Abstract: The present invention relates to a method for preparing a covalent organic framework (COF) materials—a reversible polycondensation/termination method, the COF materials prepared by the method have high crystallinity, high specific surface area, regular and controllable morphology. The present invention also relates to a method for repairing defects of COF materials—reversible degradation-recombination, the method can eliminate defects of existing COF materials, thereby increasing the crystallinity and specific surface area of COF materials and improving their morphological characteristics.

Abstract: The present invention relates to a covalent organic framework which is a two-dimensional polymer formed by repeatedly arranging structural units represented by formula I or formula II and bonding same by means of covalent bonds. The present invention also relates to a catalyst, preparation methods for the covalent organic framework and the catalyst, and applications of the covalent organic framework and the catalyst in catalyzing olefin polymerization. The covalent organic framework can be used as a support to control the stereoregular polymerization of olefins in a confined space. The catalyst has high catalytic activity and good high-temperature stability, and widens the range of types of olefin polymerization catalysts.

Abstract: The present invention relates to a method for preparing a hollow covalent organic framework (COF) material and hollow COF material prepared by said method. Said method is characterized in including a monomer displacement step in the method, thereby obtaining the hollow COF material with a controllable particle size, wall thickness and/or specific surface area.

Abstract: A method for preparing a supported olefin polymerization catalyst, comprising: step 1, activating a COF at 0° C.-800° C. for 0.1-48 hours under inert atmosphere or vacuum protection; optionally, step 2, reacting the activated COF with an auxiliary agent in a reaction medium at a temperature of 5° C.-120° C. under inert atmosphere or vacuum protection, and performing solid-liquid separation to obtain a solid phase material, wherein the auxiliary agent is selected from a metal alkyl compound, boron halothane, an alkyl aluminum oxide, a modified methyl aluminoxane, a Lewis acid, and a Grignard reagent; and step 3, under inert atmosphere or vacuum protection, reacting the solid phase material with the olefin polymerization catalyst in a reaction medium at ?30° C.-150° C., performing solid-liquid separation, and collecting the solid phase material as the supported olefin polymerization catalyst. A supported olefin polymerization catalyst and an application thereof.

Abstract: The present invention relates to a method for preparing a covalent organic framework (COF) materials—a reversible polycondensation/termination method, the COF materials prepared by the method have high crystallinity, high specific surface area, regular and controllable morphology. The present invention also relates to a method for repairing defects of COF materials—reversible degradation-recombination, the method can eliminate defects of existing COF materials, thereby increasing the crystallinity and specific surface area of COF materials and improving their morphological characteristics.

Abstract: An particle can include a first sheet comprising a layer including a first material, wherein the first sheet includes a first outer surface and a first inner surface; and a second sheet comprising a layer including a second material, where the second sheet includes a second outer surface and a second inner surface, wherein the first sheet and the second sheet form a space, the space is encapsulated by the first sheet and the second sheet.

Abstract: An particle can include a first sheet comprising a layer including a first material, wherein the first sheet includes a first outer surface and a first inner surface; and a second sheet comprising a layer including a second material, where the second sheet includes a second outer surface and a second inner surface, wherein the first sheet and the second sheet form a space, the space is encapsulated by the first sheet and the second sheet.

Abstract: A composite can include alternating layers of a first layer including a 2D material and a second layer including a polymer matrix. Fabrication methods can take a thin layer of molecular thickness and construct large composite stacks that scale exponentially with the number of processing steps. An analogous shear scrolling method can create Archimedean scroll fibers from single layers with similar scaling. These methods can produce materials that demonstrate the ??? limit while combining electrical and optical properties minimal volume fraction of the filler.