Aerogel applications electrical conductivity

The application of electrochemical investigations is an efficient method to characterize the microstructure of porous electrically conducting materials. Modifications in the chemical constitution of the skeleton which do not change the BET values can be identified by the electrochemically derived surface capacitance, as demonstrated in the case of anodically oxidized carbon aerogels. 

Carbon (C)-aerogels have been investigated for one decade as a promising material for electrochemical applications in supercapacitors, fuel cells and waste water treatment [1,2], C-aerogels are nanoporous, electrically conducting and monolithic materials that provide the unique possibility to tailor the carbon properties on a molecular scale. The surface area and the degree of microporosity can be adjusted almost independently of the overall porosity for which mainly meso- and macropores are responsible. Whereas the mesostructure is determined by the stoichiometry of the reactants in the precursor solution, the pyrolysis conditions control the micropore structure of the material [3,4]. High pyrolysis temperatures will increase the electrical conduchvity [5], an important property for many electrochemical applications. 

In fact, aerogels consist of a thin amorphous solid matrix network surrounded by nanoscale-sized pores, and therefore, they are reasonably described as transparent, highly porous, open-cell, extremely low-density materials. This extraordinary structure provides silica aerogels a variety of unique properties. For example, low thermal and electrical conductivity are a result of the low thermal conductivity of silica and nanometer pores sizes. The low thermal conductivity and other optical properties make them desirable for many applications. For example, they can be an attractive alternative in insulating applications, due to their high insulating value and environment-friendly production methods. They also possess low refractive index, low sound velocity, and low dielectric constant. 

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