Colloid and Polymer Science

, Volume 295, Issue 8, pp 1343–1349 | Cite as

Thermoresponsive behavior of poly(N-isopropylacrylamide)s with dodecyl and carboxyl terminal groups in aqueous solution: pH-dependent cloud point temperature

  • Juraj Škvarla
  • Rahul K. Raya
  • Mariusz Uchman
  • Jiří Zedník
  • Karel Procházka
  • Vasil M. Garamus
  • Anastasia Meristoudi
  • Stergios Pispas
  • Miroslav Štěpánek
Invited Article


It was recently reported that poly(N-isopropyl acrylamide) (PNIPAm) polymers synthesized by RAFT polymerization using S-1-dodecyl-S′-(α,α′-dimethyl-α′′-acetic acid)trithiocarbonate as a chain transfer agent form micelles in aqueous solutions with the core of hydrophobic terminal dodecyl groups and the corona of PNIPAm chains with carboxylic groups at the periphery, the ionization of which prevents the micelles from phase separation above the lower critical solution temperature of PNIPAm in water (Langmuir 30:7986–7992). In this paper, we study the pH- and ionic strength-dependence of the aggregation behavior of two HOOC-PNIPAm-C12 polymers, differing in the degree of polymerization, in aqueous solutions. We show that the cloud point temperature (CPT) of HOOC-PNIPAm-C12 can be shifted up to several tens of K by changing pH of the solution. The aggregation of the PNIPAms above the CPT can be efficiently accelerated by screening electrostatic repulsion between PNIPAm micelles by changing ionic strength of the solution.


Thermoresponsive polymers Aggregation Self-assembly Small-angle scattering Micelles 



M. Š. acknowledges the support from the Czech Science Foundation (Grant No. 14-11516S) and from the Ministry of Education, Youth and Sports of the Czech Republic (Operational Programme Research, Development and Education: “Excellent Research Teams”, Project No. CZ.02.1.01/0.0/0.0/15_003/0000417 – CUCAM). The support of Clement Blanchet (EMBL) is kindly acknowledged.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

396_2017_4067_MOESM1_ESM.pdf (403 kb)
ESM 1 (PDF 402 kb)


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Copyright information

© Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  • Juraj Škvarla
    • 1
  • Rahul K. Raya
    • 1
  • Mariusz Uchman
    • 1
  • Jiří Zedník
    • 1
  • Karel Procházka
    • 1
  • Vasil M. Garamus
    • 2
  • Anastasia Meristoudi
    • 3
  • Stergios Pispas
    • 3
  • Miroslav Štěpánek
    • 1
  1. 1.Department of Physical and Macromolecular Chemistry, Faculty of ScienceCharles University in PraguePrague 2Czech Republic
  2. 2.Helmholtz-Zentrum GeesthachtCentre for Materials and Coastal ResearchGeesthachtGermany
  3. 3.Theoretical & Physical Chemistry InstituteNational Hellenic Research FoundationAthensGreece

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