3D/4d printing of β-cyclodextrin-based high internal phase emulsions

Abstract

The β-cyclodextrin (β-CD) based high internal phase emulsions (HIPEs) were prepared as building blocks for engineering high-quality 3D shapes and achieving 4D color transformation. The increase of β-CD concentration, the decrease of pH value, and the addition of NaCl contributed to the adsorption of β-CD molecules at the oil-water interface and the improvement of the microstructure, rheological properties and printing quality of the Pickering HIPEs. Moreover, the 4D printing of Pickering HIPEs was achieved by introducing pH-sensitive curcumin and heat-labile NaHCO3. With the increase in heating temperature, heating time and NaHCO3 concentration, the decomposition of HCO3− to CO32− led to an elevation in pH, which induced the conformational change in curcumin, accompanied by a decrease in L* and b × values and an increase in a × value of the samples. These findings dramatically improve the pleasure of diet and take full advantage of the custom design benefits of 3D printing technology.