jp412145j_si_001.pdf (1.46 MB)
Role of Nanoparticle Selectivity in the Symmetry Breaking of Cylindrically Confined Block Copolymers
journal contribution
posted on 2014-04-10, 00:00 authored by Jay Hoon Park, Jun Yin, Vibha Kalra, Yong Lak JooWe have comprehensively studied the
effect of nanoparticle selectivity
on the self-assembly of symmetrical block copolymer (BCP) under cylindrical
confinement using simulation and experiment. For the simulation, a
coarse-grained molecular dynamics (CGMD) simulation has been utilized,
and we investigated the confined assembly using nanoparticles with
three different interactions with block copolymer: (i) neutral to
both A (wall-attractive) and B (wall-repulsive)
phases, (ii) B domain selective, and (iii) A domain selective. It is predicted that nonselective (neutral)
nanoparticles (NPs) tend to be placed near the interface between radially
alternating layers of A or B domains,
while selective (A or B) NPs swell
the corresponding phase, inducing discrete asymmetrical morphologies.
We also find that pure asymmetrical BCP forms more radially perforated
morphologies, while symmetrical BCP/NP forms more discrete morphologies.
Experimentally, we have incorporated gold or magnetite NPs with the
matching three types of selectivity toward symmetrical diblock PS-b-PI and electrospun them. The morphologies observed from
our study have been quantified by morphological classification numbers
to identify the degree of asymmetry formed. The qualitative and quantitative
comparisons between experiment and simulation confirm the validity
of the simulation tool and shed light on the NP’s role on breaking
the symmetry of BCP under cylindrical confinement.