Open AccessMolecular dynamics simulation study of polyimide/copper-nanoparticle composites
Author(s) -
Sun Wei-Feng,
Xuan Wang
Publication year - 2013
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.62.186202
Subject(s) - polyimide , materials science , nanoparticle , composite material , nanocomposite , copper , amorphous solid , isotropy , thermal stability , chemical engineering , nanotechnology , crystallography , chemistry , layer (electronics) , metallurgy , physics , quantum mechanics , engineering
Molecular dynamics simulations of polyimide/copper-nanoparticle composites are implemented to calculate the morphological structures, thermodynamic and mechanical properties, and to investigate their relationships with the nanoparticle dimension and simulation temperature. The results demonstrate that polyimide/copper-nanoparticle composites are of isotropic amorphous structures, in which the copper nanoparticles combine with polyimide matrix due to van der Waals effect and multi-layers of atoms on nanoparticle surface change into amorphous configurations, forming interface layers between them. The interface regions shrink and expand respectively with increased nanoparticle dimension and temperature. The polyimide/copper-nanoparticle composites exhibit the explicit increase of isometric heat capacity with larger nanoparticle dimension in moderated temperature dependence, resulting in lower heat capacities at relatively low temperature for nanocomposites with relatively small nanoparticle size, compared with polyimide system. The thermal pressure coefficients of polyimide/copper-nanoparticle composites are distinctly higher than those of polyimide system, and increase substantially with enlarged nanoparticle dimension and reduce slightly with elevated temperature. The thermodynamic properties of polyimide/copper-nanoparticle composites manifest obvious scale-effect and distinctly higher temperature stability than polyimide system. The mechanical properties of polyimide/copper-nanoparticle composites represent isotropic elastic constant tensors with distinctly lower Young modulus and Poisson ratio than those of polyimide system, which decrease and increase respectively with increasing simulation temperature, exactly contrary to polyimide system and with substantially higher temperature stability of Young modulus. The composites with larger nanoparticle dimension exhibit considerably higher Poisson ratio with slight change of Young modulus, indicating the remarkably different mechanical properties of new nanocomposites with Cu nanoparticle filler.