Recently a new sphere in materials science. has formed which subject is structure and properties of electret materials used in engineering, medicine, biotechnology and other branches. It is characterized by specific methods of experimental investigations based on recording charge transfer, polarization and depolarization of dielectrics and involves original techniques and physico-mathematical aids where notions that exist at the interface of several natural and technical sciences are concentrated. It embraces a vast area of applications mainly in engineering, instrument making, electronics, medical technique, biotechnology, and etc., has a specialized technological base for electric polarization of dielectrics composed of uncommon technological methods, equipment and instrumentation. Apparently, future fundamental investigations in the domain of electret materials science are to be developed at the interface of computer of dielectrics. Elaboration of a simulation, physics and physical chemistry model for electric polarization of solid media with uneven charge density distribution, complicated by surface phenomena, outer electromagnetic, heat, chemical and other effects, presents a grave methodological problem. The simulation of structures in which polarization follows diffusion mechanism of chemically active molecules or their fragments, and the development of calculation methods for polarized charge relaxation and regularities of dielectric nonlinear properties, are the most urgent objectives of current research. Success in bioelectret effect studies is anticipated to result in profound widening of natural science knowledge."

This book is devoted to a nontraditional class of materials which are manufactured by the melt-blowing process - i.e. by extrusion of polymer melt followed by fiber stretching with a gas stream. For the first time extensive data on classical and modern modifications of this technology are generalized and a review is given of extrusion head dies and subsidiary equipment. The text examines the structure and main properties of melt-blown materials as conditioned by peculiarities of overheated polymer melt spraying in an oxidizing medium. Information is given about filtering mechanisms and the main types of polymer fibrous filtering materials: electret, magnetic, adsorptional, bactericidic, and about carriers of microorganisms in biofilters. Social and ecological aspects of the application of melt-blown materials are analyzed.

Recently a new sphere in materials science* has formed which subject is structure and properties of electret materials used in engineering, medicine, biotechnology and other branches. It is characterized by specific methods of experimental investigations based on recording charge transfer, polarization and depolarization of dielectrics and involves original techniques and physico-mathematical aids where notions that exist at the interface of several natural and technical sciences are concentrated. It embraces a vast area of applications mainly in engineering, instrument making, electronics, medical technique, biotechnology, and etc., has a specialized technological base for electric polarization of dielectrics composed of uncommon technological methods, equipment and instrumentation. Apparently, future fundamental investigations in the domain of electret materials science are to be developed at the interface of computer of dielectrics. Elaboration of a simulation, physics and physical chemistry model for electric polarization of solid media with uneven charge density distribution, complicated by surface phenomena, outer electromagnetic, heat, chemical and other effects, presents a grave methodological problem. The simulation of structures in which polarization follows diffusion mechanism of chemically active molecules or their fragments, and the development of calculation methods for polarized charge relaxation and regularities of dielectric nonlinear properties, are the most urgent objectives of current research. Success in bioelectret effect studies is anticipated to result in profound widening of natural science knowledge.