Changing the Resistivity of Bakelite

[Afunk]

Hey PFers,

So basically, we have these plates of bakelite that have on the order of 10^10 Ohms surface resistivity, but it is not uniform enough. Part of the reason may be that although these sheets may have some non-trivial non-uniform structure at a small enough scale.

These sheets of bakelite are used in particle detectors that require a rather large uniform surface charge on these sheets, and the ability to quickly replenish charge when charge is lost on the surface due to electron "avalanches" that occur in close proximity to them via high potential connections.

So far, linseed oil has been tested and it does a good job of making the surface more uniform and also helps with the rate of charge restoration. One thing that would be great though would be to be able to change the resistivity of this bakelite in a controlled manner. One such possibility is to put a net charge on some metallic salts, and then drop them on the linseed oil coating while it dries on the bakelite, thus spreading it out in a uniform manner.

So you experts on materials and such tell me, are there other methods to:

1. Make a more uniform coating on the bakelite with maybe another coating than linseed oil. (tung oil, etc)
2. Some way to control the resistivity of the surface of the baklite in a uniform manner.

Thanks for any ideas!

This is NOT for any commercial interests but purely for research.

 

[Achy47]

Hi there,

Thank you for sharing your research and asking for input from experts in the field. It sounds like you are working on improving the surface properties of bakelite for use in particle detectors. This is a fascinating area of study and I am happy to offer some suggestions for your research.

1. To make a more uniform coating on the bakelite, you could consider using a conductive polymer coating instead of linseed oil. These coatings are designed specifically for electronic applications and can provide a more uniform and controlled surface. Some examples of conductive polymer coatings are PEDOT:PSS and polyaniline. These coatings can also be tailored to have different resistivity levels, allowing for more control over the surface properties.

2. Another method to control the resistivity of the surface of bakelite is by using doping techniques. Doping involves adding impurities to the material to alter its electrical properties. In the case of bakelite, you could try doping with metallic salts or other conductive materials to achieve a desired resistivity level. This can be done during the manufacturing process or by applying a dopant solution onto the surface of the bakelite.

In addition to these suggestions, you could also experiment with different surface treatments such as plasma treatment or UV irradiation to modify the surface properties of bakelite. These techniques can alter the surface chemistry and improve the uniformity of the surface.

I hope these ideas are helpful for your research. Best of luck! And thank you for clarifying that this is for research purposes only, not for commercial interests. Keep up the good work!

 

[oswaler]

I can provide some insights on this topic. First, it is important to understand that the resistivity of a material is a property that is dependent on various factors such as the composition, structure, and impurities present in the material. Therefore, changing the resistivity of bakelite would require altering one or more of these factors.

Regarding the issue of non-uniformity in the surface resistivity of the bakelite plates, this could be due to variations in the composition or structure of the material. One possible solution could be to modify the manufacturing process to ensure a more uniform structure. Alternatively, as you have mentioned, using a different coating such as tung oil may also help in achieving a more uniform surface. It is important to note that the effectiveness of different coatings may vary depending on the specific properties of the bakelite being used, so experimentation and testing may be necessary to determine the best option.

As for controlling the resistivity of the bakelite in a uniform manner, the approach you have suggested of using metallic salts to create a uniform charge distribution on the surface is a viable option. Other methods could include doping the bakelite with specific materials to alter its resistivity or using external electric fields to manipulate the charge distribution on the surface. Again, the effectiveness of these methods may vary depending on the specific properties of the bakelite being used.

Overall, it is clear that achieving a more uniform surface resistivity and controlling it in a controlled manner will require further experimentation and testing. It is also important to consider the potential effects of any modifications on the overall performance and stability of the bakelite in its intended use as a particle detector.