resumo
In this paper, we develop a new coarse-grained model, under the MARTINI framework, for Pluronic block copolymers that is able to describe the self-assembly mechanism and reproduce experimental micelle sizes and shapes. Previous MARTINI-type Pluronic models were unable to produce realistic micelles in aqueous solution, and thus our model represents a marked improvement over existing approaches. We then applied this model to understand the effects of polymer structure on the cloud point temperature measured experimentally for a series of Pluronics, including both normal and reverse copolymers. It was observed that high polyoxypropylene glycol content leads to dominant hydrophobic interactions and a lower cloud point temperature, while high hydrophilic polyoxyethylene glycol content shields the micelles against aggregation and hence leads to a higher cloud point temperature. As the concentration increases, the effect of polymer architecture (normal versus reverse) starts to dominate, with reverse Pluronics showing a lower cloud point temperature. This was shown to be due to the increased formation of cross-links between neighboring micelles in these systems, which promote micelle aggregation. Our results shed new light on these fascinating systems and open the door to increased control of their thermal responsive behavior.
palavras-chave
COARSE-GRAINED MODEL; POLY(ETHYLENE OXIDE); DYNAMICS SIMULATIONS; FORCE-FIELD; POLY(PROPYLENE OXIDE); AQUEOUS-SOLUTIONS; BLOCK-COPOLYMERS; IONIC LIQUIDS; COMPUTER-SIMULATION; TEMPLATED SYNTHESIS
categoria
Chemistry; Science & Technology - Other Topics; Materials Science
autores
Perez-Sanchez, G; Vicente, FA; Schaeffer, N; Cardoso, IS; Ventura, SPM; Jorge, M; Coutinho, JAP
nossos autores
Filipa Alexandra André Vicente
Estudante de doutoramento
Germán Pérez-Sánchez
Investigador Júnior
Inês S. Cardoso
Estudante de doutoramento
Nicolas Schaeffer
Investigador Auxiliar
Sónia Patrícia Marques Ventura
Professor AuxiliarGrupos
G4 - Materiais Renováveis e Economia Circular
G5 - Materiais Biomiméticos, Biológicos e Vivos
G6 - Materiais Virtuais e Inteligência Artificial
Projectos
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2019)
Projeto de Investigação Exploratória: Sónia Patricia Marques Ventura (IF/00402/2015)
Battery Recycling – Achieving Rare Earth Separation (BATRES)
agradecimentos
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, FCT ref. UID/CTM/50011/2019, financed by national funds through the FCT/MCTES, and when appropriate cofinanced by FEDER under the PT2020 Partnership Agreement. The authors are also grateful for the national fund through the Portuguese Foundation for Science and Technology (FCT) for the doctoral grant SFRH/BD/101683/2014 of F.A.V. S.P.M.V. acknowledges FCT for the Contract IF/00402/2015 under the Investigador FCT 2015. G.P.S. acknowledges the research contract under Project CENTRO-01-0145-FEDER-000005: SusPhotoSolutions: SolucOes Fotovoltaicas Susten6veis. N.S. would like to acknowledge financial support from the BATREARES project (ERA-MIN/0001/2015) funded by ADEME and FCT.