Doubly-grafted copolymers with hydrophilic and thermosensitive side chains: Thermosensitivity and complexation with surfactants

作者：Daktiloudis Aris; Chronaios Anastasios; Mavriki Niki; Iatridi Zacharoula; Bokias Georgios^*

来源：Journal of Colloid and Interface Science, 2014, 430: 293-301.

DOI：10.1016/j.jcis.2014.05.066

• Doubly grafted polyanions
• N,N,N,N-dodecyltrimethylammonium chloride
• Surfactant/polymer complexation
• Poly(N,N-dimethylacrylamide)
• Poly(N-isopropylacrylamide)
• Core-corona nanoparticles
• Thermosensitivity

The behavior in aqueous solution of the doubly-grafted anionic polyelectrolyte poly(sodium 2-acrylamido-2-methylpropanesulfonate-co-sodium acrylate-)-g-poly(N-isopropylacry-lamide)-g-poly(N,N-dimethylacrylamide), P(AMPSNa-co-ANa)-g-PNIPAM-g-PDMAM, was compared to that of the single-grafted anionic polyelectrolyte poly(sodium 2-acrylamido-2-methylpropanesulfonate-co-sodium acrylate)-g-poly (N-isopropylacrylamide), P(AMPSNa-co-ANa)-g-PNIPAM. The investigation through turbidimetry, pyrene fluorescence probing, viscometry and dynamic light scattering revealed that the existence of the hydrophilic poly(N,N-dimethylaciylamide), PDMAM, side chains in the doubly-grafted copolymer P(AMPSNa-co-ANa)-g-PNIPAM-g-PDMAM did not perturb the thermoresponsiveness of the poly(N-isopropylacrylamide), PNIPAM, side chains, but favoured the stabilization in water of the core-corona nanoparticles, formed upon heating the aqueous solution above the Lower Critical Solution Temperature (LCST) of PNIPAM chains. In a similar manner, the complexes formed between the cationic surfactant N,N.N,N-dodecyltrimethylammonium chloride. DTAC, and the oppositely charged backbone of the doubly-grafted copolymer P(AMPSNa-co-ANa)-g-PNIPAM-g-PDMAM were stabilized in water by the PDMAM side chains. Thus, phase separation was prevented upon heating the aqueous solution above LCST. Moreover, the H-1 NMR study revealed that the fraction of PNIPAM chains forming solid-like aggregates at high temperature increased substantially in the presence of DTAC, as a consequence of the net charge decrease of the backbone due to the polymer/DTAC complexation.

• 出版日期2014-9-15