# How durable is a silanized surface?

I have two questions regarding silanization:

1) How durable is a silanized glass surface? (i.e. How long a silanized surface can be kept without any change in its wettability or contact angle?)

2) What are the optimum conditions for keeping a silanized surface while it's idle and dry? (e.g. maintenance temperature, humidity, etc. Should it be kept in a desiccator or not necessarily?)

• Try looking up rainx – Dissenter Dec 28 '15 at 8:55

## 1 Answer

If done properly, reactions with silanes or siloxanes are effectively permanent, unless removed by serious mechanical abrasion (e.g., scraping the material below the coating) or some sort of etching underneath.

The silanization process involves creating new covalent $\ce{Si-O}$ bonds, which are quite strong.

1. The silane surface itself should be durable. However, the contact angle may change as material adsorbs on top of it. For example, a colleague has shown that hydrocarbon contaminants change the wettability of many surfaces

2. I don't think any particular storage is necessary. We store in a vacuum desiccator to minimize the effect of contamination, but as long as you clean the surface, the properties should be consistent.

• ​Therefore, I can keep my silanized glass spheres in a closed-cap bottle for a long enough time and probably wash them before I need to use. BTW, I know that with silanization by Octadeyltrichlorosilane, I can reach to CA~110 deg for glass. Do you know what is the Maximum contact angle people could reach on glass, and with what solution? Thanks – vorujak Dec 30 '15 at 21:05