"Crystallization is an essential process in the manufacture of products as varied as pharmaceuticals, electronic devices or biomimetic materials. In order to obtain a crystalline product with desirable characteristics (e.g. crystal size, morphology, structural organization) for specific applications it is crucial to control the mechanism and kinetics of crystal nucleation and growth. Yet, our understanding of the crystallization reactions remains limited, especially for organic, polymeric, and protein crystals. It is recognized that the specific chemistry of a solvent affects crystal growth and nucleation kinetics, morphology, crystal size distribution and purity of precipitates. Usually different solvents with respective properties are used for particular purposes, and organic solvents are ubiquitously applied in crystallization strategies in research and industry. However there is great concern in limiting the use of organic solvents because of their negative environmental and health impact. Ionic liquids (ILs) have earned special attention from the scientific community as alternatives to replace traditional volatile organic compounds. Some attempts have been made to exploit the unique properties of these salts in crystallization processes. Nevertheless the complexity of such systems and as yet not fully characterized chemistry of ILs make understanding of the underlying mechanisms and control of resulting precipitate characteristics quite difficult. The aim of this project is to use ILs as crystallization additives in order to design the aqueous solvent with predictable and controllable effect on respective characteristics of inorganic and protein crystals. Such an approach results from a novel concept that explains dependence of the crystallization reactions on additives present in solution by their effect on water structure and dynamics."