Final Report - Strategic Environmental Research and Development ...

Figure 3.31.
Figure 3.32.
Figure 3.33.
Figure 3.34.
Figure 3.35.
Weight loss analyses for as-received Wyoming sodium bentonite and
synthesized exchange bentonites of Ce 3+ , Pr 3+ , La 3+ and Zn 2+ .
Concentration of (a) Zn 2+ (b) Pr 3+ (c) Ce 3+ ions released from bentonite
immersed 0.5 M NaCl solution, expressed in milliequivalents/100g.
(a) An explicit equivalent circuit of a coating that exhibited two time
constant behavior and diffusion at low frequencies. (b) Simplified
circuit of a coating that exhibited two time constant behavior and
diffusion at low frequencies. (c) Simplified circuit of a coating used to
fit the data that exhibited two time constant behavior (d) Simplified
circuit of a coating used to fit the data that exhibited three time constant
behavior
Bode magnitude and phase angle plots of (a) PrB.PVA (b) SrCr.PVA
(SrCrO 4 pigmented) coating upon static exposure to 0.5M NaCl solution
for a period of 1 week (173 h). The area exposed to the solution was
14.5 cm 2 .
(a) Total impedance (b) Capacitances of PVA coatings pigmented with
exchange bentonites and SrCr.PVA standard, subject to static
immersion in 0.5 M NaCl.
150
151
153
154
154
Figure 3.36.
Bode magnitude and phase angle plots of 5ZnB.PVB (5 wt% Zn
155
bentonite) coating upon static exposure to 0.5M NaCl solution for a
period of 1 week (168 h). The area exposed to the solution was 5.55 cm 2
Figure 3.37.
Figure 3.38.
(a) Total impedance (b) Capacitances of PVB coatings pigmented with
exchange bentonites and SrCr.PVB standard, subject to static immersion
in 0.5 M NaCl.
(a) Total impedance (b) Capacitances of PVB coatings pigmented with
5 to 30 wt% of Zn bentonite and SrCr.PVB standard, during static
immersion in 0.5 M NaCl.
156
157
Figure 3.39.
Bode magnitude and phase angle plots of Neat Epoxy coating upon 158
static exposure to 0.5M NaCl solution for a period of 2 weeks (336 h).
The area exposed to the solution was 5.55 cm 2
Figure 3.40.
Figure 3.41.
(a) Total impedance (b) Capacitances of epoxy coatings pigmented with
exchange bentonites and SrCr.Ep standard, subject to static immersion
in 0.5 M NaCl.
Total impedance of epoxy coatings pigmented with 5 to 30 wt% of Zn
bentonite and SrCr.Ep standard, during static immersion in 0.5 M NaCl.
159
159
xiv