LC nanocomposites: induced optical singularities, managed nano/micro structure, and electrical conductivity

V. V. Ponevchinsky; A. I. Goncharuk; V. G. Denisenko; N. I. Lebovka; L. N. Lisetski; M. I. Nesterenko; V. D. Panikarskaya; M. S. Soskin

doi:10.1117/12.2000064

5 March 2013 LC nanocomposites: induced optical singularities, managed nano/micro structure, and electrical conductivity

V. V. Ponevchinsky, A. I. Goncharuk, V. G. Denisenko, N. I. Lebovka, L. N. Lisetski, M. I. Nesterenko, V. D. Panikarskaya, M. S. Soskin

Author Affiliations +

Proceedings Volume 8637, Complex Light and Optical Forces VII; 86370V (2013) https://doi.org/10.1117/12.2000064
Event: SPIE OPTO, 2013, San Francisco, California, United States

Abstract

Microstructure, phase transitions, electrical conductivity, and optical and electrooptical properties of multiwalled carbon nanotubes (NTs), dispersed in the cholesteric liquid crystal (cholesteryl oleyl carbonate, COC), nematic 5CB and their mixtures, were studied in the temperature range between 255 K and 363 K. The relative concentration X=СОС/(СОС+5CB) was varied within 0.0-1.0. The concentration C of NTs was varied within 0.01-5% wt. The value of X affected agglomeration and stability of NTs inside СОС+5CB. High-quality dispersion, exfoliation, and stabilization of the NTs were observed in COC solvent (“good” solvent). From the other side, the aggregation of NTs was very pronounced in nematic 5CB solvent (“bad” solvent). The dispersing quality of solvent influenced the percolation concentration C_p, corresponding to transition between the low conductive and high conductive states: e.g., percolation was observed at C_p≈1% and C_p≈0.1% for pure COC and 5CB, respectively. The effects of thermal pre-history on the heating-cooling hysteretic behavior of electrical conductivity were studied. The mechanism of dispersion of NTs in COC+5CB mixtures is discussed. Utilization of the mixtures of “good” and “bad” solvents allowed fine regulation of the dispersion, stability and electrical conductivity of LC+NTs composites. The mixtures of COC and 5CB were found to be promising for application as functional media with controllable useful chiral and electrophysical properties.

Citation Download Citation

V. V. Ponevchinsky, A. I. Goncharuk, V. G. Denisenko, N. I. Lebovka, L. N. Lisetski, M. I. Nesterenko, V. D. Panikarskaya, and M. S. Soskin "LC nanocomposites: induced optical singularities, managed nano/micro structure, and electrical conductivity", Proc. SPIE 8637, Complex Light and Optical Forces VII, 86370V (5 March 2013); https://doi.org/10.1117/12.2000064

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available