2007 APS March Meeting
Volume 52, Number 1
Monday–Friday, March 5–9, 2007;
Denver, Colorado
Session W24: Microphysical Properties of Block Copolymer Aggregates, Going Beyond Structure
2:30 PM–5:18 PM,
Thursday, March 8, 2007
Colorado Convention Center
Room: 201
Sponsoring
Unit:
DPOLY
Chair: Steve Hudson, National Institute of Standards and Technology
Abstract ID: BAPS.2007.MAR.W24.1
Abstract: W24.00001 : Solvated Block Copolymers as a Novel Class of Electroactive Nanostructured Polymers
2:30 PM–3:06 PM
Preview Abstract
Abstract
Author:
Richard Spontak
(North Carolina State University)
Microphase-ordered block copolymers serve as model systems to elucidate the
potential of molecular self-assembly and organic templates to fabricate
functionalized polymer materials. Both aspects are related to the
incorporation of secondary species such as low-molar-mass compounds or
nanoparticles within copolymer matrices. Since the resulting properties of
such functionalized copolymers depend on the morphology of the blend or
composite, the nonrandom distribution of such inclusions within the
copolymer matrix must be understood. Using a self-consistent field
theoretical approach, we first evaluate the segregation and interfacial
excess of low-molar-mass and nanoscale species in ordered triblock
copolymers as functions of block selectivity and inclusion size. The
predictions are found to agree with the morphology observed in a model
triblock copolymer/nanoparticle composite, suggesting a wide correspondence
in the structure-forming effect of molecular and nanoscale inclusions that
will have implications in the design of functional nanostructured polymers
such as conformable electroactive actuators. Such responsive materials,
stimulated by electric fields, are required for emergent technologies such
as microrobotics, micro air vehicles and responsive prosthetics. High
actuation strains ($>$50{\%}) are currently afforded by dielectric
elastomers at relatively high electric fields ($>$50 V/$\mu $m). In this
work, we demonstrate that incorporation of a low-volatility solvent into a
triblock copolymer yields physical networks that exhibit excellent
displacement under an external field. Ultrahigh actuation strains
($>$200{\%}) accompanied by low cyclic hysteresis are realized at
significantly reduced electric fields ($<$40 V/$\mu $m). Use of
nanostructured polymers whose properties can be tailored by varying
copolymer characteristics or blend composition represents an innovative and
tunable avenue to reduced-field actuation for advanced engineering,
biomimetic and biomedical applications.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.MAR.W24.1