Publications by authors named "Swanee Shin"

Aerogels are of interest for their ability to uniformly incorporate nanoscale features into macroscopic assemblies, which enabled applications that require low density, high surface area, and/or bicontinuous networks. The structure of the nanoporous network is intrinsically linked to the macroscopic properties of aerogels. Hence, control of this structure is of paramount importance.

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Compared to tedious, multi-step treatments for electroless gold plating of traditional thermoplastics, this communication describes a simpler three-step procedure for 3D printed crosslinked polyacrylate substrates. This allows for the synthesis of ultralight gold foam microlattice materials with great potential for architecture-sensitive applications in future energy, catalysis, and sensing.

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Although closely related to polystyrene, poly(divinylbenzene) (PDVB) has found limited utility due to the difficulties associated with its synthesis. As a highly cross-linked polymer, PDVB is infusible and insoluble and thus nearly impossible to shape into films by either melt or solvent-based processes. Here, we report the initiated chemical vapor deposition (iCVD) of nearly stress-free, highly transparent, free-standing films of PDVB up to 25 μm thick.

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Atomic hydrogen exists ubiquitously in graphene materials made by chemical methods. Yet determining the effect of hydrogen on the electrochemical performance of graphene remains a significant challenge. Here we report the experimental observations of high rate capacity in hydrogen-treated 3-dimensional (3D) graphene nanofoam electrodes for lithium ion batteries.

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We describe the synthesis and characterization of monolithic, ultralow density WS2 and MoS2 aerogels, as well as a high surface area MoS2/graphene hybrid aerogel. The monolithic WS2 and MoS2 aerogels are prepared via thermal decomposition of freeze-dried ammonium thio-molybdate (ATM) and ammonium thio-tungstate (ATT) solutions, respectively. The densities of the pure dichalcogenide aerogels represent 0.

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Article Synopsis
  • Aerogels have unique properties like large surface areas, fine pores, and low densities, making them useful in various applications.
  • Recent advancements in graphene aerogels have been made by reducing graphene oxide, but they still lag behind pure graphene sheets in quality due to poor crystallinity.
  • A new method for synthesizing highly crystalline graphene aerogels using high-temperature processing not only improves their structure but also enhances their thermal stability and electrical conductivity.
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The synthesis of ultralow-density (>5 mg/cm(3) ) bulk materials with interconnected nanotubular morphology and deterministic, fully tunable feature size, composition, and density is presented. A thin-walled nanotubular design realized by employing templating based on atomic layer deposition makes the material about 10 times stronger and stiffer than aerogels of the same density.

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A universal approach for on-demand development of monolithic metal oxide composite bulk materials with air-like densities (<5 mg/cm(3)) is reported. The materials are fabricated by atomic layer deposition of titania (TiO2) or zinc oxide (ZnO) using the nanoscale architecture of 1 mg/cm(3) SiO2 aerogels formed by self-organization as a blueprint. This approach provides deterministic control over density and composition without affecting the nanoscale architecture of the composite material that is otherwise very difficult to achieve.

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We report on simple and efficient routes to dope polydicyclopentadiene (PDCPD)-based aerogels and their coatings with high-Z tracer elements. Initially, direct halogenation of PDCPD wet gels and aerogels with elemental iodine or bromine was studied. Although several pathways were identified that allowed doping of PDCPD aerogels by direct addition of bromine or iodine to the unsaturated polymer backbone, they all provided limited control over the amount and uniformity of doping, especially at very low dopant concentrations.

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A tunable structural engineering of nanowires based on template-assisted alloying and phase segregation processes is demonstrated. The Au-Ge system, which has a low eutectic temperature and negligible solid solubility (<10(-3) atom %) of Au in Ge at low temperatures, is utilized. Depending on the Au concentration of the initial nanowires, final structures ranging from nearly periodic nanodisk patterns to core/shell and fully alloyed nanowires are produced.

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