Synthesis of carbon nanoblocks and carbon nanorods by Tween-80@NaCl

Abstract

• A method for the synthesis of carbon nanoblocks and carbon nanorods exploiting the strategy of self-assembled ordered aggregates @ concentrated salt was investigated. • The morphology (size and shape) and specific optical (fluorescence) properties of the synthesized Tween-80@NaCl carbon nanoparticles can be systematically tuned on demand. • Such method may be adopted as a general method for the preparation of various carbon nanostructures. Carbon nanomaterials are very versatile, but the tunable preparation of their morphology and emission colors is still very challenging. Herein, we present a simple self-assembly method for the preparation of tunable carbon nano (Tween-80@NaCl), where the key tunable parameter is the concentration. More specifically, the structural and optical properties of carbon nanomaterials can be controlled by modulating the concentration of surfactants. It is worth mentioning that salt plays an important role in separating the micelle structure and protecting the micelle morphology. The samples were characterized by Raman spectroscopy and x-ray diffraction to determine the microcrystalline structure and crystal size. The evolution of the micellar structure was established by transmission electron microscopy analysis of the transformation of the Tween-80@NaCl structure. The continuous adjustment of surfactant concentration leads to a change in micelle morphology, like from large-sized blocks to small-sized rods. In addition, carbon nanoparticles with typical fluorescence properties can be obtained by simply changing the surfactant concentration and can easily change from purple fluorescence to dark blue. Notably, this simple strategy of separating first and then carbonizing provides inspiration for future structural design of carbon nanomaterials.