurements were carried out in dilute solutions below 1 wt%, at volume fractions SiF ranging from 0.0 to 0.5. The high incompatibility of the SiF block drives aggregation at low volume fractions of the SiF block, where spherical core-Gaussian shell aggregates are detected at SiF = 0.16. In the symmetric SiF-PS complex fluid, elongated micelles were observed. The micelles exhibited unique temperature stability in comparison with the aggregates formed by diblock-copolymers in the lower segregation regime. As the temperature increases the micelles dissociate into free chains to form unimolecular micelles.

Original languageEnglish
Pages (from-to)2176-2184
Number of pages9
JournalSoft Matter
Volume8
Issue number7
DOIs
StatePublished - Feb 21 2012

Fingerprint

Dive into the research topics of 'Self-assembly of a semi-fluorinated diblock copolymer in a selective solvent'. Together they form a unique fingerprint.

Cite this