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Temperature dependence of electric current for fully aromatic and semi-aliphatic polyimide films (PIs) having different chemical structures was investigated. The current densities of PIs having a triphenylamine (TPA) structure (pyromellitic dianhydride/DATPA and 3,4,3′,4′-biphenyltetracarboxylic dianhydride/DATPA) significantly increased above 120 °C, which is mainly due to the exponential increase in thermally excited electronic carriers. In contrast, the current density of PIs without TPA structure exhibited smaller temperature dependence, which suggests that ionic current is dominant because of the limited numbers of thermally excited carriers because of their large band gaps (Eg).
The structures and electronic states in polymorphs (Forms I–IV) of PVDF were calculated by the density functional theory at PBE0/cc-pVTZ level. The calculated lattice constants agreed well with experimental values. Derived electronic and vibrational frequencies corresponded closely with the experimental vXPS and IR/Raman spectra, respectively. The amounts of spontaneous polarization in the polar crystal forms (I, III, and IV) were calculated. Those for Forms III and IV were determined for the first time.
Biomimetic dimpled and multilayered films containing black thin layers, which had multi-angle reflectivity, were successfully prepared by embossing microlens arrays on the multilayered films.
Surface texturing of catechol derivative urushiol was achieved using a thermal imprinting technique. An indented surface was obtained by thermal curing at 100 °C for 10 min while pressing an urushi film with a patterned mold. The indented surface enhanced the static water contact angle in comparison with the flat urushi film.
Rotating ring-shaped microtubule assemblies were successfully formed on dynein-coated surface through active self-organization process in a similar way to kinesin. However, no preferential direction of rotation was observed in contrast to the aforementioned results of previous kinesin studies. This indicates that dynein is less sensitive to the experimental condition than kinesin.
The injection-molded isotactic polypropylene (PP) containing a specific nucleating agent exhibits unique molecular orientation. Although the skin layer has ‘woven-cloth’ structure, in which α- and β-form crystals orient perpendicular to each other, it shows positive birefringence on average because of the stronger orientation of α-form crystals. In the core, both crystals show perpendicular orientation to the flow direction. As the average orientation direction in the skin layer is perpendicular to that in the core, the anisotropy in mechanical properties and thermal expansion is greatly reduced.
A bis(tert-butyl) isophthalate (B-IP) was utilized as a dissolution inhibitor in chemically amplified three-components resist. In extreme ultraviolet (EUV) exposed area, tert-butyl groups of B-IP were decomposed by the effect of protons generated from photo-acid generator, and B-IP was converted to a carboxylic acid, being played a role of dissolution promoter. Furthermore, B-IP was acted as a plasticizer in the resist and the protons were diffused through the resist easily. The resist containing B-IP was improved its sensitivity and dissolution contrast, although the properties are a relation of trade-off.
Poly(vinylbenzyl chloride) (PVBC) with controlled molecular weight and polydispersity was obtained by reversible addition-fragmentation chain transfer (RAFT) polymerizations of vinylbenzyl chloride using benzyl ethyl trithiocarbonate as the RAFT agent. Furthermore, amphiphilic AB diblock copolymers PVBC-b-PNIPAMs could be successfully prepared by RAFT polymerization of N-isopropylacrylamide (NIPAM) by using PVBC macro-RAFT agent.
The polysilsesquioxanes containing tetra(ethylene glycol) chains were newly prepared and modified by several kinds of hydrophobic components. The obtained polysilsequioxane derivatives showed a reversible thermoresponsive aggregation behavior in an aqueous solution. The introduction of azobenzene structure as the hydrophobic component led to the polysilsesquixane that showed the combined photo- and thermostimuli responsive properties.
We obtained a flexible nano-alloy with a continuous soft, lacy SEB matrix after blending a high-styrene-content styrene-b-styrene-co-butadiene-b-styrene triblock copolymer (S-SEB-S) with a modified poly(2,6-dimethyl-l,4-phenylene ether) (PPE). The simultaneous stress and birefringence measurements revealed that the orientation of the glassy domain is suppressed, and only the soft SEB segments are oriented from the lower strain region in the nano-alloy when compared with those in the S-SEB-S material. Consequently, the S-SEB-S/PPE nano-alloy is flexible despite its blending of the high-styrene-content S-SEB-S with a high-strength PPE.
