I wase able to prepare chitosan/tpp nanogels and successfully measure their size, PDI, and charge. However I have been facing a problem in centrifugation, every time I centrifuge at 15000 RPM for 30min I don’t seem to be getting any pellets despite measuring the size using the Malvern zeta sizer. I tried increasing the duration to up to 2 hours but still I wasn’t able to obtain them.