Layer-structured composites have broad applications but challenging to process. This research will demonstrate three examples in 1D, 2D and 3D layered structures containing polymers and nanoparticles. The first example was the use of polymer-nanoparticle interphase design to achieve 1D fibers. As well known that polymer fibers of microscale with continuous nanoparticle distribution are difficult to process due to the stiffness mismatching between polymers and nanoparticles. This example will demonstrate unique fiber spinning so that the soft macromolecules and rigid particles will be stacked along the radial or the fiber axis for enhanced mechanical, electrical, and thermal properties. The unique material system of composite fibers was used as piezo- and chemi-resistive sensors. The second example exhibited a thin composite film on compliant structures for thermoelectric generators (TEGs). The stacking of 2D films contained conjugating polymers in-situ polymerized at the presence of nanoparticles. During the processing, the polyaniline molecules were found to coat evenly on carbon nanotubes and led to high electrical conductivity, power factor, and enhanced mechanics. Thus, these compressed films were exhibited on compliant structures and used as wearable devices for human body heat collection. The generated electricity was for powering wearable sensors in detecting human movement and health conditions. The third demonstration utilized layer-by-layer-based deposition techniques. Both additive manufacturing (e.g., 3D printing) and coating methods were used on the same processing platform. One dimensional carbon nanofibers (CNF) and 2D MXene particles were used as examples to be selectively deposited on polymer surfaces with pre-printed patterns. The control of the surface patterns and the nanoparticle assembly conditions led to selective deposition and preferential alignment of nanoparticles. As a result, the conductive paths on the substrate were developed to be anisotropic, which was used for sensing and actuating purposes.

Polymer and nanoparticle layers in 1D, 2D and 3D structures

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.