I've been trying to stabilise TiO2 particles in paint using Sodium Laureth Sulfate as surfactant. So far sedimentation is still visible probably due to wrong choice of surfactant. What is the best surfactant to use in this case? How do I choose a correct surfactant?
Dear Nazarene Nickolas;
Polyvinyl acetate - to increase the viscosity, a dispersant - carboxymethylcellulose, sodium dodecylsulfate - stabilizer.
Regards.
pH is important. If the TiO2 wets then no surfactant is needed - you need a stabilizer and the optimum amount of phosphate at the right pH is usual for TiO2 remembering that too much charge stabilizer is as bad as too little. SLS is a wetting agent not a dispersing agent, to be pedantic. The only dispersing agent is energy. As suggested you may wish to increase the viscosity of the system to reduce settling (the bulk density of TiO2 is 4.2 g/cm3) and there's a bunch of ways of doing this. If you're starting with a powder then you have little hope even with excessive sonication. However see slides 45 onwards in:
Nov 11th, 2008. Dispersion and nanotechnology http://tinyurl.com/hpywsge
Please find the attached paper. take look at section "2.1. Sample preparation"
- Badges
- Science topic
- Similar topics
- Engineering
- Mechanical Engineering