graphene
High thermal conductivity through simultaneously aligned polyethylene lamellae and graphene nanoplatelets
The effect of simultaneous alignment of polyethylene (PE) lamellae and graphene nanoplatelets (GnP) on thermal conductivity (k) of PE-GnP composites is investigated. Measurements reveal a large increase of 1100% in k of the aligned PE-GnP composite using 10 weight% GnPs relative to unoriented pure PE. Rate of increase of k with applied strain for the pure PE-GnP composite with 10 wt% GnP is found to be almost a factor of two higher than the pure PE sample, pointing to the beneficial effect of GnP alignment on k enhancement.
Unusually low and density-insensitive thermal conductivity of three-dimensional gyroid graphene
http://dx.doi.org/10.1039/C7NR04455K Graphene has excellent mechanical, thermal and electrical properties. However, there are limitations in utilizing monolayers of graphene for mechanical engineering applications due to its atomic thickness and lack of bending rigidity. Synthesizing graphene aerogels or foams is one approach to utilize graphene in three-dimensional bulk forms. Recently, graphene with a gyroidal geometry has been proposed.
Postdoctoral position in nanomechanics of 2D nanomaterials
The School of Engineering and Materials Science at Queen Mary University of London has a vacancy for a Postdoctoral Research Assistant (PDRA) to develop computational models of ultra-flexible 2D nanomaterials in sheared liquids, using techniques borrowed from computational fluid and solid mechanics.
Compressible, Dense, Three-Dimensional Holey Graphene Monolithic Architecture
We demonstrated outstanding compressibility of holey graphene nanosheets, which is impossible for pristine graphene. Holey graphene powder can be easily compressed into dense and strong monoliths with different shapes at room temperature without using any solvents or binders.
ACS Nano, Article ASAP, http://pubs.acs.org/doi/abs/10.1021/acsnano.7b00227
The normal-auxeticity mechanical phase transition in graphene
When a solid object is stretched, in general, it shrinks transversely. However, the abnormal ones are auxetic, which exhibit lateral expansion, or negative Poisson ratio. While graphene is a paradigm 2D material, surprisingly, graphene converts from normal to auxetic at certain strains. Here, we show via molecular dynamics simulations that the normal-auxeticity mechanical phase transition only occurs in uniaxial tension along the armchair direction or the nearest neighbor direction. Such a characteristic persists at temperatures up to 2400 K.
Funded Ph.D. position in the Department of Mechanical Engineering- Engineering Mechanics at the Michigan Technological University
We are looking for a self-motivated PhD student to study Multi-Scale Material Modeling for different material systems such as Graphene and Polymeric Materials. This position is supported by the MEEM Department at MTU. This project will draw ideas from various subjects including Computational Mechanics and Materials Physics.
The candidate would have access to the advanced computing facilities, collaborations with researchers in other universities, and experimental collaborations.
On structured surfaces with defects: geometry, strain incompatibility, internal stress, and natural shapes
Given a distribution of defects on a structured surface, such as those represented by 2-dimensional crystalline materials, liquid crystalline surfaces, and thin sandwiched shells, what is the resulting stress field and the deformed shape? Motivated by this concern, we first classify, and quantify, the translational, rotational, and metrical defects allowable over a broad class of structured surfaces. With an appropriate notion of strain, the defect densities are then shown to appear as sources of strain incompatibility.
Free-standing graphene slit membrane for enhanced desalination
http://dx.doi.org/10.1016/j.carbon.2016.09.043 This study considers two novel ideas to further explore and enhance the graphene membrane for desalination. Firstly, while earlier molecular dynamics (MD) simulations studies have used frozen membranes, free-standing membrane is considered here. Since 2D membranes are usually embedded on porous support in the experimental reverse osmosis (RO) process, the free-standing membrane can more accurately model the behavior expected during operation.