title: Self-constructed tree-shape high thermal conductivity nanosilver networks in epoxy.
abstract: We report the formation of high aspect ratio nanoscale tree-shape silver networks in epoxy, at low temperatures (<150 °C) and atmospheric pressures, that are correlated to a ∼200 fold enhancement of thermal conductivity (κ) of the nanocomposite compared to the polymer matrix. The networks form through a three-step process comprising of self-assembly by diffusion limited aggregation of polyvinylpyrrolidone (PVP) coated nanoparticles, removal of PVP coating from the surface, and sintering of silver nanoparticles in high aspect ratio networked structures. Controlling self-assembly and sintering by carefully designed multistep temperature and time processing leads to κ of our silver nanocomposites that are up to 300% of the present state of the art polymer nanocomposites at similar volume fractions. Our investigation of the κ enhancements enabled by tree-shaped network nanocomposites provides a basis for the development of new polymer nanocomposites for thermal transport and storage applications.
authors.affiliation: School of Science, Engineering, and Technology, Pennsylvania State University, Middletown, PA 17057-4846, USA.
authors.forename: Kamyar
authors.initials: K
authors.lastname: Pashayi
authors.forename: Hafez Raeisi
authors.initials: HR
authors.lastname: Fard
authors.forename: Fengyuan
authors.initials: F
authors.lastname: Lai
authors.forename: Sushumna
authors.initials: S
authors.lastname: Iruvanti
authors.forename: Joel
authors.initials: J
authors.lastname: Plawsky
authors.forename: Theodorian
authors.initials: T
authors.lastname: Borca-Tasciuc
mesh_terms: D004553:Electric Conductivity; D004852:Epoxy Compounds / Q000737:chemistry*; D006358:Hot Temperature; D053768:Metal Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D011205:Povidone / Q000031:analogs & derivatives* / Q000737:chemistry; D012834:Silver / Q000737:chemistry*
chemical_list: D004852:Epoxy Compounds; C077842:polyvinylpolypyrrolidone; D012834:Silver; D011205:Povidone