Rheo-optical characterization (flow-birefringence and flow-dichroism) of the Tobacco Mosaic Virus

✍ Scribed by Ulf T. Reinhardt; Eleanor L. Meyer de Groot; Gerald G. Fuller; Werner-Michael Kulicke

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 786 KB
• Volume: 196
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.1995.021960103

✦ Synopsis

Abstract

Rheo‐optical techniques of determining flow‐birefringence Δ__n__′ and flow‐dichroism Δ__n__″ were employed to investigate a Tobacco Mosaic Virus (TMV) solution under steady‐state and relaxation conditions to obtain further information about molecular dynamics in terms of local and global orientation and flexibility. These effects were investigated in a concentration range of 0,5 g/L ⩽ c ≦ 2,89 g/L, i.e. below and above the critical overlap concentration c* = 2,45 g/L. Although some aggregation was unavoidable it was determined that in the region of c* the dynamic behaviour was not influenced by varying the concentration. Furthermore it was shown that these aggregates naturally appearing in TMV are sensitive to shear force and dissolve at shear rates above 1 s^−1^. Beyond the critical shear rate this rodlike molecule should show a good agreement of the orientation angles determined through dichroism and birefringence and a constant ratio Δ__n__″/Δ__n__′ which in fact was found. This reveals experimentally that in spite of the sensitivity to different length scales dichroism and birefringence exhibit similar responses to shear forces for rigid and monodisperse macromolecules.