Interfaces of solids and their interactions with gases, liquids, or other solids are of relevance to many applications in electronics. These interactions can be controlled among others by a spatially resolved functionalisation of surfaces.
Photochemical reactions are applied for the temporal and spatial control of the surface modification. However, most of the photochemical reactions applied so far for surface functionalisation cause irreversible modifications, as they produce covalent bonds that are very strong and hardly undergo chemical reactions.
With the KIT process, however, temporally and spatially controlled and reversible patterning of surfaces is possible.
“Reversible photochemical modifications can be used for many purposes,” Dr Pavel Levkin explained. “They are suited for the dynamic adjustment of interface properties, for activating and deactivating specific functions by certain stimuli, or for applying and detaching functional molecule groups.”
The scientists used UV light for the formation and breaking of disulphide bridges. UV-induced formation and reduction of disulphide bridges allow for the temporally and spatially controlled thiol-disulphide exchange.
The researchers specifically applied disulphide to thiol-modified polymer surfaces and generated precise fluorescent patterns with small structures of up to 10µm in size. Photo patterning is said to work in the opposite direction by applying thiols to disulphide-modified surfaces.