The name is absent

Appendix В

cell and put sample cell into the instrument. Laser beam can be observed from
microscope (along with the instrument). Move sample cell down until laser
beam disappears, shift the micrometer to zero. This reveals laser beam reach
the top edge of the sample. Then move sample cell up until laser beam
disappears, shift the micrometer to 100. This reveals laser beam reach the
bottom edge of the sample. Repeat several times until the top and bottom
edges of the sample correspond to positions 0 and 100.

4. Use standard mobility solution (1000 mS∕cm, mobility -4 μm∙cm∕V∙s, Beckman
Coulter, PN# 8301351) to perform the measurement at different position levels
for calibration.

5. Perform zeta potential measurement for clay samples at lower and upper
stationary levels (positions 84 and 16) for three times respectively. The
average value of zeta potentials of lower and upper stationary levels was
chosen as the zeta potential value of the sample.

6. Turn off the instrument after the measurement.

B.3. Results and discussions

Fig. B.1 shows the mobility profile of the standard mobility solution. The two
ends of the blue line are mobility values at upper and lower stationary levels.
The profile of standard mobility solution is symmetric. The measured mobility at

209

<<   222   223   224   225   226   227   228   >>

More intriguing information