A research team from Tianjin Normal University has successfully developed a new method for the precise chemical synthesis of carbon nanotubes

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A research team from Tianjin Normal University has successfully developed a new method for the precise chemical synthesis of carbon nanotubes, laying a solid foundation for the custom fabrication of this new material as needed. Carbon nanotubes possess excellent mechanical, electrical, and optical properties, and are regarded as key materials for the next generation of technologies. They hold great potential for application in various fields such as humanoid robots, targeted drug delivery, and foldable transparent displays. However, for a long time, traditional preparation methods have struggled to precisely control the diameter, length, and structure of carbon nanotubes, resulting in inconsistent product performance; this challenge has severely restricted the large-scale application of carbon nanotubes in high-end fields. To overcome this global challenge, Professor Li Chunju from the School of Chemistry at Tianjin Normal University led a team that, in collaboration with partners both domestically and internationally, developed a completely new molecular manufacturing strategy. This strategy is based on cycloparaphenylene units (CPPs) – circular molecules that serve as the basic building blocks for constructing carbon nanotubes. Professor Li Chunju used a vivid analogy: “If carbon nanotubes are compared to a train, then cyclic biphenylene is the standard carriage of that train.” By using it as a template for further growth, carbon nanotubes with precise structures and uniform properties can be theoretically produced. ” However, the synthesis of cyclophenylene is not an easy task. Due to the extremely high ring tension in its ring-shaped structure, traditional synthesis methods are akin to trying to weave an extremely tight rope at the microscopic scale; they not only involve complicated preparation steps but also rely on expensive metal catalysts. To address this, the research team broke away from the traditional approach of \"directly weaving tight ring structures\" and developed an alternative synthetic strategy of \"loosing first then tightening\": they first created large ring molecules with a relatively loose structure, and then tightened them through efficient intramolecular reactions, ultimately achieving the desired nanoring structure with precision. Professor Li Chunju said that this method is much simpler and more flexible than directly preparing tight nanorings. This synthesis method is not only highly efficient but also possesses great potential for customization on demand. In the first step of constructing relaxed macrocycles, researchers can flexibly replace different molecular units to produce nanocycles of various sizes and properties. Leveraging this simple and versatile synthetic strategy, the research team has successfully synthesized 20 cycloparaphenylene derivatives with diverse structures, and was able to precisely control their key physical properties such as light absorption and fluorescence emission. Professor Li Chunju said, “This research provides new tools for the controlled synthesis of complex nanocarbon structures, which means that in the future we will be able to tailor carbon nanotubes with precision, just as we tailor clothing.” ”