Carbon-based materials occupy a core position in many fields such as energy, electronics, and environmental protection due to their excellent electrical conductivity, thermal conductivity, and mechanical strength. Breakthroughs in dispersion technology are key to unlocking their potential value. Dispersing carbon-based materials involves breaking the agglomeration of carbon-based powders such as graphene and carbon nanotubes through specific methods, uniformly dispersing them in a medium. This solves the performance degradation problem caused by their small particle size and high surface energy, promoting their large-scale application in various industries.
The agglomeration characteristic of carbon-based materials is a major bottleneck in their application. Due to the strong van der Waals forces and π-π packing interactions between carbon-based powder particles, large secondary agglomerates are easily formed, whether in air or liquid phases. This leads to a reduction in specific surface area and decreased electrical and thermal conductivity, preventing the full utilization of the material's excellent properties. For example, in the preparation of carbon-based conductive pastes, agglomeration disrupts the continuity of the conductive network, severely affecting the electrochemical performance of electrode materials. Therefore, achieving stable dispersion of carbon-based materials is crucial.
Currently, methods for dispersing carbon-based materials are mainly divided into two categories: physical dispersion and chemical modification, each with its own advantages and limitations. Physical dispersion does not require altering the material's surface structure and is relatively simple to operate. Ultrasonic dispersion is the most widely used method, utilizing ultrasonic cavitation to generate shear stress, reducing the material's surface energy and achieving efficient dispersion. It also features small equipment size and convenient operation, but suffers from high equipment costs and the potential to damage the sample structure.
Ball milling and stirring dispersion are also commonly used physical methods. Ball milling breaks up agglomerates through the collision and friction of the grinding media and can be used for both wet and dry dispersion, but the equipment is bulky and energy-intensive. Stirring dispersion is inexpensive and highly operable, but it is prone to dead zones, affecting dispersion uniformity. Chemical modification alters the surface properties of carbon-based materials through surface modification, enhancing their dispersion stability. This is divided into covalent and non-covalent modification. The former introduces hydrophilic groups through chemical reactions, while the latter utilizes non-covalent interactions to achieve surface modification. Although the dispersion effect is more durable, it may affect the intrinsic properties of the material.
With technological advancements, the application scenarios for dispersed carbon-based materials are continuously expanding. In the energy sector, uniformly dispersed carbon-based materials can improve the energy density and cycle life of lithium-ion batteries and supercapacitors. In the electronics sector, their excellent conductivity can be used for chip heat dissipation and the fabrication of flexible electronic devices. In the environmental protection sector, dispersed carbon-based materials can enhance the specific surface area of adsorbents, improving wastewater purification efficiency.
In the future, the development of dispersed carbon-based materials will focus on green efficiency, low cost, and large-scale production. Developing dispersion technologies that do not require passivators, optimizing dispersion processes and equipment, and achieving a balance between dispersion effectiveness and material performance will become key priorities for the industry. It is believed that with continuous innovation in dispersion technology, the potential value of carbon-based materials will be fully realized, injecting new momentum into the development of the new materials industry.
