Wall materials play a vital role in the development of micro-/nanocapsules to protect the bioactive compounds against external factors. The encapsulation process and the type of polymers exert a direct impact on the development of bioactive micro-/nanocapsules, which greatly reflect in encapsulation efficiency, solubility, stability, surface permeability, and release profile of desired bioactive compounds. Among the polymers, biodegradable polymeric materials have been the focus for various applications in food, pharmaceutical, and cosmetic industries. Thus, this chapter focuses on different encapsulation techniques and the importance of biodegradable polymers employed as wall materials for developing stable and safe micro-/nanocapsules. Among the natural polymers, protein- and polysaccharide-based polymers are widely used. Similarly, the most commonly used synthetic polymers are polycaprolactone, poly(lactic-co-glycolic acid), and polyethylene glycol. Synthetic polymers have been classified based on their exogenous and endogenous responsive natures. At the end, we have also discussed on the applications of biodegradable polymers employed in the development of micro-/nanocapsules. To compile this chapter and to provide adequate information to the readers, we have explored various sources, such as reviews, research articles, books, and book chapters including Google sites.
Part of the book: Microencapsulation
Nonlinear optical (NLO) materials have gained much attention during the last two decades owing to their potentiality in the field of optical data storage, optical information processing, optical switching, and telecommunication. NLO responsive macroscopic devices possess extensive applications in our day to day life. Such devices are considered as assemblies of several macroscopic components designed to achieve specific functions. The extension of this concept to the molecular level forms the basis of molecular devices. In this context, the design of NLO switches, that is, molecules characterized by their ability to alternate between two or more chemical forms displaying contrasts in one of their NLO properties, has motivated many experimental and theoretical works. Thus, this chapter focuses on the rational design of molecular NLO switches based on stimuli and materials with extensive examples reported in the literature. The factors affecting the efficiency of optical switches are discussed. The device fabrication of optical switches and their efficiency based on the optical switch, internal architecture, and substrate materials are described. In the end, applications of switches and future prospectus of designing new molecules with references are suitably discussed.
Part of the book: Nonlinear Optics