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The positional effect of stimuli-responsive units in tri-component copolymer vesicles is studied to explore variations in the host–guest properties of the assembly. We study this by placing pH-responsive diisopropylaminoethyl moieties in three distinct locations of a block copolymer assembly. In two of the three variations, these functionalities were randomly distributed in the hydrophobic or the hydrophilic domains of an amphiphilic diblock copolymer. In a third variation, this responsive functionality was incorporated as the middle block in a triblock copolymer. The results reveal that the solvent exposure of the responsive units holds the key for controlling the rate of molecular release from these polymer vesicles. The study also shows that equilibrium changes in the morphology of an assembly are not good indicators of the responsive host–guest properties of a polymer assembly.
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Molecular simulation of the shape deformation of a polymersome
Vesicles composed of diblock copolymers, or polymersomes, have proven to possess numerous applications ranging from drug delivery to catalytically driven nano-motors. The shape of a polymersome can be responsive to external stimuli, such as light or solvent. Molecular dynamics simulations reveal that the shape change upon the contraction of the inner volume of a polymersome vesicle occurs in two separate regimes—a stretching regime and a bending regime. The barrier is shown to be dependent on the solvent environment. These results suggest that tailoring the bending modulus of polymer membranes can be used as a design methodology to engineer new stimuli-responsive vesicles.
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- Award ID(s):
- 1750694
- PAR ID:
- 10145457
- Date Published:
- Journal Name:
- Soft Matter
- Volume:
- 16
- Issue:
- 13
- ISSN:
- 1744-683X
- Page Range / eLocation ID:
- 3234 to 3244
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/C9SM02165E
