Structural rheology of focal conic domains: a stress-quench experimentElectronic supplementary information (ESI) available: Stress quench data obtained by a cone-plate shear cell made of stainless steel and a parallel plate shear cell made of quartz are compared. Spatio-temporal images used for the construction of Fig. 6 and 7 are also shown. See DOI: 10.1039/c4sm00146j

• Main Authors: Fujii, Shuji, Komura, Shigeyuki, Lu, C.-Y. David
• Format: Journal Article
• Language: English
• Published: 02.07.2014
• ISSN: 1744-683X; 1744-6848
• DOI: 10.1039/c4sm00146j

We study the dynamics of focal conic domain (FCD) formation in a thermotropic smectic phase under shear stress. It is known that increasing the shear stress induces a non-equilibrium phase transition from a smectic phase with FCDs (SmA I ) to another smectic phase (SmA II ) in which the layers are oriented. By quenching the shear stress from the SmA II phase to the SmA I phase, we find three characteristic modes in the FCD formation process. The first mode is attributed to the edge dislocation dynamics induced by climb motions. The second mode results from FCD formation. The first and second modes show slowing down close to the smectic-nematic transition temperature, implying that the dynamics are dominated by dislocation unbinding. The third mode originates from the alignment of FCDs which form oily streaks. Such an alignment occurs when the shear stress balances the line tension of the oily streaks. We study the dynamics of focal conic domain (FCD) formation in a thermotropic smectic phase under shear stress.