title: Thermal Transport across Surfactant Layers on Gold Nanorods in Aqueous Solution.
abstract: Ultrafast transient absorption experiments and molecular dynamics simulations are utilized to investigate the thermal transport between aqueous solutions and cetyltrimethylammonium bromide (CTAB)- or polyethylene glycol (PEG)-functionalized gold nanorods (GNRs). The transient absorption measurement data are interpreted with a multiscale heat diffusion model, which incorporates the interfacial thermal conductances predicted by molecular dynamics. According to our observations, the effective thermal conductance of the GNR/PEG/water system is higher than that of the GNR/CTAB/water system with a surfactant layer of the same length. We attribute the enhancement of thermal transport to the larger thermal conductance at the GNR/PEG interface as compared with that at the GNR/CTAB interface, in addition to the water penetration into the hydrophilic PEG layer. Our results highlight the role of the GNR/polymer thermal interfaces in designing biological and composite-based heat transfer applications of GNRs, and the importance of multiscale analysis in interpreting transient absorption data in systems consisting of low interfacial thermal conductances.
authors.affiliation: Department of Mechanical Engineering, University of Minnesota , Twin Cities, 111 Church Street S.E., Minneapolis, Minnesota 55455, United States.
authors.forename: Xuewang
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Mechanical Engineering, University of Minnesota , Twin Cities, 111 Church Street S.E., Minneapolis, Minnesota 55455, United States.
authors.forename: Yuxiang
authors.initials: Y
authors.lastname: Ni
authors.affiliation: Department of Mechanical Engineering, University of Minnesota , Twin Cities, 111 Church Street S.E., Minneapolis, Minnesota 55455, United States.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States.
authors.forename: Nathan D
authors.initials: ND
authors.lastname: Burrows
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States.
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Murphy
authors.affiliation: Department of Mechanical Engineering, University of Minnesota , Twin Cities, 111 Church Street S.E., Minneapolis, Minnesota 55455, United States.
authors.forename: Traian
authors.initials: T
authors.lastname: Dumitrica
authors.affiliation: Department of Mechanical Engineering, University of Minnesota , Twin Cities, 111 Church Street S.E., Minneapolis, Minnesota 55455, United States.
authors.forename: Xiaojia
authors.initials: X
authors.lastname: Wang
keywords: gold nanorods; interfacial thermal conductance; molecular dynamics simulation; thermal transport; transient absorption