Applications of freezefracture replication to problems in materials and colloid science

Understanding the relationship between the molecular structure and the macroscopic properties of polymer solutions and gels, oilwatersurfactant emulsions, lyotropic and thermotropic liquid crystals, colloidal dispersions, detergents, and other suchmicrostructured fluidsis essential to the optimal use of these commercially important materials. Modern rapidfreezing methods followed by freezefracture replication techniques are ideally suited to allow the direct visualization of the threedimensional structure of the particles or units that make up the dispersion, while simultaneously revealing their orientation and distribution with molecular resolution. This paper reviews the necessary experimental conditions required to successfully exploit the freezefracture technique as it applies to microstructured fluid systems. The benefits and limitations of structural studies by freezefracture techniques as opposed to the more commonly used light, Xray, and neutronscattering methods are discussed. Freezefracture replicas can also be imaged by scanning tunneling microscopy to reveal directly threedimensional fracture contours with improved resolution. Copyright1989 WileyLiss, Inc.