Jump to main content
Jump to site search

Issue 9, 2017, Issue in Progress
Previous Article Next Article

Thermo-reversible sol–gel transition of aqueous solutions of patchy polymers

Author affiliations

Abstract

While aqueous solutions of several amphiphilic thermo-reversible polymers show gelation upon heating, there are fewer examples of polymer solutions that exhibit gelation when cooled. This paper reports an interesting phenomenon of abrupt thermoreversible gelation of aqueous solutions of a hydrophobically modified polymer upon cooling. A high molecular weight precursor copolymer (PCP, Image ID:c6ra27030a-t1.gif) of N,N-dimethylacrylamide (70 mol%) and acrylic acid (30 mol%) was modified by reacting 10 mol% of the acrylic acid groups with n-dodecyl amine to form a hydrophobically modified copolymer (HMCP). The composition of the copolymer was ascertained using NMR spectroscopy. Cooling the solution of PCP at a controlled rate resulted in a gradual increase in its low shear viscosity as dictated by the flow activation energy. In contrast, cooling the solution of HMCP under identical conditions resulted in an abrupt and large non-Arrhenius increase in viscosity at a specific transition temperature, which decreased with decrease in polymer concentration. Fluorescence measurements and dynamic light scattering data showed that abrupt gelation happened upon cooling, when polymer coils percolate accompanied with concomitant transition in chain conformation from compact micellar coils formed by intra-chain hydrophobic associations to swollen polymer coils connected by inter-chain hydrophobic interactions.

Graphical abstract: Thermo-reversible sol–gel transition of aqueous solutions of patchy polymers

Back to tab navigation

Supplementary files

Publication details

The article was received on 19 Nov 2016, accepted on 25 Dec 2016 and first published on 17 Jan 2017


Article type: Paper
DOI: 10.1039/C6RA27030A
Citation: RSC Adv., 2017,7, 5101-5110
  • Open access: Creative Commons BY license
  •   Request permissions

    Thermo-reversible sol–gel transition of aqueous solutions of patchy polymers

    I. A. Parmar, A. S. Shedge, M. V. Badiger, P. P. Wadgaonkar and A. K. Lele, RSC Adv., 2017, 7, 5101
    DOI: 10.1039/C6RA27030A

    This article is licensed under a Creative Commons Attribution 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.

    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