Steric stabilization advantages

Steric stabilization is particularly useful and widely applied during emulsification processes. One major advantage compared to electrostatic stabilization is the relative insensitivity towards added electrolytes. An auxiliary effect promoting dispersion stability is the significant viscosity increase of the dispersion medium. 

A promising strategy towards stable and catalyticaUy active metal colloids is their preparation inside the core of micelles formed by amphiphilic block copolymers. This strategy offers a number of advantages (i) micelles represent a nano-structured environment which can be exactly tailored by block copolymer synthesis (ii) polymers act as effective steric stabilizer ]36] (iii) metal leaching might be avoided (iv) micelles allow control over particle size, size distribution and particle solubility [37] and (v) micelles are also supposed to effect catalytic activity and selectivity [38]. 

Adsorption of a non-ionic polymer (gum or cellulosic) or surfactant (polysorbate 80) of sufficient chain length creates steric hindrance and prevents adjacent suspended particles from coming close enough to join each other. Steric stabilization has the advantage over electrostatic stabilization in that it is relatively insensitive to the presence of electrolyte in the aqueous vehicle. 

One year later, Brust and Schiffrin [28,29] published a method for AuNPs synthesis which has a considerable impact on the overall field in less than a decade because it allowed the facile synthesis of thermally stable and air-stable AuNPs of reduced dispersity and controlled size for the first time. In this method, the gold colloids are sterically stabilized by organic molecules having thiol, amide or acid groups in contrast to the citrate reduction method where the gold colloids are kinetically stabilized in aqueous solutions by an electrical double layer [28,29], The main advantage of the Brust method is that the gold particles behave in a way as chemical compounds. These AuNPs can be repeatedly isolated and... 

Coagulation or flocculation of the growing polymer particles in a colloidal dispersion can be prevented by using electrostatic, electrosteric, or steric stabilization, and the use of these methods in conventional liquid solvents has been extensively reviewed [95-97]. Steric stabilization offers several advantages over the other two methods because it allows for large variations in reac-... 

Steric stabilization is widely exploited industrially and biologically because it can offer several distinct advantages over electrostatic stabilization. These will be detailed in the sections that follow. 

In aqueous dispersion media, the preparation of high solids dispersions that are stabilized electrostatically is often fui d by the gel-hke nature of the product. This is a consequence of the interactions between the double layers surrounding each particle. No comparable increase is evident in the viscosity of sterically stabilized dispersions at high solids content. Of course, in certain applications, such as in paints, the rheological properties exhibited by electrostatically stabilized dispersions at high solids may be a decided advantage rather than a drawback. 

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