Foaming With Supercritical Fluids

Foaming with Supercritical Fluids, Volume Nine provides a comprehensive description of the use of supercritical fluids as blowing agents in polymer foaming. To this aim, the fundamental issues on which the proper design and control of this process are rooted are discussed in detail, with specific attention devoted to the theoretical and experimental aspects of sorption thermodynamics of a blowing agent within a polymer, the effect of the absorbed blowing agent on the thermal, interfacial and rheological properties of the expanding matter, and the phase separation of the gaseous phase, and of the related bubble nucleation and growth phenomena. Several foaming technologies based on the use of supercritical blowing agents are then described, addressing the main issues in the light of the underlying chemical-physical phenomena. Offers strong fundamentals on polymer properties important on foaming Outlines the use of supercritical fluids for foaming Covers theoretical points-of-view, including foam formation of the polymer/gas solution to the setting of the final foam Discusses the several processing technologies and applications

Keywords: polymer surfactants, polymer blends, high pressure rheology, controlled foam nucleation, carbon dioxide, nanoporous polymers, microcellular foam, supercritical fluids.

Using SuperCritical Fluids (SCFs) in various processes is not new, because Mother Nature has been processing minerals in aqueous solutions at critical and supercritical pressures for billions of years. Somewhere in the 20th century, SCFs started to be used in various industries as working fluids, coolants, chemical agents, etc. Written by an international team of experts and complete with the latest research, development, and design, Advanced Supercritical Fluids Technologies is a unique technical book, completely dedicated to modern and advanced applications of supercritical fluids in various industries.Advanced Supercritical Fluids Technologies provides engineers and specialists in various industries dealing with SCFs as well as researchers, scientists, and students of the corresponding departments with a comprehensive overview of the current status, latest trends and developments of these technologies.Dr Igor Pioro is a professor at the University of Ontario Institute of Technology, Canada, and the Founding Editor of the ASME Journal of Nuclear Engineering and Radiation Science.

Combining the science of foam with the engineering of extrusion processes, Foam Extrusion: Principles and Practice delivers a detailed discussion of the theory, design, processing, and application of degradable foam extraction. In one comprehensive volume, the editors present the collective expertise of leading academic, research, and industry spec

SCFs are currently the subjects of intense research and commercial interest. Applications such as the RESS (rapid expansion of supercritical fluid solutions) process are part of standard industrial practice. In view of their ever-growing importance in the polymer industry there is a need to fully comprehend how supercritical fluids interrelate with polymeric materials to realise the potential that can be gained from their use. The authors review the basic principles of SCFs and their application within the polymer industry: characteristics and properties, extraction of unwanted residual products, polymerisation solvents, and polymer impregnation. Processing applications such as plasticisation, foaming and blending are also considered. There is discussion of the potential within the polymer recycling industry for use of SCFs as cleaning agents or within supercritical oxidation processes. Around 400 references with abstracts from recent global literature accompany this review, sourced from the Polymer Library, to facilitate further reading. A subject index and a company index are included.

Although supercritial fluid (SCF) technology is now widely used in extraction and purification processes (in the petrochemical, food and pharmaceuticals industries), this book is the first to address the new application of cleaning. The objective is to provide a roadmap for readers who want to know whether SCF technology can meet their own processing and cleaning needs. It is particularly helpful to those striving to balance the requirements for a clean product and a clean environment. The interdisciplinary subject matter will appeal to scientists and engineers in all specialties ranging from materials and polymer sciences to chemistry and physics. It is also useful to those developing new processes for other applications, and references given at the end of each chapter provide links to the wider body of SCF literature. The book is organized with topics progressing from the fundamental nature of the supercritical state, through process conditions and materials interactions, to economic considerations. Practical examples are included to show how the technology has been successfully applied. The first four chapters consider principles governing SCF processing, detailing issues such as solubility, design for cleanability, and the dynamics of particle removal. The next three chapters discuss surfactants and microemulsions, SCF interaction with polymers, and the use of supercritical carbon dioxide (CO2) as a cleaning solvent. The closing chapters focus on more practical considerations such as scaleup, equipment costs, and financial analysis.

Polymers are widely used in everyday life due to their properties as toughness, viscoelasticity, and the possibility to form glasses and semicrystalline structures. For that reason, it is used in mostly drug delivery systems and tissue engineering and in pharmaceutical and biomedical investigations. Foaming process allows creating porous structure into the polymer leading to scaffolds. Scaffolds are the focus of many investigations as prolonged drug delivery systems and implants or injections which are used to deliver cells, drugs, and genes into the body. Particulate leaching, freeze-drying, thermally induced phase separation, rapid prototyping, powder compaction, sol,Äìgel, and melt molding are the main techniques in front of supercritical fluid technology to prepare scaffolds. Supercritical foaming process using CO2 presents advantages as a high dissolution in polymers and a green process because CO2 is nontoxic, inexpensive, and reusable. Moreover, supercritical technology allows to do an impregnation with an active substance together with the foaming at the same time. Thus active substances entrapped into scaffolds could be fabricated in a one-step green process.

This book describes cutting edge technology using supercritical fluids for the production of foodstuffs, medicals, and polymers. It illustrates the importance and use of basic data for design and operation at industrial scale units. The book's authors have several decades of experience of applied research on how to develop large scale industrial units. It provides readers complete insight in design and operation of industrial high pressure process plants. The book is written so it may be understood for people (with?) little or no background on high pressure process technology. It will provide information on how some foodstuffs, medicals, polymers are produced using high pressure technologies. The book demonstrates the importance of fundamental data, how to measure them and how to apply them to design industrial plants. At the same time, it also serves as a textbook for students.

Supercritical fluids are neither gas nor liquid, but can be compressed gradually from low to high density and they are therefore interesting and important as tunable solvents and reaction media in the chemical process industry. By adjusting the density the properties of these fluids can be customised and manipulated for a given process - physical or chemical transformation. Separation and processing using supercritical solvents such as CO2 are currently on-line commercially in the food, essential oils and polymer industries. Many agencies and industries are considering the use of supercritical water for waste remediation. Supercritical fluid chromatography represents another, major analytical application. Significant advances have recently been made in materials processing, ranging from particle formation to the creation of porous materials. The chapters in this book provide tutorial accounts of topical areas centred around: (1) phase equilibria, thermodynamics and equations of state; (2) critical behaviour, crossover effects; (3) transport and interfacial properties; (4) molecular modelling, computer simulation; (5) reactions, spectroscopy; (6) phase separation kinetics; (7) extractions; (8) applications to polymers, pharmaceuticals, natural materials and chromatography; (9) process scale-up.

Recently, supercritical fluids have emerged as more sustainable alternatives for the organic solvents often used in polymer processes. This is the first book emphasizing the potential of supercritical carbon dioxide for polymer processes from an engineering point of view. It develops a state-of-the-art overview on polymer fundamentals, polymerization reactions and polymer processing in supercritical carbon dioxide. The book covers topics in a multidisciplinary approach starting from polymer chemistry and thermodynamics, going through monitoring, polymerization processes and ending with polymer shaping and post-processing. The authors are internationally recognized experts from different fields in polymer reaction engineering in supercritical fluids. The book was initiated by the Working Party on Polymer Reaction Engineering of the European Federation of Chemical Engineering and further renowned international experts.