Orientation of Carbon Nanotubes in a Sheared Polymer Melt
Erik K. Hobbie, Haonan Wang, H W. Kim, Sheng Lin-Gibson, E A. Grulke
Optical measurements of the shear response of dilute ensembles of multi-walled carbon nanotubes dispersed in a polybutadiene melt are presented. At low shear stress, the measurements suggest that the tubes are broadly oriented along the direction of flow. Above a critical shear stress (sc 12 kPa), the data suggest a transition in which the tubes become broadly oriented along the vorticity direction. The elastic stress present in the melt at sc (as measured by the first normal stress difference) is roughly a factor of five smaller than the shear stress, suggesting that the melt is weakly elastic. The observed vorticity alignment is in qualitative agreement with previous studies of fiber orientation in weakly elastic fluids under shear.
, Wang, H.
, Kim, H.
, Lin-Gibson, S.
and Grulke, E.
Orientation of Carbon Nanotubes in a Sheared Polymer Melt, Physics of Fluids, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=852071
(Accessed May 30, 2023)