Phase Separation for Bioinspired Novel Composites
Abstract
The recent emergence of phase separation as a key mechanism for regulation of both function and morphology in biological systems, signifies its untapped potential as an autonomous route for patterning of synthetic structural materials. Beyond the unprecedented multimaterial architectures that can be achieved, phase separated morphologies can have superior structural performance, as compared to conventional designs, and can facilitate novel functionalities for sensing, energy storage, and production applications, by fabrication of compartmentalized materials, where membraneless structures separate catalytic domains from the surrounding milieu. However, while the new appreciation of phase separation in soft materials has fueled development of experimental and theoretical models that aim to explain these phenomena, attempts to take advantage of it are in nascent state and several scientific questions remain open with regards to the key role of solid mechanics in determining the final stable morphologies that can emerge via phase separation. The proposed work aims to provide answers to these questions. To achieve this goal and to move beyond the current paradigm of trial-and-error experimental discovery, the proposed effort will employ a combination of advanced theoretical tools of continuum mechanics and high precision experimentation, to explain the complex multimaterial coupled phenomena. Once a basic understanding of the fundamental mechanisms is achieved, theoretical modeling will be further extended to systematically investigate the range of possible architectures and their associated process parameters, and will guide the fabrication of samples as a proof-of-concept. Accordingly, the proposed work will revolve around three thrusts. The first three Thrusts combine theoretical models and novel mechanical testing methods to explore the coupled phenomena in phase separating, multi-component material systems, with an emphasis on exposing the role of nonlinear solid mechanics and the irreversible deformations that ensue from the phase separation. This will be achieved by considering increasing levels of complexity, starting from just one phase separating droplet, in Thrust 1, to investigation of the interaction between multiple droplets in Thrust 2, and to prediction of macroscale architectures in Thrust 3. Different, complimentary, modeling approaches will be employed; from analytical models of spherically symmetric fields and finite element methods upon symmetry breaking in a single droplet, in Thrust 1, to investigation of mechanical interactions in presence of multiple droplets in Thrust 2, and to multiscale simulations that incorporate arrays of droplets in Thrust 3. Concurrent to the effort in Thrusts 1-3, connecting the theoretical predictions with physical observations will be the focus of Thrust 4, and will use two material systems (silkÐPVOHÐwater and silkÐwaterÐessential oil). The experimental observations will further inform the modeling effort by experimentally exploring the design space, as guided by the theoretical predictions, and will provide a proof-of concept by realizing the predicted morphologies. Finally, by exploring the spontaneous formation of stable multi-material hierarchial morphologies via phase separation, the proposed work can remove existing obstacles and pave the way for a new paradigm for design and fabrication of hierarchial composites. The experimentally validated models derived in this work will lead to rigorous and thermodynamically consistent investigation of the sensitivities of the phase separation process; it will elucidate design space to guide self-assembly phenomena, and will provide the ground work for future manufacturing efforts of bioinspired composites.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 15, 2023
- Source ID
- W911NF2310089
Entities
People
- Tal Cohen
Organizations
- Army Contracting Command
- Massachusetts Institute of Technology
- United States Army