1. Chemical and mineralogical comparison of two antibacterial clays
School of Earth & Space Exploration
Chemical and mineralogical comparison of two antibacterial clays
Amanda Turner
Dr. Lynda Williams, Dr. Shelley Haydel*, Christine Remenih* & Tanya Borchardt*

2. Investigating Antibacterial Clay Minerals
Isolating bacteria affected by clay
Isolating the antibacterial clay minerals
ANTIBACTERIAL EFFECTIVENESS
ANTIBACTERIAL MECHANISM
Testing for chemical interaction
ICP-MS, Electron Probe, pH, Eh:
Toxin provided?
Nutrient depleted?
Testing for physical interaction
SEM, Mineralogy:
Clay-cell attraction?
Physical disruption?

3. Bulk Mineralogy NONClays Clays 10.4% Qtz 44.9% Smectite
6.2% Olig 16.5% Illite
5.3% Alb 1.1% Gibbsite
6.7% Others
NONClays Clays
39.3% Qtz 21.5% Illite
3.2% Pyrite 16.2% Smectite
1.2% Barite 4.1% Kaol.
1.0% Magnetite 3.3% Pyroph.

4. Clay Mineralogy
No ONE antibacterial mineral  How about the chemistry?

5. Interlayer
Surfaces X
Adsorbed onto surface

6. OR NV Antibacterial clay Antibacterial clay graphite 10-20 nm
20 nm thick
clay laths OR
Antibacterial clay NV
10-20 nm
amorphous
particles
graphite
Antibacterial clay

7. Leachate Chemistry 200C OR07 Kills NV07 Kills
Antibacterial
Clay
X X X X X x
200C
x x x
H2O
OR07 Kills
NV07 Kills
C H O N S P F Cl Br I Hg

8. Leachate Chemistry 200C 550C OR07 Kills NV07 Kills OR07 doesn’t kill
Antibacterial
Clay
X X X X X x
200C
550C
x x x OH
x x x
H2O
OR07 Kills
NV07 Kills
OR07 doesn’t kill
NV0 partially kills
C H O N S P F Cl Br I Hg
Rb Cs Se Cd As

9. Leachate Chemistry 200C 550C 900C OR Kills NV Kills OR doesn’t kill
Antibacterial
Clay
X X X X X x
200C
550C
900C
x x x OH
x x x
H2O
OR Kills
NV Kills
OR doesn’t kill
NV partially kills
Neither Kill!
Elements not volatilized
Fe Zn Ni Cu V Co W
Cr Ag Cd Pb U
All below MIC
In oxidized form!
C H O N S P F Cl Br I Hg
Rb Cs Se Cd As

10. Non-AB clays Neutral Neutral
pH Eh (mV)
NV (<2.0µm)
OR (<2.0µm)
French clays HIGH LOW
Non-AB clays Neutral Neutral

11. 2 µm
500 nm
5 µm
Healthy E. coli
After clay incubation

12. What We’ve Learned PHYSICAL CHEMICAL Mineralogy Leachates
Antibacterial
Clay
X X X X X x
PHYSICAL
CHEMICAL
Mineralogy
Leachates
No ONE mineral responsible
SEM
pH, Eh
Heating regimes may volatilize vital elements
No visible disruption of the cell
Extreme pH, Eh values
Illite/Smectite
Agents soluble at pH ~4

13. Future Work More Imaging!
Model elemental speciation at varying pH and Eh – similarities?
Cation exchange (xc)
- remove xc’able ions
-test xc solution and xc’d clay
Electron and Ion Microscopy - clay/bacteria interactions

14. Acknowledgements NCCAM Other Colleagues Dr. Shelley Haydel
Tanya Borchardt
Christine Remeni
Amanda Cotey
Dr. Renu Sharma
Dr. Karl Weiss
Dr. Laurence GarvieDr. Gordon Moore
Zack Bowles
Dr. Panjai Prapaipong
Other Colleagues
Dr. Dennis Eberl
Dr. Ross Giese
LeRoy Eyring CSSS