What is the best material for my particles?

I'm investigating collision of a particle and a water droplet ($v\_\mathrm{drop}=1~\mathrm{m/s}$, $v\_\mathrm{particle} \approx 8\ \mathrm{m/s}$, $D\_\mathrm{d}=2.8\ \mathrm{mm}$, $D\_\mathrm{p}=2.0\ \mathrm{mm}$). Due to a head-on collision, particle penetrates into droplet and changes the droplet shape (collision outcome). I need to see that what effect particle wettability has on collision outcome. So, all other particle parameters, like density, should remain constant. I can use particles made from any material as long as I can create different contact angles on particle surface. Do you think which particles are the best for this purpose?


P.S: Currently, I've purchased glass particles and I'm trying to create different contact angles through silanization. But, any other suggestion is appreciated.


