Noncovalent interfaces play a vital role in inelastic deformation and toughening mechanisms in layered nanocomposites due to their dynamical recoverability. When interfacial engineering is applied to design layered na...
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Noncovalent interfaces play a vital role in inelastic deformation and toughening mechanisms in layered nanocomposites due to their dynamical recoverability. When interfacial engineering is applied to design layered nanocomposites, shear-lag analysis is usually implemented to evaluate the capability of interfacial loading transfer. Here, we introduce a multiscale shear-lag model that correlates macroscale mechanical properties with the molecular mechanisms to quantify the effects of interfacial configuration in graphene oxide(GO) layered nanocomposites. By investigating the mechanical responses of commensurate and incommensurate interfaces, we identify that the commensurate interface exhibits a pronounced size effect due to the nucleation and propagation of interfacial defects, whereas the incommensurate interface displays uniform deformation. Our predictions are further validated through large-scale molecular dynamics simulations for GO layered nanocomposites. This work demonstrates how size effects and interfacial configurations can be exploited to fabricate layered nanocomposites with superior mechanical properties despite relying on weak noncovalent interfaces.
The structural evolution of the ordered N-N' dibutyl-substituted quinacridone (QA4C) multilayers (3 MLs) has been monitored in situ and in real time at various substrate temperatures using low energy electron diff...
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The structural evolution of the ordered N-N' dibutyl-substituted quinacridone (QA4C) multilayers (3 MLs) has been monitored in situ and in real time at various substrate temperatures using low energy electron diffraction (LEED) during organic molecular beam epitaxy (MBE). Experimental results of LEED patterns clearly reveal that the structure of the multilayer strongly depends on the substrate temperature. Multilayer growth can be achieved at the substrate temperatures below 300 K, while at the higher temperatures we can only get one ordered monolayer of QA4C. Two kinds of structures, the commensurate and incommensurate one, often coexist in the QA4C multilayer. With a method of the two-step substrate temperatures, the incommensurate one can be suppressed, and the commensurate, on the other hand, more similar to the (001) plane of the QA4C bulk crystal, prevails with the layer of QA4C increasing to 3 MLs. The two structures in the multilayers are compressed slightly in comparison to the original ones in the first monolayer.
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