Pyrenylated hyperbranched polyethylene and its application in the preparation of graphene

Abstract

The invention discloses pyrenyl hyperbranched polyethylene and an application thereof in preparing graphene. The pyrenyl hyperbranched polyethylene is prepared by adopting the following method which comprises the steps: adding a pyrenyl-containing monomer of which the structural formula is shown in the specification and an anhydrous solvent to a reaction vessel under the protection of ethylene, and controlling temperature between 15 DEG C and 35 DEG C; then adding a Pd-diimine catalyst which is dissolved in the anhydrous solvent, and stirring to react for 12-48 hours under the condition that the temperature is 15-35 DEG C and the ethylene pressure is 0.1-6 atm; after polymerization is finished, pouring an obtained product into acidified methanol to finish the polymerization; and separating and purifying an obtained polymerization reaction mixture to obtain pyrenyl hyperbranched polyethylene. The pyrenyl hyperbranched polyethylene disclosed by the invention can be used for preparing the graphene. Due to the use of the pyrenyl hyperbranched polyethylene, the preparation of the graphene has the advantages of moderation condition and simple process and the graphene with few defects can be efficiently prepared.

Description

technical field [0001] The invention relates to a graphene preparation technology, in particular to a pyrenylated hyperbranched polyethylene (HBPE) and the application of the pyrenylated HBPE in the preparation of graphene. Background technique [0002] As a class of one-atom-thick two-dimensional carbon nanomaterials, graphene consists of a single sp 2 Composed of hybrid carbon atoms, it shows excellent electrical, thermal, mechanical and optical properties, so it has broad application prospects in the fields of energy materials, optoelectronic information, catalysis, sensing elements and high-performance polymer composite materials. However, in order to realize the large-scale application of graphene in the above-mentioned fields, we must first try to realize the efficient and macro-quantified preparation of low-defect graphene with a simple process, and obtain various high-concentration and stable graphene solutions. [0003] Around this goal, a series of graphene prepar...

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Problems solved by technology

[0003] Around this goal, a series of graphene preparation methods have been developed and reported, mainly including: (1) Graphite oxidation-reduction method: Graphene oxide is prepared through the oxidation of graphite and ultrasonic action, and further under the protection of stabilizer Chemically converted graphene is obtained by thermal or chemical reduction; the graphene obtained by this method can be stably dispersed in aqueous or organic solvents, and has the advantages of high yield, but there are disadvantages such as long process route, heavy environmental pollution and many structural defects of graphene

(2) Surfactant method: Under the stability of various surfactants, the natural graphite is peeled off by means of ultrasound to obtain a stably dispersed graphene solution. The resulting graphene has few structural defects and has the advantages of simple preparation method and environmental protection. However, The removal of surfactants is difficult, which can easily lead to a decrease in the electrical properties of graphene

(3) Special solvent method: In various special solvents such as N-methylpyrrolidone, N,N-dimethylformamide and o-dichlorobenzene, the natural graphite can be directly peeled off by ultrasound to obtain stable graphene solution, the resulting graphene has fewer structural defects, and the preparation method is simple, but the applicable solvent types are less, and have higher boiling point, toxicity and price, which is not conducive to the further functionalization and application of graphene

(4) Using the non-covalent interaction method between functional compounds or polymers and graphene surfaces: with the help of non-covalent interactions between functional compounds or polymers and graphene surfaces, such as π-π stacking, electrostatic and charge transfer, etc., ultrasonic Peel off natural graphite to obtain a stable graphene solution. The resulting graphene has few structural defects and can realize surface functional modification. However, the synthesis of the required functional compound or polymer is more complicated, and the concentration of graphene is low, which is not conducive to scale. application

(5) Other methods: such as micro-stress peeling method, chemical vapor deposition method, electrochemical method, etc., the obtained graphene concentration is generally low, the scope of application is narrow, and it is difficult to obtain wide application

However, since the above-mentioned interaction between HBPE and graphene is limited to weak hydrogen bonding (CH-π), the preparation efficiency of graphene is low, and there is still a certain distance from large-scale application.

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