Download or read book Understanding Interfacial Transport Reactions and Phase Behavior in Emulsion Systems written by Rebecca Balaj and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Complex fluids are of increasing interest because of their ability to provide a unique environment for the exploration of interfacial phenomena. Emulsions, which are mixtures of immiscible liquids, allow for separation of reagents whilst simultaneously providing a liquid-liquid interface wherein reactants can be easily transported, and reactions are able to readily occur. Thus, utilizing complex emulsions as dynamic materials is potentially important to understand localized reaction pathways and kinetics in a controllable and predictable manner. However, a significant limitation of fluid droplets for long-term applications is their eventual breakdown over time. Elucidating approaches by which to enhance droplet stability while simultaneously maintaining their reconfigurability and responsive character is therefore essential. This dissertation, thus, exists in three main sections: first, it aims to investigate a surfactant-free gelation pathway to form oil-core hydrogel capsules to stabilize complex droplets; secondly, it examines the non-equilibrium partitioning of amphiphilic surfactants into biphasic emulsions of miscible oils to dynamically and controllably induce phase separation; and, finally, it attempts to explore the reconfigurable complex droplet as a responsive soft material which can be used to easily manipulate chemical reactions at the oil-water interface. One approach to enhanced stabilization of droplets is by encapsulation, where a shell, often a polymer, encases the liquid droplet to prevent coalescence and limit exchange of droplet contents with the continuous phase. A common approach to droplet encapsulation is interfacial polymerization, where monomers dissolved in immiscible phases react to form capsules localized at the interface. Hydrogels, which are composed of crosslinked, charged polymers swollen in water, are highly permeable to molecules in the aqueous phase and would permit the diffusion of surfactants or other analytes to the droplet surface to trigger a response in droplet configuration. In the first major project of this work, we utilized a Pickering complex droplet intermediate to localize hydrogel formation at the droplet-continuous phase interface. Enhanced stability of droplets with both ionically and covalently crosslinked capsules was observed, with a complete spectrum of reconfigurability possible upon addition of droplet-internal fluorosurfactant, Capstone FS-30. The next major work examines the partitioning of surfactant molecules across the droplet oil-water interface. In general, the partitioning of chemicals across interfaces and their subsequent concentration into droplets and coacervates is important in many fields of study, including organic reaction chemistry and in mimicking individual properties of natural systems, such as living cells. When considering partitioning occurring within emulsions, the dynamics and relative concentration of all components--oil, water, and surfactant--are critical to understanding the behavior of non-equilibrium systems. We became interested in the dynamics and degree of surfactant partitioning while examining the behavior of two-component oil droplets in aqueous surfactant. We produced microscale droplets containing two oils, which in bulk at room temperature are miscible in all proportions. Upon preparing this emulsion, we expected that the droplets would remain in a single phase during their lifetime when undergoing micellar solubilization; however, we noticed phase separation occurring within the droplets. To confirm the partitioning of surfactant into these droplets, we developed a protocol for the LCMS analysis of single microscale droplets. Furthermore, we have shown that, upon addition of ionic surfactant, we can controllably and dynamically induce phase separation through various stimuli. In the last major project of this work, we examine reaction rates at oil-water interfaces and within surfactant micelles. Reactions occurring at the interface of immiscible fluids are important for a variety of different fields, largely due to the separation of reagents into distinct phases only to be reacted specifically and controllably at the interface. This allows unique opportunity to tune reaction kinetics, location, and pathways. Studies have previously been conducted observing reaction kinetics at the oil-water interfaces of emulsions, therefore exploring reactions at interfaces in complex droplets should then allow for an even more specific morphology-dependent, tunable reaction environment.
Download or read book The relationship between the phase behavior interfacial viscosity and emulsion stability of oil water surfactant systems written by Lawrence Martin Baldauf and published by . This book was released on 1981 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interfacial Transport Processes and Rheology written by David A. Edwards and published by Butterworth-Heinemann. This book was released on 1991 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook is designed to provide the theory, methods of measurement, and principal applications of the expanding field of interfacial hydrodynamics. It is intended to serve the research needs of both academic and industrial scientists, including chemical or mechanical engineers, material and surface scientists, physical chemists, chemical and biophysicists, rheologists, physiochemical hydrodynamicists, and applied mathematicians (especially those with interests in viscous fluid mechanics and continuum mechanics). As a textbook it provides materials for a one- or two-semester graduate-level course in interfacial transport processes. It may also be noted that, while separate practical and theoretical subdivisions of material have been introduced, a kind of cross-emphasis is often stressed: (i) to the academic scientist, or the importance of understanding major applications of interfacial transport; and (ii) to the industrial scientist, of the importance of understanding the underlying theory.
Download or read book Unravelling Synthesis and Transport Phenomena in Emulsion Systems with Small Angle Scattering written by Yi-Ting Lee and published by . This book was released on 2019 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emulsions are a dispersion of two immiscible liquids that can be found in a variety of products frequently used in our daily lives. These dispersions of droplets are intrinsically unstable and would phase separate if no stabilizers were present. Even if the emulsions are stabilized, the emulsion system is still extremely dynamic and multiple phenomena could occur simultaneously to affect the stability of the dispersion. Therefore, fundamentally understanding how the droplets interact with each other is crucial when designing emulsion-based products. Small angle scattering is a unique technique that can provide information of a sample in its native environment. Moreover, custom-built sample environments could also be utilized with this technique to provide additional controllable parameters such as the application of acoustic forces to alter the dynamics in emulsion system. Thus, small angle scattering is an optimal method for characterizing emulsion systems. In this dissertation, three different fundamental interactions that occur in emulsion systems are probed using both small angle X-ray scattering and small angle neutron scattering. The role of acoustic forces in solid particle stabilized Pickering emulsion formation using sonication is first investigated. Cavitation events are found to be crucial in inducing particle adsorption onto the oil-water interface. Mass transport kinetics between emulsions are also presented in this dissertation. When the emulsions are at rest, oil molecules can exchange between oil droplets spontaneously by directly diffusing through the aqueous phase or via direct emulsion contact. When emulsions are sonicated, the acoustic-force induced cavitation can significantly accelerate the oil exchange process. Moreover, the electrostatic repulsion, Gibbs elasticity of the oil-water interface provided by the presence of surfactants, and the emulsion size all played a role in the acoustic force induced oil exchange process. This dissertation will demonstrate our work towards understanding the interactions in emulsion systems on a molecular scale to provide a fundamental knowledge on how to design an emulsion-based system.
Download or read book Chemical Reactions and Mass Transport in Emulsion Liquid Membrane written by Huifang Fan and published by . This book was released on 1999 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emulsion liquid membrane (ELM) systems are an important technique for wastewater cleanup. For this purpose, emulsion globules are dispersed in wastewater (external phase), each emulsion globule consisting of many tiny aqueous droplets (internal phase) enclosed in oil (membrane phase). Hazardous chemicals in the wastewater are transported into the internal droplets by mass transfer mechanisms. Since Li first invented an ELM system in the 1960s, much research effort has been devoted to experimentally finding the optimal conditions for ELM recovery of various chemicals. Such studies would have benefited greatly from the guidance of mathematical models, especially those that provide analytical predictions. However, mathematical modeling of ELM systems is highly challenging due to the interplay of transport phenomena and chemical reactions. In carrier mediated mass transfer in an ELM system, the hazardous chemical in the external phase are extracted by reactions at the external membrane interface to form a complex with the carrier compound in the membrane phase. The complex then diffuses to the internal-membrane interface, where the hazardous chemical is stripped from t1le complex and the carrier freed. This thesis establishes a mathematical model of carrier mediated mass transfer in ELM systems. This model yields analytical solution that accurately predicts experimental results. This solution provides theoretical guidance to optimal recovery conditions and maximum achievable recovery efficiency. Using metal recovery as an example, this thesis conducts a first-principle study of the extraction chemical reactions at the external-membrane and the stripping chemical reactions at the internal-membrane interfaces and derives the extraction and stripping distribution coefficients. This thesis also finds chemical reactions in the internal phase greatly improve equilibrium recovery efficiency but also greatly lengthen the time to reach equilibrium. The analytical concentration profiles consist of converging series of infinite terms each involving an eigenvalue of a certain eigenvalue equation. When external resistance exceeds internal resistance, this eigenvalue equation exhibits a remarkable singular behavior with significant impact on the concentration profiles. Also remarkable is the metal accumulation phenomenon.
Download or read book Microfluidics written by Yu Song and published by John Wiley & Sons. This book was released on 2018-05-07 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book offering a global overview of fundamental microfluidics and the wide range of possible applications, for example, in chemistry, biology, and biomedical science. As such, it summarizes recent progress in microfluidics, including its origin and development, the theoretical fundamentals, and fabrication techniques for microfluidic devices. The book also comprehensively covers the fluid mechanics, physics and chemistry as well as applications in such different fields as detection and synthesis of inorganic and organic materials. A useful reference for non-specialists and a basic guideline for research scientists and technicians already active in this field or intending to work in microfluidics.
Download or read book Green Technologies in Food Production and Processing written by Joyce I. Boye and published by Springer Science & Business Media. This book was released on 2012-01-10 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examining the full cycle from farm to fork, this book reviews the current status of green processing in the agriculture and agri-food sector, and provides strategies for enhancing the use of environmentally-friendly technologies for production and processing.
Download or read book Nanoscience written by Victor M. Starov and published by CRC Press. This book was released on 2011-06-03 with total page 1610 pages. Available in PDF, EPUB and Kindle. Book excerpt: The common perception is that nanoscience is something entirely new, that it sprung forth whole and fully formed like some mythological deity. But the truth is that like all things scientific, nanoscience is the natural result of the long evolution of scientific inquiry. Following a historical trail back to the middle of the 19th century, nanoscience is the inborn property of colloid and interface science. What’s important today is for us to recognize that nanoparticles are small colloidal objects. It should also be appreciated that over the past decades, a number of novel nanostructures have been developed, but whatever we call them, we cannot forget that their properties and behavior are still in the realm of colloid and interface science. However one views it, the interest and funding in nano-science is a tremendous opportunity to advance critical research in colloid chemistry. Nanoscience: Colloidal and Interfacial Aspects brings together a prominent roster of 42 leading investigators and their teams, who detail the wide range of theoretical and experimental knowledge that can be successfully applied for investigating nanosystems, many of which are actually well-known colloidal systems. This international grouping of pioneering investigators from academia and industry use these pages to provide researchers of today and tomorrow with a full examination of nano-disperse colloids, homogeneous and heterogeneous nano-structured materials (and their properties), and shelf-organization at the nano-scale. This cutting-edge reference provides information on investigations into non-linear electrokinetic phenomena in nano-sized dispersions and nano-sized biological systems. It discusses application aspects of technological processes in great detail, providing scientists and engineers across all fields with authoritative commentary on colloid and interface science operating at the nanoscale. Nano-Science: Colloidal and Interfacial Aspects provides an authoritative resource for those wanting to familiarize themselves with current progress as well as for those looking to make their own impact on the development of new technologies and practical applications in fields as diverse as medicine, materials, and environmental science to name but a few. Whether you call the technology nano or colloids, the field continues to be ripe with opportunity.
Download or read book A Research Agenda for Transforming Separation Science written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-10-30 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: Separation science plays a critical role in maintaining our standard of living and quality of life. Many industrial processes and general necessities such as chemicals, medicines, clean water, safe food, and energy sources rely on chemical separations. However, the process of chemical separations is often overlooked during product development and this has led to inefficiency, unnecessary waste, and lack of consensus among chemists and engineers. A reevaluation of system design, establishment of standards, and an increased focus on the advancement of separation science are imperative in supporting increased efficiency, continued U.S. manufacturing competitiveness, and public welfare. A Research Agenda for Transforming Separation Science explores developments in the industry since the 1987 National Academies report, Separation and Purification: Critical Needs and Opportunities. Many needs stated in the original report remain today, in addition to a variety of new challenges due to improved detection limits, advances in medicine, and a recent emphasis on sustainability and environmental stewardship. This report examines emerging chemical separation technologies, relevant developments in intersecting disciplines, and gaps in existing research, and provides recommendations for the application of improved separation science technologies and processes. This research serves as a foundation for transforming separation science, which could reduce global energy use, improve human and environmental health, and advance more efficient practices in various industries.
Download or read book Food Emulsions written by David Julian McClements and published by CRC Press. This book was released on 2015-08-21 with total page 714 pages. Available in PDF, EPUB and Kindle. Book excerpt: Continuing the mission of the first two editions, Food Emulsions: Principles, Practices, and Techniques, Third Edition covers the fundamentals of emulsion science and demonstrates how this knowledge can be applied to control the appearance, stability, and texture of emulsion-based foods. Initially developed to fill the need for a single resource co
Download or read book 20th European Symposium of Computer Aided Process Engineering written by Sauro Pierucci and published by Elsevier. This book was released on 2010-06-03 with total page 1373 pages. Available in PDF, EPUB and Kindle. Book excerpt: ESCAPE-20 is the most recent in a series of conferences that serves as a forum for engineers, scientists, researchers, managers and students from academia and industry to present and discuss progress being made in the area of "Computer Aided Process Engineering" (CAPE). CAPE covers computer-aided methods, algorithms and techniques related to process and product engineering. The ESCAPE-20 scientific program reflects the strategic objectives of the CAPE Working Party: to check the status of historically consolidated topics by means of their industrial application and to evaluate their emerging issues. - Includes a CD that contains all research papers and contributions - Features a truly international scope, with guest speakers and keynote talks from leaders in science and industry - Presents papers covering the latest research, key topical areas, and developments in computer-aided process engineering (CAPE)
Download or read book Pattern Formation In Complex Dissipative Systems Fluid Patterns Liquid Crystals Chemical Reactions written by S Kai and published by World Scientific. This book was released on 1992-09-15 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this volume, the problems of pattern formation in physics, chemistry and other related fields in complex and nonlinear dissipative systems are studied. Main subjects discussed are formation mechanisms, properties, statistics, characterization and dynamics of periodic and nonperiodic patterns in the electrohydrodynamics in liquid crystals, Rayleigh-Benard convection, crystallization, viscous fingering and Belouzov-Zhabotinsky chemical reaction. Recent developments in topological and defect-mediated chaos, chaos in systems with large degrees of freedom and turbulence-turbulence transitions are also discussed.
Download or read book Encyclopedia of Surface and Colloid Science written by P. Somasundaran and published by CRC Press. This book was released on 2006 with total page 1152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reactions And Synthesis In Surfactant Systems written by John Texter and published by CRC Press. This book was released on 2001-06-26 with total page 1100 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work offers a comprehensive review of surfactant systems in organic, inorganic, colloidal, surface, and materials chemistry. It provides practical applications to reaction chemistry, organic and inorganic particle formation, synthesis and processing, molecular recognition and surfactant templating. It also allows closer collaboration between synthetic and physical practitioners in developing new materials and devices.
Download or read book Handbook of Microemulsion Science and Technology written by Promod Kumar and published by Routledge. This book was released on 2018-05-02 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt: Demonstrating methods for overcoming stability issues in paints, wax dispersions, cosmetics, food products, and other industrial applications, this reference probes theoretical and practical issues surrounding microemulsion science and technology. Featuring the work of 51 international experts and containing almost 1000 instructive tables, equations, and illustrations, this book reviews the performance of, and prospects for, experimental methods such as X-ray diffraction, transmission electron microscopy (TEM), light scattering, small angle neutron scattering, viscosimetry, and nuclear magnetic resonance (NMR) to characterize various aspects of the dispersed phase of microemulsions.
Download or read book Emulsion Science written by Jerôme Bibette and published by Springer. This book was released on 2003-07-01 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emulsions occur either as end products or during the processing of products in a huge range of areas including the food, agrochemical, pharmaceuticals, paints and oil industries. As end products, emulsions allow to avoid organic solvent in processing hydrophobic coatings. Emulsion technology is a suitable approach to vehicle viscous phases. It is also a remarkable mean of targeting actives or capturing specific species. The range of applications of emulsions progresses and their manufacturing becomes more and more sophisticated. Besides this broad domain of technological interest, emulsions are raising a variety of fundamental questions at the frontier between physic and chem istry. Indeed, as a class of soft colloidal materials, emulsions science is linked to various aspects of these disciplines: phase transitions, surface forces and wetting, metastability and hydrodynamic instabilities, mechanical properties and flow. The aim of this book is to review the main important concepts governing emulsion science. In Chapter 2, repulsive interactions between liquid films are discussed as well as adhesive interaction related to wetting. In Chap ter 3, consequences of weak and strong attractions are presented, related to the well accepted liquid solid transition analogy. In Chapter 4, the basics of both bulk compressibility and shear elasticity are presented, the role of disorder being the most important aspect of the elastic behavior of these soft systems. In Chapter 5 the central question of the emulsion lifetime related to metastability is discussed.
Download or read book Bulletin of Chemical Thermodynamics written by and published by . This book was released on 1985 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt:
