Size oriented morphological properties of expanded graphite

Expanded graphite's (EG) high surface pore structure makes it versatile for numerous applications. Even for some of them a specific particle size range is necessary, such as bipolar plate composite materials for polymer electrolyte fuel cells. This article adopted the microwave expansion method to obtain EG and then classified the produced samples by particle size. An analysis was made on the surface morphology of the most representative specimens followed by surface carbon and sulfur identification. Higher particle size values are obtained in lesser proportions but present the best characteristics, whereas smaller ones suggest non-existent expansion and minor pore structure. Finally, a sieving method is recommended to categorize EG by size for different applications since not all particles are equally enhanced.