Imidazolium-type ionic liquid-based carbon quantum dot doped gels for information encryption
Yiqing Wu‡, Yongyuan Ren‡, Jiangna Guo, Ziyang Liu, Lili Liu and Feng Yan *（严锋）
Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Department of Polymer Science and Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China
‡Authors with equal contributions.
Nanoscale, 2020, 12, 20965--20972
Here, a strategy for the preparation of adjustable imidazolium-type ionic liquid (IL)-based carbon quantum dots (CQDs) was reported. The effect of chemical structure, including carbon chain length of the N-substitution and the type of anion, on the amphiphilicity of CQDs was systematically investigated. It was found that the hydrophobicity of CQDs can be increased with the increase of carbon chain length for substitution at the N3 position. Moreover, the amphiphilicity of CQDs was also switched by changing the hydrophilic anions to hydrophobic anions. Due to adjustable amphiphilicity, the hydrophilic and hydrophobic CQDs were used for the preparation of fluorescent hydrogels and organogels, respectively. The fluorescent CQD-doped gels showed light- and force-dual stimuli responsiveness, which provides more secure information encryption than traditional single encryption inks.