cyclic voltammograms were taken for these two carbons by varying the scan rate from 5 mV/s to 50 mV/s, the SNU-2 carbon kept the rectangular-shape up to a scan rate of 20 mV/s (Fig. 5b, solid line). In contrast, the MSC-25 carbon showed a deformed cyclic voltammogram at a scan rate of 10 mV/s and a completely collapsed one at a scan rate of 20 mV/s (Fig. 5b, dotted line). A detailed discussion on the electrochemical studies of the material will be presented in a forthcoming paper.In conclusion, we have made a new high surface area mesoporous carbon using Al-HMS as a template. From this research we discovered that the pores of HMS are 3D interconnected, unlike the originally proposed disordered hexagonal structure. The EDLC performance of the carbon material was superior to the commercially available carbon MSC-25 due to improved mesoporosity. The CV of the mesoporous carbon showed ideal rectangular shapes at a high scan rate of 20 mV/s.
Spin-coated films of an ethylhexyl derivative of polyfluorene can be converted on a pretreated
polyimide substrate into highly oriented films by annealing in the liquid crystalline state. Together with
improving orientation segregation of the wormlike molecules with respect to chain lengths and lamella
formation proceeds. End groups are preferentially assembled in interlamellar regions. This morphological
feature is thought to influence all measurements of intrinsic properties of polyfluorene films with similar
histories. Electron diffraction patterns of the film are identical with X-ray fiber diagrams of fibers drawn
from the melt and annealed in the liquid crystalline state. The experimental data show that the polymer
molecules adopt a helical (5/q) conformation, packing in a trigonal unit cell. Molecular modeling based
on ab initio MO calculations have been carried out to obtain independent estimates of chain geometry
and conformation. These calculations are more in favor of a 5/2 rather than a 5/1 helix, with the argument
of the observed packing of the individual PF chains and a plausibly low torsion angle of adjacent fluorene
building blocks only for a 5/2 helix.
Monodisperse polyphenylene dendrimers up to the fourth generation were synthesized using
a divergent growth protocol. By varying the core, dendrimers with dumbbell-, tetrahedral- and propeller-like structures were synthesized. Because of the high-density packing of benzene rings within their
branches, these dendrimers are stiff and thus shape persistent. To obtain these dendrimers with a globular
shape, a 4-fold (A4B) dendrimer building unit was introduced. In this case, monodisperse dendrimers are
obtained only up to the second generation due to the significantly increased density of benzene rings
within the structure. For structure elucidation methods, like MALDI−TOF mass spectrometry, NMR
spectroscopy, GPC, VPO, TGA, and DSC were used. Dendrimers of the third and fourth generations
were visualized by transmission electron microscopy.
A series of amphiphilic diacetylene monocarbonic acids was synthesized, and their ability to form monolayers at the air–water interphase was investigated. Acids with total number of C atoms ≥20 and mp >45°C form surface states suitable to be used for buildup of multilayers by the Langmuir–Blodgett technique. Using the LB technique, multilayers of defined thickness were built up on quartz substrates. The multilayers were polymerized by exposure to a UV light source according to the mechanism of solid‐state polymerization of diacetylenes without destruction of the layer structure and with retention of the packing in the individual layers. Thus well‐defined polymer multilayers were obtained. The monomer and polymer multilayers were characterized by UV spectra, x‐ray small‐angle diffraction, and interference microscopic and electron microscopic techniques. The polyconjugated backbones of the polymer chains are all stretched out in the plane of the substrate but not over macroscopic dimensions because the multilayers have a crystalline domain structure. The polymer multilayer films are quite stable under ambient conditions.
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