Preparation of Aqueous Solutions with Information on Solids Using Natural Polymers by Solid‐State Mixing

Some organic molecules exhibit multiple properties such as chiral crystal formation, crystal polymorphism, room-temperature phosphorescence, mechanochromism, and fluorescence detection by molecular recognition only in their solid, self-aggregated states (crystalline or amorphous states). These functionalities either disappear or converge to a single physical property when these molecules are dispersed in a solvent. To address this limitation, self-aggregated guest molecules are dissolved in water using natural polymers as solubilizing agents. However, conventional solid-liquid extraction methods such as heating and stirring or ultrasonic irradiation are rendered ineffective in completely dissolving the functional guest molecules in water. These molecules are mixed with natural polymers via grinding or high-speed vibration milling, followed by extraction with water, to enhance their water solubility while maintaining their functions. These systems are referred to as aqueous solutions with information (properties) on solids.