Juan Mateu, technical director at JEEN International in Fairfield, New Jersey, USA, says that there has been a move away from synthetic ethoxylated alcohols in recent years due to worries about residual 1,4-dioxane, a suspected carcinogen that is a by-product in their manufacture.
Naturally derived glucosides have been suggested as replacements for some applications. Prior to Jeesperse, manufacturers had to heat emulsifiers in the oil phase to melt them, and then add the melted emulsifier to the aqueous phase and cool the emulsion at a controlled rate down to room temperature. In contrast, Jeesperse allows the emulsion to be made in a single kettle at room temperature, resulting in significant savings of money and time.
The secret ingredients in Jeesperse products are polyelectrolytes, such as sodium polyacrylate. The polyelectrolytes are polar molecules that can induce polarity in nonpolar waxes, enabling them to dissolve in cold water a polar solvent. Mateu says that in the lab, he can make an emulsion with the cold process in about 20 minutes, as opposed to several hours of mixing, heating, and cooling with the conventional process. A short video demonstrating the cold-process formulation of a lotion with a Jeesperse emulsifier.
Many household cleaners and laundry detergents contain surfactants that emulsify oily dirt particles so that they can be diluted and washed away. Ethoxylated alcohols are a common ingredient of laundry detergents. Many detergents contain a blend of nonionic and anionic emulsifiers to lift stains out of textiles. According to Sabatini, removing triglycerides such as fats, bacon grease, and vegetable oils from fabrics is particularly challenging.
His lab has shown that extended surfactants, which are surfactants with intermediate polarity groups e. Emulsifiers allow metalworkers to make use of both the lubricating properties of oils and the cooling capabilities of water. Anionic and nonionic emulsifiers are often used together in metalworking fluids. Cationic emulsifiers are rarely used because they are unstable in the alkaline solutions pH 8—9. Emulsions and microemulsions have been applied to environmental technologies such as subsurface remediation and biofuel production.
For example, when oil or gas is spilled, the oil becomes trapped in pores in the soil and rock. In , Sabatini and several colleagues founded a company called Surbec Environmental, LLC, to implement this technology. Since then, Surbec has assisted with the environmental cleanup of multiple sites in the United States and abroad. Examples include a gas station with a leaky underground tank and a military site contaminated with jet fuel. Sabatini has also applied his emulsions research to the more efficient production of biofuel.
Biodiesel is a vegetable oil, such as soybean oil, that has been chemically modified through a transesterification reaction to reduce its viscosity. As it turns out, microemulsification of vegetable oils can reduce viscosity without the need for the transesterification reaction. This would save time and allow more of the raw material to be used as fuel.
However, Sabatini notes that the research is still in its early stages. Although humans have been making emulsions for hundreds, if not thousands, of years, we are only now beginning to appreciate their diverse applications in many fields. Complex emulsions, such as microemulsions and multilayer emulsions, promise to further expand the repertoire of applications, particularly in emerging areas such as functional foods and biodiesel production.
Now if only we could find an emulsifier for that difficult coworker. She has a Ph. The terms surfactant, emulsifier, and detergent are often used interchangeably, but there are distinctions. Surfactant is the broadest term: Both emulsifiers and detergents are surfactants. Surfactants, or surface-active agents , are compounds that lower the surface tension between two liquids or between a liquid and a solid. Surfactants are amphiphilic, meaning that they contain hydrophilic water-loving head groups and hydrophobic water-hating, or oil-loving tails.
Surfactants adsorb at the interface between oil and water, thereby decreasing the surface tension. An emulsifier is a surfactant that stabilizes emulsions. Emulsifiers coat droplets within an emulsion and prevent them from coming together, or coalescing.
An emulsion is a mixture of two or more liquids, with or without an emulsifier, that are normally immiscible. A suspension is a solid dispersed in a liquid. Learning Resources. Each collection features resources to Know about, Show, Explore, and Relate to an engaging theme for learners and educators. Data for the People. Science for all, straight from the source, with an emphasis on the process of science.
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In the agricultural industry, emulsions are used as delivery vehicles for insecticides , fungicides and pesticides. These water insoluble biocides must be applied to crops at very low levels, usually by spraying through mechanical equipment. Emulsion technology allows these chemicals to be effectively diluted and provides improved sprayability.
Nonionic emulsions are often used in this regard due to their low foaming properties and lack of interaction with biocidal agents they are carrying.
In cosmetics, emulsions are the delivery vehicle for many hair and skin conditioning agents. Anionic and non-ionic emulsions are used to deliver various oils and waxes which provide moisturization, smoothness and softness to hair and skin.
Emulsions formed with cationic emulsifiers are themselves effective conditioning agents since their positive charge is attracted to the negative sites on the hair, thus allowing them to resist rinse off. Many paints and inks are based on emulsions.
Such products may be true liquid-in-liquid emulsions or they may be dispersions. Dispersions are similar to emulsions except that the dispersed phase is usually finely divided solid particles.
The same surfactant technology used to formulate emulsions is used to create dispersions of pigments that are used in paints and inks. These dispersions are designed to dry quickly and form waterproof films, while not affecting the color. In this regard emulsions provide benefits over solvent containing systems because of reduced odor and flammability. Many food products are in the form of emulsions. An example of a naturally occurring food emulsion is milk which contains globules of milk fat cream dispersed in water.
The whiteness of milk is due to light scattering as it strikes the microscopic fat particles. Salad dressings, gravies and other sauces, whipped dessert toppings, peanut butter, and ice cream are also examples of emulsions of various edible fats and oils. In addition to affecting the physical form of food products, emulsions impact taste because emulsified oils coat the tongue, imparting "mouth-feel.
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