10.1021/acs.macromol.8b00292.s001
Yulong Chen
Yulong
Chen
Qian Xu
Qian
Xu
Yangfu Jin
Yangfu
Jin
Xin Qian
Xin
Qian
Li Liu
Li
Liu
Jun Liu
Jun
Liu
Venkat Ganesan
Venkat
Ganesan
Design of End-to-End Assembly of Side-Grafted Nanorods
in a Homopolymer Matrix
American Chemical Society
2018
entropic steric repulsions
Homopolymer Matrix Coarse-grained
NR morphologies
NR aspect ratio
homopolymer matrix
assembly
van der Waals
polymer chains
2018-05-23 18:51:39
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Design_of_End-to-End_Assembly_of_Side-Grafted_Nanorods_in_a_Homopolymer_Matrix/6332195
Coarse-grained molecular dynamics
simulations were carried out
to identify the conditions under which the nanorods (NRs) side-grafted
with polymer chains can assemble in end-to-end configurations in a
homopolymer matrix, a structure of significant importance for optimal
property characteristics. Our results demonstrate that by adjusting
the grafting density and the grafted chain length, three different
NR morphologies can be obtained, viz., side-by-side aggregation, end-to-end
alignment and homogeneous dispersion. To understand the underlying
mechanism, the chain characteristics around the NRs were systematically
investigated. We find that the transition of NR morphologies from
side-by-side aggregation to others is correlated to the mushroom-to-brush
transition of the grafted chain configurations. At high grafting densities
corresponding to the brush regime, the entropic steric repulsions
between the polymer brushes prevent the NRs from approaching in side-by-side
configurations. Instead, end-to-end assembly and homogeneous dispersion
are observed. Within such regimes, we observe that the splaying of
the grafted polymer chains at the edges of the NRs plays a critical
role in determining the occurrence of end-to-end assembly. When the
extent of splaying cannot overcome the van der Waals and depletion
attractions between the NR ends, which occurs at relatively short
graft lengths, the end-to-end assembly is preferred. We find that
this manner of self-assembly will be further promoted by increasing
the NR loading but is retarded by increasing the NR aspect ratio.
In general, our study identifies conditions to enable the end-to-end
assembly of NRs in a homopolymer matrix, enabling significant practical
applications.