Tunable shear thickening, aging, and rejuvenation in suspensions of shape-memory-endowed liquid crystalline particles

• 成果类型: Article
• 署名作者: Chen, Chuqiao; Narvaez, Carina D. V. Martinez; Chang, Nina; Jimenez, Carlos Medina; Dennis, Joseph M.; Jaeger, Heinrich M.; Rowan, Stuart J.; de Pablo, Juan J.
• 署名单位: University of Chicago; United States Department of Defense; United States Army; US Army Research, Development & Engineering Command (RDECOM); US Army Research Laboratory (ARL); University of Chicago; University of Chicago; University of Chicago; United States Department of Energy (DOE); Argonne National Laboratory; New York University; New York University; New York University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8945
• DOI: 10.1073/pnas.2425373122
• 发表日期: 2025-07-08
• 关键词: elastomers; anisotropy; actuators; roundness; glasses; image

摘要

The morphological features of particles, notably shape anisotropy, critically influence the rheological properties of dense suspensions, spanning both natural and engineered systems. This work explores the potential of using shape memory particles to dynamically regulate suspension fluid flow through controllable shape transformations. First, we synthesize shape-memory particles with programmable anisotropy from liquid crystal elastomers, such that the stiffness and shapes of the particles can be tuned by manipulating temperature. Our findings reveal that suspensions from such particles exhibit significant tunability in shear thickening behavior, transitioning from discontinuous shear thickening to a Newtonian-like response within a narrow temperature range of 60 degrees C. This capability to modulate rheological responses in situ presents an approach for addressing processing challenges in many applications where control over flow behavior is paramount. Furthermore, we also show that suspensions composed of these anisotropic particles can undergo physical aging, and evolve into a glassy state. This state can be escaped upon activation of the shape memory effect. This reversibility underscores the potential for using such materials to engineer systems that can enter or come out of kinetic arrest by leveraging internal mechanical responses to external stimuli. The insights gained here not only broaden our understanding of the interplay between particle geometry and suspension dynamics but also pave the way for leveraging ensembles of stimuli-responsive objects to precisely control collective behaviors in many-body systems.