Chemical modifications current applications

In the previous edition of this book, Dryhurst and McAllister described carbon electrodes in common use at the time, with particular emphasis on fabrication and potential limits [1]. There have been two extensive reviews since the previous edition, one emphasizing electrode kinetics at carbon [2] and one on more general physical and electrochemical properties [3]. In addition to greater popularity of carbon as an electrode, the major developments since 1984 have been an improved understanding of surface properties and structure, and extensive efforts on chemical modification. In the context of electroanalytical applications, the current chapter stresses the relationship between surface structure and reproducibility, plus the variety of carbon materials and pretreatments. Since the intent of the chapter is to guide the reader in using commonly available materials and procedures, many interesting but less common approaches from the literature are not addressed. A particularly active area that is not discussed is the wide variety of carbon electrodes with chemically modified surfaces. 

The understanding and prediction of such effects and the development of milder and more selective synthetic transformations, applicable to the synthesis of highly complex structures or to the selective chemical modification of proteins, DNA, or even living cells will continue to be the challenge for current and future generations of chemists. 

Abstract Phthalocyanines represent a versatile class of functional dyes which have found applications in various disciplines ranging from materials science, catalysis, nanotechnology to medicine. The intrinsic properties of the macrocycles as well as their molecular arrangements, both in solution and in the condensed phase, can be altered through rational chemical modification. Conjugation of other functional units to phthalocyanines can also complement the characteristics of the macrocycles. All these approaches can improve the performance of these macro-cyclic compounds as advanced functional materials. The purpose of this article is to provide an up-to-date review of the current research status of phthalocyanine-containing supramolecular systems. The formation, structures, and properties of self-assembled phthalocyanines as well as the non-covalent hetero-arrays containing phthalocyanines and other functional units are reviewed herein. 

The selection and chemical modification of the current generation of chemically and physically robust stationary phases with narrower particle and pore size distributions has been based on the developmental effort that has occurred over the past 20 years. Initially chemically modified, deformable polymeric gels were used, such as the crosslinked agaroses, dextrans, or acrylate-based copolymers, but more recently various classes of highly refined type I and type II silicas and other ceramic materials, or new classes of controlled porosity polymeric organic materials have found increasing application. 

Siliceous substrates are used extensively in industry and applied research. These materials can undergo a variety of chemical modifications that make them useful for applications such as catalysis and chromatography. An increased understanding of the nature of surface reactions and reaction products would facilitate current and future applications of these... 

Several kinds of enzymes have been used in many industries including food industries because enzymes catalyze the reaction at very moderate conditions and the reaction is very speciflc. Since enzymes are so useful and important, searching for a new enzyme with required characteristics such as higher heat stability, broader substrate specificity, etc. is inevitable. Altering some character of the currently used enzyme is extremely difficult. Immobilization of enzymes can sometimes stabilize enzymes but this is not applicable for all cases (7). Chemical modification of the enzyme also does not help so much to improve the enzyme character (2). There have been no appropriate methods to improve a character of the enzyme. 

Many chemical modifications have been applied to natural polymers to create new materials and applications. A very large number of compovmds made of modified cellulose or other modified natural polymers is currently in... 

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