Issue 20, 2016

Dilatational rheology studies on a semicrystalline ferroelectric copolymer at the air–water interface

Abstract

We report dilatational rheology studies on a Langmuir film of a ferroelectric copolymer, poly(vinylidene fluoride–trifluoroethylene) (70 : 30), under various surface pressures, temperatures and frequencies using the oscillatory barrier technique. We have employed both the Fourier transform method and Lissajous curves to extract the viscoelastic moduli corresponding to the fundamental mode and nonlinear parameters during the compression and expansion cycles, respectively. Strain sweep studies show that the dominant storage modulus increases, overshoots at 1.5% of strain and saturates beyond that; which is typical of the semicrystalline copolymer. Further, the nonlinear parameters show strain hardening of the film. Fixing the angular frequency and at a small strain regime, the temperature sweep studies on the film at the air–water interface provide evidence for the order–disorder phase transition with a pronounced discontinuity in dilatational moduli at 298 K which is also seen in nonlinear parameters. Frequency sweep studies show that the storage moduli are dominant over the loss moduli till a crossover point after which a reversal in this trend is observed. The crossover point is found to shift towards lower frequency and is sensitive to temperature.

Graphical abstract: Dilatational rheology studies on a semicrystalline ferroelectric copolymer at the air–water interface

Article information

Article type
Paper
Submitted
19 Dec 2015
Accepted
26 Jan 2016
First published
09 Feb 2016

RSC Adv., 2016,6, 16673-16678

Dilatational rheology studies on a semicrystalline ferroelectric copolymer at the air–water interface

C. Kumar and P. Viswanath, RSC Adv., 2016, 6, 16673 DOI: 10.1039/C5RA27184C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements