Wet SEM Analysis of Quantum dot emulsions - Rice University

ubbles. The surface morphology of the emulsion droplets turns from a smooth gray surface
into bubbles with much smoother surface than observed in Test run 3. No formation of
“Strawberry” type shape droplets like observed in Test run 3. No details other than bubble
formation could be obtained.
Drying: This step was performed to check if the dried form of the emulsion reveals more of
the emulsion details. Apply Vacuum to dry sample. Morphology Analysis of emulsion.. In this
phase the emulsion seems to be stable and no enhanced violent bubbling of the emulsion like in
Test run 3 (left gray region) could be observed probably caused by the vacuum and the heat of
the electron beam as it scans along the Interface. No details of Qdot aggregation could be
obtained
Rehydration: This step was added in this Test run. The rehydration was performed after the
drying step.
Room temp.: The Rehydrated emulsion was put back on Room temperature to check emulsion
behavior. Emulsion seems to be stable: As the electron beam scans along the sample the no
building of “Strawberry” type of emulsion droplets or development of additional micro bubbles
on the surface of droplets could be observed. No details of Qdot aggregation could be obtained.
40º C: This step was added in this Test run to simulate the Temperature conditions in the
emulsion Preparation protocol (See Appendix B, Dr. Dean’s protocol). The Temperature was
increased to 40º C to investigate what effect on the emulsion it has. The morphology started to
reveal probably the “waxy” part 1 (Polyglyceryl-3 distearate + Cetearyla alcohol + mineral oil)
of the emulsion.
60º C: This step was added in this Test run to simulate the Temperature conditions in the
emulsion Preparation protocol (See Appendix B, Dr. Dean’s protocol). The Temperature was
increased to 60º C to investigate what effect on the emulsion it has. The morphology we
believe reconfirmed the “waxy” part 1 (Polyglyceryl-3 distearate + Cetearyla alcohol + mineral
oil) of the emulsion: We suspect that the emulsion breaks down to a fluid (mineral oil) and
white colored spheres started to appear which might be crystals of the buffer used to prepare
emulsion..
At the end images of the Qdot sample were taken in secondary electron mode (see Figure 1)
and Back scattering mode (see Figure 2 and 3). In secondary electron mode an Energy
Dispersive X-Ray Spectroscopy (EDS) was performed and X-ray energy emission spectrum
was taken to obtain Elemental Analysis data. (shown in Figure 4 and 5)