Electrochemical synthesis advantages

The microtubular electrode concept described here also offers another possible advantage. In these concentric tubular electrodes, each particle of the Li intercalation material (the outer tube) has its own current collector (the inner metal microtubule). This could be an important advantage for Li+ intercalation materials with low electrical conductivity. This advantage was not demonstrated here because TiS2 has relatively high electronic conductivity. We have recently shown that electrochemical synthesis can be used to coat the gold microtubular current collector with outer mbes of a... 

In the past few years, however, very efficient new methods of cyclisation proceeding via radical intermediates have been developed and several reviews [19a] and a comprehensive book by Giese [19b] have been published. Rather than reactions involving the dimerisation of two radicals -as in the Kolbe electrochemical synthesis [20] or the radical induced dehydrodimerisation developed by Viehe [21]-more important are the reactions between a radical with a non-radical species. The advantage of this type of reaction is that the radical character is not destroyed during the reaction and a chain-reaction may be induced by working with catalytic amounts of a radical initiator. However, in order to be successful two conditions must be met i) The selectivities of the radicals involved in the chain-reaction must differ from each other, and ii) the reaction between radicals and non-radicals must be faster than radical combination reactions. 

Let us now discuss some applications of microemulsions in catalytic processes. It has been shown in [298] that the use of microemulsions instead of organic solvents for electrochemical reactions is advantageous from both economical and ecological reasons. The electrode/fluid interface in microemulsions probably consists of a dynamic layer of surfactant molecules packed more loosely on the electrode than in aqueous solutions. Microemulsions provide good yields of carbon-carbon addition products in reactions catalysed by cobalt complexes when preparing vitamin B 2. Excellent stereo-selective control in microemulsions made with the cationic surfactant cetyl trimethyl ammonium bromide was demonstrated for the catalytic cyclisation of 2-(4-bromobutyl)-2-cycIohexene-l-one to 1-decalone. Electrochemical synthesis may be a viable future approach to environmentally friendly chemical methods. 

In conclusion, a variety of parameters, whether they are internal or external to the aniline molecule, can affect the electrochemical synthesis of polyaniline as well as its physicochemical properties. By taking advantage of these effects, one can work out strategies to enhance the growth rate of the polymer and also modify the properties of the polymer in a desirable direction. 

Electrochemical synthesis is an attractive method to prepare oxide ceramic films and powders, because it offers the several advantages such as low processing temperature, low cost, high purity, normal handling pressure, and controlled microstructure. In the electrochemical synthesis of oxide fine particles, both anodic... 

CPs can be fabricated through a variety of routes which are classified as either predominantly electrochemical or chemical. While electrochemical synthesis has been more widely used for preparing nanoscale CP thin films for biomedical applications, chemical polymerization can produce large quantities of CP thick films or colloidal dispersions at low cost. Despite these advantages, chemical techniques have found relatively little application in biomedical applications. The advantages and disadvantages of electrodeposition and chemical synthesis are summarized in Table 18.2. 

Conducting polymers (CPs) are very popular matrices suitable for biomolecule immobilization in biosensors [44]. They show a suitable flexibility and can be chemically modified as required. The advantage of CPs is that their electrochemical synthesis allows direct deposition of a polymer on the electrode surface while... 

There are several industrial processes for succinic acid production (1) oxidation of paraffins forms a mixture of different carboxylic acids, followed by separation of succinic acid (2) catalytic hydrogenation of maleic acid or trani-maleic acid (3) electrochemical synthesis from maleic anhydride in a bipolar membrane or nonmembrane cell (4) production from acetylene, carbon monoxide, and water catalyzed by [Cq(CO) ] in an acid medium under a pressure of 2.94-49.03 MPa at 80-250°C. Among them, electrochemical synthesis is a generally applied process for succinic acid, which has the advantage of high yield, low cost, high purity of... 

Ultrasound, applied via a simple cleaning bath, has been shown to be beneficial in the electrochemical synthesis of Se2 and Se anions [41]. The method shows considerable advantages over previous techniques used for the preparation of these anions involving electro-reduction with a sacrificial Se electrode. A further major advantage of the sonoelec-trochemical method is that it is also applicable to the synthesis of the corresponding Te2 and Te anions. The Se and Te anions produced electrochemically can be used in situ for the synthesis of selenides and tell-urides in good yield (60 to 90%) via nucleophilic displacement from haloalkanes (Scheme 10.14) [42]. 

Despite all these advantages, alternative chemical methods of synthesis are being developed and improved [19-25] that will partly take the place of electrosynthesis, even for electrochemical applications such as batteries and sensors. This is associated in part with the great difficulties in correlating the properties of the material with the conditions of synthesis. This is a consequence of the complexity of electrochemical synthesis, which involves different experimental variables, both chemical (nature of the solvent, the monomer, and the dopant salt) and physical (temperature, electrical conditions, nature and shape of the electrodes, geometry of the cell). In addition, the effects of all these variables are interdependent. As a consequence, adequate control of polymer electrosynthesis, and hence of the polymer properties, will require analysis of the effects of the individual parameters and their reciprocal dependence. This will be the objective of the first part of the chapter. 

Numerous applications have been proposed and suggested for conducting polymers [397], Electrochemical synthesis will undoubtedly become an advantageous technique for many of these applications. Through electrochemical polymerization, conducting polymers may be directly synthesized onto any conducting substrate or form coatings for sensor materials or electrodes. 

Preparative electroorganic chemistry and natural product chemistry impinge on one another in several ways. First, electroorganic reactions have been used to synthesize natural materials of many types. Second, knowledge of the biogenetic reactions that are used in nature to make compounds has been used as a guide in the electrochemical synthesis of natural compounds. Finally, advantage has been taken of the unique polyfunctionality and stereochemistry that exist in many natural materials to learn about new electrochemical reactions. 

It seems likely that the use of liquid ammonia media may offer some advantages in the direct electrochemical synthesis of low oxidation state complexes. We hope to investigate this matter in the future. 

Simple and conventional catalytic synthesis method and stoichiometric organic or inorganic synthesis methods have an economic advantage as industrial process to compare with conventional electrochemical synthesis methods. A serious disadvantage of electrochemical method is complicated cell structure and components. Thus, excellent performances of product yield and selectivity by using unique electrocatalysis is essential to achieve a new green and sustainable electrochemical process in future. 

Application of reactive metal electrode gives several advantages in electrochemical synthesis. 

The conditions for the feasibility of the electrochemical synthesis of PHCs are that the monomer oxidation (or reduction, depending on the route) is accessible via a suitable solvent system and that the produced species reacts to form the polymer preferentially. Electrochemical synthesis has the advantage of producing the material on an electrode on which to perform analysis of the growing process and further experiments by electrochemical and/or spectroscopic techniques. Furthermore, the method allows easy control of the film thickness by the deposition charge. 

Electrochemistry has recently emerged as a powerful tool in a different field of research, i.e. the preparation of nanostructured conducting polymers [205] in fact electrochemical synthesis offers several advantages with respect to chemical polymerization, first of all the easy control of the thickness of a deposited polymer layer on any conducting surface. In modem synthesis, mild conditions such as low temperature and anhydrous atmosphere are often employed in order to achieve selectivity and high yields and electrochemical reactions generally fit this request. 

Conjugated polymers can often also be synthesized using a chemical oxidative polymerization. Distinct advantages of the chemical route over electrochemical synthesis are that there is no need for electrochemical instruments such as a potentiostat and that also nonconductive siufaces can be coated. Moreover, chemical polymerization is known to be simple and fast mefliod and strongly recommended if... 

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