Considerations about the sol-gel process: From the classical sol-gel route to advanced chemical nanotechnologies

This paper was given on occasion of receiving the first Life Time Award by the International Society on Sol-Gel Science and Technology. Its intention is to provide an insight on the development of this field, its driving forces and especially on its impact on application and industrial technologies. The motivation of the work carried out in the last decades is that in the early days of the sol-gel technologies, where this route started to interest industry as well as scientists, the author got interested in a field which was clearly application-driven and strongly anchored in the material scientist community rather than in fundamental chemistry. If one is talking about application-oriented technologies, of course, markets and industrial needs have to be taken into consideration, because the restrictions or bottle-necks, but also chances provided by economical needs strongly may govern the field. In opposition to these fields, only driven by science, may not have these restrictions as far as it is possible to raise funds for the scientific work. For this reason, the attempt is made to point out the connections between application and science in the sol-gel field. Since I am working in the sol-gel field since 1975, strongly focused on industrial applications, it should be understandable that many of my own development examples are used to demonstrate this way.