Are there different kinds of aerogels?
Yes. They include silica aerogels and carbon aerogels and resorcinol-formaldehyde (RF) aerogels. Silica aerogels feature extremely light weight (down to under 0.005 grams per cubic centimeter), excellent thermal insulating properties, high temperature stability, very low dielectric constants and extremely large surface areas. The standard density is nominally 0.1 grams per cubic centimeter with a surface area of about 800 square meters per gram. Electrically conductive carbon aerogels are the newest form of aerogel materials. They are available in block, thin film and powders forms. Carbon aerogels are composed of covalently bonded, nanometer-sized particles that are arranged in a three-dimensional network. These materials have high porosity (in excess of 50 percent), pores that are less than 100nm in diameter and surface areas ranging from 400 to 1000 square meters per gram. They are available in solid shapes, powders and composite paper.
