Abstract
The effect of poly(ethylene glycol) (PEG) on the nonlinear viscoelasticity of Laponite suspensions containing NaCl was investigated with large amplitude oscillatory shear rheology. The molecular weight ( M w) of PEG was 4k, 10k and 35k, and the concentration of PEG was varied from 0.063 wt% to 2.4 wt%. The dynamic strain sweep showed that the nonlinearity appeared at γ 0 > 30% with a stress overshoot at γ 0 = 50–70%. The intensity ratio I 3/1 from Fourier-transform increased with γ 0 when entering the nonlinear regime and leveled off at γ 0 ≥ 100% with higher slope and constant value for the PEG of higher M w or lower concentration. I 3/1 revealed the structure difference in the suspensions induced by adsorbing PEG in the nonlinear regime. The minimum- and large-strain rate viscosities η M and η L from the Lissajous curve were found to be sensitive to the nonlinear viscoelasticity and the peak of η M and η L appeared at lower γ 0 with higher maximum following the same dependency as I 3/1 on PEG M w and concentration. The overall nonlinearity parameters N E and N V were proposed in this paper and demonstrated to reflect the difference in the Laponite suspensions with PEG more clearly and more effectively.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
