An electrochemical route to poly( p-phenylenevinylenes) (PPVs) is described which involves cathodic cleavage of bis(dibromomethy1)arenes at a mercury pool cathode. Insoluble and organosolv PPVs are obtained in good yields and are characterised as regular and linear. Copolymers are obtained by co-electrolysis of different bis(dibromomethy1)arenes. The method is versatile and much functionality is tolerated. The polymers can be made conducting by doping with BF, or SO3. The effect of substituents on conductivity correlates, roughly but significantly, with Hammett o-values.Poly( p-phenylenevinylene), the parent PPV, forms conducting blends with poly(viny1 alcohol).-f This paper is Part 44 of a series entitled 'Electroorganic Reactions'.

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Sodium tungstate (Na 2 WO 4 ) and hexamethylene tetramine (HMTA) are both eco-friendly corrosion inhibitors. In this work, their synergistic corrosion inhibition effects on reinforcing steel in the simulated polluted concrete pore solution containing Cl − were studied by electrochemical techniques including electrochemical impedance spectroscopy and potentiodynamic anodic polarization curve measurements. The morphologies and compositions of the steel surface were characterized by Electron Micro-Probe Analyzer, X-ray photoelectron spectroscopy, and Raman spectroscopy. The results showed that the serious steel corrosion took place in the solution with pH 11.00 and 0.5 M NaCl. However, a stable passive region occurred in the anodic polarization curve of the steel and its corrosion current density decreased dramatically after addition of a mixed inhibitor with 0.01 M Na 2 WO 4 and 0.01 M HMTA to the solution. The inhibition efficiency of the mixed inhibitor reached 97.1%. The surface analyses revealed that a protective composite film was formed on the steel in the solution with the mixed inhibitor, which indicated that the mixed inhibitor had a synergistic inhibition effect on the steel corrosion. Our study also indicated that the mixed inhibitor could effectively control corrosion of the reinforcing steel in cement mortar.Reinforcing steel in concrete is normally protected from corrosion by the passive film formed on its surface under high alkaline conditions of concrete. However, the passivity of the reinforcing steel may be destroyed and corrosion take place while aggressive species from the environment such as Cl − , CO 2 , SO 2 , etc., reach the steel-concrete interface through the porous concrete. 1-4 The damage of reinforced concrete structures and economic losses caused by reinforcing steel corrosion are still serious problems. Hence, many techniques have been developed to protect reinforcing steel from corrosion. The application of corrosion inhibitors is one of the most practical methods to control the corrosion of reinforcing steel. 5-7 In recent years, increasing attention has been paid to the environment-friendly corrosion inhibitors and natural products such as plant extracts, amino acids, some inorganic salts, proteins and bio-polymers. [8][9][10][11][12][13][14][15][16][17][18][19] Tungstate has been extensively studied in the protection of iron as an environmental-friendly anodic type inorganic corrosion inhibitor, 20-27 and is one of the most effective corrosion inhibitor. However, tungstate is not feasible to be used alone for corrosion protection of carbon steel due to its low oxidizing ability, high cost and low efficiency at a low concentration. Therefore, many co-inhibitors are used, such as polyaspartic acid, 28-30 metaborates and metaphosphates, 22,24,31 sodium silicate, 27 sodium tartrate, 32 phosphates and zinc salts. 26 The compounds of tungstate synergistically in combination with small molecule compounds (such as amine) for the protection of steel are supposed to be good corrosion inhibi...

SnO 2 nanoparticle films on transparent conductive glass substrates were fabricated by a pulse current deposition technique, and the electrochemically deposited SnO 2 films were applied as photoanodes to achieve effective photocathodic protection of metals. The results indicated that the films were composed of crystallized SnO 2 nanoparticles. The photoelectrochemical properties of the films were improved by annealing. The annealed film was more stable than the unannealed one. Photoelectrochemical measurements showed that both the unannealed SnO 2 film and the annealed SnO 2 film could provide effective photocathodic protection effects on 403 stainless steel in a 0.5 M NaCl solution under white light illumination.Since Yuan and Tsujikawa reported that the TiO 2 coating could provide a photocathodic protection effect on copper substrates, 1 the preparations and the photoelectrochemical properties of TiO 2 films have attracted great interests in the field of corrosion and protection of metals. Many relevant investigations on TiO 2 films for corrosion protection of other metals have also been carried out. 2-6 However, there are some problems for practical applications of a pure TiO 2 material. 7-12 One limitation is its low photoelectric conversion efficiency resulting from the fast recombination of the photoinduced charge carriers. 7-9 Another drawback is that the pure TiO 2 cannot provide effective photocathodic protection for metals under dark conditions. 10-12 These problems may be overcome by using composite films consisting of TiO 2 and electron storage materials or by selecting other alternative materials. Crystalline tin dioxide (SnO 2 ) as an important n-type semiconductor is similar in photoelectrochemical properties to TiO 2 . Besides, its electron mobility is higher than that of TiO 2 for both single crystals and the corresponding nanostructures, 13-15 which makes SnO 2 a good candidate for high performance photoelectric devices. Studies in the literature show that SnO 2 is often used as an energy storage material. 16,17 Thus, it is expected that a SnO 2 nanoparticle film can offer a good photocathodic protection effect on metals under illumination.SnO 2 is a promising functional material that has been extensively used in photocatalysis, 18,19 gas sensing, 19,20 solar cells 21,22 and lithiumion batteries. 23,24 Therefore, developing a facile and effective method to prepare SnO 2 nanomaterial films under mild conditions is of great importance for practical applications. Among the various preparation methods, electrochemical deposition is a cost-effective and convenient technique suitable for large scale production of SnO 2 films. Additionally, it allows for the direct contact of the active material with the substrate without any intermediate linkers and favors the interfacial charge transfer process. Consequently, we can obtain SnO 2 nanomaterials with a larger capacity per unit weight and superior photoelectrochemical properties by electrochemical deposition techniques. In the previous reports, 25-27 ele...

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