Journal article
Light-triggered unfolding of single linear molecular bottlebrushes from compact globular to wormlike nano-objects in water
Polymer chemistry, v 8(17), pp 2702-2712
07 May 2017
Abstract
This article reports on the light-triggered unfolding of single stimuli-responsive linear molecular bottle-brushes, composed of either homografted poly(methoxydi(ethylene glycol) acrylate-co-o-nitrobenzyl acrylate) (P(DEGMA-co-NBA)) or heterografted poly(ethylene oxide) (PEO) and poly(o-nitrobenzyl acrylate) (PNBA) side chains, from compact globular to wormlike shapes in an effort to mimic the triggered unravelling of proteins such as the von Willebrand factor and talin. PDEGMA is a thermosensitive polymer with a lower critical solution temperature (LCST) of 38 degrees C in water. The hydrophobic o-nitrobenzyl group can be cleaved by UV irradiation, yielding a hydrophilic carboxylic acid group. This increased the LCST or solubility of the corresponding side chains in water, triggering the shape transitions of brush molecules from globular to wormlike. The brushes were synthesized by a "grafting to" method using the copper-catalyzed cycloaddition of alkyne end-functionalized side chain polymers and an azide-bearing backbone polymer. For 0.2 mg g(-1) P(DEGMA-co-NBA) molecular brushes in water, a dynamic light scattering study showed that the apparent hydrodynamic size decreased with increasing temperature, with the LCST occurring at 23 degrees C. Atomic force microscopy revealed that the brush molecules changed from an extended wormlike morphology at 4 degrees C to compact globular nano-objects upon heating to 30 degrees C. UV irradiation of the solution at 30 degrees C for 70 min unfolded the brushes to an extended wormlike conformation. For heterografted PEO/PNBA molecular brushes, the collapsed compact nano-objects in water, stabilized by PEO side chains, were prepared by gradually adding a DMF solution of brushes into water, followed by dialysis to remove DMF. Similarly, upon UV irradiation, the brush molecules changed to wormlike conformations.
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Details
- Title
- Light-triggered unfolding of single linear molecular bottlebrushes from compact globular to wormlike nano-objects in water
- Creators
- Daniel M. Henn - University of Tennessee at KnoxvilleC. Maggie Lau - University of Tennessee at KnoxvilleChristopher Y. Li - Drexel UniversityBin Zhao - University of Tennessee at Knoxville
- Publication Details
- Polymer chemistry, v 8(17), pp 2702-2712
- Publisher
- Royal Soc Chemistry
- Number of pages
- 11
- Grant note
- 1607076 / Division Of Materials Research; National Science Foundation (NSF); NSF - Directorate for Mathematical & Physical Sciences (MPS) DMR-1607076; DMR-1308958 / NSF; National Science Foundation (NSF)
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Materials Science and Engineering
- Web of Science ID
- WOS:000400337000014
- Scopus ID
- 2-s2.0-85021714033
- Other Identifier
- 991019168586604721
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Collaboration types
- Domestic collaboration
- Web of Science research areas
- Polymer Science