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Important progress in the preparation of graphene oxide in 2 minutes
2022/3/15
Source: Science and Technology Daily
Science and Technology Daily News (reporter Wu Changfeng) Reporter learned from the University of Science and Technology of China on March 9 that Professor Zhu Yanwu's team cooperated with the Shanghai Institute for Advanced Studies of the Chinese Academy of Sciences, Changzhou Sixth Element Materials Technology Co., LTD., and Shanghai Jiao Tong University to adopt a microchannel reactor with a hundred micron size and continuous flow characteristics. By making full use of the characteristics of efficient mass and heat transfer in microchannels, an efficient and intrinsically safe graphite oxidation process has been achieved, and important progress has been made in the preparation of graphene. The research results were published in Advanced Materials.
Graphite oxide and its stripping product, graphene oxide, play an important role in many fields as a key precursor for the large-scale production of graphene. At present, in scientific research and industrial preparation, mainly based on the Hummers method proposed in 1958, the chemical oxidation of graphite in a concentrated sulfuric acid system using a strong oxidizing agent is further stripped to obtain graphene oxide. In recent years, researchers have proposed many improvement measures for Hummers method, but due to the slow diffusion of oxidants between graphite layers and the production and accumulation of explosive intermediates, the reaction time is long, the safety risks are big, and the quality control is difficult. The large volume reactor and low heat transfer efficiency in large-scale production scenarios further aggravate these challenges. Therefore, it is urgent to develop an efficient, safe and scalable graphene oxide preparation technology.
Through the enhanced microflow reaction, the research team can achieve the oxidation degree of graphite in 2 minutes, which can be achieved in a traditional reactor in several hours; By changing the configuration of the microreactor and the parameters of the reaction fluid, the oxidation degree and the types of oxygen-containing functional groups of graphene oxide can be finely adjusted within a certain range. In addition, the small and transparent microreactors make it possible to detect oxidation processes in real time using spectroscopy. By characterizing in situ the evolution of Raman G peak in graphite oxidation, the researchers analyzed the effects of flow rate, raw graphite type and sheet diameter on the oxidation kinetics, and based on the results, it is predicted that the continuous production line with an annual output of 60 tons requires only about 6.5 liters of microreactors.
On this basis, the researchers demonstrated the thermal and electrical conductivity of graphene oxide products, which laid a foundation for the preparation and application of graphene oxide using microfluidic technology.
Science and Technology Daily (7th edition, March 15, 2022)
http://digitalpaper.stdaily.com/http_www.kjrb.com/kjrb/html/2022-03/15/content_532034.htm?div=-1
Science and Technology Daily News (reporter Wu Changfeng) Reporter learned from the University of Science and Technology of China on March 9 that Professor Zhu Yanwu's team cooperated with the Shanghai Institute for Advanced Studies of the Chinese Academy of Sciences, Changzhou Sixth Element Materials Technology Co., LTD., and Shanghai Jiao Tong University to adopt a microchannel reactor with a hundred micron size and continuous flow characteristics. By making full use of the characteristics of efficient mass and heat transfer in microchannels, an efficient and intrinsically safe graphite oxidation process has been achieved, and important progress has been made in the preparation of graphene. The research results were published in Advanced Materials.
Graphite oxide and its stripping product, graphene oxide, play an important role in many fields as a key precursor for the large-scale production of graphene. At present, in scientific research and industrial preparation, mainly based on the Hummers method proposed in 1958, the chemical oxidation of graphite in a concentrated sulfuric acid system using a strong oxidizing agent is further stripped to obtain graphene oxide. In recent years, researchers have proposed many improvement measures for Hummers method, but due to the slow diffusion of oxidants between graphite layers and the production and accumulation of explosive intermediates, the reaction time is long, the safety risks are big, and the quality control is difficult. The large volume reactor and low heat transfer efficiency in large-scale production scenarios further aggravate these challenges. Therefore, it is urgent to develop an efficient, safe and scalable graphene oxide preparation technology.
Through the enhanced microflow reaction, the research team can achieve the oxidation degree of graphite in 2 minutes, which can be achieved in a traditional reactor in several hours; By changing the configuration of the microreactor and the parameters of the reaction fluid, the oxidation degree and the types of oxygen-containing functional groups of graphene oxide can be finely adjusted within a certain range. In addition, the small and transparent microreactors make it possible to detect oxidation processes in real time using spectroscopy. By characterizing in situ the evolution of Raman G peak in graphite oxidation, the researchers analyzed the effects of flow rate, raw graphite type and sheet diameter on the oxidation kinetics, and based on the results, it is predicted that the continuous production line with an annual output of 60 tons requires only about 6.5 liters of microreactors.
On this basis, the researchers demonstrated the thermal and electrical conductivity of graphene oxide products, which laid a foundation for the preparation and application of graphene oxide using microfluidic technology.
Science and Technology Daily (7th edition, March 15, 2022)
http://digitalpaper.stdaily.com/http_www.kjrb.com/kjrb/html/2022-03/15/content_532034.htm?div=-1
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