Research

Updated by 2017

Cell Uptake of Nanoparticles [30,35,38,41,45,46,54,56]

A fundamental understanding of cell uptake of nanoparticles is of essential importance to a broad range of applications including drug delivery, biomedical imaging, virology and nanoparticle hazard prevention. Our theoretical analysis indicates that, while soft nanoparticles require stronger adhesion energy to achieve successful internalization than stiff ones [15,17,18,22-24], the receptor-mediated endocytosis of the former is kinetically faster than that of the latter [23]. Rod-shaped nanoparticles undergo either a dramatic morphological change experience or a sharp reorientation, depending on the particle stiffness [17]. Our results suggest that precise control of the particle elasticity can be an appealing way to control cellular uptake.

Cellular Interaction with High-aspect Ratio Nanomaterials [16,19,20,21,27,28,29,34]

The biological and environmental interactions of two-dimensional nanomaterials can be found in our recent review article [20], where we consider three fundamental interaction modes: (i) chemical interactions and phase transformations, (ii) electronic and surface redox interactions, and (iii) physical and mechanical interactions that are unique to near-atomically-thin, high-aspect-ratio solids.

Mechanical Behaviors of Metallic Materials [36,40,44,47,48,59,61,67]

Nanocrystalline (NC) metals exhibit outstanding mechanical properties compared with their bulk counterparts. We propose a size-dependent model considering the influence of grain size on the intragranular dislocation storage ability and unify the Hall–Petch (HP) and inverse HP relations for NC metals [55]. In the case of high-strength grain boundaries, extended HP behaviors are observed with decreasing grain size for grains around ten nanometers [55]. To reveal the underlying mechanism of inverse HP elimination by high hydrostatic pressure, pressure-dependent crystal plasticity constitutive models for both grain boundaries (GBs) and grain interiors (GIs) have been developed [62].

Surface/Interface Effects on Mechanical Properties of Nanomaterials [51]

Nanomaterials exhibit strong size and surface/interface effects owing to the enormous surface-to-volume ratio. We present a theoretical framework to reveal the effect of the surface stress induced by interactions of adsorbates and surface roughness on the deflection and frequency of microcantilevers [12,13]. For heterogeneous nanocomposites, the inclusion size and properties of the interface between the inclusions and the matrix play important roles in regulating the Eshelby tensor [3,4,6,7,10], effective modulus [8,9] and effective conductivities [1,2,5,11] of the composites.