Destabilization, hydrotropic

The results are straight forward and the interpretation immediately evident. The liquid crystalline phase formed in these extremely water rich systems was destabilized by the dicarboxylic acid and transformed to an isotropic solution. The conclusion that the hydrotropic action of the dicarboxylic acid is intimately related to its capacity to destabilize a liquid crystalline phase also under the water-rich conditions during actual laundering conditions appears well justified. 

The interest in the conformation of the hydrotrope is primarily related to its behavior at an oll/water Interface in conjunction with surfactant molecules. In addition, molecules from an "oily dirt" may be present. Finally, it is essential to realize that the action of the hydrotrope is to destabilize a liquid crystalline phase and transform it to an isotropic liquid. 

The evaluation of the conformation of the diacid monosoap from these results is unambiguous. Both the polar groups of the raonosoap are located at the water surface, giving a conformation such as the one in Fig. 6. This conformation readily provides an explanation for the hydrotropic action of the dicarboxylic acid. When acting at an interface, the molecule does not posess the extended conformation of Fig. 2 its conformation is as shown in Fig, 6. Hence, the destabilizing action may be intuitively understood in the same manner as for the traditional aromatic hydrotrope, Fig. 1. 

The molecular mechanism behind the destabilization of liquid crystals was subsequently clarified [25], The specific disordering promoted by the hydrotrope in the water-surfactant-oily liquid crystal was first determined, followed by an investigation into the conformation of the diacid molecule itself [92],... 

Figure 2.13 is obviously the one encountered in the liquid crystal. As a comparison, the addition of oleic acid with one polar group located at the interface gives the expected increase in interlayer spacing, as shown in Figure 2.14. Destabilization of the lamellar liquid crystal is not only affected by the diacid it appears to be a general property shared by other hydrotropes, such as alkanols, short-chain...

The formulation of food systems as microemulsions is not easy, since addition of triglycerides to inverse micellar systems results in a phase change to a lamellar liquid crystalline phase. The latter has to be destabilized by other means than adding co-surfactants, which are normally toxic. An alternative approach to destabilize the lamellar phase is to use a hydrotrope, a number of which are allowed in food products. 

Figures 3 and 4 depict the phase behaviors of various triglycerides, ethox-ylated mono/diglycerides, and water in conjunction with hydrotropes such as ethanol, propylene glycol, and sucrose [13,18]. It can be seen from Fig. 3 that a w/o microemulsion (L2 phase) was easily formed at a ratio of 75 25 wt% of ethoxylated mono/diglycerides. In a certain region of the phase diagram, blue phase, droplets separated by lamellar liquid crystals were observed. Ethanol was reported to act synergistically with sucrose to destabilize...

---