Preparing a Silicone Microemulsion (With Cosurfactant)
Preparing a Silicone Microemulsion (With Cosurfactant)


To make the silicone
microemulsions, first what we want to
do is prepare the water that we’ll be putting
into the aqueous phase. We’re going to use the MCP. This is the MCP setup. We have the distilled
or deionized water, our buffers ranging from– in the case of acrylics–
from 5.0, 5.5, 6.0, 6.5, our citrates– same pHs,
5.0, 5.5, 6.0, 6.5– the EDTAs– same pH, 5.0– and then our surfactants– which
we won’t be using– and then our rinse solutions that are
pH adjusted and conductivity adjusted. We’re going to do a
6.0 EDTA solution. So we’re going to take
1 mil of the 6.0 EDTA and put in our cup. And we’ll also take 1 mil
of the 6.0 buffer solution, put it a little measuring cup. And because these are
concentrated and expecting a dilution of one
to five, we’ll take 3 mils of distilled
deionized water to bring the total
volume to 5 mils. That was 2 and 1. So we can always check on the
graduated markings on this that we’re at 5 mils. Now that’s the aqueous
phase of microemulsions. Now we’ll use our phase
diagram or more conveniently a tabular form. We’ll be making microemulsion
H on the phase diagram, which is 50% cyclomethicone,
25% Ecosurf EH-3– the surfactant– and 25%
of our aqueous phase. We’ll be using the
MCP that we made. We can also use the
6.5 pH adjusted water or even deionized water. Making the
microemulsion, we want to start out with 1
gram of our components per 10% on our chart. So we’re going to do
50% cyclomethicone. So that’s 5 grams
of cyclomethicone in our little bottle. So we do 5 grams
of cyclomethicone. That’s 2.4, 4.0, 5.0 grams. We tare the balance,
and we’ll do 25% of the ECOSURF
EH-3 or 2.5 grams. 1, 2, 2.5. You’ll notice that
the Ecosurf is soluble in the cyclomethicone. So just shaking them up, we
should have a clear solution. This demonstrates the fact
that we can clear this material with the cyclomethicone, that
the surfactant will dissolve in the cycle of
methadone on clearing on the surface of the painting. Now I want to add
2.5 grams, 25%, 2.5 grams of the aqueous phase. Because this is a
microemulsion, the energy of the aqueous phase and the
energy of the cyclomethicone have been balanced by
the choice of surfactant. So it takes very little
agitation to make the microemulsion. So here we have
our microemulsion. Ideally, it should be clear. It’s very temperature dependent. So sometimes it will
be a little milky depending on the temperature
we’ve made it at. But basically, this is
a homogeneous material. You can see the
viscosity is relatively low unlike a
conventional emulsion.

3 thoughts on “Preparing a Silicone Microemulsion (With Cosurfactant)”

  1. Ana Vilela says:

    Thank for this!

  2. Gloria Velandia Ludmer says:

    Chris, thanks indeed. You just saved the day 🙂

  3. Sheikh Umar says:

    But it's not a clear solution.

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