From micro to macro
From the perspective of a chemical engineer, particulate gels are the stuff of modern life. These materials, in which small pieces of one kind of substance are suspended or distributed within another, can be found in such construction products as concrete, inks, and paints; foods like cheese, yogurt, and ice cream; and in a range of cosmetic- and health-related staples including shampoo, toothpaste, and vaccines. In sum, says James W. Swan, the Texaco-Mangelsdorf Career Development Professor in Chemical Engineering, "a massive variety of real-world, everyday things bear particles." Many of these ubiquitous gels, creams, emulsions, and compounds evolved through "trial-and-error experimentation," says Swan. Engineering such materials often proves to be a prolonged and sometimes inefficient hit-or-miss process. But now Swan and collaborators from other universities have devised a framework that will help guide the design of new materials involving such particulate compounds. An account of their research, which began in 2015, appears...