阅读说明：本技术 类球形氧化石墨烯及其制备方法与应用 (Spheroidal graphene oxide and preparation method and application thereof ) 是由 党小飞 郁博轩 李炯利 *** 于 2019-09-30 设计创作，主要内容包括：本发明涉及氧化石墨烯纳米材料制备技术领域,具体而言,涉及一种类球形氧化石墨烯的制备方法与应用。所述方法包括：将氧化石墨烯与改性剂分散均匀得到的氧化石墨烯料液进行喷雾干燥组装得到所述类球形氧化石墨烯；所述改性剂用于引入C3～C8的烃基和/或取代烃基,以及任选的芳香基和取代芳香基；在所述氧化石墨烯料液中,所述氧化石墨烯的含量为0.05wt％～1wt％,所述改性剂的含量为石墨烯含量的0.03wt％～0.10wt％。本发明制备得到了类球形氧化石墨烯,其更加利于加工和运输,更加适合产业上的大规模的工业化生产,可用于负载型催化剂以及原位聚合等领域。(The invention relates to the technical field of preparation of graphene oxide nano materials, in particular to a preparation method and application of sphere-like graphene oxide. The method comprises the following steps: carrying out spray drying and assembling on graphene oxide feed liquid obtained by uniformly dispersing graphene oxide and a modifier to obtain the spheroidal graphene oxide; the modifier is used for introducing C3-C8 alkyl and/or substituted alkyl, and optional aryl and substituted aryl; in the graphene oxide feed liquid, the content of the graphene oxide is 0.05 wt% -1 wt%, and the content of the modifier is 0.03 wt% -0.10 wt% of the content of the graphene. The sphere-like graphene oxide prepared by the method is more beneficial to processing and transportation, is more suitable for industrial large-scale industrial production, and can be used in the fields of supported catalysts, in-situ polymerization and the like.)

1. A preparation method of spheroidal graphene oxide is characterized by comprising the following steps:

carrying out spray drying and assembling on graphene oxide feed liquid obtained by uniformly dispersing graphene oxide and a modifier to obtain the spheroidal graphene oxide;

the modifier is used for introducing C3-C8 alkyl and/or substituted alkyl, and optional aryl and/or substituted aryl;

in the graphene oxide feed liquid, the content of the graphene oxide is 0.05 wt% -1 wt%, and the content of the modifier is 0.03 wt% -0.10 wt%.

2. The method for preparing spheroidal graphene oxide according to claim 1, wherein the temperature of the spray drying is 185 ℃ to 225 ℃.

3. The method for preparing spheroidal graphene oxide according to claim 1, wherein the substituted hydrocarbon group is selected from a hydroxyalkyl group and/or an alkoxy group.

4. The method for preparing spheroidal graphene oxide according to claim 1, wherein the hydrocarbon group is at least one selected from the group consisting of an alkyl group, an alkenyl group, and an alkynyl group.

5. The method for preparing spheroidal graphene oxide according to claim 1, wherein the modifier is an amine-based compound.

6. The method for preparing spheroidal graphene oxide according to any one of claims 1 to 5, wherein the modifier is a linear or branched compound.

7. The method for preparing spheroidal graphene oxide according to any one of claims 1 to 5, wherein the graphene oxide is prepared by a Hummers method.

8. The method for preparing spheroidal graphene oxide according to any one of claims 1 to 5, wherein the method for uniformly dispersing is one or more of an ultrasonic method, a grinding method, a stirring method, a high-speed homogenizing method and a ball milling method, preferably one or more of an ultrasonic method, a high-speed homogenizing method and a ball milling method, and further preferably an ultrasonic method.

9. The spheroidal graphene oxide prepared by the method of any one of claims 1 to 8.

10. A method of preparing a supported catalyst, comprising:

the method of any one of claims 1 to 8, wherein the graphene oxide feed liquid is co-sprayed with at least one of a catalyst carrier, a catalyst precursor and a catalyst promoter other than graphene oxide during the spray drying.

11. The method of claim 10, wherein the metal oxide catalyst support comprises TiO₂、Al₂O₃、SiO₂、CeO₂、LiCoO₂、ZnO、Fe₂O₃And ZrO₂At least one of (1).

12. A supported catalyst prepared by the process of any one of claims 10 to 11.

13. A composite material obtained by in-situ polymerizing the spheroidal graphene oxide according to claim 9 with a resin monomer.

14. The composite material according to claim 13, the resin monomer being selected from at least one of polypropylene resin, polyethylene resin, polyvinyl chloride resin, polystyrene resin, acrylonitrile-butadiene-styrene copolymer resin, and polyester resin.

Technical Field

The invention relates to the technical field of preparation of graphene oxide nano materials, in particular to a preparation method and application of sphere-like graphene oxide.

Background

Graphene (graphene) has extremely high strength and large specific surface area, and has multiple functions, so that extensive research and application are carried out in recent years, for example, when the graphene (graphene) is used as a filler of a resin matrix, the graphene (graphene) not only has obvious reinforcing effect [ L.Valentini,2018], but also can bring a plurality of new functions to a composite material, such as conductivity [ Marc ao A.Milani,2013, Jin-Yong Dong, Yuan Liu,2015], electromagnetic shielding performance [ Wei-Li Song,2014, Sima Kashi,2016, Yu-Dong Shi,2019], dielectric performance [ ZHenho Lun, 2017, ZHen-Zhen He,2018], anti-icing performance [ L.Vatinli, S.Bittolo Bon, M.Hern ndez, M.A.Lopez-Man, N.M.Pugno,2018] and the like.

Graphene can be efficiently dispersed in a matrix in an in-situ compounding manner, and has good compatibility with the matrix, so that the development of a graphene-based polymerization catalyst becomes a key point of composite material research in recent years; meanwhile, the basic structure skeleton of the graphene is stable, and the performances of strength, conductivity and the like enable the graphene to be used as high-performance and multifunctional filler; the graphene has a large specific surface area, and different catalytic functions can be purposefully designed by introducing different groups on the surface of the graphene [ Friedel-crafts, envelop, 2009, Changwei, 2013, Chuangang Hu,2017, Qing Han,2017], and the graphene is applied to different polymerization reactions [ Renpeng Gu,2014 ]; in-situ polymerization carried out by taking graphene as a catalytic carrier is widely used for compounding various polymers, and graphene carrier catalysts suitable for different polymerization methods such as free radical polymerization, ion-initiated polymerization, ring-opening polymerization, ATRP, SET-CRP and RAFT are developed, and the catalysts are directly combined in a nano structure of a nano filler, and the like.

The research of graphene oxide in catalysis mainly focuses on the design of surface groups, charge transfer between graphene oxide and catalytic active species, regulation of energy bands of photocatalyst by graphene oxide and the like, or introduces graphene oxide into different polymerization systems to realize in-situ compounding. Various modifications of graphene can be realized by methods such as ammoniation, esterification, in-situ reduction, common coagulation and the like of surface active groups to obtain different functional materials, but the researches focus on the realization of functions or the research of a certain catalytic mechanism, and the contents of the morphology change and the morphology regulation of graphene oxide particles are not related to much. In recent years, many studies have been made on the morphology of a catalyst and a supporting process, and this field is also a field in which a great deal of effort has been put into various international chemical industries, and each progress of the morphology of a catalyst and the supporting process means a great leap forward of the entire chemical industry.

In recent years, graphene oxide loading and application thereof in various catalytic fields are developed vigorously, but the graphene oxide loading and application is limited by the control of graphene oxide morphology, and the industrial application of the graphene oxide loading and application is a bottleneck. The form of the graphene supported catalyst influences the catalytic efficiency, and meanwhile, the loading state of the graphene supported catalyst plays a decisive role in the selection of a subsequent separation process and has great influence on the separation of products and the purity and quality of the products. In addition, most of graphene oxide in the prior art is in a flake or irregular powder shape, and in some applications, for example, graphene oxide as a carrier can keep the shape in an in-situ polymerization process, and then the shape of a product obtained by in-situ polymerization can be 'copied' to the shape of the graphene oxide, if the shape is not ideal or too thin, problems of adhesion, wall scaling, blockage, unsmooth transportation and the like are easily formed, and even danger is generated; or when the graphene oxide is used as a catalyst to participate in some liquid phase reactions, the graphene oxide is difficult to separate if the graphene oxide is in a flake shape or a fine powder shape. This requires the morphology of graphene oxide to be controlled.

Disclosure of Invention

The present invention aims to provide a novel method for preparing spheroidal graphene oxide, which can stably prepare spheroidal graphene oxide and flexibly adjust the size of the spheroidal graphene oxide, in view of the above-mentioned disadvantages in the prior art.

In order to achieve the above purpose of the present invention, the following technical solutions are adopted:

specifically, the invention relates to a preparation method of spheroidal graphene oxide, which comprises the following steps:

carrying out spray drying and assembling on graphene oxide feed liquid obtained by uniformly dispersing graphene oxide and a modifier to obtain the spheroidal graphene oxide;

the modifier is used for introducing C3-C8 alkyl and/or substituted alkyl, and optional aryl and/or substituted aryl;

in the graphene oxide feed liquid, the content of the graphene oxide is 0.05 wt% -1 wt%, and the content of the modifier is 0.03 wt% -0.10 wt%.

The sphere-like graphene oxide prepared by the method is more beneficial to processing and transportation, is more suitable for industrial large-scale industrial production, and can be used in the fields of supported catalysts, in-situ polymerization and the like.

The invention also relates to application of the sphere-like graphene oxide, which can be used for preparing a supported catalyst or a composite material.

The supported catalyst is obtained by co-spraying the graphene oxide feed liquid and at least one of other catalyst carriers, catalysts and catalytic auxiliaries except the graphene oxide.

The composite material is obtained by in-situ polymerization of the spherical-like graphene oxide and a resin monomer.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is an electron micrograph, x200, of the modified graphene oxide prepared in comparative example 1;

fig. 2 is an electron micrograph, x2000, of the modified graphene oxide prepared in comparative example 1;

fig. 3 is an electron micrograph, x1000, of the spheroidal graphene oxide prepared in example 2;

fig. 4 is an electron micrograph, x2000, of the spheroidal graphene oxide prepared in example 2;

fig. 5 is an electron micrograph, x5000, of the spheroidal graphene oxide prepared in example 3;

fig. 6 is an electron micrograph, x5000, of the spheroidal graphene oxide prepared in example 3;

fig. 7 is an electron micrograph, x2000, of the modified graphene oxide prepared in comparative example 2;

fig. 8 is an electron micrograph, x5000, of the modified graphene oxide prepared in comparative example 2;

fig. 9 is an electron micrograph, x5000, of the spheroidal graphene oxide prepared in example 1.

Detailed Description

Reference will now be made in detail to embodiments of the invention, one or more examples of which are described below. Each example is provided by way of explanation, not limitation, of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used on another embodiment to yield a still further embodiment.

It is therefore intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. Other objects, features and aspects of the present invention are disclosed in or are apparent from the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention.

The invention relates to a preparation method of spheroidal graphene oxide, which comprises the following steps:

carrying out spray drying and assembling on graphene oxide feed liquid obtained by uniformly dispersing graphene oxide and a modifier to obtain the spheroidal graphene oxide;

the modifier is used for introducing C3-C8 alkyl and/or substituted alkyl, and optional aryl and/or substituted aryl;

in the graphene oxide feed liquid, the content of the graphene oxide is 0.05 wt% -1 wt%, and the content of the modifier is 0.03 wt% -0.10 wt%.

According to the invention, by controlling the number of carbon atoms of the modifier and controlling the proportion of the graphene oxide and the modifier, the graphene oxide composite material has proper density and length when the modifier is coupled with the graphene oxide, the molecular acting force between the modifiers is moderate, and the shape of the graphene oxide can be better adjusted to be closer to a spherical shape.

In some embodiments, the solvent of the graphene oxide solution is mainly water, but organic solvents such as ethanol and acetone may be mixed in different proportions to adjust the hydrophilicity and the form of the graphene in dispersion and spray drying.

In some embodiments, modifiers may also be used to introduce the above compounds of 4, 5, 6, or 7 carbon atoms.

In some embodiments, the content of the graphene oxide in the graphene oxide feed liquid is 0.05 wt% to 1 wt%, and may also be 0.10 wt%, 0.15 wt%, 0.20 wt%, 0.25 wt%, 0.30 wt%, 0.35 wt%, 0.40 wt%, 0.50 wt%, 0.60 wt%, 0.70 wt%, 0.80 wt%, and 0.90 wt%.

In some embodiments, the content of the modifier in the graphene oxide feed liquid is 0.03 wt% to 0.10 wt% of the content of graphene, and may also be 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%.

In some embodiments, the temperature of the spray drying is 185 ℃ to 225 ℃, and can also be selected, for example, from 190 ℃, 200 ℃, 210 ℃, 220 ℃.

The air speed of the spray drying may be, for example, 50m³/h～300m³And the wind speed can be calibrated according to the yield.

According to the preparation method, the obtained graphene oxide assembly form and size are related to the temperature in the spray drying stage, and the proper spray drying temperature can better maintain the assembled shape of the modified graphene so that the modified graphene can more easily form a sphere-like shape.

In some embodiments, the substituted hydrocarbyl is selected from hydroxyalkyl and/or alkoxy.

In some embodiments, the hydrocarbyl group is selected from at least one of an alkyl group, an alkenyl group, and an alkynyl group.

In some embodiments, the modifier is an amine-based compound.

In some embodiments, the modifier is a linear or branched compound.

In some embodiments, the modifier may be selected from diethylenetriamine, triethylenetetramine, pentylamine, octylamine, ethanolamine, butanolamine; in some embodiments, the modifier may also add some aromatic amine based compounds such as para-aminophenol.

In some embodiments, the graphene oxide is prepared via Hummers or Brodie methods, preferably Hummers. Currently, in the methods for preparing graphene oxide by chemical methods, the Hummers method is the most widely used method, and compared with the Brodie method, the Hummers method has less reaction time and does not generate toxic gases such as chlorine and the like.

In some embodiments, the method for dispersing uniformly is one or more of an ultrasonic method, a grinding method, a stirring method, a high-speed homogenizing method and a ball milling method, preferably one or more of an ultrasonic method, a high-speed homogenizing method and a ball milling method, and more preferably an ultrasonic method.

The ultrasonic treatment can further control the particle size of the graphene oxide, promote dispersion and accelerate the reaction. In some embodiments, the power of the ultrasound may be 50W to 300W, such as 50W, 100W, 150W, 200W, 250W, 300W, and a range of any two of the above values; the ultrasonic time can be selected from 0.5h to 3h, such as 0.5h, 1h, 1.5h, 2h, 2.5h and 3 h; the frequency of the ultrasound may be selected from 10kHz to 100kHz, such as 10kHz, 20kHz, 30kHz, 40kHz, 50kHz, 60kHz, 70kHz, 80kHz or 90 kHz.

The particle size of the graphene oxide can be controlled by adjusting the sheet diameter and the sheet thickness of the graphene oxide by, for example, the degree of oxidation, the oxidation time, the raw material crushing method, and the like, of the graphene raw material used for the graphene oxide dispersion liquid obtained by the Hummers method, or during the implementation of the Hummers method.

In order to prepare a catalyst carrier/supported catalyst with wider application and better performance, in some embodiments, the graphene oxide feed liquid is co-sprayed with at least one of other catalyst carriers, catalysts, catalyst precursors and catalyst promoters except for graphene oxide during the spray drying.

The substances can be sprayed with the graphene oxide feed liquid in an aerosol form for spray drying.

In some embodiments, the other catalyst support other than graphene oxide is a metal oxide catalyst support.

In some embodiments, the metal oxide catalyst support comprises TiO₂、Al₂O₃、SiO₂、CeO₂、LiCoO₂、ZnO、Fe₂O₃And ZrO₂At least one of (1).

In some embodiments, the catalyst comprises at least one of Pt, Pd, Ni, V, Au, Cu, and Co.

In some embodiments, the catalyst precursor can be treated to provide the catalyst as is known in the art.

In some embodiments, the promoter is selected from MoO₃、WO₃、Nb₂O₅、MnO₂、GaCO₃、LaO₃And SnO₂At least one of (1).

In some embodiments, the particle size of the spheroidal graphene oxide is 1 μm to 30 μm, and may also be 1 μm to 20 μm, or 1 μm to 10 μm.

The invention also relates to the spheroidal graphene oxide prepared by the method.

When the catalyst, the catalytic assistant and/or other catalyst carriers except the graphene oxide are co-sprayed in the preparation process, the prepared spheroidal graphene oxide can be used as a supported catalyst.

The invention also relates to a composite material which is obtained by in-situ polymerization of the spherical-like graphene oxide and a resin monomer.

In some embodiments, the resin monomer is selected from at least one of a polypropylene resin, a polyethylene resin, a polyvinyl chloride resin, a polystyrene resin, an acrylonitrile-butadiene-styrene copolymer resin, and a polyester resin.

The composite material can also keep a quasi-spherical structure, and further retain the characteristics of easy processing, separation, transportation and the like.

Embodiments of the present invention will be described in detail with reference to examples.