1k ccd camera

TEM studies
were conducted using a Philips CM 100 instrument operating at 100
kV and equipped with a Gatan 1 k CCD camera. A single droplet of a
0.10% w/w diblock copolymer dispersion was placed onto a carbon-coated
copper grid using a pipet and allowed to dry, prior to exposure to
ruthenium(VIII) oxide vapor for 7 min at 20 °C.^{29 (link)} This heavy metal compound acted as a positive stain for
the core-forming PTFEMA block to improve contrast. The ruthenium(VIII)
oxide was prepared as follows: ruthenium(IV) oxide (0.30 g) was added
to water (50 g) to form a black slurry; the addition of sodium periodate
(2.0 g) with continuous stirring produced a yellow solution of ruthenium(VIII)
oxide within 1 min at 20 °C.

Transmission electron
microscopy (TEM) studies were conducted using a Philips CM 100 instrument
operating at 100 kV and equipped with a Gatan 1 k CCD camera. Diluted
block copolymer solutions (< 0.50% w/w) were placed on carbon-coated
copper grids and exposed to ruthenium(IV) oxide vapor for 7 min at
20 °C prior to analysis.⁴⁶ This heavy
metal compound acted as a positive stain for the core-forming PBzMA
block to improve contrast. The ruthenium(IV) oxide was prepared as
follows: ruthenium(II) oxide (0.30 g) was added to water (50 g) to
form a black slurry; addition of sodium periodate (2.0 g) with stirring
produced a yellow solution of ruthenium(IV) oxide within 1 min.

As-synthesized
copolymer dispersions were diluted at 20 °C to generate 0.10%
w/w dispersions. Copper/palladium TEM grids (Agar Scientific) were
surface-coated in-house to yield a thin film of amorphous carbon.
The grids were then plasma glow-discharged for 30 s to create a hydrophilic
surface. Individual samples of aqueous copolymer dispersions (0.1%
w/w, 12 μL) were adsorbed onto the freshly glow-discharged grids
for 20 s and then blotted with filter paper to remove excess solution.
To stain the copolymer dispersions, uranyl formate (0.75% w/v) solution
(9 μL) was soaked on the sample-loaded grid for 20 s and then
carefully blotted to remove excess stain. The grids were then dried
using a vacuum hose. Imaging was performed on a Phillips CM100 instrument
at 100 kV, equipped with a Gatan 1 K CCD camera. A similar protocol
was followed for the emulsion droplet grid preparation. The emulsion
was shaken and a sample (12 μL) was adsorbed onto the freshly
glow discharged grid. The grids were not blotted with filter paper
to remove excess dispersion—instead, the hexane oil droplet
evaporated after several minutes at ambient temperature. The staining
protocol was the same as that for the aqueous copolymer dispersions.