Tuning Nanostructure Morphology and Gold Nanoparticle "Locking" of Multi-Responsive Amphiphilic Diblock Copolymers
Document Type
Article
Publication Date
4-28-2009
Department
Polymers and High Performance Materials
Abstract
Reversible addition-fragmentation chain transfer (RAFT) polymerization was utilized to prepare multiresponsive, self-assembling amphiphilic poly [(N,N-dimethylaminoethyl methacrylate)(x)-b-(N-isopropylacrylamide)(y)] (DMAEMA(x)-b-NIPAM(y)). Controlling block lengths, solution pH, and NaCl concentration to elicit changes in the hydrophilic mass fraction resulted in specific. morphological changes upon thermally induced assembly. At y = 102 (68 wt % DMAEMA), DMAEMA(165)-b-NIPAM(102) Copolymers self-assemble into simple core-shell micelles (58 nm). Increasing y to 202 (48 wt % DMAEMA) leads to a mixture of spherical micelles (78 nm) and worm-like micelles (D = 50-100 nm, L = 400-500 nm). Further increasing y to 435 (36 wt % DMAEMA) produces vesicular structures (179 nm). Significantly, reversible assembly of these nanostructures from the present stimuli-responsive diblock copolymers can be accomplished directly in aqueous media without the necessity of dialysis or manipulation with cosolvents. Additionally, the associated nanostructures can be shell cross-linked above the critical aggregation temperature via the in situ formation of gold nanoparticles yielding assemblies with long-term aqueous stability.
Publication Title
Macromolecules
Volume
42
Issue
8
First Page
2958
Last Page
2964
Recommended Citation
Smith, A. E.,
Xu, X.,
Abell, T. U.,
Kirkland, S. E.,
Hensarling, R. M.,
McCormick, C. L.
(2009). Tuning Nanostructure Morphology and Gold Nanoparticle "Locking" of Multi-Responsive Amphiphilic Diblock Copolymers. Macromolecules, 42(8), 2958-2964.
Available at: https://aquila.usm.edu/fac_pubs/1174