Influence of the Electrical Surface Activity

Two forms of electrical activity may appear on the coating surface, dry band arcing during a period of hydrophobicity loss and corona. The energy supplied in both cases can support physical and chemical changes of the material surface and thus affect the amount of LMW PDMS molecules present. 

The possible mechcuiisms initiated due to dry band arcing have been investigated by Kim et al. [58]. The chemical reactions that occur cffe cissociated with the following processes  

Scission and interchange of bonding or chains Reduction of the chcun size is observed due to scission and interchange, thus ui increase of the LMW molecules cunount can be assumed. 

Hydrolysis of the siloxane bonds and hydrocarbon groups Hydrolysis reactions require the presence of water, thus mist, fog or rain. In linear polymers, random chain scissions are observed leading to a rapid decrease of the molecular mass (Reaction 1.9). Consequently, in this case an increase of the LMW molecules amount can also be assumed. 

Oxidation of hydrocarbon groups and crosslinking of siloxane bonds Hydrolysis reactions are usually followed by oxidation of hydrocarbon groups and crosslinking of the siloxane bonds (for example. Reaction 1.10). In this case, a number of LMW molecules are connected to the crosslinked network (crosslinking) and therefore the amount of LMW molecules is decreased. 

---