Public Abstract

DE-SC0020847: Non-Equilibrum Processing of Hierarchical Nanofilled Semicrystalline Polymers Made from Sustainable Sources

Award Status: Active

Institution: The University of Vermont and State Agricultural College, Burlington, VT
UEI: Z94KLERAG5V9
DUNS: 066811191

Most Recent Award Date: 02/18/2026
Number of Support Periods: 6
PM: Chen, Shawn

Current Budget Period: 01/01/2026 - 12/31/2026
Current Project Period: 01/01/2024 - 12/31/2026
PI: Schadler, Linda

Supplement Budget Period: N/A

Public Abstract

Non-Equilibrium Synthesis of Hierarchical Semicrystalline Polymer Architectures for Sustainability Applications Linda S. Schadler, University of Vermont (Principle Investigator) Sanat K. Kumar, Columbia University (Co-Investigator) Composites consisting of spherical nanoparticles (NPs) in a polymer matrix have shown considerable promise for improving the mechanical, electrical, and optical properties of polymers. One of the critical factors in achieving property enhancements is controlling how the NPs are organized in the polymer matrix. Most prior work has focused on organizing NPs in amorphous polymers, but ~70% of all polymers sold annually are semicrystalline. Inspired by this disconnect we have previously demonstrated that crystallization can be used to synthesize semicrystalline polymer composites with carefully controlled NP ordering, i.e., where the inorganic NPs are selectively placed in the amorphous regions of the lamellar morphology. This work builds off nearly 50 years of work, first pioneered by Keith and Padden, who suggested that an amorphous polymer diluent can be segregated during the crystallization of semicrystalline polymers. The result, especially in the case of polymer nanocomposites, is a locally layered but overall disordered, NP morphology that reflects the underlying space filling spherulitic arrangement of the polymer. To achieve further ordering, we have developed a zone annealing process to directionally solidify nanocomposites and have achieved directional NP ordering on the length scale of centimeters. This discovery of NP ordering has exciting potential for a variety of applications relying on improved mechanical and dielectric properties. For example, dielectric materials with higher breakdown strength, longer voltage endurance, higher permittivity, and lower loss can be synthesized to increase the efficiency of energy transmission, and rectification. These have potential applications in cable insulation, capacitors for rectification, termination joints and more. While we have established this non-equilibrium processing approach, the data and mechanism imply that we can decrease the timescales for organization by (further) increasing the mobility of the NPs and creating a driving force for directional organization. This will result in our ability to process much larger samples over shorter times, thus making these ideas more appropriate for applications. There is also an opportunity to extend this work sustainable polymers and polymer mixtures. More specifically, we will focus on three areas: 1. Studying the impact of external fields (acoustic and electric) on NP organization during crystallization as a function of the particle size, the grafted brush structure, and the acoustic and electric forces. 2. Combining acoustic or electric fields with zone annealing to both decrease the time for directional solidification over relevant length scales and to study the impact of the two fields on crystallization behavior and filler organization. 3. Extend this work to both matrix polymers created from sustainable sources, and mixtures of recycled or sustainable polymers as a means of upscaling the properties of sustainable or recycled polymers. These objectives underly a fundamental and overarching goal to: Combine theory and experiments to understand the mechanisms that control external field, kinetically driven, non-equilibrium, processes to create hierarchical, layered diluent (either an amorphous polymer or NPs) ordering that transformatively impacts the dielectric, and thermomechanical properties of a polymer in a manner that is not achievable by other current means. Our proposed work will address these interrelated goals by tightly integrating synthesis, structural characterization, key property measurements and modeling.

Non-Equilibrium Synthesis of Hierarchical Semicrystalline Polymer Architectures for Sustainability Applications

Linda S. Schadler, University of Vermont (Principle Investigator)

Sanat K. Kumar, Columbia University (Co-Investigator)

Composites consisting of spherical nanoparticles (NPs) in a polymer matrix have shown considerable promise for improving the mechanical, electrical, and optical properties of polymers. One of the critical factors in achieving property enhancements is controlling how the NPs are organized in the polymer matrix. Most prior work has focused on organizing NPs in amorphous polymers, but ~70% of all polymers sold annually are semicrystalline. Inspired by this disconnect we have previously demonstrated that crystallization can be used to synthesize semicrystalline polymer composites with carefully controlled NP ordering, i.e., where the inorganic NPs are selectively placed in the amorphous regions of the lamellar morphology. This work builds off nearly 50 years of work, first pioneered by Keith and Padden, who suggested that an amorphous polymer diluent can be segregated during the crystallization of semicrystalline polymers. The result, especially in the case of polymer nanocomposites, is a locally layered but overall disordered, NP morphology that reflects the underlying space filling spherulitic arrangement of the polymer. To achieve further ordering, we have developed a zone annealing process to directionally solidify nanocomposites and have achieved directional NP ordering on the length scale of centimeters. This discovery of NP ordering has exciting potential for a variety of applications relying on improved mechanical and dielectric properties. For example, dielectric materials with higher breakdown strength, longer voltage endurance, higher permittivity, and lower loss can be synthesized to increase the efficiency of energy transmission, and rectification. These have potential applications in cable insulation, capacitors for rectification, termination joints and more.

While we have established this non-equilibrium processing approach, the data and mechanism imply that we can decrease the timescales for organization by (further) increasing the mobility of the NPs and creating a driving force for directional organization. This will result in our ability to process much larger samples over shorter times, thus making these ideas more appropriate for applications. There is also an opportunity to extend this work sustainable polymers and polymer mixtures. More specifically, we will focus on three areas:

1. Studying the impact of external fields (acoustic and electric) on NP organization during crystallization as a function of the particle size, the grafted brush structure, and the acoustic and electric forces.

2. Combining acoustic or electric fields with zone annealing to both decrease the time for directional solidification over relevant length scales and to study the impact of the two fields on crystallization behavior and filler organization.

3. Extend this work to both matrix polymers created from sustainable sources, and mixtures of recycled or sustainable polymers as a means of upscaling the properties of sustainable or recycled polymers.

These objectives underly a fundamental and overarching goal to: Combine theory and experiments to understand the mechanisms that control external field, kinetically driven, non-equilibrium, processes to create hierarchical, layered diluent (either an amorphous polymer or NPs) ordering that transformatively impacts the dielectric, and thermomechanical properties of a polymer in a manner that is not achievable by other current means. Our proposed work will address these interrelated goals by tightly integrating synthesis, structural characterization, key property measurements and modeling.