Block Copolymers Featuring Highly Photostable Photoacids Based on Vinylnaphthol: Synthesis and Self-Assembly.
Macromol Rapid Commun
; 41(6): e1900607, 2020 Mar.
Article
in En
| MEDLINE
| ID: mdl-32037620
ABSTRACT
The synthesis of a photoresponsive amphiphilic diblock quarterpolymer containing 5-vinyl-1-naphthol (VN) as a photostable photoacidic comonomer is presented. The preparation is realized via a sequential reversible addition fragmentation chain transfer (RAFT) polymerization starting from a nona(ethylene glycol) methyl ether methacrylate (MEO9 MA/"O") hydrophilic block, which is then used as a macro-RAFT agent in the terpolymerization of styrene (S), 2-vinylpyridine (2VP), and TBS-protected VN (tVN). The terpolymerization proceeds in a controlled fashion and two diblock quarterpolymers, P(Om )-b-P(Sx -co-2VPy -co-VNz ), with varying functional comonomer compositions are prepared. These diblock quarterpolymers form spherical core-corona micelles in aqueous media according to dynamic light scattering (DLS) and cryogenic transmission electron microscopy (cryo-TEM). Upon irradiation, the photoacids within the micellar core experience a drastic increase in acidity causing a proton transfer from the photoacid to neighboring 2VP units. As a result, the hydrophilic/hydrophobic balance of the entire assembly is shifted, and the encapsulated cargo is released.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Polymers
/
Naphthols
Language:
En
Journal:
Macromol Rapid Commun
Year:
2020
Document type:
Article
Affiliation country:
Germany