Applied Photochromic Polymer Systems

1 Optical applications of organic photochromic polymer systems.- 1.1 Introduction.- 1.2 Potential for erasable optical storage in photochromic polymer systems.- 1.3 Photochromic imaging in ordered systems or in systems exploiting ordering effects.- 1.4 Applications in optical signal processing and in integrated optics.- 1.5 Conclusions.- References.- 2 Spiroxazines and their use in photochromic lenses.- 2.1 Introduction.- 2.2 Chemistry of spiroxazines, spiropyrans and related organic photochromic compounds.- 2.2.1 Nomenclature.- 2.2.2 Synthesis.- 2.2.3 Photochemistry of the spirophotochromics.- 2.3 Required properties of photochromic systems for eyewear.- 2.3.1 General.- 2.3.2 Absorption spectra of unactivated and activated states.- 2.3.3 Kinetics of photochromic lens processes.- 2.3.4 Fatigue resistance (eyewear lifetime).- 2.4 Structure-property relationships of spiroxazines.- 2.4.1 Indolinospiroxazines.- 2.4.2 Other spiroxazines.- 2.5 Stabilization of spiroxazines.- 2.6 Development of a commercial system for plastic photochromic eyewear.- 2.6.1 Plastic lens manufacturing.- 2.6.2 Processes for photochrome incorporation.- 2.6.3 The finished lens.- References.- 3 Fulgides and fulgimides - a promising class of photochromies for application.- 3.1 Introduction to fulgides and fulgimides.- 3.2 Aryl fulgides.- 3.2.1 Introduction.- 3.2.2 Spectroscopic properties.- 3.2.3 Photochromism.- 3.2.4 Fatigue resistance.- 3.3 Fulgides with heteroaromatic groups - fatigue-resistant fulides.- 3.3.1 (E)-0?-2,5-(hmemyl-3-furylethylidene (isopropylidene)succinic anhydride.- 3.3.2 Structural modification of fulgides with heteroaromatic groups.- 3.4 Heliochromic compounds.- 3.4.1 Definition.- 3.4.2 Development of heliochromic fulgide derivatives.- 3.5 Fulgides and fulgimides in polymer matrices.- 3.5.1 Introduction.- 3.5.2 Investigations of photochemistry of fulgides in polymers.- 3.6 Applications of fulgides and fulgimides.- 3.6.1 Introduction.- References.- 4 Photochromic liquid crystal polymers.- 4.1 Introduction.- 4.1.1 Mesomorphic phases.- 4.1.2 Important photochromic systems.- 4.2 Search for photochromic mesophases - Quasiliquid crystals (QLCs).- 4.3 Photochromic liquid crystal polymers.- 4.3.1 Synthesis of copolymers.- 4.3.2 Thermodynamic properties.- 4.3.3 Thermochromism.- 4.3.4 Photochromism.- 4.4 Non-linear optical properties.- 4.4.1 Basic concepts.- 4.4.2 Theory of SHG from a mesophase containing high-ß dye.- 4.4.3 Non-linear optical susceptibility measurements.- 4.4.4 Two-dimensional asymmetry and optical non-linearity upon poling by an electrostatic field.- 4.5 Optical information recording and storage.- References.- 5 Photoresponsive polymers: reversible control of polymer conformation in solution and gel phases.- 5.1 Introduction.- 5.2 Photostimulated conformation changes of polymers in solution.- 5.3 Photostimulated phase separation of polymer solutions - another approach to induce the conformation changes of polymers.- 5.4 Photostimulated shape changes of polymer gels - continuous change.- 5.5 Photostimulated volume phase transition of gels - discontinuous change.- References.- 6 High and low molecular weight photochromic viologen-based systems.- 6.1 Introduction.- 6.2 Synthesis of viologens bearing vinyl groups and their polymers.- 6.3 Reversible colour development (photochromism) of viologens by photoreduction mechanisms (in matrices).- 6.4 Generation of viologen radical cations in solution.- 6.5 Photochromism of viologen crystals.- 6.6 Preparation of polar aprotic viologen copolymers and their photochromic behaviour.- 6.7 Photochromism of N-aryl viologens.- 6.8 Viologens developing infrared absorption peaks (near 800 nm) by redox photochromism.- 6.9 Comparison of various viologens and photochromic reaction mechanism in the poly(N-vinyl-2-pyrrolidone) (PVP) matrix.- 6.10 Photomemories based on viologen photochromism..- References.

Photochromic polymer systems are of two main types - those which are merely solid solutions of photochromes in polymeric matrices and those custom-designed polymers which inherently exhibit photochromism. This book provides a concise review of developments in such systems over the past two decades. The coverage has been limited specifically to applied systems, or areas with potential applications, although over 500 references cite much of the literature on the fundamentals of the subject. The book aims to complement existing and recent books on photochromism which deal with low molecular weight photochromic systems mainly from a more fundamental perspective. It should appeal to industrial and academic researchers in materials science, chemistry, physics and electronics.