TOKYO, June 11, 2019 /PRNewswire/ -- The study presents a new and efficient method for the preparation of 2D carbon materials from sheet-like cellulosic materials, such as paper and fabrics.
According to Encyclopedia, Cellulose is a substance that is found in plant cell walls and this makes it probably the most abundant organic compound on Earth. Cellulosic materials have a renewable character and are easy to process. They have a multitude of uses such as fiber, cloth and paper. It is observed that regenerated cellulosic materials chemically derived from natural celluloses have equal advantages. Studies have shown that cellulose-based carbon materials have potential uses in various fields such as electrochemical energy storage and medicine of the medical field.
Most of the times cellulosic materials are carbonized via pyrolysis at high temperatures. Cellulose molecules are known to thermally decompose during the pyrolysis process at high temperatures, thereby giving rise to complex degradation reactions, which led to the formation of low molecular weight compounds. As a result, it was seen that the final carbon yield was usually less than the 20% weight.
In addition to the above, carbonized cellulosic materials are extremely fragile and very prone to form black particles. Findings show that low carbon yield and weakness are characteristics of carbonized cellulosic materials obtained by pyrolysis. Kyotani and the team performed chemical carbonization of cellulosic materials in the presence of some organic and inorganic acids. This was done with the objective and the aim to enhance carbon yield.
According to the experiments conducted by Kyotani and the team, it was shown that iodine-treated helical polyacetylene films could almost be fully carbonized without thermal decomposition whilst retaining their initial morphology. After that, Kyotani reported that cellulosic papers treated with iodine could be "carbonized with a little thermal decomposition with carbon yield up to 30 wt%."
Through the research study, Kyotani has attempted to use organic sulfonic acids instead of iodine as catalysts for chemical carbonization of cellulosic materials. In particular, methane sulfonic acid (MSA) was the most effective catalyst. Handy 2D carbon materials were prepared from MSA-treated sheet-like cellulosic materials via chemical carbonization method without thermal decomposition at high temperatures. This resulted in success as carbon yields close to the theoretical carbon content of cellulose were obtained. Kyotani has further mentioned that the graphitic structure, mechanical properties, and electrical conductivity of the carbon materials were enhanced by the heat-treatment at higher temperatures.
Kyotani's research is significant because electrical conductive materials were obtained by carbonization of cellulosic ones being insulations. Obtained carbon materials are flexible and can be useful in a wide range of application for example, in electrodes and gas absorbents. Moreover, one dimensional carbon materials having high mechanical properties are able to prepare from cotton threads and rayon filaments using the chemical carbonization method. The in-depth paper displays the intellect of Kyotani and the team. This work will inspire younger scientists to work in this sphere and will aid in promoting research.
More info about Mutsumasa Kyotani's research can be found here: https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/gch2.201700061
Amy R Fife
SOURCE Mutsumasa Kyotani