Studies on supramolecular gel aggregates via supramolecular interactions are very fascinating and impressive. The interactions of gelator with solvent and inorganic salt can functionalize, activate, or control the properties of supramolecular gels. A lot of work on this area has been done, but all these contributions are only at an early stage. In this work, we tuned the gel formation conditions and properties by using low-molecular-weight gelator (LMWGs), amide-functionalized imidazolium-based surfactant , viz., N-cetyl-N′-acetamido imidazolium bromide ([N-C 16 , N′-CONH 2 -Im]Br), in different solvents and with inorganic salt additives. Under chemical (Cu 2+ /H 2 O 2 ) and physical (temperature) stimuli, gel-sol phase transition occurred in the gel formed from 2 wt% [N-C 16 , N′-CONH 2 -Im]Br in the solvent formamide (FM). Accompanied with increased mechanical strength of the gels, morphology alternation from initial straight stripe-shaped structures to curly belt-like textures was observed in the addition of CuBr 2 . From Small-angle X-ray scattering (SAXS) measurements, bilayer units with interdigitated hydrocarbon tails of the gelator were testified to appear in the gels. Comparative experiments demonstrate that the π-π interaction, H-bonding, and hydrophobic interaction between the gelator molecules are the main driving forces for the gelation . The low-cost gelator, facile preparation, and coordination-driven assembly process make the robust gel a good candidate in various applications, such as material templates and drug deliveries.
Kun Chen,Xin Peng,Meng Dang,Jun Tao,Jingbo Ma,Zhijie Li,Liuhai Zheng,Xiaodan Su,Lianhui Wang,Zhaogang Teng
Artificial nanomotors are undergoing significant developments in several biomedical applications. However, current experimental strategies for producing nanomotors still have inherent drawbacks such as the requirement for expensive equipment, strict controlling of experimental conditions, and strenuous processes with several complex procedures. In this study, we describe for the first time a facile single-step thermodynamic-controlled coating method to prepare Janus mesoporous organosilica nanomotors. By controlling the total free energy of organosilica oligomers (G) from a low development level to a high level in the reaction system, the nonspontaneous nucleation on the platinum (Pt) nanosurface and the spontaneous nucleation in a solvent can be controlled, respectively. More importantly, we reveal that the molecular arrangement and contact angle of deposited organosilica on Pt cores vary with the total free energy of organosilica oligomers (G). Different values of θ would change the trend of detachment from Pt for organosilica nucleated cores and carry out diverse coating modes. These are indicated by the morphology evolution of platinum/organosilica hybrids, from naked platinum nanoparticles, evenly distributed organosilica shell/core, nonconcentric to typical Janus nanomotor. The prepared Janus mesoporous nanomotor (JMN) showed typical mesopore structures and active propelling behaviors under H2O2 stimulation. In addition, the JMN modified with hyaluronic acid exhibited excellent biocompatibility and improved tumor penetration under H2O2 stimulation. The successful construction of other nanomotor frameworks based on a gold-templated core proves the perfect applicability of the thermodynamic-coating method for the production of nanomotors. In conclusion, this work establishes a manufacturing methodology for nanomotors and drives nanomotors for promising biomedical applications.
危险品化学品经营许可证（带存储）