High Pressure Homogenizer is the best method to prepare Nanosuspensions. However, Proper selection of stabilizer is the key to achieve the reproducible size. You can prepare the nanosuspension by solvent based techniques if you want translate your product in a commercial scale.

Eknath D. Ahire

It depends on what type of nanosuspension or colloid you wish to make. This could be a metal colloid (produced by reduction), a ceramic or paint nanosuspension produced by a top down approach from a powder (very poor energy efficiency) - wetting, separation, stabilizer being the key steps, a crystallization process stopped early, a nanoemulsion produced by a high shear process, a colloid mill, and so on. Various approaches can be seen in these 2 webinars (registration needed):

• Dispersion and nanotechnology https://www.malvernpanalytical.com/en/learn/events-and-training/webinars/W190528DispNanoMat
• Metal colloids - their preparation, application and characterization https://www.malvernpanalytical.com/en/learn/events-and-training/webinars/W160218MetalColloids.html

Polaka Suryanarayana The danger of generalizations is that there are always exceptions. Please tell us how you would produce a 2 nm Au colloid from a high pressure homogenizer... (BTW, I prefer the term high shear rather than high pressure in this type of system. Tells you more of how the process is occurring rather than a factor involved).

Eknath D. Ahire Please confirm your industry. The pharmaceutical industry generally considers anything sub-micron to be a nanosuspension. Other industries limit the term (or nano anything) to less than 100nm.

If the first, you have many more options available.

Thanks John Francis Miller