Low-density graphitic films prepared from iodine-doped enzymatically synthesized amylose films as carbonization precursors

• Published in: Carbohydrate polymers 2018-09, Vol.196, p.332-338
• Main Authors: Yan, Bairu, Matsushita, Satoshi, Suzuki, Shiho, Kitamura, Shinichi, Kaiho, Tatsuo, Akagi, Kazuo
• Format: Article
• Language: English
• Subjects: Amylose - chemical synthesis; Amylose - chemistry; Carbohydrate Conformation; Carbon - chemistry; Chemistry Techniques, Synthetic; Enzymatically synthesized amylose; Enzymes - metabolism; Graphite - chemistry; Iodine - chemistry; Iodine-doped amylose; Low-density graphitic films; Models, Molecular; Morphology-retaining carbonization; Supercapacitor
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2018.05.050

[Display omitted] •Low-density graphitic film was prepared from iodine-doped ESA by heat-treatment.•Iodine-doped ESA films retained their film morphologies after the heat-treatment.•Iodine doping plays an indispensable role in retaining film morphology.•Carbonization yields of the ESAs were highly depended on the doping conditions.•This approach may broaden the application and swill processing of polysaccharides. We have developed a novel approach for preparing low-density graphitic films using iodine-doped enzymatically synthesized amyloses (ESAs) with strictly controlled molecular weights as carbonization precursors. All of the iodine-doped ESA films retained their film structures and morphologies, even after the heat-treatment at 800 °C and 2600 °C. Therefore, iodine doping plays an indispensable role in retaining film structure and morphology during the carbonization of ESA polysaccharides. It was also elucidated that the carbonization yields of the ESA films can be controlled by changing the conditions of iodine doping process. The bulk densities of the graphitic films are varied from 0.08 to 0.42 g/cm3 dependent on the doping level. In addition, the capacitance performances of the graphite films prepared from the ESAs are investigated using cyclic voltammetry and galvanostatic charge/discharge procedures. The potential utility of the carbonized and graphitized ESA films for supercapacitors was revealed. This approach may broaden the application and even the swill processing of polysaccharides.