阅读说明：本技术 一种真空等离子体修饰富勒烯分子表面的方法 (Method for modifying fullerene molecule surface by vacuum plasma ) 是由 孙永青 张永春 李智安 蔺峰 于 2020-06-28 设计创作，主要内容包括：本发明涉及一种真空等离子体修饰富勒烯分子表面的方法,该真空等离子体修饰富勒烯分子表面的方法,在真空条件下,通过等离子体源分别作用富勒烯蒸汽分子和修饰气体,以使离化形成的富勒烯离子,与等离子体中的离子、激发态原子(分子)等高能态粒子,即与离化的修饰气体发生共价键键合反应,来实现对富勒烯分子表面的离子修饰,获得富勒烯衍生物。本申请采用物理方法来修饰富勒烯表面,以形成富勒烯衍生物,这种方法形成的富勒烯衍生物纯度较高,基本等同于富勒烯原料的纯度,这明显高于化学方法合成的富勒烯衍生物。(The invention relates to a method for modifying the surface of a fullerene molecule by vacuum plasma, which comprises the steps of respectively acting fullerene steam molecules and modification gas by a plasma source under the vacuum condition so as to enable ionized fullerene ions to generate covalent bond reaction with high-energy-state particles such as ions, excited-state atoms (molecules) and the like in plasma, namely with ionized modification gas, thereby realizing the ion modification on the surface of the fullerene molecule and obtaining a fullerene derivative. The method adopts a physical method to modify the surface of the fullerene to form the fullerene derivative, and the fullerene derivative formed by the method has higher purity which is basically equal to the purity of the fullerene raw material, and is obviously higher than the fullerene derivative synthesized by a chemical method.)

1. A method for modifying the surface of fullerene molecules by vacuum plasma features that under vacuum condition, the fullerene vapour molecules and modifying gas are respectively acted by plasma source, and the ionized fullerene vapour molecules and modifying gas are bonded to form fullerene derivative with ionized functional group.

2. The method for modifying the surface of a fullerene molecule by vacuum plasma as claimed in claim 1, wherein the fullerene derivative is obtained by the steps of:

s1: preparing a fullerene powder raw material, and putting the fullerene powder raw material into an evaporation device of a plasma reaction chamber;

s2: vacuumizing the plasma reaction chamber;

s3: starting an evaporation device to evaporate the fullerene powder raw material into fullerene vapor molecules;

s4: introducing modifying gas into the plasma reaction chamber, simultaneously turning on the plasma source, forming fullerene ions by fullerene vapor molecules under the action of the plasma source, forming specific ions or ion groups by the modifying gas under the action of the plasma source, and forming the fullerene derivative with the ionized functional groups by the covalent bond combination of the specific ions or the ion groups.

3. The method for modifying the surface of a fullerene molecule by vacuum plasma according to claim 1 or 2, wherein the modifying gas is one of methanol gas, methane gas and nitrogen gas.

4. The method of vacuum plasma modifying fullerene molecule surface as claimed in claim 2, wherein the reaction pressure of the plasma reaction chamber is 0.01-0.1M Pa.

Technical Field

The invention relates to the field of fullerene surface modification, in particular to a method for modifying the surface of fullerene molecules by vacuum plasma.

Background

Due to the unique spatial structure of fullerenes, there are many excellent properties, such as: superconductivity, high pressure resistance, chemical corrosion resistance and the like, thereby having potential application prospect in the fields of light, electricity, magnetism and the like. However, pure fullerene molecules also have certain limitations: the defects of solubility, dispersibility, mechanical strength of crystals and the like can be better solved through the functionalization of the fullerene molecule surface, so that the fullerene and the derivatives thereof have wider application prospects. Meanwhile, the nano material has unique physical and chemical properties such as light, points, magnetism, heat and the like due to the special surface effect, small-size effect, quantum size effect and the like, and is widely applied to the fields of electrochemical catalysis, biosensing, biological imaging and the like.

Due to the unique structure of fullerene, the fullerene can generate a plurality of chemical reactions, including a pericyclic reaction, a hydrogenation reduction reaction, a hydroxylation reaction, an oxidation reduction reaction, a carbon cage inner complex generation reaction of fullerene structure with metal, a carbon cage outer bonding reaction and the like. Currently, chemical modification of fullerene is mainly focused on its chemical activity, reaction and mechanism research and the design and synthesis of functional compounds including its secondary derivatives. According to different modification methods, the method can be divided into three main categories of classical organic chemical reaction, metal organic chemical reaction and electrochemical synthesis.

Fullerenes have the properties of typical electron-deficient aromatics and readily react with electron-donating nucleophilic groups. In many cases, the nucleophile attacks the double bond shared by the 6,6 rings of the fullerene molecule, and may rearrange to obtain a derivative having the double bond shared by the 5,6 rings inserted therein. The fullerene can be chemically modified by various reagents through different reactions to obtain various fullerene organic group derivatives. The simplest addition product has an open structure and forms different derivatives such as a three-membered ring, a four-membered ring, a five-membered ring, a six-membered ring and the like.

The most studied of the classical organic chemical reactions of fullerenes is the cycloaddition reaction, of which the [4+2] cycloaddition reaction is the most reported, for example, with cyclopentadiene. Fullerene is easily reacted with nucleophilic free radicals, but the product is relatively complex, and the addition reaction with carbene is reported in many cases.

The fullerene metal organic derivative synthesized so far is almost prepared by directly reacting fullerene molecules with corresponding metal organic complexes in an organic solvent, the used solvent is generally benzene, toluene or o-diphenyl, and the reaction conditions comprise reflux, illumination and the like. The fullerene organometallic derivative is relatively simple in preparation method, but is weak in the ability to coordinate with a metal, so that it is very important to select an appropriate reaction condition, particularly a solvent.

The current methods for performing surface modification treatment on nanoparticles are mainly divided into two types, namely surface physical modification and surface chemical modification, and the main modification methods comprise: a coupling agent method, a surfactant method, a surface grafting method, a polymer coating method, and an unsaturated organic acid coating method.

The preparation method adopts a chemical method, and chemical reaction is carried out in a specific solvent, so that the prepared fullerene derivative has limited varieties, low purity, low utilization rate of raw materials and complicated operation steps, and can generate chemical wastes to cause environmental protection treatment pressure.

Disclosure of Invention

In order to make up for the defects of the prior art, the invention provides a method for modifying the surface of a fullerene molecule by vacuum plasma, which comprises the steps of respectively acting fullerene steam molecules and modification gas by a plasma source under a vacuum condition, so that fullerene ions formed by ionization and high-energy-state particles (formed by the action of the plasma source on the modification gas) such as ions, excited-state atoms (molecules) and the like in plasma are subjected to bonding reaction, and the ion modification on the surface of the fullerene molecule is realized, thereby obtaining the fullerene derivative.

The method adopts a physical method to modify the surface of the fullerene to form the fullerene derivative, the fullerene derivative formed by the method has higher purity which is basically equal to the purity of the fullerene raw material, and the purity is obviously higher than that of the fullerene derivative synthesized by a chemical method, because the chemical synthesis always dopes part of reaction solvent, the product purity is reduced, and the physical method does not have solvent and cannot dope.

Specifically, in one embodiment, the fullerene derivative is prepared by the following steps:

s1: preparing a fullerene powder raw material, and putting the fullerene powder raw material into an evaporation device of a plasma reaction chamber, wherein the evaporation device can adopt a structure comprising an evaporation vessel or a crucible and put fullerene powder into the evaporation device;

s2: vacuumizing the plasma reaction chamber;

s3: starting an evaporation device to evaporate the fullerene powder raw material into fullerene vapor molecules;

s4: and introducing a modifying gas into the plasma reaction chamber, and simultaneously turning on the plasma source. The fullerene vapor molecules form fullerene ions under the action of a plasma source, the modified gas forms specific ions or ion groups under the action of the plasma source, and the specific ions or ion groups are combined by covalent bonds to form the fullerene derivative with the ionized functional groups.

Wherein the modifying gas is one of methanol gas, methane gas and nitrogen gas.

When the modifying gas is methane gas, the solubility of the obtained fullerene derivative in water is about 0.25 mg/mL.

When the modification reaction gas is methane gas, the solubility of the obtained fullerene derivative in the lipophilic solvent is about 0.5mg/mL, wherein the lipophilic solvent can be benzene solution, toluene solution and the like.

When the modification reaction gas is nitrogen, the yield of the obtained fullerene derivative is about 10 percent, which is obviously higher than 1 percent of the yield of the chemical synthesis.

The invention adopts the structure, and has the advantages that: the fullerene derivative obtained by a method of modifying the surface of a fullerene molecule by vacuum plasma, namely a physical modification method, has higher purity which is equivalent to that of a fullerene raw material, because other components cannot be doped in the synthesis process; in addition, the yield of the fullerene derivative is high, and the utilization rate of raw materials is greatly improved.

Detailed Description

In order to more clearly explain the overall concept of the present application, the following detailed description is given by way of example. In the following description, specific details are given to provide a more thorough understanding of the present application. It will be apparent, however, to one skilled in the art, that the present application may be practiced without one or more of these specific details.