Active (also called "smart") coatings and thin films are defined as those that are capable of sensing their environment and appropriately responding to that external stimulus. This Special Issue "Active Organic and Organic-Inorganic Hybrid Coatings and Thin Films: Challenges, Developments, Perspectives" collected a series of papers that outline the current frontiers in the development of smart coatings and thin films for corrosion and other types of materials applications. The first four papers focus on novel discoveries on coatings with corrosion protection properties. These include environmentally-friendly polyurethane loaded with cerium nitrate corrosion inhibitor for mild steel protection, hot-pressed organic polymer coatings for the protection of pre-treated aluminum alloy surfaces exposed to NaCl aqueous solutions, functional epoxy coating with modified functional TiO2 for steel substrates protection, and hybrid composites against the thermo-oxidative corrosion of the metal parts of the internal combustion engines, turbines, and heaters. The next paper explores the potential of organic polymer/ceramic composite coatings to enhance the scratch resistance of typical floor laminates. The next three papers highlight other types of smart coatings and thin films, including low-temperature curable hybrid dielectric materials for field-effect transistors, bilayer antireflective coatings for optoelectronic devices, and organic polymers as the thin-film component for enthalpy exchanger systems in air conditioning applications. The final two papers focus on important research specific to coatings that serve as protection and preservation cultural heritage materials.

Materials are at the center of all technological advances; it is evident in considering the spectacular progress that has been made in fields as diverse as engineering, medicine, biology, etc. Materials science and technology must develop researches allowing the generation of new methods of protection to reduce fundamentally the losses of human life as well as the economic ones. The former are impossible of quantifying, while the latter are highly significant; thus, only those derived from corrosive processes in their different forms reach, in technologically developed countries, about 4% of the Gross National Product (GNP), while those derived from fire action range from 0.5 to 1.0% of the mentioned GNP. The book, in the different chapters, displays original systems of superficial protection and of low environmental impact to minimize the losses by corrosion and the fire action.

The operation of numerous components that are critical to safety in industries around the world relies on protective coatings. These coatings often allow process equipment to serve a purpose in environments well beyond the operational limit of the uncoated components. Durability, ease of application, repairability, reliability and long-term performance of such coatings are all key to their application. Therefore, this book, Coatings for Harsh Environments, is devoted to research and review articles on the metallic, non-metallic and composite coatings used in aggressive environments. In particular, the topics of interest include, but are not limited to: coatings for high temperature and molten salt applications; thermal spray and cold spray coatings for aggressive environments; corrosion, wear and cavitation resistant coatings; coatings for mitigating marine corrosion; coatings for chemical and petrochemical plants; thermal barrier coatings.

This book covers a broad range of materials science that has been brought to bear on providing solutions to the challenges of developing self-healing and protective coatings for a range of metals. The book has a strong emphasis on characterisation techniques, particularly new techniques that are beginning to be used in the coatings area. It features many contributions written by experts from various industrial sectors which examine the needs of the sectors and the state of the art. The development of self-healing and protective coatings has been an expanding field in recent years and applies a lot of new knowledge gained from other fields as well as other areas of materials science to the development of coatings. It has borrowed from fields such as the food and pharmaceutical industries who have used, polymer techniques, sol-gel science and colloidosome technology for a range encapsulation techniques. It has also borrowed from fields like hydrogen storage such as from the development of hierarchical and other materials based on organic templating as “nanocontainers” for the delivery of inhibitors. In materials science, recent developments in high throughput and other characterisation techniques, such as those available from synchrotrons, are being increasing used for novel characterisation – one only needs to look at the application of these techniques in self healing polymers to gauge wealth of new information that has been gained from these techniques. This work is largely driven by the need to replace environmental pollutants and hazardous chemicals that represent risk to humans such as chromate inhibitors which are still used in some applications.

Organic-inorganic coatings based on poly(methyl methacrylate) (PMMA)-silica and PMMA-cerium oxide hybrids provide effective and active corrosion protection of metallic surfaces. For both hybrid materials, the covalent conjugation of inorganic silica or ceria nanodomains with the PMMA matrix, provided by molecular coupling agents, leads to homogenous and highly cross-linked nanocomposites, which act in the form of coatings as an efficient diffusion barrier. The addition of lithium salts (500,Äì2000¬†ppm) into PMMA-silica hybrid and optimized ceria fraction in PMMA-cerium oxide coatings results in active corrosion inhibition by the self-healing effect. Results of electrochemical assays of aluminum- and steel-coated samples, performed in a 3.5% NaCl solution, show an excellent corrosion resistance (impedance modulus up to 100¬†GŒ©¬†cm2) and durability (up to 350¬†days) of the 10-Œom-thick passive barrier layer. Time-of-flight secondary ion mass and X-ray photoelectron spectroscopies evidenced the self-healing ability of coatings induced by lithium/cerium ion leaching toward corrosion spots or artificial scratches, which are restored by a protective layer of precipitated phases. Results presented in this book chapter evidence the active role of lithium and cerium species in improving the hybrid structure and providing through self-healing a significantly extended service life of metallic components.

This book provides the latest research & developments and future trends in photoenergy and thin film materials—two important areas that have the potential to spearhead the future of the industry. Photoenergy materials are expected to be a next generation class of materials to provide secure, safe, sustainable and affordable energy. Photoenergy devices are known to convert the sunlight into electricity. These types of devices are simple in design with a major advantage as they are stand-alone systems able to provide megawatts of power. They have been applied as a power source for solar home systems, remote buildings, water pumping, megawatt scale power plants, satellites, communications, and space vehicles. With such a list of enormous applications, the demand for photoenergy devices is growing every year. On the other hand, thin films coating, which can be defined as the barriers of surface science, the fields of materials science and applied physics are progressing as a unified discipline of scientific industry. A thin film can be termed as a very fine, or thin layer of material coated on a particular surface, that can be in the range of a nanometer in thickness to several micrometers in size. Thin films are applied in numerous areas ranging from protection purposes to electronic semiconductor devices. The 16 chapters in this volume, all written by subject matter experts, demonstrate the claim that both photoenergy and thin film materials have the potential to be the future of industry.