Direct Cross-Link Promoters

Cross-linking of polymeric materials can also be promoted by the incorporation of additives often known as cross-linking enhancers [39] or cross-link promoters [33]. They are classified as (a) indirect cross-link promoters and (b) direct cross-link promoters. 

The acrylic compounds, maleimides, dimaleimides, and thiols are known as direct cross-hnk promoters, since they enter directly into the cross-linking reaction and become interconnecting molecular links [243]. 

There are essentially two types of promoters of radiation cross-linking or prorads.32 One group, indirect cross-link promoters, do not enter directly into the cross-linking reaction, but merely enhance the formation of reactive species such as free radicals,... 

In order to improve the sensor response time, a thin hydrogel layer was directly deposited onto the backside of the bending plate covered with a 220 nm thick PECVD silicon nitride film and with a 17 run thick adhesion promoter layer (Fig. 2c). The final thickness of the dried and then cross-linked hydrogel layer was 4... 50 pm. 

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