Jump to main content
Jump to site search

Issue 46, 2017, Issue in Progress
Previous Article Next Article

Micellization and gelatinization in aqueous media of pH- and thermo-responsive amphiphilic ABC (PMMA82-b-PDMAEMA150-b-PNIPAM65) triblock copolymer synthesized by consecutive RAFT polymerization

Author affiliations

Abstract

The multi-stimuli-responsive amphiphilic ABC triblock copolymer of poly(methyl methacrylate)-block-poly[N,N-(dimethylamino) ethyl methacrylate]-block-poly(N-isopropylacrylamide) (PMMA-b-PDMAEMA-b-PNIPAM) was synthesized by sequential reversible addition–fragmentation chain transfer (RAFT) polymerizations. Due to the pH- and thermo-responsive blocks of PDMAEMA and thermo-responsive blocks of PNIPAM, the copolymer solution properties can be manipulated by changing the parameters such as temperature and pH, and it formed diverse nanostructures and had gel behavior in different conditions. In detail, when the pH was below 7.3, the pKa of DMAEMA, tertiary amino groups were protonated, the polymer micellar solution like weak gel changed into free-standing gel at around 40 °C even at a low concentration of 2 wt%. Further, the gel behavior and morphology of the system were studied by rheology, turbidimetry measurements, transmission electron microscopy (TEM) and scanning electron microscopy (SEM), respectively. When the pH was above the pKa, the triblock copolymer self-assembled into diverse micellar structures including shell–core, corona–shell–core and shell–shell–core nanoparticles as the temperature increased, but no free-standing gelation. The two-step thermo-responsive behavior, corresponding to the different LCSTs of PNIPAM block and DMAEMA block, was evidenced by turbidity analysis. The assembled structures rapidly collapsed due to the enhanced hydrophobic interaction when the temperature further increased. Dynamic light scattering (DLS) was used to confirm the transitions.

Graphical abstract: Micellization and gelatinization in aqueous media of pH- and thermo-responsive amphiphilic ABC (PMMA82-b-PDMAEMA150-b-PNIPAM65) triblock copolymer synthesized by consecutive RAFT polymerization

Back to tab navigation

Supplementary files

Publication details

The article was received on 18 Apr 2017, accepted on 23 May 2017 and first published on 30 May 2017


Article type: Paper
DOI: 10.1039/C7RA04351A
Citation: RSC Adv., 2017,7, 28711-28722
  • Open access: Creative Commons BY-NC license
  •   Request permissions

    Micellization and gelatinization in aqueous media of pH- and thermo-responsive amphiphilic ABC (PMMA82-b-PDMAEMA150-b-PNIPAM65) triblock copolymer synthesized by consecutive RAFT polymerization

    Y. Huang, P. Yong, Y. Chen, Y. Gao, W. Xu, Y. Lv, L. Yang, R. L. Reis, R. P. Pirraco and J. Chen, RSC Adv., 2017, 7, 28711
    DOI: 10.1039/C7RA04351A

    This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material and it is not used for commercial purposes.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements