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Two-dimensional (2D) polymers are organic analogues of graphene. Compared to graphene, 2D polymers offer a higher degree of tunability in regards to structure, topology, and physical properties. The thermal transport properties of 2D polymers play a crucial role in their applications, yet remain largely unexplored. Using the equilibrium molecular dynamics method, we study the in-plane thermal conductivity of dubbed porous graphene that is comprised of π-conjugated phenyl rings. In contrast to the conventional notion that π-conjugation leads to high thermal conductivity, we demonstrate, for the first time, that π-conjugated 2D polymers can have either high or low thermal conductivity depending on their porosity and structural orientation. The underlying mechanisms that govern thermal conductivity were illustrated through phonon dispersion. The ability to achieve two orders of magnitude variance in thermal conductivity by altering porosity opens up exciting opportunities to tune the thermal transport properties of 2D polymers for a diverse array of applications.
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This content will become publicly available on December 1, 2026
Thermal transport of polyethylene oxide (PEO) nanofibers fabricated from near-field electrospinning: effect of molecular weight and molecular concentration.
Polymers are thermally insulating due to randomly oriented molecular chains, limiting their effectiveness in thermal management. However, when processed into nanofibers, polymers can exhibit significantly higher thermal conductivity, primarily due to enhanced internal structures such as crystallinity and molecular alignment. Characterizing these structural parameters at the single nanofiber level remains a challenge, limiting understanding of thermal transport mechanisms. Here, we investigate the relationship between internal structure and thermal conductivity of single polyethylene oxide (PEO) nanofibers fabricated from near-field electrospinning (NFES). By varying molecular weight and concentration of PEO, their impact on thermal conductivity and internal structure are examined. Crystallinity is examined using conventional Raman spectroscopy, while molecular orientation is assessed through polarized Raman and polarized FTIR spectroscopy. Results reveal that enhanced thermal conductivity in PEO nanofibers is primarily attributed to increased molecular orientation. A maximum thermal conductivity of 2.7 W/m·K is achieved in PEO nanofibers, representing a notable improvement over bulk PEO (0.2 W/m·K). These findings demonstrate the potential of structurally engineered PEO nanofibers for thermal applications including electronic packaging and thermal interface materials. Further, the approach presented in this work can provide a framework for exploring thermal transport mechanisms in other polymer systems.
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- Award ID(s):
- 2340208
- PAR ID:
- 10654561
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Materials Today Communications
- Volume:
- 49
- Issue:
- C
- ISSN:
- 2352-4928
- Page Range / eLocation ID:
- 114377
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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