You're right—graphite is naturally hydrophobic, which means it doesn’t mix well with water-based solutions like sodium silicate. Instead of dispersing evenly, the graphite tends to clump together or float on the surface, making it hard to get a uniform mixture.

Will It Work?

As it is? Not really. If you just try to stir graphite into sodium silicate, it won’t mix well, and you’ll likely get a lumpy, uneven mess. But that doesn’t mean it’s impossible! With the right tricks, you can get a more even mixture.

How to Make It Work

Here are a few ways you can improve the mixing process:

1. Add a Surfactant (Wetting Agent)

Graphite repels water, so using a surfactant can help break the surface tension and make it more mixable. A tiny amount (0.1–1%) of one of these should help:

• Sodium lauryl sulfate (SLS) (common in shampoos)
• Triton X-100 (used in lab dispersions)
• Tween 20 or Tween 80 (mild emulsifiers)

2. Pre-Wet the Graphite

Instead of dumping the dry graphite straight into sodium silicate, you can pre-mix it with a little ethanol, isopropyl alcohol (IPA), or even acetone. This helps coat the particles and makes them easier to blend into the sodium silicate.

3. Use High-Shear Mixing

If you have access to a high-speed mixer or ultrasonic homogenizer, you can break up the clumps and force the graphite to disperse.

4. Adjust the pH & Concentration

Sometimes, adjusting the alkalinity of sodium silicate (raising pH above 11) can help improve dispersion. You could also try adding a small amount of ethanol or IPA directly into the sodium silicate before adding graphite.

5. Modify the Graphite

If you want to get fancy, you could try oxidizing the graphite (turning it into graphene oxide) or coating it with a dispersant, but this is a more advanced approach.

Mixing graphite with sodium silicate is tricky because of its hydrophobic nature, but it's not impossible. If you're having trouble, your best bets are:

Of course, graphite should be previously hydrophilized by treating with concentrated sulfuric acid, then washed up and thoroughly dried.

This question lies outside my profession.