Insight into the self-assembly of water-soluble perylene bisimide derivatives through a combined computational and experimental approach.
Nanoscale
; 11(34): 15917-15928, 2019 Aug 29.
Article
in En
| MEDLINE
| ID: mdl-31414112
ABSTRACT
We use a combination of computational and experimental techniques to study the self-assembly and gelation of water-soluble perylene bisimides derivatised at the imide position with an amino acid. Specifically, we study the likely structure of self-assembled aggregates of the alanine-functionalised perylene bisimide (PBI-A) and the thermodynamics of their formation using density functional theory and predict the UV-vis spectra of such aggregates using time-dependent density functional theory. We compare these predictions to experiments in which we study the evolution of the UV-Vis and NMR spectra and the rheology and neutron scattering of alkaline PBI-A solutions when gradually decreasing the pH. Based on the combined computational and experimental results, we show that PBI-A self-assembles at all pH values but that aggregates grow in size upon protonation. Hydrogel formation is driven not by aggregate growth but reduction of the aggregation surface-charge and a decrease in the colloidal stability of the aggregation with respect to agglomeration.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Nanoscale
Year:
2019
Document type:
Article