Study on Surface Pore Characteristics and Hydrophilicity of Carbon Materials in HTGR

Abstract

Lots of porous carbon materials, including boroncontaining carbon (BC) and isostatic pressure graphite (IG-110), are used in high-temperature gas cooled reactor (HTGR). To prevent corrosion caused by carbon-water reaction at high temperature, water absorbed in the materials needs to be removed before the reactor operation. It has become the consensus of the researchers that the pore morphology of the material has an important influence on the physical adsorption and desorption process of the gas. Therefore, it is significant to explore the migration mechanism of moisture in carbon materials by studying the pore characteristics and hydrophilic properties of the material surface. Scanning electron microscopy (SEM) and contact angles tests were used to study the surface pore characteristic and hydrophilicity of BC and IG-110. The results of SEM scanning show that a large number of irregular micropores and cracks were found on the surface of BC, while the structure of IG-110 was more compact, and the size and number of pores were obviously smaller. 3 μL and 5 μL water drops were used to contact angle tests, it was found that the average contact angle of the BC surface with water droplets is 118.04°, which is greater than that of IG-110, measured as 112°. Finally, the water vapor absorption experiment of these two materials were carried out to verify that the pore structure and hydrophilicity have an effect on water absorption, and the pore structure has a more decisive effect on moisture absorption than the hydrophilicity.