Shear-Induced Alignment Before Photocure: Fibres, Platelets and Orientation Retention Beyond Liquid-Crystal Elastomers

Shear-induced orientation should be qualified through the competition between hydrodynamic rotation, particle interactions, confinement and cure arrest rather than through a single mean angle. Shear history can align fibres or platelets while simultaneously changing dispersion and viscosity, and confinement can bias the accessible orientation distribution near walls. The proposed evidence combines controlled-history rheometry with flow birefringence or polarised imaging, three-dimensional orientation tensors from microscopy or CT, and mechanical testing along and across the programmed direction. A step-shear experiment followed by a variable dark delay directly measures orientation retention before gelation. This framework supports decisions on the shear rate, residence time and cure timing required to achieve a target anisotropy with known relaxation margin.

ER-358.