I've been conducting ball mill operation to reduce the size of Nano-Titania (TiO2) particles. Machine used: FRITSCH Planetary Ball Mill PULVERISETTE 7 with Sintered Corundum Cups and Corundum balls. Based on particle size analysis, the longer the milling process is conducted, the bigger the measurement of particle size which is most likely due to agglomeration. How do I overcome this issue?
Normally, organic additives such as alcohols are added in amounts of less than 0.1 wt% to reduce agglomeration and hence improve grinding efficiency.
Other reference: Amine, glycol & increasingly polycarboxylate polymer (PCE) based
grinding aids can improve grinding efficiency at low dosage rate of 0.02 –0.05% by neutralizing the electrical charges formed on the surfaces & cracks of particles to reduce agglomeration and coating formation on media & liners
Dear Nazarene Nickolas;
The procedure depends on their use. For magnetic liquids hydrocarbon add oleic acid. For aqueous magnetic fluids, add electrolyte. Sample AFM - isopropyl alcohol.
Regards.
Wet milling not dry milling is preferred. I don't understand though that you claim to start with nano-TiO2 - really? Below 100 nm starting material? As a powder? You have a set of fused (aggregated) post and sub-micron material and the dry milling process with the heat and contacts will produce more aggregation as you have seen. Take a look at this webinar and the earlier ones referenced in slide 3:
Nov 11th, 2008. Dispersion and nanotechnology http://tinyurl.com/hpywsge
Also research 'comminution limit' and look at:
January 31st, 2013 The importance of size reduction and agglomeration processes in the mining, minerals, and metals industries
https://www.brainshark.com/malvern/vu?pi=931031164&text=M021507
October 2nd, 2013 The PSD, zeta potential, and rheology of ceramic materials and ceramic slurries/suspensions
https://www.brainshark.com/malvern/vu?pi=97328853&text=M021507
November 3rd, 2015 Adhesion and cohesion http://tinyurl.com/zwb2wlh
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