[11hamsamb]

Hi there, I'm looking to functionalize some silica micro-particles (SMP) to use in an epoxy resin as part of my engineering dissertation project. I have ordered some 3-Methacryloxypropyltrimethoxysilane (MPS) and some SMP's.

With my research, I have found that I need to add somewhere in the region of 2-3% of the mass of SMP's of MPS. This is to be dissolved in ethanol at 40-50 degrees centigrade. I have also heard adding a small amount of water helps.

Issue is, I need to do all of this in my kitchen. I have some PYREX freezer to oven trays which should be borosilicate glass. I have silicone tools for stirring, I have a glass mercury thermometer to keep an eye on the temperature. Plan is, heat up the ethanol and water to appropriate temp on induction stove. Use a double boiler if necessary, but I believe the lowest settings will work fine based off of how slowly it heats water. Crank up the extraction fan. Add in SMP's and make sure my it is all dispersed, add in the MPS and stir for a couple of hours. Presumably ethanol will boil off quickly, and I will be left with a fairly concentrated solution of treated microparticles. Would these need to be washed? I need this as a powder, so would I be able to dry them suitably in a very low temp oven (~60 degrees centigrade) without too much agglomeration or causing issues with the functional groups in some way?

Using 25 grams of SMP's: Ethanol (125 ml) and water (4 ml) heated to 40-50 degrees > Add in SMP's (25 grams) > Add in MPS (0.75 gram) > Stir for 2 hours at constant temp > Dry off back to powder form in 60 degree oven.

Any horrifically glaring issues with this process, any easy (kitchen suitable) ways to improve the process?

I would very much appreciate any help with this!
Thanks, Sam.

[marquis]

When your MPS reacts with the silica (SMP), it should generate methanol.  This is from the chemical bond formed between the MPS and the silica. Double check that with your supplier.  Also, can you get,away with a smaller amount of ethanol( a more concentrated solution)?  The methanol in the kitchen is something to be careful of. 

Many vendors sell these same materials.  Can you do a little more research and talk to some of their tech reps as well as read their info for a better idea?

Often, small batches were done in a small "batch " mixer.   The silica or clay was added and then the silane was added. There are all kinds of silanes.  The one typical thing is they three (methoxy, ethoxy, or propoxy) groups attached.  These groups attach to the silica.  Or they are supposed to.  It takes a small amount of water for this to happen, so, as you indicated, a small amount of water is usually added. The other group attached to the silane is supposed to interact with the polymer.  It looks like you have the chemistry down pat. 

The batch mixer operated at relatively low temps.  Ethanol might be a good sustitute.  But it might not be needed at all.  But the mixing is definitely needed.  Good luck.

[marquis]

A further note.  Some silicas can lead to silicosis.  These are usually listed as of the crystalline variety instead of the amorphous variety.  Use care and read the SDS.  Even with the amorphous variety, there will be some safety precautions recommended.  Protect your lungs.