阅读说明：本技术 一种多羰基官能团的氧化石墨及其制备方法 (Graphite oxide with multi-carbonyl functional groups and preparation method thereof ) 是由 张强 杨玉莹 秦禄昌 范慧清 李爽爽 于 2019-11-26 设计创作，主要内容包括：本发明涉及一种多羰基官能团的氧化石墨及其制备方法。操作简单,安全环保,得到的氧化石墨不会引入新的杂质元素,确保了氧化石墨的使用效果,与Hummers方法比较反应物中无硝酸钠,避免了有毒气体一氧化氮、二氧化氮的产生。在反应体系采用低浓度发烟硫酸可以有效吸收反应产生的水分,确保反应体系中无水分存在,无氢氧根和氢离子存在,故可确保石墨基面上引入的氧化剂高锰酸钾官能团不会被氢氧根取代,由于高锰酸钾官能团的体积与质量远大于氢氧根,石墨基面上相邻的高锰酸钾官能团产生的空间位阻变大,降低了碳碳键的稳定性,导致碳碳键断裂,碳原子进一步被氧化,形成两个羰基,最终产物氧化石墨中的羰基含量显著提升进。(The invention relates to a graphite oxide with multi-carbonyl functional groups and a preparation method thereof. The method is simple to operate, safe and environment-friendly, new impurity elements cannot be introduced into the obtained graphite oxide, the use effect of the graphite oxide is ensured, and compared with the Hummers method, the method has the advantages that sodium nitrate is not contained in reactants, and the generation of toxic gases of nitric oxide and nitrogen dioxide is avoided. Adopt the moisture that low concentration oleum can effectively absorb the reaction and produce at the reaction system, ensure that no moisture exists in the reaction system, no hydroxyl and hydrogen ion exist, so can ensure that the oxidizing agent potassium permanganate functional group that introduces on the graphite basal plane can not be replaced by the hydroxyl, because the volume and the quality of potassium permanganate functional group are far greater than the hydroxyl, the steric hindrance grow that adjacent potassium permanganate functional group produced on the graphite basal plane, the stability of carbon-carbon bond has been reduced, lead to the fracture of carbon-carbon bond, carbon atom is further oxidized, form two carbonyls, the carbonyl content in the final product graphite oxide obviously promotes further.)

1. A preparation method of graphite oxide with multi-carbonyl functional groups is characterized by comprising the following steps:

the graphite is oxidized by mixing low-concentration oleum and potassium permanganate, and the reaction system is in an anhydrous state in the oxidation process of the graphite through the application of the low-concentration oleum, so that the proportion of carbonyl in graphene oxide is regulated and improved, and the graphite oxide with multi-carbonyl functional groups is prepared.

2. The method according to claim 1, wherein the concentration of said low-concentration oleum is 99-103%.

3. The method of claim 1, wherein the oxidizing of graphite with low-concentration oleum mixed with potassium permanganate comprises:

uniformly mixing the low-concentration fuming sulfuric acid and graphite to obtain sulfuric acid intercalated graphite;

mixing the sulfuric acid intercalated graphite with potassium permanganate and reacting at a low-temperature reaction temperature to oxidize the graphite in a reaction system.

4. The method for preparing a polycarbonyl functional graphite oxide according to claim 3, wherein the mass ratio of the volume of the low-concentration oleum to the reactant graphite is 30:1 to 45:1, mL/g, and the reaction temperature is 13 to 23 ℃.

5. The method for preparing a polycarbonyl functional group graphite oxide according to claim 3, wherein the mass ratio of the potassium permanganate to the graphite is 4:1 to 7: 1.

6. The preparation method of the multi-carbonyl-functional-group graphite oxide according to claim 1, wherein after the graphite is oxidized by mixing low-concentration fuming sulfuric acid and potassium permanganate, the temperature of a reaction system is reduced, deionized water is slowly added, then the mixture is mixed with hydrogen peroxide, and the graphite oxide with the multi-carbonyl-functional groups is obtained by washing and drying, wherein the reaction system is kept at a temperature of 5-20 ℃ in the deionized water adding process, so that the defect of a graphite basal plane structure caused by generation of a large amount of heat is prevented.

7. The method for preparing a polycarbonyl functional graphite oxide according to claim 6, wherein the mass ratio of the deionized water to the low-concentration oleum is 0.8: 1-1.2: 1, mL/g.

8. The preparation method of the multi-carbonyl-functional-group graphite oxide according to claim 6, wherein the mass ratio of the volume of the hydrogen peroxide to the potassium permanganate is 0.8: 1-1.5: 1, the temperature of the reaction system is controlled to be 5-15 ℃ in the hydrogen peroxide addition process, and after the hydrogen peroxide addition is finished, the temperature of the reaction system is increased to 25-35 ℃.

9. A polycarbonyl functional graphite oxide, which is produced by the method according to any one of claims 1 to 8, wherein the proportion of carbonyl groups in the polycarbonyl functional graphite oxide is 50% to 60%.

10. The polycarbonyl-functional graphite oxide according to claim 9, wherein the graphite oxide is used in the biomedical field.

Technical Field

The invention belongs to the field of chemical synthesis, and particularly relates to graphite oxide with multi-carbonyl functional groups and a preparation method thereof.

Background

The graphene oxide has a single-layer honeycomb hexagonal planar structure of graphene and contains a large number of functional groups such as hydroxyl, carboxyl, epoxy, carbonyl and the like, so that the graphene oxide has excellent performances such as good dispersibility, hydrophilicity, surface modification, compatibility with polymers and the like.

At present, the graphene oxide material is generally prepared on a large scale by a Hummers method, but the graphite oxide obtained by the method has low proportion of carbonyl groups to carboxyl groups, high hydroxyl and epoxy group content and low stability (the hydroxyl and epoxy groups have weak stability), so that the graphite oxide can not meet the performance requirements of catalyst frameworks or loaded drug delivery, and the application in the biomedical field can not be realized. In addition, the application of the raw material sodium nitrate in the method inevitably causes the generation of toxic gases of nitric oxide and nitrogen dioxide, harms the personal safety of operators and cannot meet the national requirements on environmental protection.

Disclosure of Invention

In order to solve the above problems, an object of the present invention is to provide a graphite oxide having a multi-carbonyl functional group and a method for preparing the same.

According to one aspect of the present invention, there is provided a method for preparing a multi-carbonyl functional graphite oxide, comprising the steps of:

a preparation method of graphite oxide with multi-carbonyl functional groups is characterized by comprising the following steps:

the graphite is oxidized by mixing low-concentration oleum and potassium permanganate, and the reaction system is in an anhydrous state in the oxidation process of the graphite through the application of the low-concentration oleum, so that the proportion of carbonyl in graphene oxide is regulated and improved, and the graphite oxide with multi-carbonyl functional groups is prepared.

In a low-concentration oleum system, carbon atoms in raw material graphite are oxidized to form an intermediate connected with an oxidant potassium permanganate functional group, and the low-concentration oleum ensures that the acid concentration of the reaction system is basically unchanged in the reaction process, can absorb moisture generated by the reaction, and ensures that no moisture exists in the reaction system and no hydrogen oxygen radical and hydrogen ions exist, so that the oxidant potassium permanganate functional group introduced on a graphite basal plane can be ensured not to be replaced by the hydroxyl radical, and because the volume and the mass of the potassium permanganate functional group are far larger than those of the hydroxyl radical, the steric hindrance generated by the adjacent potassium permanganate functional group on the graphite basal plane is increased, the stability of a carbon-carbon bond is reduced, the carbon-carbon bond is broken, the carbon atoms are further oxidized to form two carbonyl groups, the content of the carbonyl groups in the final product graphite oxide is remarkably increased from the original value of less than 30 percent (such as an XPS electronic energy spectrum of the existing graphite oxide in figure 1) to 50-60 percent (the XPS detects the peak Volume ratio) can be applied to commercial production. The raw materials of the invention are reasonably prepared, no new impurity or impurity element is introduced into the product graphite oxide, and the common raw material sodium nitrate in the conventional Hummers method is not adopted, so that the generation of toxic gases of nitric oxide and nitrogen dioxide in the preparation process is avoided, and the green and environment-friendly production is really realized.

Further, the concentration of the low-concentration oleum is 99-103 percent, and the concentration is calculated by sulfuric acid。

Further, adopt low concentration oleum and potassium permanganate to mix and carry out the oxidation to graphite, include:

uniformly mixing the low-concentration fuming sulfuric acid and graphite to obtain sulfuric acid intercalated graphite;

mixing the sulfuric acid intercalated graphite with potassium permanganate and reacting at a low-temperature reaction temperature to oxidize the graphite in a reaction system.

Furthermore, the mass ratio of the volume of the low-concentration oleum to the reactant graphite is 30: 1-45: 1 (mL/g).

Further, the reaction temperature is 13-23 ℃, and the reaction time is 48-96 h. In the oxidation reaction, the reaction temperature can reduce the diffusion rate of an oxidant from the edge of the graphite to the inside of the graphite so as to prolong the time required by oxidation, because carbon atoms at the edge of the graphite firstly react with the oxidant in the oxidation reaction, the time for the carbon atoms at the edge to carry out the oxidation reaction is long, simultaneously, the carbon atoms at the edge have large stress relative to the carbon atoms in the graphite and relatively low stability, the carbon atoms are easily and excessively oxidized to form carbonyl groups, because the reaction system is continuously in an anhydrous state due to the existence of the low-concentration fuming sulfuric acid, the quantity of carboxyl groups formed in the oxidation process of the graphite is small, and the quantity of carbonyl functional groups formed by excessive oxidation is large, so that the multi-carbonyl functional groups in the product oxidized graphite are effectively improved.

Further, the mass ratio of the potassium permanganate to the graphite is 4: 1-7: 1.

Further, after the graphite is oxidized by mixing low-concentration fuming sulfuric acid and potassium permanganate, the temperature of a reaction system is reduced, deionized water is slowly added, stirring reaction is carried out for 1-4 hours after water is added, then the mixture is mixed with hydrogen peroxide, and then the graphite oxide with the multi-carbonyl functional group is obtained through washing and drying, wherein the reaction system is kept at the temperature of 5-20 ℃ in the deionized water adding process, the ion exchange process is ensured to be slow and orderly, and the problem that a large amount of heat is generated to cause the structural defect of the graphite basal plane in the product is solved.

Further, the mass ratio of the deionized water to the low-concentration fuming sulfuric acid is (0.8: 1) - (1.2): 1, mL/g.

Further, the mass ratio of the volume of the hydrogen peroxide to the potassium permanganate is 0.8: 1-1.5: 1, the temperature of a reaction system in the hydrogen peroxide adding process is controlled to be 5-15 ℃, after the hydrogen peroxide is added, the temperature of the reaction system is increased to 25-35 ℃, and the reaction is carried out for 0.5-2 hours.

According to the invention, the reaction system concentration, the material ratio, the reaction temperature and the post-treatment process are further optimized, the dynamic process of graphite and potassium permanganate is further changed, and the functional group distribution of graphite oxide is further regulated and controlled, so that the graphite oxide with multi-carbonyl functional groups is obtained.

According to another aspect of the present invention, there is provided a polycarbonyl functional graphite oxide prepared by any one of the above methods, wherein the proportion of carbonyl groups in the obtained polycarbonyl functional graphite oxide is 50% to 60%. The method is applied to the field of biological medicine, and particularly can be used for catalyst framework or loaded drug delivery.

Compared with the prior art, the invention has the following beneficial effects:

1. the preparation method of the graphite oxide with the multi-carbonyl functional groups, disclosed by the invention, is simple to operate, the raw materials are reasonably prepared, new impurity elements cannot be introduced into the obtained graphite oxide, the use effect of the product graphite oxide is ensured, and compared with a Hummers method, sodium nitrate is not contained in reactants, so that the generation of toxic gases, namely nitric oxide and nitrogen dioxide in the preparation process is avoided, and the green and environment-friendly production is really realized. The low-concentration oleum can effectively absorb the water generated in the reaction process of graphite oxidation by adopting the low-concentration oleum in the reaction system, so as to ensure that no water exists in the reaction system and no hydrogen oxygen radical and hydrogen ion exist, so that the potassium permanganate functional group of the oxidant introduced on the graphite basal plane can be ensured not to be replaced by hydroxyl, the volume and the mass of the potassium permanganate functional group are far larger than those of hydroxyl, the steric hindrance generated by the adjacent potassium permanganate functional group on the graphite basal plane is enlarged, the stability of a carbon-carbon bond is reduced, the carbon-carbon bond is broken, the carbon atom is further oxidized to form two carbonyl groups, the content of the carbonyl group in the final product graphite oxide is obviously improved, the content of the carbonyl group in the product graphite oxide can be improved to 50-60 percent from the original content of less than 30 percent, the whole preparation process is simple, convenient and easy to operate, has no pollution, the, is suitable for the industrial preparation of graphite oxide with multi-carbonyl functional groups and is worth popularizing.

2. The multi-carbonyl functional group graphite oxide has the carbonyl proportion of 50-60 percent and can form a stable solution in water or other organic solvents; the graphite oxide has strong functional group activity, is easy to modify and functionalize, can be applied to the field of biological medicine, and particularly can be used for catalyst frameworks or loaded drug delivery to prepare popularization.

Drawings

FIG. 1 is an XPS electron energy spectrum of a conventional graphite oxide;

FIG. 2 is an XPS electron spectrum of graphite monoxide of an example.

Detailed Description

In order to better understand the technical solution of the present invention, the following embodiments are provided to further explain the present invention.