Interfacial Synthesis of Cellulose-Derived Solvent-Responsive Nanoparticles via Schiff Base Reaction

Herein, a facile and easy scale-up method of interfacial covalent assembly was presented to fabricate solvent-responsive nanoparticles (NPs) through Schiff base reaction between dialdehyde cellulose (DAC) and aniline. Due to the presence of highly reactive aldehyde groups, DAC can be easily modified via interfacial Schiff base coupling, giving rise to the formation of DAC-aniline nanoparticles (DANPs). Two techniques were performed to achieve diverse liquid/liquid interfaces as the curved oil droplets-in-water interface and the planar oil-water interface for the Schiff base reaction. The average diameters of DANPs formed at the planar oil-water interface (96–212 nm) were much smaller than those of the DANPs from the droplets interface (402–842 nm). The sizes of DANPs can be well controlled by altering the molar ratios of reactants, and they displayed a time-dependent feature. Moreover, DANPs exhibited solvent-responsive properties and size-switchable swelling behaviors as shown by changing the volume ratios of ethanol to water. Furthermore, Rhodamine B (RhB) as a model molecule was loaded into the polymeric network of DANPs-0.5. Due to the swelling property, the resulting RhB@DANPs-0.5 nanoparticles exhibited an effective release of RhB molecules in response to ethanol. These merits allow the use of DANPs in potential applications in various fields, such as stimuli-responsive functional materials and sensors.