Polarization measurement and an accelerated life test of the oxide-coated titanium anodes in relatively dilute solutions of NaCl and in HClO4 solution were conducted. The OCTA failed at potentials higher than 1.3V vs. SCE, probably due to anodic oxidation of RuO2 and passivation of Ti substrate. An accelerated life test based on those results has been investigated to estimate the OCTA. The polarizing current decreases quickly when the OCTA becomes inactive, and the service life of material is evaluated by the time-to-failure from the start-up.A n u m b e r of the oxide-coated titanium anodes (OCTA) consisting of RuO2 and TiO~ are being used because of durability and low chlorine overvoltage in chlor-alkali cells. But eventually the OCTA becomes inactive and a part of the oxide drops out (arrow in Fig. 1). Low oxygen overvoltage is another problem for this oxide anode in chlorine cells.The OCTA is stable and its chlorine overvoltage is p r e f e r a b l y low in concentrated NaC1 solutions even a t high current densities, whereas it is attacked g r a d u a l l y and the anode potential becomes high in dilute N a C 1 solutions.Since the OCTA has come into the m a r k e t in early 1970's, m a n y articles on its preparation, modification, physico-chemical properties, electrochemical characteristics, and applications have been published. Degradation and deactivation of its unique material have also been discussed. With those articles and patents, degradation of the OCTA in chlor-alkali cells can be classified into three types: (i) coating dissolution, (ii) substrate a t t a c k , and (iii) substrate oxidation leading to electrical insulation, as stated by W a r r e n et al., who have studied the P t -I r alloy coated anodes for chlorate cells (1, 2).Extensive studies on the OCTA as well as the solid Ru metal anodes in sulfuric acid solution and solid p o l y m e r electrolyte have been conducted as a part of new developments in high-performance water electrolysis. Low oxygen overvoltage of those materials is a reason. However, dissolution a n d / o r degradation of the anode material at high potential ranges, and hence at high current densities, is a problem (3).Experiment of the OCTA under the operating conditions of chlorine cells are time-consuming, about one y e a r or more for only one run. Consequently, this paper deals mainly~with an accelerated life test and its procedure for the OCTA. The procedure is simple and requires minimum labor even for a prolonged period. The test specimen of the OCTA is electrolyzed in a mixed solution of HC104 and NaCI or in HC104 single solution under a constant terminal voltage, and the current is recorded until the test specimen breaks down. The concept is based on gradual degradation of the active material due to oxygen evolution. ExperimentsTest specimen.--Titanium sheet of 5 m m wide, about 150 m m long, and 0.5 m m thick was pickled with 10% oxalic acid at about 80~ for about 3 hr, rinsed Fig. I. SEM photograph ot degraded surface of OCTA 1439 ) unless CC License in place (s...

An efficient cathode material with high transparency (93%) based on conducting polymer poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and single wall carbon nanotubes (SWCNTs) has been developed for the fabrication of highly transparent and flexible field electron emitters (FEE). This kind of material showed superior field emission (FE) performance with very high current density (10–3A/cm2) at very low electric field. The FE performance of the hybrid materials was dramatically improved compared to either SWCNTs and PEDOT:PSS. Thus the hybrid structures of conducting polymer and SWCNTs might be a good choice for use as a cathode material to enhance the FE performance and for potential application in future portable displays. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Carbon nanotubes (CNTs) have been widely used in various fields such as transparent and flexible field emission displays (FEDs) [1], scanning probes [2], solar cells [3], transistors [4] and supercapacitors [5] etc., because of their extraordinary electronic and mechanical properties [6,7]. CNTs are very effective for FEDs due to their sharp emission tips and high aspect ratio [8][9][10][11]. Materials such as conical nanocarbon structures (CNCSs) [12], graphene [13][14][15][16], and zinc oxide (ZnO) based nanostructures [17][18][19][20] Recently, carbon based transparent and flexible FEE of graphene with multi-wall carbon nanotubes (MWNTs) have been reported [27]. In our recent reports, we used a very straightforward method of the random networks of single-walled carbon nanotubes (SWCNTs) on flat polymer substrates to fabricate transparent and flexible FEE [28]. Recent reports have been focused on the fabrication of CNCSs on nafion substrate at room temperature [29,30]. The low transmittance of the CNCSs and high turn-on and threshold field were major drawbacks towards the fabrication of transparent and flexible FEEs. Replacing the metal layer by other transparent materials on the CNCSs surface could be very interesting to enhance the FEE performance and the transparency of the device. However, the controlled growth of the hybrid nanostructure on heat-sensitive substrate is a challenging task and We demonstrate a unique strategy to fabricate highly transparent and flexible field electron emitters (FEEs) based on combined carbon nanostructures, i.e., conical nanocarbon structures (CNCSs) and single-walled carbon nanotubes (SWNTs). The combined structure was prepared by spray coating of 1,2-dichloroethane (DCE) dispersed SWNTs onto neon ion (Ne + ) irradiation induced CNCSs on nafion substrate. The field emission (FE) property of SWCNTs on both flat nafion and CNCSs surfaces increased with increasing the SWCNTs amount. The best FE result was attained for the highest amount of SWCNTs on the CNCSs substrate. This kind of collective structures is found to be effective emitters on transparent and flexible ion-irradiated nafion substrate.Moreover, the combined carbon nanostructures showed improved transparency and emission performance compared to the individual nanostructures. The FE properties of 0.5 ml SWCNTs solution on CNCSs surfaces were equal to those of 1.5 ml SWCNTs solution on flat nafion surface. The hybrid structure based emitters (CNCSs and SWCNTs) produced by this method are lower-cost cathode materials than hybrid structures of SWCNTs and flat nafion. Thus the combined nanostructures of SWCNTs/CNCSs might have huge prospects for the fabrication of efficient transparent and flexible FEEs and their broad application in next-generation portable display devices.

Highly transparent (transparency 96.5%), flexible and antireflective superhydrophobic (water contact angle >150°) surfaces have been fabricated at room temperature by the ion irradiation method. This one‐step fabrication route was fairly easy to carry out without any heat or chemical treatment and can be completed within few seconds. This novel chemical free fabricating strategy could be extended to numerous polymeric substrates to achieve transparent and flexible superhydrophobic structures for their potential applications in diverse fields. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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