6 research outputs found
Temperature Control of Light Transmission Using Mixed System of Silica Hollow Particles with Nanoparticle Shell and Organic Components
We
reported before that a silica hollow particle whose shell consists
of silica nanoparticle (<b>SHP-NP</b>) has a high light reflection
ability to prevent light transmission through the particle, which
is caused from the intensive light diffusion by the hollow structure
and the nanoparticle of the shell. Since the difference in the refractive
indices between silica and air is responsible for the strong light
reflection, the mixing of the particle with organic components having
refractive indices close to that of silica such as tetradecane produced
transparent mixtures by suppression of the light reflection. The transparency
of the mixtures thus prepared could be controlled by temperature variation.
For example, the mixture of the particle <b>SHP-NP</b> with
tetradecane was transparent at 20 °C and opaque at 70 °C,
while the mixture with <i>n</i>-hexyl cyclohexane was opaque
at 20 °C and transparent at 70 °C. As the refractive indices
of organic components changed with temperature more than 10 times
wider than that of silica, the temperature alternation produced a
significant change in the difference of the refractive indices between
them to achieve complete control of the transparency of the mixtures.
This simple control of the light transmission that can automatically
regulate sunlight into the room with temperature alteration is expected
to be suitable for smart glass technology for energy conservation
Origin of the High Carrier Mobilities of Nonperipheral Octahexyl Substituted Phthalocyanine
The carrier transport properties
of nonperipheral octahexyl substituted
phthalocyanine H<sub>2</sub>PcÂ(C<sub>6</sub>H<sub>13</sub>)<sub>8</sub><sup>np</sup> in its crystal
and columnar (Col) liquid crystal (LC) phase were investigated using
density functional theory (DFT) calculations in combination with molecular
dynamics (MD) and kinetic Monte Carlo (KMC) simulations. In the crystal
phase, we found that the nonperipherally substituted chains of H<sub>2</sub>PcÂ(C<sub>6</sub>H<sub>13</sub>)<sub>8</sub><sup>np</sup>, that interpenetrate adjacent phthalocyanines
(Pcs), significantly alter the Pc-core stacking such that higher hole
mobilities are observed for this system than for the nonsubstituted
H<sub>2</sub>Pc. This chain interpenetration was found to be inherited
by the column stacking in the Col phase and hindered the Pc-core in-plane
rotations between adjacent Pcs. This rotational hindrance further
caused a nonuniform distribution of the adjacent dimer Pc-core in-plane
orientation configurations. The relatively high carrier mobility in
the Col phase in this system can be rationalized by the nonuniform
distribution of the dimer configurations that give relatively high
electronic coupling between the adjacent dimers. Our results show
the remarkable effects of nonperipheral substitutions on the carrier
transport properties in both the crystal and Col LC phases
Manipulation of Liquid Filaments on Photoresponsive Microwrinkles
Microwrinkle grooves serve as open microchannel capillaries,
where
the capillary action depends on the wettability of a liquid on the
groove surface. Here, we report the photoinduced capillary action
of a liquid in such microwrinkle grooves. The wettability is changed
through the irradiation of a photoresponsive microwrinkle surface.
By utilizing micropattern light-projection apparatus, we prepare liquid
filaments that fill only the microgrooves prescribed by the patterned
light, with micrometer-scale spatial resolution. This new technology
enables the precise spatial control of liquids on a solid surface,
and thus, is applicable in the fields of micropatterning and open-channel
microfluidics
Manipulation of Liquid Filaments on Photoresponsive Microwrinkles
Microwrinkle grooves serve as open microchannel capillaries,
where
the capillary action depends on the wettability of a liquid on the
groove surface. Here, we report the photoinduced capillary action
of a liquid in such microwrinkle grooves. The wettability is changed
through the irradiation of a photoresponsive microwrinkle surface.
By utilizing micropattern light-projection apparatus, we prepare liquid
filaments that fill only the microgrooves prescribed by the patterned
light, with micrometer-scale spatial resolution. This new technology
enables the precise spatial control of liquids on a solid surface,
and thus, is applicable in the fields of micropatterning and open-channel
microfluidics
Dynamics of Discotic Fluoroalkylated Triphenylene Molecules Studied by Proton NMR Relaxometry
The Larmor frequency and temperature dependence of the
proton nuclear magnetic resonance (NMR) spinâlattice relaxation
time was measured in the isotropic and columnar phases of both chain-end
fluorinated triphenylene disk-like and fully hydrogenated molecules.
In the columnar phase, the results are interpreted in terms of the
collective motions, due to the deformations of the columns, and individual
molecular translational self-diffusion displacements and rotations/reorientacions.
In the isotropic phase, local molecular motions and order fluctuations
as a pretransitional effect were considered. The activation energies
of the molecular motions of the partially fluorinated molecule were
found to be higher than those corresponding to the hydrocarbon homologue.
Our findings show a clear difference in the relaxation dispersion
between the two liquid crystals homologues. In particular it is observed
that the columnar undulations have a much stronger contribution to
the relaxation rate in the low frequency regime in the case of the
fully hydrogenated triphenylene. The effect of fluorination of the
pheripheral chain enhances the columnar mesophaseâs stability
Correction to âSegregated DonorâAcceptor Columns in Liquid Crystals That Exhibit Highly Efficient Ambipolar Charge Transportâ
Correction
to âSegregated DonorâAcceptor
Columns in Liquid Crystals That Exhibit Highly Efficient Ambipolar
Charge Transport