title: Effects of Molecular Geometry on the Properties of Compressed Diamondoid Crystals.
abstract: Diamondoids are an intriguing group of carbon-based nanomaterials, which combine desired properties of inorganic nanomaterials and small hydrocarbon molecules with atomic-level uniformity. In this Letter, we report the first comparative study on the effect of pressure on a series of diamondoid crystals with systematically varying molecular geometries and shapes, including zero-dimensional (0D) adamantane; one-dimensional (1D) diamantane, [121]tetramantane, [123]tetramantane, and [1212]pentamantane; two-dimensional (2D) [12312]hexamantane; and three-dimensional (3D) triamantane and [1(2,3)4]pentamantane. We find the bulk moduli of these diamondoid crystals are strongly dependent on the diamondoids' molecular geometry with 3D [1(2,3)4]pentamantane being the least compressible and 0D adamantane being the most compressible. These diamondoid crystals possess excellent structural rigidity and are able to sustain large volume deformation without structural failure even after repetitive pressure loading cycles. These properties are desirable for constructing cushioning devices. We also demonstrate that lower diamondoids outperform the conventional cushioning materials in both the working pressure range and energy absorption density.
authors: Department of Geological Sciences, Stanford University , Stanford, California 94305, United States.
authors: Fan
authors: F
authors: Yang
authors: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.|Department of Chemistry, Stanford University , Stanford, California 94305, United States.
authors: Yu
authors: Y
authors: Lin
authors: Geophysical Laboratory, Carnegie Institution of Washington, Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors: Maria
authors: M
authors: Baldini
authors: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Jeremy E P
authors: JE
authors: Dahl
authors: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Robert M K
authors: RM
authors: Carlson
authors: Department of Geological Sciences, Stanford University , Stanford, California 94305, United States.|Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Wendy L
authors: WL
authors: Mao