 |
HALathon : 25 mai - 19 juin 2021 |  |
Journal articles
Intramolecular micellization and nanopatterning in pH- and thermo-responsive molecular brushes
Abstract : Conformational transitions and nanoscale self-organization triggered in double pH- and thermo-responsive molecular brushes by varying environmental conditions are studied by means of analytical mean-field theory and numerical Scheutjens–Fleer self-consistent field modelling. Such molecular brushes are composed of multiple thermo-responsive side chains end-grafted onto the main chain (backbone) and are capable of acquiring ionic charges via reversible (de)protonation of the monomer units. Competition of long-range Coulomb repulsion with short-range solvophobic interactions leads to complex patterns in the intramolecular self-organization of molecular brushes. In particular, we observed formation of pearl necklace-like structures with multiple dense nanodomains formed by weakly ionized collapsed side chains and stabilized by a fraction protruding into the solution and strongly ionized ones. Such structures are thermodynamically stable in a certain parameter range and can be termed as intramolecular micelles. The stimuli-induced intramolecular nanopatterning occurs via a sequence of quasi-first order phase transitions corresponding to splitting/fusion of collapsed domains accompanied by jumps in the average degree of ionization and macromolecular dimensions. A re-entrant sequence of transitions is observed when the salt concentration is used as a control parameter. These theoretical predictions provide guidelines for design of smart unimolecular devices, for example multicompartment nanocarriers of active substances or nanosensors.
https://hal-univ-pau.archives-ouvertes.fr/hal-02429714
Contributor : Sylvie Blanc <>
Submitted on : Monday, January 6, 2020 - 6:10:43 PM
Last modification on : Tuesday, February 2, 2021 - 2:58:06 PM
Contributor : Sylvie Blanc <>
Submitted on : Monday, January 6, 2020 - 6:10:43 PM
Last modification on : Tuesday, February 2, 2021 - 2:58:06 PM