Lanternarene-Based Self-Sorting Double-Network Hydrogels for Flexible Strain Sensors.

Conductive flexible hydrogels have attracted immense attentions recently due to their wide applications in wearable sensors. However, the poor mechanical properties of most conductive polymer limit their utilizations. Herein, a double network hydrogel is fabricated via a self-sorting process with cationic polyacrylamide as the first flexible network and the lantern[33]arene-based hydrogen organic framework nanofibers as the second rigid network. This hydrogel is endowed with good conductivity (0.25 S m-1) and mechanical properties, such as large Young's modulus (31.9 MPa), fracture elongation (487%) and toughness (6.97 MJ m-3). The stretchability of this hydrogel is greatly improved after the kirigami cutting, which makes it can be used as flexible strain sensor for monitoring human motions, such as bending of fingers, wrist and elbows. This study not only provides a valuable strategy for the construction of double network hydrogels by lanternarene, but also expands the application of the macrocycle hydrogels to flexible electronics.

Macrocycle Self-Assembly Hydrogel for High-Efficient Oil-Water Separation.

Supramolecular hydrogels involved macrocycles have been explored widely in recent years, but it remains challenging to develop hydrogel based on solitary macrocycle with super gelation capability. Here, the construction of lantern[33 ]arene-based hydrogel with low critical gelation concentration (0.05 wt%), which can be used for efficient oil-water separation, is reported. The lantern[33 ]arenes self-assemble into hydrogen-bonded organic nanoribbons, which intertwine into entangled fibers to form hydrogel. This hydrogel which exhibits reversible pH-responsiveness characteristics can be coated on stainless-steel mesh by in situ sol-gel transformation. The resultant mesh exhibits excellent oil-water separation efficiency (>99%) and flux (>6 × 104 L m-2 h-1 ). This lantern[33 ]arene-based hydrogel not only sheds additional light on the gelation mechanisms for supramolecular hydrogels, but also extends the application of macrocycle-based hydrogels as functional interfacial materials.

Two-Dimensional Conductive Metal-Organic Frameworks Based on Truxene.

Two dimensional conductive metal-organic frameworks (2D cMOFs) have been widely applied as electrocatalysts, electronic devices, and sensors. In addition, their intrinsic electronic properties could be efficiently tuned via varying the conjugated linkers. Herein, we report a novel 2D cMOF based on complexation of 2,3,7,8,12,13-hexahydroxyl truxene and copper ions via the energy economical interfacial reaction. This 2D cMOF was obtained as a brilliant black powder and showed a bulk electrical conductivity of 3.5 × 10-3 S cm-1 at 30 °C. Additionally, the cMOF-modified glassy carbon electrode could act as an electrochemical sensor for sensing paraquat with a limit of detection at 4.1 × 10-8 M (S/N = 3). The accession of truxene-Cu to the cMOF family would shed new light on the impact of the organic conjugated linker and broaden the scope of cMOFs' applications.