Synthesis & Characterization of Micro- and Meso-porous Spherical Carbon Aerogel Particles by Emulsion-Gelation Method

Abstract

Aerogels are a class of highly porous materials, especially carbon aerogels having high surface area (400-900 m2/g) and ultrafine pore size (˂ 100 nm).1 These porous carbon materials can be applied in electrochemical energy storage, catalysis, adsorption, fuel cells, etc.1 Carbon monolithic aerogels are synthesized conventionally by the sol-gel polymerization of Resorcinol (R) and Formaldehyde (F) in a basic medium followed by supercritical CO2 drying and further carbonization in an inert atmosphere.2 Compared to carbon monoliths, microparticles have attracted several researchers over the years because of their smooth surface, mechanical strength, microstructures, high packing density and easy processability.3 They find an extensive application in various fields such as catalysis, health care, energy, environment, electronics, etc.4 The main objective of this work was to synthesize spherical RF and carbon aerogel particles by using an emulsion-gelation method.5 RF aerogel particles were dried by both supercritical CO2 drying (SCD) and ambient drying (AD) methods. The dried RF particles were carbonized under an Argon atmosphere to form spherical carbon particles in the size range of 150-200 µm. The as prepared carbon particles were characterized using different characterization methods such as gas pycnometry, N2 adsorption, XRD and SEM. The supercritically dried carbon particles have surface areas greater than 1000 m2/g with pores in the sizes of micro- & meso- regions whereas ambient dried carbon microparticles have surface areas of around 800 m2/g with pores predominant in the range of micro- region. The morphologies of the different carbon particles are quite similar to that of their RF particles.5 Further studies are in progress to understand their properties for various applications and also to produce them in large scale.