resumo
Symmetrical poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEG-PPG-PEG) triblock copolymer with 82.5% PEG as the hydrophilic end blocks, and PPG as the hydrophobic middle block, was chosen to study the effect of ionic liquids (ILs) on the critical micellization temperature (CMT) of block copolymers in aqueous solution. In the present work, cholinium-based ILs were chosen to explore the effect of the anions on the copolymer CMT using fluorescence spectroscopy, dynamic light scattering (DLS), viscosity (Z), FT-IR spectroscopy, nuclear magnetic resonance (NMR), and direct visualization of the various self-assembled nanostructures by scanning electron microscopy (SEM). The result suggests that ILs have the ability to decrease the CMT of the aqueous copolymer solution which is dependent on the nature of the anions of the ILs. The present study reveals that the hydrophobic part PPG of the copolymer has more influence on this behavior than the PEG hydrophilic part.
palavras-chave
AMPHIPHILIC BLOCK-COPOLYMERS; PPG-PEG-PPG; BIPHASIC SYSTEMS; AGGREGATION BEHAVIOR; TETRAETHYLENE GLYCOL; POLYETHYLENE-GLYCOL; FTIR SPECTROSCOPY; PHASE-SEPARATION; MICELLAR SYSTEMS; WATER
categoria
Chemistry; Physics
autores
Khan, I; Umapathi, R; Neves, MC; Coutinho, JAP; Venkatesu, P
nossos autores
Imran Khan
Bolseiro de pós-Doutoramento
Márcia Carvalho Neves
Investigador AuxiliarGrupos
G4 - Materiais Renováveis e Economia Circular
G5 - Materiais Biomiméticos, Biológicos e Vivos
agradecimentos
We acknowledge the financial support from the Department of Science and Technology (DST), New Delhi, India (grant no. SB/SI/PC-109/2012). This work was developed in the scope of the project CICECO - Aveiro Institute of Materials (ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and co-financed by FEDER under the PT2020 Partnership Agreement. Author I. Khan acknowledges FCT exploratory project EXPL/QEQ-PRS/0224/2013 and postdoctoral grants SFRH/BPD/76850/2011.