I am trying to coat Gamma-APTES solution around 100nm Silica (in ultrapure water) by string continuously for 24hours.
Then, centrifuge at 3500rpm for 30 minutes. Resultant of this procedure, causing pallet appear at the bottom of microtube.
Can anyone suggest any trick to avoid this phenomena? I need silica sedimentation (without aggregation) before further procedure. Thank you in advance.
Three ethoxy-groups of Gamma-APTES will hydrolise in water to form silanol groups, which further react to form a siloxane network. With particles embedded in the matrix it can cause significant precipitation.
I can recommend either switching to ethanol as solvent with controlled addition of water (3:1 as H2O:APTES molar ratio)
or adjusting the pH to
Can you elaborate? Is the precipitate settling in the form of pellets? Centrifugation will result in your dispersed particles settling down.
Can you dry the sample? If you can, try ultrasonicating the sample after centrifugation in a little water and dry it at a low temperature (~40C)
Three ethoxy-groups of Gamma-APTES will hydrolise in water to form silanol groups, which further react to form a siloxane network. With particles embedded in the matrix it can cause significant precipitation.
I can recommend either switching to ethanol as solvent with controlled addition of water (3:1 as H2O:APTES molar ratio)
or adjusting the pH to
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