Formation of Nanoparticles and Nanostructures-An Industrial Perspective on CaCO3, Cement, and Polymers

Nanotechnology enables the design of materials with outstanding performance. A key element of nanotechnology is the ability to manipulate and control matter on the nanoscale to achieve a certain desired set of specific properties. Here, we discuss recent insight into the formation mechanisms of inorganic nanoparticles during precipitation reactions. We focus on calcium carbonate, and describe the various transient stages potentially occurring on the way from the dissolved constituent ions to finally stable macrocrystals—including solute ion clusters, dense liquid phases, amorphous intermediates, and nanoparticles. The role of polymers in nucleating, templating, stabilizing, and/or preventing these structures is outlined. As a specific example for applied nanotechnology, the properties of cement are shown to be determined by the formation and interlocking of calcium‐silicate‐hydrate nanoplatelets. The aggregation of these platelets into mesoscale architectures can be controlled with polymers. Intermediate nanostructures occurring during crystallization reactions play an important role in understanding and controlling the formation of particles and hybrid materials. The use of polymers allows the range of achievable properties to be broadened through their specific effects at the nanoscale—as is exemplified in this Review with calcium carbonate, zinc oxide, and cementitious systems.