KRYSTA BOCCUZZI, RAJ BASU, CHARLES ROSENBLATT

Effect of Carbon Nanotubes on Chirality in Liquid

Crystals

Outline

Introduction to Liquid Crystals and Carbon Nanotubes

Method8S5 and Carbon NanotubesCould this be the result of an artifact?Conclusions

Introduction to Liquid Crystals

Nematic

Smectic A

Smectic C

A liquid crystal is chiral when the mirror image of the molecule cannot be superimposed on the molecule.

Liquid crystals have properties between those of liquids and solids.

Introduction to Carbon Nanotubes

• The liquid crystal anchors at the surface of the carbon nanotubes.

• The axis of the nanotube aligns along the director.

The Electroclinic Effect

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The electroclinic effect only occurs when the liquid crystal is chiral.

Cell Preparation

• Indium Tin Oxide (ITO) coated glass was spin coated with RN1175.

• The liquid crystal and nanotube mixture was made by dispersing the nanotubes in acetone, shaking them in a vortex mixer for 15 minutes, and sonicating them for 2 hours.

• The cell was filled in the nematic phase and cooled to the Smectic A phase.

ITO coating

alignment polymer

glass

rubbing direction

rubbing direction

Experimental set-up

Laser

Polarizer(22.5° from director)

Analyzer

LensSample

Detector

Digital Multimeter

Lock-in Amplifier

Function generator

Computer

8S5 and Carbon Nanotubes

Could this be the result of an artifact?

• Chemical analysis by the manufacturer showed no chiral impurities.

• Washed in acetone.

• Washed in toluene.

Conclusions

The carbon nanotubes transfer chirality to the liquid crystal.

Future work will focus on finding the cause of this chirality.