Delta crystalline phase

The crystallization of amorphous, water-containing sodium silicate to anhydrous crystalline layered sodium disilicate is crucial. It is effected in a further step. The formation of delta-crystal phase is an exothermic process at 685°C [89],... 

Mixed Soap Crystals in Nonsuper-Fatted Formulation Soap bars consist of mixture of soaps with different chain lengths and chain saturations. They are classified as soluble soaps and insoluble soaps. The soluble soaps usually form a hexagonal liquid crystalline phase with water, as shown in Fig. 2.1, which dissolves in water during washing and provides lather. The insoluble soaps stay in crystalline formats in the bar and provide mechanical strength. The solid crystals present in a soap bar can include kappa, zeta, eta, and delta phases. 

Tan delta responds in a systematic way to an increase in the amorphous phase volume fraction, as can be seen in the example of zinc chloride addition to poly(vinyi alcohol), which reduces the crystallinity [23] Fig. 8. 

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