Mica primary function

In addition to its primary function as a high aspect ratio mechanical property enhancer, mica is also used as a modifier of electrical properties and as an important component of sound-deadening formulations it is also used for reducing permeability, improving dimensional stability, and as a modifier of optical properties. The multiple functions of mica are compared to those of other fillers in Table 1.4. 

The amount of substitution in the tetrahedral and octahedral sheets and the ratio of octahedral to tetrahedral sheets are the primary differentiating characteristics between the many clay minerals (Fig. 3.6). For example, clays that have one tetrahedral sheet and one octahedral sheet are known as 1 1 clay minerals (e.g., kaolin group) (Fig. 3.7) clays that have two tetrahedral sheets and one octahedral sheet are known as 2 1 clay minerals (e.g., smectite group) (Fig. 3.8) or mica and vermiculite (Fig. 3.9), while clays that have two tetrahedral sheets and two octahedral sheets are known as 2 2 clay minerals (e.g., chlorite) (Fig. 3.10). These sheet arrangements give rise to various mineral surface identities such as magnitude (specific surface), functional groups, and interactions with solution species. 

For higher coverage, the structure of the irreversibly adsorbed monolayer is changed, which can be seen in Fig. 62 (latex particles adsorbed on mica, 0 = 0.24, ionic strengths 10-3 M and 2 X 10 3 M, respectively [142]). In this case, the pair-correlation function exhibits an oscillatory character with a well-pronounced primary peak at short separations. The height of... 

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