1. NANOTECHNOLOGY APPLICATIONS FOR TREATMENT: COST EFFECTIVE AND RAPID TECHNOLOGIES; SMART MATERIALS OR ACTIVE SURFACE COATINGS
Wilfred Chen
Chemical and Environmental Engineering
University of California, Riverside

2. Why Nanomaterials?
Ability to manipulate, control and build materials at the atomic and molecular level
Provide novel affinity, capacity, and selectivity because of their unique physical, chemical and biological properties.
Create large structures with new molecular organization that will facilitate recovery

3. Types of Nanomaterials for Environmental Treatments
1. Smart modified surfaces or membranes
2. Nanostructured materials
3. Molecularly imprinted polymers
4. Nanoscale Biopolymers

4. Smart Surfaces or Membranes

5. Active Membranes for Heavy Metal Removal

6. Types of modifying peptides
poly-L-glutamate or aspartate
poly-L-lysine or arginine
poly-L-cysteine
Ritche et al. ES&T 2001

7. Metal Chelating Behavior
poly-L-lysine or arginine - oxyanion such as As

8. Results with poly-cysteine membrane
The temperature profile for turbidity formation was used to measure the onset of folding and aggregation of the biopolymers. The value of Tt, which is defined as the temperature at which 50% turbidity occurred, was used to indicate the phase transition properties of the different biopolymers.

9. Tunable Surfaces for Biofouling
Ista et al. Appl. Environ. Microbiol. 1999

10. Nanostructured Materials

11. Poly(amidoamine) Dendrimers
Diallo et al. ES&T 1999

12. Binding properties
Repeating cycles of metal binding with Ela78H12 biopolymers. Five microgram of cadmium were added in each cycle. S: Cd2+ remained in solution; P: Cd2+ removed by biopolymers; AS: Average amount of Cd2+ remained in biopolymers after stripping.

13. Polymeric Nanoparticles
Tungittiplakorn et al. Appl. Environ. Microbiol. 2004

14. Enhance PAH Desorption

15. Amphiphilic Polyurethane Nanoparticles
Kim et al. Journal of Applied Polymer Science 2004
90 nm in size

16. Enhanced PAH Solubility

17. PHEMA Beads containing N-Methacryloylhistidine
Say et al. Macromol. Mater. Eng. 2002

18. Metal Removal

19. Molecularly Imprinted Polymers

21. Atrazine-Imprinted Polymers
Cacho et al. Anal Bioanal Chem 2002

22. Imprinted Polymers for Virus Removal
Infection Frequency of
Spodoptera frugiperda 9 (Sf9) cells 0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
6.89E+05
6.89E+04
6.89E+03
6.89E+02
Dilution (pfu/mL)

23. Reactive Polymer Hydrogel for Phosphate Removal
Kiofinas et al. ES&T 2003

24. Efficiency of Removal

25. Perchlorate Removal
Kioussis et al. Journal of Applied Polymer Science 2001

26. Efficiency of Removal

27. Tunable Biopolymer with Metal-Binding Property
Elastin Domain Metal Binding Domain
Fine tune affinity with different binding sequence
Fine tune DT by controlling amino acid sequence and no. of repeating unit (VPGXG)n

28. Genetic and Protein Engineering Methodology
Synthetic gene
Recombinant
plasmid
Plasmid
Enzyme
ELP biopolymers
Microbial expressions of artificial genes provides a means of easily producing ELP. amino acid sequences are chosen to create specific folding patterns and desired material properties. The primary amino acid sequence can then be reverse-translated into a corresponding nucleotide sequence. There are 2 methods of obtaining the needed DNA fragments. One possibility is to clone these sequences from an organism that produces the desired structural protein. The second option is to synthesize artificial genes by solid phase techniques. The second method of course allows maximum freedom in designing the target sequence. Because many structural proteins are characterized by repetitive amino acid sequences, it is often possible to multimerize a smaller oligonucleotide sequence to prepare an artificial gene that codes for proteins of high molecular weight.

29. Metal Removal
Recycling DT
Cd2+ +
Cd2+
Regeneration
Cd2+ DT
Cd2+

30. Production of Biopolymers
A B C D E
Biopolymer
Protein yield
(mg/3 L)
A, Ela38H6
B, Ela58H6
C, Ela78H6
D, Ela78
E, Ela78H12
Ela38H6
289
Ela58H6
295
Ela78H6
Ela78
Ela78H12
207
191
168
Kostal et al. Marcomolecules, 34, , 2001

31. MerR can serve as a specific mercury binding domain
Hg2+
C123
C79
C114
C114
C79
C123
The high binding affinity of mercury binding by MerR is in accordance with the fact that three different cysteine residues from the two MerR subunits are involved in sequestering mercury, which results in a high-affinity tricoordinate mercury binding site.
MerR-Hg complex

32. Selective Binding of Mercury by Ela153-MerR Biopolymer
Acidic waste water (pH 4)
Selectivity of the ELP153MR biopolymer. Binding of mercury by ELP153MR in the presence of competing heavy metals. One nmol of biopolymer was mixed with 0.5 nmol of HgCl2 and various amounts of competing heavy metals.
Kostal et al. ES&T 2003

33. Exploratory Research: Nanotechnology
Acknowledgement
R829606
Exploratory Research: Nanotechnology