We present real-time visualization of flow-induced microstructural changes in a surfactant solution using rheo-polarized imaging (RPI). Combining a stress-controlled rheometer with a high-speed polarization camera, RPI simultaneously measures rheology and birefringence. In a constant-shear startup, a high-birefringence wave propagated inward, followed by a spiral pattern toward the center. Irregular patterns later revealed spatiotemporal microstructural fluctuations. These results show that micellar structures evolve dynamically from flow onset, with RPI capturing transient mesoscale features-waves, spirals, and instabilities-offering new insight into soft matter startup dynamics.
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