4 research outputs found
Comparison results of dynamic shift functions.
Comparison results of dynamic shift functions.</p
Comparison of PSOLFWM with other meta-heuristic algorithms using t-Test.
Comparison of PSOLFWM with other meta-heuristic algorithms using t-Test.</p
Optically Active Chiral CuO âNanoflowersâ
Helical symmetry
can be found in most flowers with a rotation of
contort petal aestivation. For micro- and nanoscale analogies, flower
mimicking structures have been reproduced; however, the conceptual
chirality of ânanoflowersâ has not yet been defined.
Here, the chirality of the âflowerâ was defined by its
nanosized chiral structure and consequent optical activity (OA), opening
new horizons for the physical theory and chiral materials. We report
the surfactant-mediated hydrothermal synthesis of chiral CuO nanoflowers
using sodium dodecyl sulfate (SDS) as a structure-directing agent,
an amino alcohol as a symmetry-breaking agent, and cupric salt as
the inorganic source. Two levels of hierarchical chirality exist for
a CuO nanoflower including primary helically arranged ânanoflakesâ
and secondary helical âsubnanopetalsâ that form ânanopetalsâ.
The nanoflowers exhibited a prominent optical response to circularly
polarized light (CPL) at the absorption bands characteristic of CuO
Synthesis and Characterization of Macroporous Photonic Structure that Consists of Azimuthally Shifted Double-Diamond Silica Frameworks
A macroporous silica with azimuthally
shifted double-diamond frameworks
has been synthesized by the self-assembly of an amphiphilic ABC triblock
terpolymer polyÂ(<i>tert</i>-butyl acrylate)-<i>b</i>-polystyrene-<i>b</i>-polyÂ(ethylene oxide) and silica source
in a mixture of tetrahydrofuran and water. The structure of the macroporous
silica consists of a porous system separated by two sets of hollow
double-diamond frameworks shifted 0.25<i>c</i> along âš001â©
and adhered to each other crystallographically due to the loss of
the mutual support in the unique synthesis, forming a tetragonal structure
(space group <i>I</i>4<sub>1</sub>/<i>amd</i>).
The unit cell parameter was changed from <i>a</i> = 168
to âŒ240 nm with <i>c</i> = â2<i>a</i> by tuning the synthesis condition and the wide edge of the macropore
size was âŒ100 to âŒ140 nm. Electron crystallography was
applied to solve the structure. Our studies demonstrate electron crystallography
is the only way to solve the complex structure in such length scale.
Besides, this structure exhibits structural color that ranged from
violet to blue from different directions with the bandgap in the visible
wavelength range, which is attributed to the structural feature of
the adhered frameworks that have lower symmetry. Calculations demonstrate
that this is a new type of photonic structure. A complete gap can
be obtained with a minimum dielectric contrast of 4.6, which is inferior
to the single diamond but superior to the single gyroid structure.
A multilayer coreâshell bicontinuous microphase templating
route was speculated for the formation of the unique macroporous structure,
in which common solvent tetrahydrofuran in hydrophobic shell and selective
solvent water in hydrophilic core to enlarge each microphase sizes