7/9/2023 0 Comments Emulsion wax![]() ![]() Emulsion ProcessingĬonventional emulsion processing involves separately mixing and heating water and oil phases, bringing the two phases together and mixing with high shear. ![]() Common ingredients used in emulsion systems are: water oils/waxes emulsifiers emollients, often lipophilic moisturizers, often hydrophilic natural extracts active ingredients essential oils fragrances, which are volatile and temperature-sensitive preservatives and colors or tints. When formulating an emulsion, one can tailor the texture, body and sensory characteristics of the finished product by choosing specific ingredients. Further, Griffin defined the hydrophilic-lipophilic balance (HLB) theory to provide formulators with a tool to assist in the selection of the correct balance of emulsion system, although this theory is not without flaws or exceptions. hydrophilic or lipophilic chemical behavior efficiency and/or cost. Numerous types of emulsifiers are available and the selection criteria can be based on: chemical functionality-i.e., esters, silicones, ethoxylates, etc. While droplet size, temperature and entropy also contribute to the thermodynamic stability of the emulsion, the use of emulsifiers provides a simple route to form a stable product. From a thermodynamic standpoint, the emulsifier reduces the surface energy of the dispersed phase, thus increasing the thermodynamic drive to form a stable emulsion. Emulsion IngredientsĮmulsifiers are molecules that contain both hydrophilic and lipophilic chemical groups. Creaming of the oil droplets can be reversed by re-mixing the emulsion however, coalescence can only be reversed by re-formulating the emulsion. The upper yellow layer shows the oil phase, appearing after the oil droplets have coalesced. The cloudy region in the emulsion is the manifestation of creaming in the system, where the oil droplets are attracted to each other. Figure 1 shows an emulsion separating into its oil and water phases. In fact, Gibbs stated, in reference to emulsion stability, “the only point in time where an emulsion is stable is when it is completely separated.” 2 In the real world, this implies that emulsions will always have a tendency to separate into their oil and water phases, although viscosity and stabilizing components slow this separation process. The same probability can be applied to other ingredients, so there may be some dissolution, to a minor extent, into the less-favored phase.Įmulsions are considered thermodynamically metastable systems, i.e., they can exist in a long lived-state that is not its most stable form. Theoretically, oil and water phases are completely immiscible, but there is always a statistical possibility that some oil may dissolve in the water phase and vice versa. Other components such as natural extracts, active ingredients, essential oils, fragrances, preservatives, colors and tints all exhibit a preference to either the oil or water phase. ![]() For example, emollient components tend to be lipophilic in nature, whereas moisturizers demonstrate mostly hydrophilic characteristics. Emulsion science provides the personal care industry with the means to formulate a cream or lotion that contains both oil-miscible and water-soluble components. Generally, in cosmetics and personal care, the two phases in an emulsion are oil and water/aqueous phases. What is an emulsion? As most readers know, an emulsion can be considered a dispersion of one material inside of another, non-miscible phase. In this article, traditional emulsions and emulsion processing are reviewed and compared with cold-processed emulsions. 1 With the current market focus on eco-friendly materials and processes, cold process emulsion technologies have gained popularity, reducing both the energy demand and manufacturing time required. However, conventional methods for processing such emulsions require significant quantities of energy and time it has been estimated that heating and cooling alone accounts for over 90% of the total energy cost for the production of an emulsion. Editor’s note: Emulsion science is widespread throughout the personal care industry, providing the means to formulate creams or lotions that contain both oil-miscible and water-soluble components. ![]()
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