Abstract
The band texture of the hydroxypropylcellulose (HPC) film is observed after cessation of shear by optical microscopy and scanning electron microscopy (SEM). The sinusoidal supramolecular structure associated with the band texture of HPC is verified by polarized optical microscopy, so the band texture corresponds to the spatial periodicity of local director or molecular orientation. On the other hand, however, the pleated morphology, a depth periodicity, is confirmed by SEM and the pleat period is consistent with the band period. What is more, even without polarizer and analyser, the bands can still be found in an optical microscope with the same periodicity as those under cross polars, and these bands might be attributed to a density periodicity. Both the depth and density periodicities result from the mass flow after cessation of shear and must be coupled to the orientation periodicity resulting from director rotation. As a consequence, we propose that the back-flow effect is striking in the formation of band textures and should be taken into consideration in order to give a plausible and explicit mechanism of band formation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.