Research On The Preparation And Application Of Colloids And Two-dimensional Materials With Asymmetric Structure

Through bottom-up chemical design methods,a variety of colloidal particles have been successfully prepared in recent years.At the same time,composite microspheres with multiple functions are also increasingly favored by various chemical modification methods.The composite microspheres have more functions,stronger chemical or physical properties,and a wider range of applications.Janus was originally the name of the ancient Roman double-faced god.In 1992,former Nobel laureate de Gennes first proposed Janus to represent particles with different physical or chemical properties on both sides.In recent years,with a lot of exploration and research,people have not only developed a variety of methods for preparing Janus colloidal particles,but also extended this special chemical structure from one dimension to a broader field,not only oil-water separation or battery separators,but also the two-dimensional Janus film which uses Janus particles for the construction of functional coatings.In this thesis,four Janus structural materials were prepared based on Janus materials,ranging from Janus colloidal microspheres to 2-dimensional Janus films.The main contents are as follows:(1)Using the interface protection method to prepare multi-functional,multi-component Janus colloidal microspheres with dopamine as a bridge,firstly dispersed the PS colloidal particles at the water-air interface and forrnd a two-dimensional close-packed structure,then used PDMS to make the particles transferred and embedded in the cured PDMS elastomer,and then the exposed part of the microspheres was modimcated by dopamine,and finally the dopamine was used as a bridge to modify the chemical properties of dopamine to form multi-component Janus colloidal particles.(2)By using the gas-liquid volatile method,anon-crosslinked PS microsphere was dispersed at the water-air interface by a similar device,and a volatile organic solvent such as dichloromethane was used as an "etchant" in a closed system.The vapor was condensed on the exposed surface of the PS microsphere,and as time passes,asymmetrical particles of various morphologies were prepared.At the same time,the deformation rate of the PS template microspheres could be controlled by adding ethanol to the volatile solvent species.This method is also applicable to inorganic particles represented by silica colloidal particles.(3)Firstly,the PS microsphere array was used as a template to form an ordered array at the interface between Tris-Buffer and air,and then added dopamine to polymerize onto the lower part of the PS microsphere array.Finally,the PS microspheres were etched.Then through the ultraviolet photopolymerization,PNIPAAm grafting was introduced into to prepare a two-dimensional ordered array and tested for its controlled adhesion properties.(4)By using simple ultrasonic method,Co(NO3)2·6H2O and 2-methylimidazole(C4H6O2)were prepared as precursors.By controlling the ratio of the two materials,Co-LDH was prepared.Then it was tested for its OER properties,proved to have great potential for replacing precious metal catalysts such as commercial RuO2.