NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
D J. Fry, B Langhorst, Haonan Wang, Barry J. Bauer, Erik K. Hobbie
Abstract
We have used a polarization modulation technique to investigate optical anisotropy of multi-walled and single-walled carbon nanotubes suspended in a variety of solvents. Measurement of birefringence and dichroism have been performed as a function of shear rate and tube concentration. Both increase with increasing shear rate as a result of enhanced flow alignment and also with increasing tube concentration at fixed shear. There does not appear to be a simple scaling between the tube volume fraction and the magnitude of optical anisotropy, implying a rather complex behavior of these suspensions. By considering the rotary tube diffusivity as a function of tube length and diameter, solvent viscosity and tube concentration we have found a universal scaling for both the birefringence and dichroism with rotary Peclet number.
Fry, D.
, Langhorst, B.
, Wang, H.
, Bauer, B.
and Hobbie, E.
(2006),
Rheo-Optic Studies of Carbon Nanotube Suspensions, Journal of Chemical Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=852402
(Accessed October 13, 2025)