CN108314031A - The preparation method of vinyl functionalization graphene - Google Patents

Abstract

The preparation method of vinyl functionalized graphene relates to a kind of preparation method of graphene, the first step of the method is to oxidize and peel graphite by improving the Hummers method, and obtain graphene oxide after freeze-drying; in the second step, the first The graphene oxide obtained in the first step is dispersed in a suitable solvent, and at a certain temperature, the silane coupling agent containing vinyl is hydrolyzed to generate Si-OH groups and reacts with graphene oxide for a certain period of time to generate Si-O-C bonds, thereby obtaining ethylene Based functionalized graphene, ultrasonically dispersed in a suitable solvent to obtain functionalized graphene, the product is filtered, centrifuged, washed, dried, etc., to obtain a black solid powder that is vinyl functionalized graphene. The vinyl-functionalized graphene prepared by the invention has good strengthening and toughening effects, simple preparation method, easy control of conditions, and convenient post-treatment, and has potential application value in resin reinforcement, toughening or other fields.

Description

Preparation method of vinyl functionalized graphene

technical field

The invention relates to a preparation method of graphene, in particular to a preparation method of vinyl functionalized graphene.

Background technique

Graphene is a single-layer graphite sheet with a honeycomb structure composed of sp ² hybridization. The first paper on graphene was published in 2004. It was the first time to prepare a two-dimensional material that exists stably at room temperature, breaking the breakthrough that two-dimensional materials cannot The statement that it exists stably at room temperature earned its discoverer the 2010 Nobel Prize in Physics. Because graphene has excellent mechanical and electrical properties and high light transmittance, it has attracted much attention as a new member of the carbon family. A large number of researchers are studying the preparation of single-layer or few-layer graphene in large areas; There are also many researchers studying the preparation of graphene powder materials, among which the oxidation-reduction method is currently the most commonly used method for preparing graphene powder, and it is also the most potential method for large-scale preparation of graphene powder. At the same time, many researchers are studying graphene derivatives, graphene hybrid materials, etc. The modification of graphene can make it more suitable for the requirements of a certain field.

The research direction of graphene is increasingly tending to two aspects, one is the preparation of large-area single-layer or few-layer graphene, and the other is the preparation of graphene powder, including the preparation of modified graphene powder. In order to improve or improve the properties and applications of graphene, introducing other atoms or functional groups into graphene through chemical doping can better expand its physical and chemical properties. Vinyl-modified graphene has excellent mechanical properties. Conductive properties, mechanical properties and flame retardant properties.

Contents of the invention

The object of the present invention is to provide a kind of preparation method of vinyl functionalized graphene, this method is by improving Hummers method graphite oxidation, exfoliation, obtains graphene oxide after freeze-drying; OH groups react with graphene oxide for a certain period of time to generate Si-O-C bonds, thereby obtaining vinyl-functionalized graphene. The vinyl-functionalized graphene prepared by the present invention has good strengthening and toughening effects, making it suitable for resin reinforcement, It has potential application value in toughening or other fields.

The purpose of the present invention is achieved through the following technical solutions:

The preparation method of vinyl functionalized graphene, described method comprises following preparation process:

The preparation method of the vinyl-functionalized graphene is carried out in two steps. In the first step, graphene oxide is prepared from graphite through a modified Hummers method; in the second step, graphene oxide is dispersed in a suitable solvent and mixed with ethylene The base compound was reacted for several hours, and the product was centrifuged, washed, and dried to obtain a black solid powder;

In the first step of synthesizing graphene oxide, the persulfate used in the pre-oxidation process is any one or a mixture of sodium persulfate, potassium persulfate, and ammonium persulfate; the reaction temperature is controlled at 80°C; the reaction time 3-6h; during the low-temperature stage of the preparation of graphene oxide, the temperature of the system must be controlled below 15°C, and the temperature must be controlled below 30°C during the dilution process;

In the second step, the solvent used is water or any one of methanol, ethanol, THF, DMF or a mixture of several with water; in the second step, the reaction temperature is controlled between 40-60°C, and the reaction time 6-8h; KH-570 silane coupling agent, A-151 silane coupling agent, A-171 silane coupling agent and A-172 silane coupling agent, etc., the ratio of vinyl-containing reagents to graphene oxide is 5 :1-10:1; the washing solvent is water and freeze-dried.

The preparation method of the described vinyl functionalized graphene, the described vinyl functionalized graphene structure prepared according to the above method is as follows:

.

Advantage and effect of the present invention are:

1. The vinyl-functionalized graphene provided by the present invention has a simple preparation method, low equipment requirements, easy-to-obtain raw materials, and can be used for material modification.

2. The preparation method provided by the present invention is simple, the conditions are easy to control, and the post-processing is convenient.

3. The vinyl-functionalized graphene prepared by the present invention has better follow-up utilization value and can be used to obtain high polymers containing graphene.

4. The vinyl-functionalized graphene prepared by the present invention is a black solid powder, has good strengthening and toughening effects, simple preparation method, easy control of conditions, and convenient post-processing. The present invention aims at synthesizing vinyl-functionalized graphene, so that it can have potential application value in resin reinforcement, toughening or other fields.

Detailed ways

The present invention will be described in detail below in conjunction with examples.

Example 1:

Step 1: Add 30ml of concentrated sulfuric acid to a 250ml three-necked flask equipped with a reflux condenser, thermometer and magnet, add 8.5g of ammonium persulfate, 8.5g of phosphorus pentoxide, add 10g of graphite after heating to 80°C, and keep warm for the reaction After 3.5h, dilute to 1L with water, suction filter, wash to PH≈7, and dry in an oven at 80°C overnight to obtain pre-oxidized graphite; mix 375ml of concentrated sulfuric acid and the obtained graphite oxide in an ice bath, and slowly dissolve 40gKMnO ₄ Add to the mixed solution, keep the temperature lower than 15°C during the period, raise the temperature of the water bath to 35°C after the addition, keep it warm for 2 hours, dilute the obtained mixed solution to 3L with water under the condition of ice bath, keep the temperature lower than 30°C, add H ₂ O ₂ 60ml, the system is an orange-yellow solution, after standing overnight, remove the supernatant, wash 3 times with 5% dilute hydrochloric acid, wash 3 times with distilled water, add water to the system mixture to make 2L, sonicate for 5h, freeze-dry After graphene oxide.

Step 2: Weigh 0.5g of graphene oxide, 50ml of distilled water, and obtain a 10mg/ml graphene oxide aqueous solution after ultrasonication for 1h, transfer it to a 250ml three-neck flask, add 1gKH-570 silane coupling agent, and keep warm at 40°C After reacting for 6 hours, after cooling down to room temperature, carry out centrifugation washing, about 3-5 times of washing with distilled water, and obtain black powder after freeze-drying, which is vinyl-functionalized graphene.

Example 2:

The first step: with embodiment 1.

Step 2: Weigh 0.5g graphene oxide, 25ml distilled water, 75ml ethanol, and obtain 5mg/ml graphene oxide ethanol aqueous solution after ultrasonication for 1h, transfer it to a 250ml three-necked flask, add 1gKH-570 silane coupling agent, Insulate and react at 40°C for 6 hours, and after cooling down to room temperature, perform centrifugal washing, about 3-5 times with distilled water, and freeze-dry to obtain black powder, which is vinyl functionalized graphene.

Example 3:

The first step: with embodiment 1.

Step 2: Weigh 0.5g of graphene oxide, 50ml of distilled water, and obtain a 10mg/ml graphene oxide aqueous solution after ultrasonication for 1h, transfer it to a 250ml three-necked flask, add 1g of A-172 silane coupling agent, and heat at 40°C Insulate and react for 6 hours, and after cooling down to room temperature, carry out centrifugal washing, about 3-5 times with distilled water, and freeze-dry to obtain black powder, which is vinyl functionalized graphene.

Example 4:

The first step: with embodiment 1.

Step 2: Weigh 0.5g of graphene oxide, 50ml of distilled water, and obtain a 10mg/ml graphene oxide aqueous solution after ultrasonication for 1h, transfer it to a 250ml three-necked flask, add 1g of A-151 silane coupling agent, and heat at 40°C Insulate and react for 6 hours, and after cooling down to room temperature, carry out centrifugal washing, about 3-5 times with distilled water, and freeze-dry to obtain black powder, which is vinyl functionalized graphene.

Example 5:

The first step: with embodiment 1.

Step 2: Weigh 0.5g of graphene oxide, 50ml of distilled water, and obtain a 10mg/ml graphene oxide aqueous solution after ultrasonication for 1h, transfer it to a 250ml three-necked flask, add 1g of A-171 silane coupling agent, and heat at 40°C Insulate and react for 6 hours, and after cooling down to room temperature, carry out centrifugal washing, about 3-5 times with distilled water, and freeze-dry to obtain black powder, which is vinyl functionalized graphene.

Claims (2)

1. the preparation method of vinyl functionalized graphene, is characterized in that, described method comprises following preparation process: The preparation method of the vinyl-functionalized graphene is carried out in two steps. In the first step, graphene oxide is prepared from graphite through a modified Hummers method; in the second step, graphene oxide is dispersed in a suitable solvent and mixed with ethylene The base compound was reacted for several hours, and the product was centrifuged, washed, and dried to obtain a black solid powder; In the first step of synthesizing graphene oxide, the persulfate used in the pre-oxidation process is any one or a mixture of sodium persulfate, potassium persulfate, and ammonium persulfate; the reaction temperature is controlled at 80°C; the reaction time 3-6h; during the low-temperature stage of the preparation of graphene oxide, the temperature of the system must be controlled below 15°C, and the temperature must be controlled below 30°C during the dilution process; In the second step, the solvent used is water or any one of methanol, ethanol, THF, DMF or a mixture of several with water; in the second step, the reaction temperature is controlled between 40-60°C, and the reaction time 6-8h; KH-570 silane coupling agent, A-151 silane coupling agent, A-171 silane coupling agent and A-172 silane coupling agent, etc., the ratio of vinyl-containing reagents to graphene oxide is 5 :1-10:1; the washing solvent is water and freeze-dried. 2. the preparation method of vinyl-functionalized graphene according to claim 1, is characterized in that, described vinyl-functionalized graphene structure prepared according to the method is as follows: .