Korea-Australia Rheology Journal

, Volume 31, Issue 4, pp 249–254 | Cite as

Rheological characterization of BCC and FCC structures in aqueous diblock copolymer liquid crystals

  • Connor S. Valentine
  • Lynn M. WalkerEmail author


Low molecular weight, amphiphilic diblock copolymers in selective solvent exhibit complex phase behavior and macroscopic properties that affect the processing and application of these materials. The mechanical properties of the crystalline phases seen in concentrated solutions are dependent on nanoscale structure and sample history. The goal of this study is to characterize macroscopic properties and thermal history effects of lyotropic liquid crystals in aqueous diblock copolymer solutions. Rheological temperature ramps are used to characterize three aqueous concentrations of diblock copolymer [Brij-58®, C16H33(CH2CH2O)20OH]. Between these three samples the order-disorder transitions (ODTs) for BCC and FCC are accessible in addition to the order-order transition (OOT) between BCC and FCC. These transitions are distinguished using rheology. Frequency sweeps are performed across a range of temperatures and parameterized with a loglinear fit to the phase angle data to extract the crossover frequency. We find that a single frequency sweep does not distinguish BCC and FCC structures. By normalizing the temperature with respect to the ODT, we are able to use a series of frequency sweeps to distinguish characteristic trends in the response of BCC and FCC structures to thermal history.


liquid crystals block copolymers viscoelasticity rheology hysteresis 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.



The authors would like to thank Mahesh Mahanthappa and Ashish Jayaraman at the University of Minnesota for providing access to the pre-print phase diagram of Brij- 58® and water in addition to complementary SAXS data.


  1. Bang, J. and T. Lodge, 2003, Mechanisms and epitaxial relationships between close-packed and BCC lattices in block copolymer solutions, J. Phys. Chem. B 107, 12071–12081.CrossRefGoogle Scholar
  2. Eiser, E., F. Molino, and G. Porte, 2000a, Correlation between the viscoelastic properties of a soft crystal and its microstructure, Eur. Phys. J. E 2, 39–46.CrossRefGoogle Scholar
  3. Eiser, E., F. Molino, G. Porte, and X. Pithon, 2000b, Flow in micellar cubic crystals, Rheol. Acta 39, 201–208.CrossRefGoogle Scholar
  4. Garti, N., P. Somasundaran, and R. Mezzenga, 2012, Self-Assembled Supramolecular Architectures: Lyotropic Liquid Crystals, John Wiley & Sons, Hoboken.CrossRefGoogle Scholar
  5. Hamley, I., 2005, Block Copolymers in Solution: Fundamentals and Applications, John Wiley & Sons, Chichester.CrossRefGoogle Scholar
  6. Jayaraman, A., D.Y. Zhang, B.L. Dewing, and M.K. MahanthappaMahanthappa, 2019, Path-dependent preparation of complex micelle packings of a hydrated diblock oligomer, ACS Cent. Sci. 5, 619–628.CrossRefGoogle Scholar
  7. Jones, J.L. and T.C.B. McLeish, 1995, Rheological response of surfactant cubic phases, Langmuir 11, 785–792.CrossRefGoogle Scholar
  8. LaFollette, T.A. and L.M. Walker, 2011, Structural and mechanical hysteresis at the order-order transition of block copolymer micellar crystals, Polymers 3, 281–298.CrossRefGoogle Scholar
  9. Lodge, T.P., B. Pudil, and K.J. Hanley, 2002, The full phase behavior for block copolymers in solvents of varying selectivity, Macromolecules 35, 4707–4717.CrossRefGoogle Scholar
  10. May, A., K. Aramaki, and J.M. Gutiérrez, 2011, Phase behavior and rheological analysis of reverse liquid crystals and W/I2 and W/H2 gel emulsions using an amphiphilic block copolymer, Langmuir 27, 2286–2298.CrossRefGoogle Scholar
  11. Mezzenga, R., C. Meyer, C. Servais, A.I. Romoscanu, L. Sagalowicz, and R.C. Hayward, 2005, Shear rheology of lyotropic liquid crystals: A case study, Langmuir 21, 3322–3333.CrossRefGoogle Scholar
  12. Mohan, P.H. and R. Bandyopadhyay, 2008, Phase behavior and dynamics of a micelle-forming triblock copolymer system, Phys. Rev. E 77, 041803.CrossRefGoogle Scholar
  13. Park, M.J., J. Bang, T. Harada, K. Char, and T.P. Lodge, 2004, Epitaxial transitions among FCC, HCP, BCC, and cylinder phases in a block copolymer solution, Macromolecules 37, 9064–9075.CrossRefGoogle Scholar
  14. Park, M.J., K. Char, J. Bang, and T.P. Lodge, 2005, Interplay between cubic and hexagonal phases in block copolymer solutions, Langmuir 21, 1403–1411.CrossRefGoogle Scholar
  15. Pozzo, D.C., K.R. Hollabaugh, and L.M. Walker, 2005, Rheology and phase behavior of copolymer-templated nanocomposite materials, J. Rheol. 49, 759–782.CrossRefGoogle Scholar
  16. Rodríguez-Abreu, C., M. García-Roman, and H. Kunieda, 2004, Rheology and dynamics of micellar cubic phases and related emulsions, Langmuir 20, 5235–5240.CrossRefGoogle Scholar
  17. Speziale, C., R. Ghanbari, and R. Mezzenga, 2018, Rheology of ultraswollen bicontinuous lipidic cubic phases, Langmuir 34, 5052–5059.CrossRefGoogle Scholar
  18. Walz, M., M. Wolff, N. Voss, H. Zabel, and A. Magerl, 2010, Micellar crystallization with a hysteresis in temperature, Langmuir 26, 14391–14394.CrossRefGoogle Scholar

Copyright information

© The Korean Society of Rheology and Springer 2019

Authors and Affiliations

  1. 1.Department of Chemical EngineeringCarnegie Mellon UniversityPittsburghUSA

Personalised recommendations