Dispersion of multi walled carbon nanotubes in a hydrogen bonded liquid crystal

In a newly synthesized self assembled system, namely, hydrogen bonded liquid crystal, multi walled carbon nanotubes (MWCNTs) are dispersed. This self assembly system of liquid crystal is realized by formation of hydrogen bond between levo tartaric acid and undecyloxy benzoic acid. The proposed structure is confirmed by FTIR and P-NMR studies. Thermal and electrical properties of this system dispersed with MWCNT are studied. Alignment of carbon nanotubes in the nematic phase of the self assembled system is responsible for the observation of bistable electrical states namely ON and OFF. Optical textural observations of these two states are recorded and the light intensity complexly decays and unwinding of the helix with the application of external field indicates an optical shuttering action. It is interesting to note that a small threshold value of 3.5 V/mu m is sufficient to realize an optical shutter. DSC studied reveals that the enthalpy values pertaining to liquid crystal dispersed with MWCNT is approximately two fold to that of the pure liquid crystal. Results of conductance relating to the liquid crystal with MWCNT dispersion are discussed. (C) 2010 Elsevier B.V. All rights reserved.