Dynamics of Nematic Liquid Crystal Elastomers
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Dynamics of Nematic Liquid Crystal Elastomers Peter Palffy-Muhoray, Kent State University, DMR 0606357 Nematic liquid crystal elastomers (NLCEs) are anisotropic rubbers that contain orientationally ordered molecules. NLCEs consist of three basic components: polymer, mesogen and crosslinker, and they can be synthesized by utilizing a custom-built spin casting device. The goals of this research are to (1) determine the elastic modulus for elastomers with different crosslink density and (2) study the stretching dynamics of these elastomers over time. 0.0 0.1 0.2 0.3 0.4 0.5 0 10 20 30 40 50 5.0% 7.5% 10.0% 12.5% S tress (kP a) S train % modulu s (kPa) 5.0 6.9 7.5 18.2 10. 0 61.8 12. 5 97.2 Elastomer stress-strain response summary. The best fit line slopes correspond to the elastic moduli listed in the table. Strain response for 7.5% crosslink density elastomer to increasing applied stress.
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Dynamics of Nematic Liquid Crystal Elastomers Peter Palffy-Muhoray , Kent State University, DMR 0606357. - PowerPoint PPT Presentation
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Dynamics of Nematic Liquid Crystal ElastomersPeter Palffy-Muhoray, Kent State University, DMR 0606357
Nematic liquid crystal elastomers (NLCEs) are anisotropic rubbers that contain orientationally ordered molecules. NLCEs consist of three basic components: polymer, mesogen and crosslinker, and they can be synthesized by utilizing a custom-built spin casting device. The goals of this research are to (1) determine the elastic modulus for elastomers with different crosslink density and (2) study the stretching dynamics of these elastomers over time.
0.0 0.1 0.2 0.3 0.4 0.5
0
10
20
30
40
50
5.0%
7.5%
10.0%
12.5%
Stre
ss (k
Pa)
Strain
% modulus (kPa)
5.0 6.9
7.5 18.2
10.0
61.8
12.5
97.2
Elastomer stress-strain response summary. The best fit line slopes correspond to the elastic moduli listed in the table.
Strain response for 7.5% crosslink density elastomer to increasing applied stress.
Michael Madison spent ten weeks conducting research funded by NSF REU and New Liquid Crystal Materials Facility (NLCMF) grants at the Liquid Crystal Institute in Kent State University. He had previously worked as an electrician for over 25 years, but after being laid off, he enrolled at a local community college and became interested in science. As an REU student at the NLCMF, with the help of graduate and postdoctoral assistants, he learned to synthesize nematic liquid crystal elastomers with different cross-link densities and elastic properties. Michael then characterized these samples by determining their elastic moduli and studying their fast and slow deformations under constant stress as a function of time. Michael will continue his pursuit of a career in science. In Fall 2010, he will enroll at Kent State University, where he has received a five year scholarship, to work towards a Bachelor of Science degree. His goal is to conduct research on artificial muscles and limbs.
Education outreach to non-traditional students
REU student Michael Madison attaching a thermostatted spin casting head (left) and weighing chemicals for synthesis (right).
Dynamics of Nematic Liquid Crystal ElastomersPeter Palffy-Muhoray, Kent State University, DMR 0606357
