Ow, wo nonionic surfactants surfactant mixtures micellar emulsions microemulsions ionic surfactants macroemulsions. In some respects, microemulsions can be considered as smallscale. Microemulsions are thermodynamically stable, and their formation is facilitated by the ultralow interfacial tension of these systems, which leads to the formation of extremely small droplets of the dispersed phase. As the name implies, water is the dispersed phase in wo emulsions, whereas oil is the dispersed phase in ow emulsions 1, 2. Surfactant associates emulsions and microemulsions. Emulsions and microemulsions emulsions and microemulsions emulsion. This book provides an assessment of some issues influencing the characteristics and performance of the microemulsions, as well as their main types of applications. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. In this paper, the authors present the preparation of waterborne polymers with the use of raft reversible additionfragmentation chain transfer polymerisation. Microemulsion and its mechanism of formation this video gives an explanation of microemulsion and its mechanism of formation. Microemulsions as a new working medium in physical chemistry. Emulsions part 3 microemulsions miniemulsions remarks to.
Ppt microemulsions powerpoint presentation free to. Emulsions and microemulsions for topical and transdermal. Emulsions, microemulsions, and nanoemulsions emulsion. The interfacial tension between phases, amount of energy required for formation, droplet sizes, and visual appearance are only a few of the differences seen when comparing emulsions to microemulsions. Sep 30, 2016 microemulsions for paper applications. Emulsions and microemulsions for topical and transdermal drug. View microemulsion ppts online, safely and virusfree. In contrast to ordinary emulsions, microemulsions form upon simple mixing of the components and do not require the high shear conditions generally used in the formation of ordinary emulsions. There are, however, violations to this bancroft rule, and the goal of the paper is to delineate the conditions of validity of the rule.
Preparation of microemulsions 203 tion of a stable microemulsion is more specific and thus greatly limited in variety. The principle objective of formulation of lipidbased drugs is to enhance their bioavailability. Mechanism of formation and structure of micro emulsions by. Sep 22, 1998 an advantage of using the preferred anionic surfactants is that relatively small amounts of the preferred anionic surfactants are needed to provide the high water content, oil continuous microemulsions and emulsions of this invention. Our new crystalgraphics chart and diagram slides for powerpoint is a collection of over impressively designed datadriven chart and editable diagram s guaranteed to impress any audience. These products provide a ph neutral solution that can improve dewatering, enhance conditioning, extend belt life and reduce downtime. One of the main differences between macroemulsions and microemulsions is that the size of the droplets of the dispersed phase of microemulsions is between 5 and 100 nm, while that of macroemulsions is 100 nm. The key to understanding reactivity in organized surfactant media is that reaction mechanisms are consistent with a discrete. These microemulsions can take different forms which include, among others, oil, water, and oilwater bicontinuous microemulsions. Micro emulsions are clear, transparent, thermodynamically stable dispersions of oil and water, stabilized by an interfacial film of surfactant frequently in combination with a cosurfactant.
To model chemical reactivity in heterogeneous emulsions. This book deals first with the commercial history of microemulsions, from the discovery of carnauba wax emulsions to polymer emulsions. Microemulsion and its mechanism of formation youtube. Emulsions and microemulsions ppt video online download. Emulsions definition an emulsion is a thermodynamically unstable system consisting of at least two immiscible liquid phases one of which is dispersed as globules in the other liquid phase stabilized by a third substance called emulsifying agent. Investigations of phase equilibria in systems of watersurface active substancesorganic compounds have related the properties of micellar liquid and liquid crystalline phases with the formation, existence and properties of microemulsions, hydrotropic solutions and emulsions. Finally, we illustrate how to clear up this misconception using simple experiments. In some aspects, micro emulsions can be considered as small scale versions of emulsions,i.
A dispersion of droplets of one liquid in another, immiscible liquid macroemulsions. How to explain microemulsions formed by solvent mixtures. In most cases, in both micro and macroemulsions, the phase in which the surfactant is most soluble constitutes the continuous phase. Although there is similarity between emulsion and microemulsion, the latter vary in that the average drop size does not grow with.
Microemulsions combine the advantages of emulsions with those of nanocarriers, overcoming the stability problems of the former and providing facile scalable systems with compartments adequate for. Historical background definition composition of microemulsion major goals advantages disadvantages macroemulsion vs microemulsion types of microemulsions preparation methods of microemulsions equipments used for the preparation of microemulsions formation of microemulsion factors affecting. Analytical applications of emulsions and microemulsions. Chart and diagram slides for powerpoint beautifully designed chart and diagram s for powerpoint with visually stunning graphics and animation effects. Coarse emulsions can be stabilized by a wide variety of surfactants, application of high energy apparatus turbine mixers, sonicators, etc. Microemulsions, macroemulsions, and the bancroft rule.
Microemulsions based on soybean phosphatidylcholine and. The rapidly increasing number of applications for microemulsions has kept this relatively old topic still at the top point of research themes. A dispersion of droplets of one liquid in another, immiscible liquid. Danielsson and lindman a micro emulsion is a system, of water,oil and an amphiphile which is a single optically isotropic and thermodynamically stable liquid solution. The three basic types of microemulsions are direct oil dispersed in water, reversed water dispersed in oil, and bicontinuous. Microemulsions are flexible nearzero curvature structures whose thermodynamic stability implies an ultra low interfacial tension so that interfacial deformation is easy.
Interfacial tension, measurement, effect of surfactant on oilwater interface. Lipidbased drug delivery systems lbdds are one of the emerging technologies designed to address challenges like the solubility and bioavailability of poorly watersoluble drugs. The only real disadvantage of microemulsions is the relatively higher level of emulsifier required. Emulsions, microemulsions, and nanoemulsions free download as powerpoint presentation. Silicone polymers provide a broad range of performance benefits in many applications including but not limited to lubricity, shinegloss, chemical inertness, low coefficient of friction, low surface tension, softness, hydrophobicity, substantivity, uv stability, environmental protection and antiadherence. Two important and unsolved problems in the food industry and also fundamental questions in colloid chemistry are how to measure molecular distributions, especially antioxidants aos, and how to model chemical reactivity, including ao efficiency in opaque emulsions. In chapter 1 a short introduction about the background, various aspects and applications. Following these clarifications, we show how the confusion between nano emulsions and micro emulsions appears in the literature and how most of the microemulsion systems referred to are actually nanoemulsion systems. Preparation of microemulsion microemulsions were prepared at 27c by a titration method. Microemulsions, hydrotropic solutions and emulsions, a. The drug is be dissolved in the lipophilic part of the microemulsion i. This book is divided into seven chapters that explore the physics and chemistry of microemulsions. Raft emulsions, microemulsions and dispersions springerlink. Pdf application of emulsions and microemulsions in.
A dispersion of droplets of one liquid in another, immiscible liquid macroemulsions d nm miniemulsions 100 nm powerpoint ppt presentation displayed as a flash slide show on id. This website and its content is subject to our terms and conditions. Since microemulsions were discovered approximately six decades ago, their applications in several fields, including cosmetics, have been increased due to their good appearance, thermodynamic stability, high solubilization power, and ease of preparation. Surfactants are the principal agents that enable oil and water to mix. The stability of detergentless micelles or microemulsions in such mixtures was. Select ion of ou r books inde xed in the boo k ci tation i ndex.
Characterization of microemulsions prepared using isopropyl. Apr 19, 2016 beginning over 40 y ago, a curious type of microemulsionsas transparent dispersion of two immiscible liquids separated by an interfacial filmat thermodynamic equilibrium has been described as preouzo, detergentless, or surfactantfree microemulsions. Interfacial tension, measurement, effect of surfactant on oil. Am muhlenberg, d14476 golm, germany microemulsions miniemulsions remarks to. This chapter discusses the emulsions and microemulsion for topical and transdermal drug delivery with the factors affecting it. Apr 25, 2001 a read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Replacing conventional solvents with microemulsions. Tes global ltd is registered in england company no 02017289 with its registered office at 26 red lion square london wc1r 4hq. Download figure open in new tab download powerpoint. Definition and history one of the best definitions of microemulsions is from danielsson and lindman 1 a microemulsion is a system of water, oil and an amphiphile which is a single optically isotropic and thermodynamically stable liquid solution.
Microemulsions have been incorporated into highly effective press felt cleaning formulations. Emulsions and microemulsions are both stable dispersions of oilinwater or waterinoil. Or an emulsion is a dispersion in which the dispersed phase is composed of small. Microemulsions are considered to be infinitely stable, thereby providing improved stability over traditional macroemulsion systems. Microemulsions are really single phase systems in which the structure contains fusioned oil balls and fusioned water balls, with no actually dispersed phase. Scribd is the worlds largest social reading and publishing site.
We have studied the phase behavior and microstructure of water1propanolsoybean phosphatidylcholine sbpctriglyceride systems. Microemulsions are formed with both mediumchain triglycerides mct and longchain triglycerides. The experiments in ternary systems containing one hydrotropic cosolvent were ambiguous, and therefore, there was no need to. In the case of microemulsions, the smallk behavior of the sijk has a specific form called the. Waterinoil microemulsions are also known as reverse micelles. Ppt emulsions and microemulsions powerpoint presentation. Theory and practice covers the development of the theory and practice of microemulsion systems. Emulsions are stable dispersions of immiscible liquids, but they are not thermodynamically stable. A dispersion of droplets of one liquid in another, immiscible liquid macroemulsions d nm miniemulsions 100 nm. Macroemulsions d nm miniemulsions 100 nm microemulsions 10 nm and water do not mix what we need for making macroemulsions. How to explain microemulsions formed by solvent mixtures without. The socalled living or controlled polymerisation techniques afford an easy route to a broad diversity of unique polymers with precisely controlled architecture, composition, molecular weight, molecularweight distribution, and. One of them, r1, compares the interactions in the bulk. Preparation, optimization and characterization of microemulsions microemulsions are isotropic systems, which are difficult to formulate than ordinary emulsions because their formulation is a highly specific process involving.
In addition, microemulsions can enhance skin permeation of the loaded substances. Preparation, optimization and characterization of microemulsions 167 5. Ppt emulsion technology powerpoint presentation free to. Emulsions are heterogeneous systems composed of at least two. Application of emulsions and microemulsions in enhanced oil recovery and well stimulation. Oil and the water phases can be combined with surfactant and a cosurfactant is then added at slow rate with gradual stirring untill the system is transparent. For microemulsions two ratios are significant from this point of view.