Ammonia assisted shape control synthesis of carbon microspheres: An effective pore-filling material to carbon–carbon (C/C) composite

Abstract

Herein, we report the formation mechanism of smooth microspheres (CMS) to the wrecked structure of carbon by altering the pH of the synthesis medium. The CMS obtained was highly smooth surfaces at pH 8, while increasing the solution strength to more basic, a gradual peel-off will occur and leads to coarse aggregated particles. The physicochemical analysis illustrates that pH plays a vital role in controlling sphere formation. There are different types of reactions that were identified for the formation; among them, the unique Maillard reactions will be responsible for the structural changes. The CMS has been utilized as pore-filling material for carbon–carbon matrix in high-temperature applications. The results illustrate that the smooth CMS particles penetrate the pores and cover them to maintain the heat and compound loss during the high-temperature operation.