This book covers the design, synthesis, properties, and applications of functional photoactive soft materials, including aspects of polymers, block copolymers, elastomers, biomaterials, liquid crystals, chemical and physical gels, colloids, and host-guest systems. It combines, in a unified manner, authoritative accounts describing various structural and functional aspects of photoactive soft materials. Photoactive Functional Soft Materials: Preparation, Properties, and Applications: * Brings together the state-of-the-art knowledge on photoactive functional soft materials in a unified manner * Covers a vibrant research field with tremendous application potential in areas such as optoelectronics, photonics, and energy generation * Appeals to a large interdisciplinary audience because it is highly useful for researchers and engineers working on photonics, optoelectronics, imaging and sensing, nanotechnology, and energy materials Photoactive Functional Soft Materials: Preparation, Properties and Applications focuses on the design and fabrication of photoactive functional soft materials for materials science, nanophotonics, nanotechnology, and biomedical applications.

The MRS Symposium Proceeding series is an internationally recognised reference suitable for researchers and practitioners.

Photonic band gap structures are ordered, periodic dielectric structures, which have interesting optical properties and many applications including preventing spontaneous emission and filtering. Using the sol-gel process, colloidal polystyrene particles were fully coated with silica and titania and then the coated spheres were crystallized into an ordered arrangement of spheres by heating. The sol-gel titania was fully dense and shrank 30.4% from the green state to the sintered state. The colloidal polystyrene particles decomposed during heating at 335°C while the sol-gel titania goes through a three step transformation starting at 400°C and ending at 550°C. After heating to 550°C, X-ray diffraction shows that the titania is anatase in structure. Inverse structures, with dimensions in the optical range, were developed with varying degrees of order. Slow drying in a high humidity atmosphere, decreased sample mold thickness, and a sol-gel precursor with large R groups aided in improving the short-range periodicity. dip-coating. Areas of ordered holes separated by thick titania sections were created using dip-coating. The best order was obtained by centrifuging the coated spheres. As an alternative route, the uncoated polystyrene spheres crystallized into well-ordered grains which could be infiltrated by the sol-gel solution. Spectroscopy results did not indicate a definite band gap where expected due to imperfection of the periodicity and surface roughness.

This volume contains the papers presented at the NATO Advanced Research Workshop on Localization and Propagation o[ Classical Waves in Random and Periodic Media held in Aghia Pelaghia, Heraklion, Crete, May 26- 30, 1992. The workshop's goal was to bring together theorists and experimentalists from two related areas, localization and photonic band gaps, to highlight their common interests. The objectives of the workshop were (i) to assess the state of-the-art in experimental and theoretical studies of structures exhibiting classical wave band gaps and/or localization, (ii) to discuss how such structures can be fabricated to improve technologies in different areas of physics and engineering, and (iii) to identify problems and set goals for further research. Studies of the propagation of electromagnetic (EM) waves in periodic and/or disordered dielectric structures (photonic band gap structures) have been and continue to be a dynamic area of research. Anderson localization of EM waves in disordered dielectric structures is of fundamental interest where the strong ei-ei interaction efFects entering the eIectron-localization are absent.

Over the last ten years, photonic band gap (PBG) theory and technology have become an important area of research because of the numerous possible applications ranging from high-efficiency laser diodes to optical circuitry. This research concentrates on reducing the length scale in the fabrication of layered photonic band gap structures and developing procedures to improve processing consistency. Various procedures and materials have been used in the fabrication of layered PBG structures. This research focused on an economical micro transfer molding approach to create the final PBG structure. A poly dimethlysiloxane (PDMS) rubber mold was created from a silicon substrate. It was filled with epoxy and built layer-by-layer to create a 3-D epoxy structure. This structure was infiltrated with nanoparticle titania or a titania sol-gel, then fired to remove the polymer mold, leaving a monolithic ceramic inverse of the epoxy structure. The final result was a lattice of titania rods that resembles a face-centered tetragonal structure. The original intent of this research was to miniaturize this process to a bar size small enough to create a photonic band gap for wavelengths of visible electro-magnetic radiation. The factor limiting progress was the absence of a silicon master mold of small enough dimensions. The Iowa State Microelectronics Research Center fabricated samples with periodicities of 2.5 and 1.0 microns with the existing technology, but a sample was need on the order of 0.3 microns or less. A 0.4 micron sample was received from Sandia National Laboratory, which was made through an electron beam lithography process, but it contained several defects. The results of the work are primarily for from the 2.5 and 1.0 micron samples. Most of the work focused on changing processing variables in order to optimize the infiltration procedure for the best results. Several critical parameters were identified, ranging from the ambient conditions to the specifics of the procedure. It is believed that most critical for fabrication of high quality samples is control of the temperature of the sample during and after infiltration, and the rate and amount of time spent applying epoxy to the PDMS.

This book is a comprehensive study of the subject of ionic interactions in macromolecules. The first parts of the book review and analyze the conventional treatments of fixed charges (e.g. in polyelectrolytes and polyampholytes), including screening and condensation by mobile ions. The interaction of ions with less polar sites on the macromolecule (e.g. amide bonds), and the origin of the lyotropic effects (focusing on binding versus condensation) will also be extensively addressed. The book also explores complex micellar organizations involving charged macromolecules (e.g. DNA) and low-molecular-weight ampholytes and strong protein associations. The resulting structures are relevant to a variety of functional biological systems and synthetic analogs. The contribution of electrostatic and hydrophobic interaction to the stability of proteins and other supramolecular structures will also be analyzed. There are chapters on applications such as deionization and cosmetic formulation. This 21-chapter book is divided into three sections: Fundamentals Mixed Interactions Functions and Applications