During the last two decades, the production of polymers and plastics has been increasing rapidly. In spite of developing new polymers and polymeric materials, only 40~60 are used commercially on a large scale. It has been estimated that half of the annual production of polymers is employed outdoors. The photochemical instability of most polymers limits their outdoor application as they are photodegraded quickly over periods from months to a few years. To the despair of technologists and consumers alike, photodegradation and environmental ageing of polymers occur much faster than can be expected from knowledge collected in laboratories. In order to improve polymer photostability there has been a very big effort during the last 30 years to understand the mechanisms involved in photodegradation and environmental ageing. This book represents the author's attempt, based on his 25 years' experience in research on photodegradation and photo stabilization, to collect and generalize a number of available data on the photodegradation of polymers. The space limitation and the tremendous number of publications in the past two decades have made a detailed presentation of all important results and data difficult. The author apologizes to those whose work has not been quoted or widely presented in this book. Because many published results are very often contradictory, it has been difficult to present a fully critical review of collected knowledge, without antagonizing authors. For that reason, all available theories, mechanisms and different suggestions have been presented together, and only practice can evaluate which of them are valid.

In this book on physical characteristics and practical aspects of polymer photodegradation Rabek emphasizes the experimental work on the subject. The most important feature of the book is the physical interpretation of polymer degradation, e.g. mechanism of UV/light absorption, formation of excited states, energy transfer mechanism, kinetics, dependence on physical properties of macromolecules and polymer matrices, formation of mechanical defects, practics during environmental ageing. He includes also some aspects of polymer photodegradation in environmental and space condition.

Photodegradation of Water Pollutants, the only complete survey available of current photocatalytic methods for treating water pollutants, covers all aspects of light-stimulated detoxification. Ideal for researchers and students, this new book explains methods for pollution treatment that have proven more effective than conventional biodegradation. Photodegradation of Water Pollutants examines advanced oxidation processes that have been successful in treating the chemical substances produced by industrial effluents and intensive agriculture. These oxidation processes include irradiation with ultraviolet or visible light, the use of homogenous sensitizers, such as dyes, and the use of heterogeneous photocatalysts, such as dispersed semiconductors. In addition, Photodegradation of Water Pollutants addresses the naturally occurring self-cleaning of some pollutants in sunlit surface waters, as well as several alternative non-photochemical approaches to water treatment. Available treatment options are discussed for the main groups of water pollutants, including toxic inorganic ions (cyanides, heavy metals), hydrocarbon derivatives (oil spills, surfactants, pulp and paper wastes), halocarbons, organo-N, organo-P, and organo-S compounds. The text also contains a unique section on the economics of advanced oxidation pollution treatments.

Advanced Functional Materials and Methods for Photodegradation of Toxic Pollutants addresses the potential role of visible active photocatalytic methods for the removal of various emerging and persistent organic pollutants (POPs.) Describing the classification, sources and potential risks of emerging organics in water bodies and the environment, the book covers the different synthesis methods of visible active structured photocatalysts and structure related properties to their applications in photocatalytic processes for the removal of antibiotics, pharma and heavy metal pollutants. This book provides an invaluable reference to academics, researchers and technicians in chemical engineering, chemistry and environmental science. In addition, the mechanistic insights associated with the interaction of advanced functional materials and water pollutants along with the possible reaction pathway occurring during the visible light induced photocatalytic processes together with toxicity are discussed in detail along with the reutilization of catalysts, supporting the inherent reaction conditions performed with natural conditions. Covers the recent progress in nano photocatalytic materials Explores the mechanism of photocatalytic degradation of pollutants Includes the controlled synthesis of nanostructured photocatalysts and their modifications for targeted pollutants

Recent development of plasmonic photocatalysts for photodegradation of organic pollutants / Tao Li, Huijuan Jing and Deliang Chen -- Photodegradation of profoxydim herbicide; kinetics, phytotoxicity bioassay and determination of relevant parameters by QSAR models / P. Sandín-España, J. J. Villaverde, B. Sevilla-Morán, M. J. Patiño-Ropero, J. L. Alonso-Prados and I. Santín-Montanyá -- Photodegradation mechanism of cyanine dyes / Masanori Fuyuki -- Photochemistry of cobalamins / Kiran Qadeer, Adeel Arsalan, Zubair Anwar and Iqbal Ahmad -- Two dimensional (2D) tungsten disulfide (WS2) as a cocatalyst for degradation of organic pollutants / S. V. Prabhakar Vattikuti -- Photodegradation of water contaminants and humic acids of different nature and genesis using various light sources / Irina V. Sokolova and Olga N. Tchaikovskaya.

Degradation of Polymers