The Novel Polymer-free Lamellar Hydrogel Based Of Self-assemble Of Small Molecules And Its Property Study

The supramolecular self-assembly of small molecule via noncovalent interactions has exhibited important roles in developing novel biomaterials,smart devices,information science,and nanotechnology,which renders this interdisciplinary research subject as one of the key scientific issues.This dissertation is mainly about the development of the novel self-assemble system by designing the molecular structure.We discovered a new molecule HGM which can form special polymer-free iridescent lamellar hydrogels.Unlike common hydrogels that consist of fibers/discrete polymer chains-based network,the anisotropic hydrogel with one-dimensional periodic lamellar structure has extremely thick water layer up to sub-micrometer scale sandwiched by lamellar bilayer membranes of a self-assembled HGM molecule.The origin of hydrogel is ascribed to the formation of certain amount of edge-dislocation defects derived from curved bilayer membranes,which effectively restrain the flow of water.The particular lamellar hydrogel was used as a soft 2D-template to guide the growth of 2D single-crystalline Au sheets.Free-standing,ultrathin,and ultralarge single-crystalline Au membranes with atomically smooth surface were successfully synthesized and exhibited interesting optical and electrical properties.The unique hydrogel system with highly ordered water layers opens a new way for producing various 2D nanomaterials and its abundant water/biomembrane interfaces are very promising to be used in bio-related field.Based on the study of HGM,we have designed another non-ionic surfactant,Dodecyl Glyceryl Itaconate(DGI).DGI small molecules exhibit similar self-assembly behavior to HGM in water.By introducing polymerizable monomers into DGI layered hydrogels and in situ polymerization,layered hydrogels with good mechanical properties have been obtained,on this basis,the applications of DGI layered hydrogels in capacitors and sensors are explored.The results show that the hydrogel prepared on the basis of DGI small molecule maintains good layered structure.The flexible stretchable supercapacitor made from DGI small molecule as electrolyte has good capacitive properties and is suitable for various electrodes.The capacitive flexible electronic skin device based on the hydrogel also has good performance.Under external stimulation,the deformation of the device directly results in the change of capacitance signal,and the corresponding color change due to periodic change of its layers,which realizes the accurate measurement and visualization of stimulus-response.In the above research process,we found that flexible stretchable supercapacitors with good performance can be prepared by using hydrogel as electrolyte,but their mechanical behavior needs further optimization.Based on the original device structure,we use a self-healing,ultra-stretchable hydrogel as electrolyte and study its device performance.The hydrogel can be stretched to 50 times of the original and has good cyclic resilience.The capacitor prepared by pre-stretching with the hydrogel as electrolyte can still work normally when stretched to 10 times of the original.The energy storage behavior of the device increases with the increase of the contact area between the stretched electrode and the hydrogel electrolyte.The whole capacitor has good flexibility,self-healing and cyclic stability,and has a good application prospect in the new generation of wearable flexible electronic devices.