Environmental Nanotechnology

Dr John P HanrahanDept of Chemistry, Materials Science

and Supercritical Fluids Centre ERI-UCC

22nd January 2008

What is Nanotechnology?

?

1 Nanometer (nm) = 1 x 10-9meters

Properties of Substances Change when they approach the nano-scale

Whats the big deal with Nanotech?

What is Nanotechnology? Nanotechnology refers broadly to a field of applied science and

technology whose unifying theme is the control of matter on the atomic and molecular scale, normally 1 to 100 nanometers, and the fabrication of devices with critical dimensions that lie within that size range.

Engineering on an extremely small scale-1 billionth of a metre

Change in Chemical properties of materials at a nano-scale compared to Bulk

Colour Density Magnetic Properties Conductivity Tensile Strength –CARBON NANOTUBES 1000 STRONGER THAN STEEL Anti-Bacterial

What Nanotechnology Is NOT!!

Forbes Magazine Top 10 Nano Tech Products

1. Stain repellent and wrinkle-resistant threads 2. High-performance Ski Wax 3. Deep penetrating skin care 4. OLED Digital Camera 5. High performing sun-glasses 6. Smart motorcycle visor 7. Nano-socks 8. Nanocrystalline sunscreen 9-10. High-tech tennis rackets and balls

Pancrea or Nightmare?

Samsung Silver Wash Washing Machine Withdrawn From Market due to concern over toxicity of ‘free’ silver nanoparticles

New nanotech products will have to have toxicity verified

Toxicity of Nanoparticles?

Nano-Engineered Silicas as Environmental Adsorbents

Mesoporous SiO2

Surface Areas in excess of 1000m2g-1

Honeycomb structure

Application in Adsorption, Separations, Catalysis etc.

Nano-Engineered Silicas as Adsorbents in-

Phosphate Removal From Waste Waters

Metal Ion Removal From Waste Waters

Indoor VOC Removal Mycotoxin Removal From Animal

Feeds

Phosphate and Metal Ion Removal From Waste Waters

Material Cr3+ Loading (μmol/g) Reference

Dianion 1200 Soylak et al (2006)

Amine Grafted mesoporous silica

3840 Burke et al (2008-in prep.)

Ni Cr Fe Mn Pd0

500

1000

1500

2000

2500

3000

3500

4000

Con

cent

ratio

n R

emov

ed (

umol

/g)

(i) (ii)

VOC Removal

Evacuated bronze urn,Burrell collection Glasgow

Sodium acetate trihydrate

Results of Mycotoxin Removal (AFB1)

100

0

70

21 18 17 19 8 6 26 4 23 5 7 10 13 1 3 16 22 15 20 27 12 29 30 14 24 28 25 2 9 11

Silica materials (No.)

Ad

sorb

ed

AF

B1

(%

)

2 µg/ml (pH 7)

2 µg/ml (pH 3)

In vitro ability of silica materials (0.1% w/v) to adsorb AFB1 (2 µg/ml). The materials were tested in buffer solutions at pHs 7 and 3

Products to be selected

Figure 1:Thirty Samples Originally Tested (concentration 2μg/ml)

O O

O

O

O

OCH3

Silica Nanoparticles

Silica-Synthesis Stober Fink Bohn Method Control of Particle size through reactantConcentrations (TEOS, H2O,NH4OH, EtOH) Control over Purity Introduction of Porosity (m-SFB, CTAB) Surface Chemistry (Modification) High Yield Facile Introduction of ‘entities’

0 100 200 300 400

0

5

10

15

20

25

30

TE

OS

:H2

O

Particle Size (nm)

Cut of point: approx 400nm

Fluorescent labelling of Silica NPs

Labelling-During Synthesis and Post Synthesis Dyes-Rhodamine 6G and Fluorescein NIR Dyes Singularly labelled and multi labelled dye (Fluorescein/R6G) Controlled Loadings (1-10wt%)

Nano-Toxicolgy of Silica Nanoparticles

•anywhere in body <35 nm passes Blood Brain barrier•anywhere in cell <100 nm enters cell, <40 nm nucleus

Fundamentally new departure

Nanomedicine: novel targeted delivery systems and new therapies

Nanodiagnostics: targeted reporters for diagnosis of diseases

Nanotoxicology: unintended nanomaterial-biological impacts

Key Length Scales

Nano-Interactions

Understand particle protein complex (epitope map), predict interactions with receptors or intracellular apparatus, connect to cellular responses. LOGICAL CONNECTIONS BETWEEN PARTICLE AND BIOLOGICAL OUTCOME

Identification of proteins bound tonanoparticles in biological fluids

?

Microscopy Results

Interaction with Proteins

•Protein Aggregation or fribrillation in the presence of CeO2 nanoparticles-A worrying concept

•NOT proof that that nanoparticle cause disease

Pervaporation

Dr Donal Keane

Pervaporation

Process is energy efficient but the throughput and selectivity can be unacceptable

Need to engineer the porosity much better Size control and structural arrangement

Characterisation Equipment

Physical Analysis Microscopies: confocal, SEM (ERI), TEM, EDX,

AFM/STM (TCD/UCD/TCD/Intel) State of the art EM (HR-SEM/TEM) facilities under development (infrastructural deficit addressed)X-ray: XRD (UCC), x-ray reflectometry (UCC), SAXS (hopefully)

Surface analysis: XPS/SIMS/AES (UCC), ellipsometry (UCC)

Spectroscopies: UV-vis (all), FTIR (all), Raman (TCD)

Other: INS, SAXS, EXAFS, XANES (UCC), particle sizing (UCC/industry), mass-spec techniques

Embracing Nanotechnology…

Acknowledgments

Prof M A Morris Dr J D Holmes Dr Donal Keane Paul Delaney/Aoife Burke ERI EPA