VUV modification of silicones

Silicone elastomers are omnipresent and used in a wide variety of products. These materials have valuable features − these particularly include their high elasticity and extensibility, their thermal stability, and their biocompatibility.

However, silicone elastomers also have some shortcomings. The high tackiness of the surface causes:

  • High friction
  • Difficulties with cleaning
  • Dust attraction
  • Unpleasant haptic properties

The Plasma Technology and Surfaces (PLATO) department at Fraunhofer IFAM has developed a way to overcome these disadvantages without changing the desirable properties of silicones.

By using VUV lamps to modify the surfaces and near-surface regions of the silicones, their surfaces become smoother and harder, bringing to the fore different properties:

  • Minimal friction
  • Dust repellency
  • Pleasant haptic properties

What is unique:

  • Same base material (no coating / no fluorine incorporation)
  • No change to the bulk material

 

New applications via surface modification

This innovative treatment allows the mechanical properties of the bulk silicone to remain unchanged whilst the modified surface layer provides an improved resistance and opens up a new range of applications.

Surface modification also changes the surface in such a way that the adhesion abilities are improved.  This way, an expansive range of potential adhesives for joining silicone components becomes applicable. For example, epoxy resins, polyurethane adhesives, and acrylates can be successfully used after surface activation.  

VUV treatment was tested using a large number of different silicones and can be readily adapted for specific customer requirements. Potential products include:

  • Prostheses and operating panels with optimized haptic properties
  • Dirt-repelling keypads
  • Simplified assembly of hoses, rings, and plugs
  • Silicone components with abrasion resistance
  • On-site pretreatment for adhesive bonding