Studies on surface properties of asbestos. I. Active sites on surface of chrysotile and amphiboles.

The study of the acid-base properties of asbestos reveals a striking analogy between amphiboles and chrysotile. The high sites' density with basic character, evidenced by use of various probe molecules, is very similar for the two asbestos types (chrysotile and crocidolite) and on the same order as the density encountered in some catalysts. Discussion of the surface structure reveals that it is the noncrypting lateral surfaces which possess an electron donor character while the surfaces of the extremities of the fibers with crypting character possess a null or very weakly positive charge.