Session N29: Block Copolymers II
8:00 AM–10:48 AM, Wednesday, March 23, 2005
LACC Room: 504
Sponsoring Unit:
DPOLY
Chair: Thomas Epps, NIST
Abstract ID: BAPS.2005.MAR.N29.10
Abstract: N29.00010 : The Effect of Counterion Valency and Solvent Properties on Charged Amphiphilic Triblock Copolymer Assembly into Disks, Cylinders, or Spheres
9:48 AM–10:00 AM
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Abstract 
Authors:
Zhibin Li
(Material Science and Engineering, University of Delaware)
Zhiyun Chen
(Department of Chemistry, Washington University in Saint Louis)
Honggang Cui
Kelly Hales
(Material Science and Engineering, University of Delaware)
Kai Qi
Karen Wooley
(Department of Chemistry, Washington University in Saint Louis)
Darrin Pochan
(Material Science and Engineering, University of Delaware)
Amphiphilic triblock copolymer with one charged/ion-containing block, polystyrene-b-polymethacrylate-b-polyacrylic acid (PS-PMA-PAA), was studied in a water/THF cosolvent system. By adding an amine-based divalent counterion, polymeric disc micelles were formed. Discs or cylinders can be purposefully formed by choosing the type and amount of the divalent counterions in the system. In comparison, systems without counterion or with monovalent amine counterions will also be discussed. In addition to the counterion effect, the charges and the ionization along the PAA chain can also be tuned by changing the water ratio in the solvent system. This PAA tunability through counterions and solvent content allows one to direclty tune the micellar structure formed during assembly. The system was studied using dynamic light scattering (DLS), transmission electron microscopy (TEM), cryogenic transmission electron microscopy (cryo-TEM), and small angle neutron scattering.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2005.MAR.N29.10