Lignosulfonates aqueous phase

Figure 5 illustrates the type of encapsulation process shown in Figure 4a when the core material is a water-immiscible Hquid. Reactant X, a multihmctional acid chloride, isocyanate, or combination of these reactants, is dissolved in the core material. The resulting mixture is emulsified in an aqueous phase that contains an emulsifier such as partially hydroly2ed poly(vinyl alcohol) or a lignosulfonate. Reactant Y, a multihmctional amine or combination of amines such as ethylenediamine, hexamethylenediamine, or triethylenetetramine, is added to the aqueous phase thereby initiating interfacial polymerisation and formation of a capsule shell. If reactant X is an acid chloride, base is added to the aqueous phase in order to act as an acid scavenger. 

Lignosulfonate has been reported to increase foam stabihty and function as a sacrificial adsorption agent (175). Addition of sodium carbonate or sodium bicarbonate to the surfactant solution reduces surfactant adsorption by increasing the aqueous-phase pH (176). 

To the organic phase from Step 2 add an equal volume of distilled water. Stir the mixture and adjust the pH to 9 with sodium hydroxide (or other alkali hydroxides if necessary). Pour the mixture into a separatory funnel and allow 24 h for the phases to separate while keeping the temperature at 50-60°C. Recover sodium lignosulfonate (or other metal salts) from the aqueous phase. 

Table 9pH of the Aqueous Phase of the Lignosulfonate-and Kraft Lignin-Stabilized Emulsions... 

The emulsions stabilized by lignosulfonates are extremely stable under a wide range of condition. Therefore, the conventional emulsion breaking techniques are not very effective to separate oil and aqueous phases. The most effective method to break lignosulfonate-stabilized... 

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