Development of radiation chemistry

The scientific development of radiation chemistry is reviewed from the discovery in 1895 of x-rays and radioactivity by Roentgen and Becquerel through to the present. 

The purpose of this article is to review the development of radiation chemistry which began with the discovery of x-rays by Roentgen(l) in 1895 and shortly afterwards of radioactivity by Becquerel(2), which in both cases Involved the observation of chemical change in photographic plates and luminescence in certain phosphors. Clearly, in the space available, the review will be restricted and subjective, but will, it is hoped, give the general framework in which the subject has developed. 

In the course of this lecture I have attempted to outline the development of radiation chemistry from its beginnings. The main historical theme has been the elucidation of the extent to which neutral free radicals as opposed to Ionic species contributed to the overall chemistry. Our present understanding leads to the view that the interplay between free radical and ionic processes is very dependent on the system being considered, particularly its dielectric properties and the presence, or absence, of solutes which can react with electrons or cations. 

Detailed accounts of the development of radiation chemistry and its tools can be found elsewhere. The purpose of this chapter is to describe the basic characteristics of continuous and pulsed sources of ionizing radiation for radiolysis studies, and to provide a broad overview of the present and near-future status of radiolysis instrumentation worldwide, for the benefit of readers who would like to use these powerful techniques to advance their own research. It is inevitable under the circumstances that some facilities may be missed and that future developments will soon render this overview out-of-date, however the substantial progress that has been made in the years since the previous reviews appeared [14-16] merits description here. 

These few examples illustrate the versatility and the broad applicability of radiation processing to polymers, from simple performance improvement for commodity plastics to advanced developments of radiation chemistry for nanotechnologies. 

Theory has played an essential role in the development of radiation chemistry, especially in its early days when experiment was unable to probe the early events that set the stage for the observable chemical reactions. Three themes that were established early on were scattering processes, electronic structure determinations, and track simulations. Work done in the 1950s through 1970s depended greatly on formal development, both because the basic possibilities needed to be identified and because the available computational tools could not tackle the complexity of the problems. The decades that followed... 

Ionizing radiation produces ionized and excited atoms and molecules in all materials. Excited molecules formed directly or by recombination reactions between electrons and cations decompose in the vast majority of systems to highly reactive free radicals. The reactive species formed on radiolysis are precursors of further reactions, such as reduction, oxidation, polymerization, cross linking and so on. It should therefore be possible to apply radiation chemical methods to industrial processes and, consequently, extensive applied research and development of radiation chemistry has been carried out during the past three decades. 

The Royal Institute of Chemistry publishes a Lecture Series formerly known as Lectures, Monographs and Reports series which consists mainly of lectures on various subjects, several of which are issued each year as individual booklets. Each author is a prominent personality and many of the lectures are provided with useful bibliographies. Many of these publications are in the nature of reviews, e.g. Some Recent Advances in Physical Chemistry, by A. R. J. P. Ubbelohde (1954, No. 3), The Development of Radiation Chemistry and Radiochemistry, by J. Cockroft (1954, No. 1), Modern Aspects of Thermochemistry, by H. A. Skinner(1958,No. 3), Recent Progress in the Chemistry of Dyes and Pigments, by W. Bradley (1958, No. 5), Recent Studies in Boron Chemistry, by H. G. Heal (1960, No. 1), and Recent Developments in Polarography, by G. W. C. Milner (1961, No. 3). 

In studies of this kind, methods developed in radiation chemistry and photochemistry are often applied The methods of pulse radiolysis and flash photolysis allow one to investigate the mechanism of reactions in which free radicals, electrons and positive holes are the intermediates. In order to understand the mechanisms of processes that occur on colloidal particles it is important to know how free radicals... 

Allen, A.O. The story of the radiation chemistry of water. In Early Developments in Radiation Chemistry, Kroh, J., Ed. Royal Society of Chemistry London, 1989 p 1. 

It is clear that the development of nuclear technology is impossible without the support of radiation chemistry. Thus the radiation chemistry is important not only in basic science, but also in technology. 

Okamura S (1989) A short history of applied radiation polymer chemistry in Japan. In Kroh J (ed) Early developments in radiation chemistry. Royal Soc. Chem., London, 321... 

The history of the development of radiation uses in the polymer field is an interesting example of how a new technology is transferred from the laboratory to industry. It is concerned with classical techniques in polymer chemistry, suddenly confronted with a new tool, radiation, which at first is only available on a small scale, suitable for fundamental research but which, under the pressure of new and valuable results, is finally accepted by industry in spite of its frightening environment. Today we witness the development of this technology in many different branches of industry. It is, however, still in its infancy and further growth is expected to follow from presently known facets as well as from the discovery of new applications. 

Radiation chemistry has developed very similarly to photochemistry. Max Matheson, one of the pioneers of radiation chemistry, said, Radiation chemistry always trails photochemistry in time response. That trend continues today. 

Please also excuse errors in summarizing the earlier experiments. Information about these was obtained by reading the literature and by reading review articles by the relevant authors, as I was not in the field yet. In particular, I will be making use of the information in Early Developments in Radiation Chemistry edited by Jerzy Kroh, a book that collected the personal accounts of many of the most prominent radiation chemists of the middle of the 20th century, and The Chemieal Effects of Alpha Particles and Electrons by Samuel C. Lind, which discussed much of the radiation chemistry up to 1928. 

During World War II, the atomic-bomb-development effort in the United States required a sudden increase in the knowledge of radiation chemistry. Water was going to be part of the reactors that were to produce plutonium to make bombs. Materials, including vacuum pumps, hoses, connectors and oils were to be exposed to very high levels of neutron and gamma radiation. Previous work was totally insufficient to understand the effects on these materials. 

The development of the sources led to studies in polymers, solids, organic systems, which were too numerous to mention. One only needs to look at the chapters by Dole, Willard and others in the book on the history of radiation chemistry to find the wide range of chemical systems that could be studied. ... 

Hart EJ. (1989) Radiation chemistry at the biological laboratory, Cold Spring Harbor, Long Island, New York (1928-1938). In Kroh J (ed.), Early Developments in Radiation Chemistry. Royal Society of Chemistry, Cambridge, England, pp. 217-232. 

Recent Trends presents a picture of radiation chemistry as a vibrant field of international venue, still addressing fundamental challenges as it continues to grow into its second century. This image is reinforced, and both broadened and deepened, by a number of edited volumes Rndintion Chemistry Present Status and Future Trends — Jonah and Rao (2001) Char ed Particle and Photon Interactions with Matter — Mozumder and Hatano (2004) Radiation Chemistry From Basics to Applications in Material and Life Sciences— Belloni et al. (2008) which have appeared within the last few years. A clear articulation of prospects for future development was also presented at the recent visionary meeting Radiation Chemistry in the 21st Century held at Notre Dame in July, 2009. 

In this book, we have made an effort to provide an overall view of the emerging trends in radiation chemistry authored by experts in the field. The introductory chapter covers the history of radiation chemistry, underlining its achievements and issues that need to be addressed in future research. By renewing its research directions and capabilities in recent years, radiation chemistry research is poised to thrive because of its critical importance to today s upcoming technologies. Detailed accounts of fast and ultrafast pulse radiolysis instrumentation development and recent advances on ultrafast... 

The purpose of the book is to expose graduate students and young scientists working in the field to recent developments in radiation chemistry research and to demonstrate to scientists, engineers and other technologists the utility of radiation chemical techniques in advancing their scientific pursuits. The fact that radiation chemistry is... 

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