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Reverse nonequilibrium molecular dynamics simulations were used to study heat transport in solvated gold interfaces which have been functionalized with a low-molecular weight thiolated polyethylene glycol (PEG). The gold interfaces studied included (111), (110), and (100) facets as well as spherical nanoparticles with radii of 10 and 20 Å. The embedded atom model (EAM) and the polarizable density-readjusted embedded atom model (DR-EAM) were implemented to determine the effect of metal polarizability on heat transport properties. We find that the interfacial thermal conductance values for thiolated PEG-capped interfaces are higher than those for pristine gold interfaces. Hydrogen bonding between the thiolated PEG and solvent differs between planar facets and the nanospheres, suggesting one mechanism for enhanced transfer of energy, while the covalent gold sulfur bond appears to create the largest barrier to thermal conduction. Through analysis of vibrational power spectra, we find an enhanced population at low-frequency heat-carrying modes for the nanospheres, which may also explain the higher mean interfacial thermal conductance (G) value.
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A review of heat transport in solvated gold nanoparticles: Molecular dynamics modeling and experimental perspectives
Turning gold nanoparticles (AuNPs) into nanoscale heat sources via light irradiation has prompted significant research interest, particularly for biomedical applications, over the past few decades. The AuNP’s tunable photothermal effect, notable biocompatibility, and ability to serve as vehicles for temperature-sensitive chemical linkers enable thermo-therapeutics, such as localized drug/gene delivery and thermal ablation of cancerous tissue. Thermal transport in aqueous AuNP solutions stands as the fundamental challenge to developing targeted thermal therapies; thus, this review article surveys recent advancements in our understanding of heat transfer and surface chemistry in AuNPs, with a particular focus on thermal boundary conductance across gold- and functionalized-gold-water interfaces. This review article highlights computational advances based on molecular dynamics simulations that offer valuable insights into nanoscopic interfacial heat transfer in solvated interfaces, particularly for chemically functionalized AuNPs. Additionally, it outlines current experimental techniques for measuring interfacial thermal transport, their limitations, and potential pathways to improve sensitivity. This review further examines computational methodologies to guide the accurate modeling of solvated gold interfaces. Finally, it concludes with a discussion of future research directions aimed at deepening our understanding of interfacial heat transfer in solvated AuNPs, crucial to optimize thermoplasmonic applications.
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- PAR ID:
- 10647795
- Publisher / Repository:
- Royal Society of Chemistry
- Date Published:
- Journal Name:
- Nanoscale
- Volume:
- 17
- Issue:
- 36
- ISSN:
- 2040-3364
- Page Range / eLocation ID:
- 20803 to 20830
- Subject(s) / Keyword(s):
- Heat transfer, nanoparticles, molecular dynamics
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1039/D5NR02521D
