Hydrophile-lipophile balance application

The performance of secondary alkanesulfonates in applications as emulsifiers in the widespread emulsion polymerization of vinyl monomers can be assessed by their hydrophilic-lipophilic balance (HLB) numbers. The HLB numbers can... 

Sucrose reacts with fatty acids to produce esters with degrees of esterification (DE) from 1 to 8 and hydrophilic/lipophilic balances that provide them with numerous applications. Primary producers are Japan and the Nethedands, with total production at 6000 t/yr. Sucrose esters are nontoxic and biodegradable, and are approved for use in the EC, Japan, and the United States. 

Vol. 9 Hydrophile-Lipophile Balance of Surfactants and Solid Particles. Physicochemical Aspects and Applications. By P.M. Kruglyakov Vol. lO Particles at Fluid Interfaces and Membranes. Attachment of Colloid Particles and Proteins to Interfaces and Formation of Two-Dimensional Arrays. 

A useful index for choosing surfactants for various applications is the hydrophilic-lipophilic balance (HLB), which is based on the relative percentage of hydrophilic-to-lipophilic groups in the surfactant molecule(s). Surfactants with a low HLB number normally form W/O emulsions, whereas those with a high HLB number form a O/W emulsion. A summary of the HLB range required for various purposes is given in Table I. 

The type of emulsion formed (normally water-in-oil or oil-in-water, commonly expressed as wlo or olw, w denoting the aqueous phase and o the organic phase) is determined by the volume ratio of the two liquids and also by the phase addition sequence and the nature of any additives used to promote emulsification [29] the affinity of emulsifiers for oil and water is measured on the hydrophile-lipophile balance (HLB) scale [30]. Oil-in-water emulsions are most common in all application fields. 

Kruglyakov, P.M., Hydrophilic - Lipophilic Balance Physicochemical Aspects and Applications, in Studies in Interface Science , vol.9, D. Mobius, R. Miller (Editors), Elsevier, Amsterdam, 2000... 

The w/o/w or o/w/o emulsions are important, in particular when the protection of sensitive ingredients or controlled release of active substances is required [54]. Silicone-based emulsifiers are suited for these applications. They are strongly adsorbed at the oil interface, and do not migrate from one interface to the other, thus preventing the destabilization. Two emulsifiers have to be used to stabilize these multiphase emulsions. The hydrophilic-lipophilic balance (HLB) values of the emulsifiers should be above 10 for the hydrophilic emulsifier and below 6 for the hydrophobic emulsifier [54]. 

Surfactants adsorb on liquid-air and oil-water interfaces and decrease surface and interfacial tensions and the corresponding works of adhesion. Thus, they facilitate the cleaning of various surfaces. Important characteristics in surfactant science, and for understanding their action in cleaning and other applications, include both parameters of the surfactants (CMC, Krafft point, hydrophilic/lipophilic balance) and of the (often aqueous) solution they are in (temperature, salts, co-surfactants, time). We will discuss all of these parameters in this chapter. 

The isolation and pre-concentration of polyphenolic compounds from biological fluids is usually carried out on solid phase extraction (SPE) columns of different packing materials (24, 25, 33-36). These compounds are usually extracted from urine and plasma samples by means of the Oasis HLB columns (26-30). The sorbents of this column are a copolymer of w-divinylbenzene and A -vinylpyrrolidone, which determines its broad uses. The application of hydrophile-lipophile balance (HLB) sorbents obtains high recoveries for a number of polyphenolic compounds with different physicochemical properties. The preparation of plasma samples for the analysis was also carried out by liquid-liquid extraction (LLE) where ethyl acetate was used as an extraction solvent (22,31). 

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