The recent, rapid expansion in our understanding of the structure-properties relationship of many chemical compositions at the molecular level enables us design new functional materials useful for practical applications. One such group of materials is the so-called “smart materials”, which are also called “stimuli-responsive” or “intelligent” materials. Some scientists and engineers prefer to describe them as “designed materials”. “Smart materials”, responding to external stimuli, undergo alteration in their functional properties of mechanical, optical, including spectroscopic or electromagnetic, behavior due to changes occurring in their molecular structure, composition or morphology. I believe that there would be no objection to calling this century “the age of smart materials”. These materials are leading the rapid innovative developments that we are presently experiencing in many technological fronts, responding to pressing global demands.

This book, Mechanochromic Fluorescent Materials: Phenomena, Materials and Applications, is a valuable addition to the limited list of monographs published on the topic of smart materials. This book is unique in that its content covers a complete spectrum of the science and engineering of mechanofluorochromic compounds and materials: low molar mass compounds, polymers and their composites, organometallic complexes and molecular aggregates or assemblies. This book not only guides us to novel exciting new discoveries about how some of compounds and polymers reveal optical and spectroscopic responses to external stimuli, but also teaches us molecular-level understanding of the changes, both in the chemical structural and micro- or macro-morphological levels. There are many expectations that those materials will soon find a wide variety of advanced technical applications. The topics of each chapter are superbly connected and the overall contents are very well balanced. This book is expected to be very helpful for advanced undergraduates, graduate students and those who would like to enter this particular area of research to attain an overall, but relatively comprehensive view of the subject of this monograph.

I would like to extend a warm compliment to Prof. Jiarui Xu and Prof. Zhenguo Chi, editors of this book, and all the contributors, for bringing us the science of the exciting new developments on the phenomena and materials of mechanofluorochromism. It is my sincere hope that this book decorates brilliantly the desks and bookshelves of concerned students, scientists and engineers. On behalf of the authors, I would like to thank the Royal Society of Chemistry for having selected such a wonderful topic and helping to publish this book in a very timely fashion.

Jung-Il Jin

Former President of IUPAC

Distinguished Professor of Korea University