SHORT-RANGE STRUCTURE IN AGGREGATES, GELS, AND SEDIMENTS

Colloidal particles commonly come together to form semirigid, disordered structures such as aggregates, gels, and sediments. Examples can be found in the commercially important areas of material science, biotechnology, and food processing: the formation of random silicates as precursors in glassmaking and ceramics; flocculation of yeast cells during beer fermentation; and coagulation of casein micelles into curd during cheesemaking. The concept of the pair distribution function, g(R), used to describe structures in concentrated stable colloids, is also useful for quantifying short-range structures in aggregated colloids. By comparing g(r) plots for simulated sediments formed at two different ionic strengths, it is demonstrated that the short-range aggregate structure is sensitive to colloidal interactions.