%0 DATA
%A Arjita, Kulshreshtha
%A Kevin J., Modica
%A Arthi, Jayaraman
%D 2019
%T Impact of Hydrogen Bonding Interactions on Graft–Matrix
Wetting and Structure in Polymer Nanocomposites
%U https://acs.figshare.com/articles/Impact_of_Hydrogen_Bonding_Interactions_on_Graft_Matrix_Wetting_and_Structure_in_Polymer_Nanocomposites/7874498
%R 10.1021/acs.macromol.8b02666.s001
%2 https://acs.figshare.com/ndownloader/files/14661950
%K CG model
%K graft chain conformations
%K matrix monomer CG beads
%K donor CG beads
%K matrix chain length
%K matrix polymer chains
%K PNC
%K acceptor
%K interaction
%K matrix polymer chains increase
%K graft chain length
%K Hydrogen Bonding Interactions
%K matrix chain lengths
%K matrix chains
%X We
present a new coarse-grained (CG) model that captures directional
interactions between graft and matrix polymer chains in polymer nanocomposites
(PNCs) comprising polymer
grafted spherical nanoparticles in a matrix polymer. In this CG model
we incorporate acceptor and donor CG beads along with graft and matrix
monomer CG beads and optimize the bonded and nonbonded interactions
to mimic directional and specific H-bonding between the acceptor and
donor sites on graft and matrix chains, respectively. Using this CG
model and molecular dynamics simulations we show that H-bonding interactions
between graft and matrix polymer chains increase the grafted layer
wetting by matrix chains compared to that at the purely entropic limit.
One can achieve equivalent grafted layer wetting in PNCs with directional
acceptor–donor interactions and PNCs with isotropic graft–matrix
interactions, but the directional acceptor–donor interaction
strength needs to be much stronger than the isotropic graft–matrix
monomer attraction strength. Strikingly, despite equivalent grafted
layer wetting and graft chain conformations, on average, each graft
chain interacts with fewer matrix chains and has a lower free volume
in PNCs with H-bonding interaction as compared to PNCs with isotropic
graft-matrix attraction. These trends are seen both at high (brush-like)
and low grafting densities, and in PNCs with equal graft and matrix
chain lengths as well as PNCs with matrix chain length three times
the graft chain length.