Self-assembly of dual-responsive amphiphilic POEGMA-b-P4VP-b-POEGMA triblock copolymers: effect of temperature, pH, and complexation with Cu2+

Author(s)

Zanata, Daniela de Morais ^[1] ; Felisberti, Maria Isabel ^[1]

Affiliation

^[1] Univ Campinas UNICAMP, Inst Chem, POB 6154, BR-13083970 Campinas, SP - Brazil

• Document type: Journal article
• Source: Polymer Chemistry; v. 12, n. 32 JUL 2021.
• Web of Science Citations: 0

Abstract

Amphiphilic and stimuli-responsive triblock copolymers are an important class of smart materials due to their low critical micellar concentration in solution and capacity of self-assembly into different structures depending on the environment. In this context, the synthesis of a thermo-responsive poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) macro-RAFT using S,S `-bis(alpha,alpha `-dimethylacetic acid) trithiocarbonate (CMP) as a RAFT agent, followed by copolymerization with a pH-responsive poly(4-vinyl pyridine) (P4VP) is reported. The thermo- and pH responsiveness and critical micellar concentration of the POEG(x)MA(y)-b-P4VP(z)-b-POEG(x)MA(y) copolymers in aqueous solutions were investigated by dynamic light scattering. Cryo-TEM images showed that the POEG(5)MA(24)-b-P4VP(36)-b-POEG(5)MA(24) copolymers self-assemble as spherical and interconnected micelles depending on the composition and environmental conditions. Nanostructures with a hydrodynamic radius (R-H) between 15 and 300 nm are formed. These nanostructures can encapsulate hydrophobic molecules, such as Nile red at pH >= 7 and 25 degrees C. Finally, the P4VP blocks of the triblock copolymer coordinate with Cu2+, generating a thermo- and pH-responsive nanogel whose R-H reduces from 90 to 25 nm by a thermo- or pH-induced deswelling. (AU)

• FAPESP's process: 15/25406-5 - Organizing matter: colloids formed by association of surfactants, polymers and nanoparticles
• Grantee: Watson Loh
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/24938-9 - Multiresponsive triblock copolymers based on poly(oligo(ethylene glycol) methyl ether methacrylate) and poly(4-vinylpyridine): synthesis and solution properties
• Grantee: Daniela de Morais Zanata
• Support Opportunities: Scholarships in Brazil - Doctorate