Hydrophilic emulsifer

Uses Hydrophilic emulsifer, solubilizer, softener for lotions, creams, milk lotions, shampoos... 

Emulsification involves the joining of two mutually insoluble materials, such as petroleum oil and water. The surfactant, which usually has a hydrophilic or water-soluble end and a hydrophobic or oil-soluble end, holds the oil and water together in much the same manner that a fastener holds two pieces of material. Often, the emulsion which forms is unstable, subsequently breaking up and releasing the oil from the water. Break-up is actually preferred, because the oil then floats to the surface, whereas the surfactant is free to emulsify more oil. 

At low temperature, nonionic surfactants are water-soluble but at high temperatures the surfactant s solubUity in water is extremely smaU. At some intermediate temperature, the hydrophile—Hpophile balance (HLB) temperature (24) or the phase inversion temperature (PIT) (22), a third isotropic Hquid phase (25), appears between the oil and the water (Fig. 11). The emulsification is done at this temperature and the emulsifier is selected in the foUowing manner. Equal amounts of the oil and the aqueous phases with aU the components of the formulation pre-added are mixed with 4% of the emulsifiers to be tested in a series of samples. For the case of an o/w emulsion, the samples are left thermostated at 55°C to separate. The emulsifiers giving separation into three layers are then used for emulsification in order to find which one gives the most stable emulsion. 

These characteristics are typically classified as a hydrophile-lipophile balance (HLB value). For example, hydrophilicity may be denoted within a range of 2 to 20, with true solutions being obtained at HLB values >14 and poor dispersibility occurring at HLB values <6. Oil-in-water emulsification requires a high HLB value surfactant, while water-in-oil emulsification needs a low HLB value surfactant. 

GA is well recognized as emulsifier used in essential oil and flavor industries. Randall et al., 1998, reported that the AGP complex is the main component responsible for GA ability to stabilize emulsions, by the association of the AGP amphiphilic protein component with the surface of oil droplets, while the hydrophilic carbohydrate fraction is oriented toward the aqueous phase, preventing aggregation of the droplets by electrostatic repulsion. However, only 1-2% of the gum is absorbed into the oil-water interface and participates in the emulsification thus, over 12% of GA content is required to stabilize emulsions with 20%... 

The preparation of a ferrofluid emulsions is quite similar to that described for double emulsions. The starting material is a ferrofluid oil made of small iron oxide grains (Fe203) of typical size equal to 10 nm, dispersed in oil in the presence of an oil-soluble surfactant. The preparation of ferrofluid oils was initially described in a US patent [169]. Once fabricated, the ferrofluid oil is emulsifled in a water phase containing a hydrophilic surfactant. The viscosity ratio between the dispersed and continuous phases is adjusted to lie in the range in which monodisperse fragmentation occurs (0.01-2). The emulsification leads to direct emulsions with a typical diameter around 200 nm and a very narrow size distribution, as can be observed in Fig. 1.33. 

The top-down approach involves size reduction by the application of three main types of force — compression, impact and shear. In the case of colloids, the small entities produced are subsequently kinetically stabilized against coalescence with the assistance of ingredients such as emulsifiers and stabilizers (Dickinson, 2003a). In this approach the ultimate particle size is dependent on factors such as the number of passes through the device (microfluidization), the time of emulsification (ultrasonics), the energy dissipation rate (homogenization pressure or shear-rate), the type and pore size of any membranes, the concentrations of emulsifiers and stabilizers, the dispersed phase volume fraction, the charge on the particles, and so on. To date, the top-down approach is the one that has been mainly involved in commercial scale production of nanomaterials. For example, the approach has been used to produce submicron liposomes for the delivery of ferrous sulfate, ascorbic acid, and other poorly absorbed hydrophilic compounds (Vuillemard, 1991 ... 

All hydrophilics are currently processed by the prepolymer method. The emulsification of the prepolymer and water are the primary determinants of cell size. The water also serves as a heat sink to moderate the temperature of the reaction. By adjusting the temperatures of the prepolymer and the water, one can control the kinetics described above. The mass of the water limits the destructive exotherm. 

Katoh et al. [3] prepared w/o emulsions composed of salt solution, polyglycerin polyricinolate (PGPR) at 2%wt and com oil. It has been proven that the disperse-phase flux was increased 100-fold using a hydrophilic membrane pretreated by immersion in the oil phase. This made the membrane emulsification system practical for large-scale production of a w/o emulsion in food application. 

The function of a surfactant depends on its hydrophilicity-lipo-philicity balance (HLB). Efficient emulsification of oil generally requires a low HLB, while the whipping characteristic arises at a larger HLB. This chapter is an attempt to prepare proteinaceous surfactants with different HLBs by the enzymatic attachment of amino acid esters with different lipophilicity. For this purpose L-leucine n-alkyl esters (Leu-OQ), the alkyl chain length, i, varying from 2 to 12, were used. As... 

The surfactant selection determines the emulsion properties, such as stability, particle size, viscosity, and internal phase content. A correct balance between the hydrophobic and hydrophilic character of the emulsifier is necessary for minimizing the surfactant concentration at the resin-water interface. The surfactants used in resin emulsification can be ionic (in most cases anionic), nonionic, polymeric, or a combination of these. 

Surfactants are frequently used in detergents and food products to alter the properties of solution interfaces, mediating between immiscible phases because of their hydrophobic and hydrophilic moieties. The addition of surfactants increases the concentration of hydrophobic compounds in the water phase by solubilization or emulsification above a specific threshold, the critical micellar concentration (CMC), where surfactant molecules aggregate to micelles [130]. Two widely utilized nonionic surfactants, Tween 80 and Triton X-100, were evaluated in terms of enzyme interaction, by calculating the inactivation coefficient (kA) under static conditions. Concentrations lower than CMC were studied in order to avoid diffusional limitations in the interaction of the enzyme and the PAH in the micellar phase. The concentration 0.25 CMC was considered the most favorable for the enzyme, with Triton X-100 being the surfactant that led to the lowest inactivation coefficients for all the concentrations tested and was 2.5 times lower than kd in control experiment. 

Emulsification of grease. In a soapy solution, grease is emulsified by forming micelles coated by the hydrophilic carboxylate groups of the soap. 

A comparison of the curves of Figure 7 with those of Figures 4 and 5 clearly shows that the solubility and the emulsifying capacity are not correlated. The optimal conditions for emulsification seem to be at a DH-value where the hydrolysate consists of approximately equal amounts of soluble and insoluble material. Emulsification involves both hydrophilic and hydrophobic groups in the same molecules and it is therefore important that the molecules are not too small. Also, film formation and surface de-naturation play a role, and this also implies that the molecules should not be too small. On the other hand, a certain solubility seems to be necessary for achieving the maximum emulsifying capacity. 

Hydrophilic-hydrophobic. These are mostly influenced by the amphoteric nature of proteins emulsification, fat absorption, and fat holding. 

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