introduction to environmental nanotechnologyfy.chalmers.se/~fogelstr/gordonyang/lecture1.pdf ·...

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MCC025 MCC025 NanoscienceNanoscienceIntroduction to Environmental Nanotechnology (1)Introduction to Environmental Nanotechnology (1)

Professor Gordon C. C. YangProfessor Gordon C. C. YangInstitute of Environmental Engineering Institute of Environmental Engineering

National Sun National Sun YatYat--SenSen UniversityUniversityKaohsiung 80424, TaiwanKaohsiung 80424, Taiwan

ee--mailmail:: [email protected]@mail.nsysu.edu.tw

September 2006September 2006

http://www.chalmers.se/en/

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Course OutlineCourse Outline

1. 1. Nanotechnology and the Environment: An OverviewNanotechnology and the Environment: An Overview2. 2. NanomaterialsNanomaterials: Preparation, Fabrication, and Characterization: Preparation, Fabrication, and Characterization

3. 3. PhotocatalystsPhotocatalysts for Applications in Environmental Treatmentfor Applications in Environmental Treatment

and Sensingand Sensing

4. Carbon 4. Carbon NanomaterialsNanomaterials for Environmental Applicationsfor Environmental Applications

5. 5. NanoironNanoiron and and NanoscaleNanoscale Bimetals for Subsurface Remediation Bimetals for Subsurface Remediation


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Nanotechnology and the Environment: An OverviewNanotechnology and the Environment: An Overview(September 5, 2006)(September 5, 2006)

In this lecture an overview of nanotechnology and the In this lecture an overview of nanotechnology and the environment will be delivered. First, various unique propertiesenvironment will be delivered. First, various unique propertiesof of nanomaterialsnanomaterials and the significance of nanotechnology and the significance of nanotechnology toward human life will be presented. Second, toward human life will be presented. Second, nanomaterialsnanomaterialsfrom cradle to grave will be introduced including their from cradle to grave will be introduced including their applications and ESH (environment/safety/health) implications.applications and ESH (environment/safety/health) implications.


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NanomaterialsNanomaterials: Preparation, Fabrication, and Characterization: Preparation, Fabrication, and Characterization(September 6, 2006)(September 6, 2006)

In this lecture an overview of various fabrication methods for In this lecture an overview of various fabrication methods for preparing different preparing different nanomaterialsnanomaterials will be briefly presented first. will be briefly presented first. Then an introduction of various methods for characterizing Then an introduction of various methods for characterizing nanomaterialsnanomaterials will be followed so that those unique properties will be followed so that those unique properties of of nanomaterialsnanomaterials for novel applications could be realized.for novel applications could be realized.


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PhotocatalystsPhotocatalysts for Applications in Environmental Treatment for Applications in Environmental Treatment and Sensingand Sensing

(September 13, 2006)(September 13, 2006)

In this lecture the principles of In this lecture the principles of photocatalysisphotocatalysis will be will be introduced first. Then various commonly used introduced first. Then various commonly used photocatalystsphotocatalystsand their applications in environmental treatment and sensing and their applications in environmental treatment and sensing will be followed.will be followed.


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Carbon Carbon NanomaterialsNanomaterials for Environmental Applicationsfor Environmental Applications(September 20, 2006)(September 20, 2006)

In this lecture various carbon In this lecture various carbon nanomaterialsnanomaterials (including carbon (including carbon nanotubesnanotubes and and nanostructurednanostructured films/membranes) will be films/membranes) will be introduced and their applications in environmental treatment introduced and their applications in environmental treatment will be followed.will be followed.


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NanoironNanoiron and and NanoscaleNanoscale Bimetals for Subsurface RemediationBimetals for Subsurface Remediation(September 27, 2006)(September 27, 2006)

In this lecture various In this lecture various nanoscalenanoscale metal particles will be first metal particles will be first introduced with an emphasis on introduced with an emphasis on nanoironnanoiron and its bimetals. Then and its bimetals. Then the principles and methods for preparing their the principles and methods for preparing their suspensions/slurries will be followed. Finally, the applicationsuspensions/slurries will be followed. Finally, the applications s of of nanoironnanoiron and and nanoscalenanoscale Pd/Fe bimetal in remediation of Pd/Fe bimetal in remediation of various subsurface contaminants will be presented.various subsurface contaminants will be presented.


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AcknowledgmentsAcknowledgments

This series of lectures is a part of a joint Erasmus This series of lectures is a part of a joint Erasmus MundusMundusMaster Course entitled Master Course entitled ““NanoscienceNanoscience and nanotechnologyand nanotechnology””(EMM(EMM--NanoNano).). It is made possible through a Erasmus It is made possible through a Erasmus MundusMundusscholarship and kind assistance from Professor scholarship and kind assistance from Professor GGÖÖranran WendinWendin, , Department of Department of MicrotechnologyMicrotechnology and and NanoscienceNanoscience, Chalmers , Chalmers University of Technology, University of Technology, GGÖÖteborgteborg, Sweden., Sweden.


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(To be continued)(To be continued)


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MCC025 MCC025 NanoscienceNanoscience

Introduction to Environmental NanotechnologyIntroduction to Environmental Nanotechnology

Professor Gordon C. C. YangProfessor Gordon C. C. Yang

Institute of Environmental Engineering Institute of Environmental Engineering National Sun National Sun YatYat--SenSen UniversityUniversity

Kaohsiung 80424, TaiwanKaohsiung 80424, Taiwanee--mailmail:: [email protected]@mail.nsysu.edu.tw


1111

Nanotechnology and the Environment: An OverviewNanotechnology and the Environment: An Overview(September 5, 2006)(September 5, 2006)

In this lecture an overview of nanotechnology and the In this lecture an overview of nanotechnology and the environment will be delivered. First, various unique propertiesenvironment will be delivered. First, various unique propertiesof of nanomaterialsnanomaterials and the significance of nanotechnology and the significance of nanotechnology toward human life will be presented. Second, toward human life will be presented. Second, nanomaterialsnanomaterialsfrom cradle to grave will be introduced including their from cradle to grave will be introduced including their applications and ESH (environment/safety/health) implications.applications and ESH (environment/safety/health) implications.


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What is Nanotechnology?What is Nanotechnology?

A friend of MargaretaA friend of Margareta’’s mom asked her, s mom asked her, ““What What is this is this nanotechnologynanotechnology that your daughter is that your daughter is doing?doing?””

She answered, She answered, ““Well, you see, there is Well, you see, there is SmallSmall, , then there is then there is MacroMacro, then , then MicroMicro, and then , and then comes comes NanoNano..””

Right on!Right on! You may also say something further You may also say something further like like You take something small, and you make it You take something small, and you make it work the way you want it towork the way you want it to..


1313(National Nanotechnology Initiative, 2003)


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So, What Is Environmental Nanotechnology All About?So, What Is Environmental Nanotechnology All About?

““Well, an employment of nanotechnology for the Well, an employment of nanotechnology for the purposes of improving the qualities of our globe purposes of improving the qualities of our globe and its living creatures and avoiding harm and its living creatures and avoiding harm toward them is in the realm of toward them is in the realm of Environmental Environmental NanotechnologyNanotechnology..”” said Gordon Yang. said Gordon Yang.

RememberRemember,, applications of nanotechnology not applications of nanotechnology not only can yield some benefits to us but pose risks only can yield some benefits to us but pose risks to the environment and human health. In other to the environment and human health. In other words, words, nanotechnology per se is a beauty and nanotechnology per se is a beauty and beast as well.beast as well.


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Introduction (1)Introduction (1)

MacroscopicMacroscopic vs. vs. MesoscopicMesoscopic vs. vs. MicroscopicMicroscopic

MesoscopicMesoscopic: clusters, : clusters, nanosystemsnanosystems (1(1--100 nm),100 nm), and suband sub--micron systems (0.1micron systems (0.1--11μμm )m )

The The diameter of a single atomdiameter of a single atom can vary from 0.1 to 0.5 nm can vary from 0.1 to 0.5 nm depending on the type of element (e.g., ~0.15 nm or 1.5 depending on the type of element (e.g., ~0.15 nm or 1.5 AngerstronsAngerstrons for carbon atom).for carbon atom).

Nobel laureate Nobel laureate Richard FeynmanRichard Feynman said said ““The principles of The principles of physics, as far as I can see, do not speak against the physics, as far as I can see, do not speak against the possibility of possibility of manoeuvringmanoeuvring things atom by atomthings atom by atom”” (1959).(1959).


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If If Richard P. FeynmanRichard P. Feynman was a philosopher, then was a philosopher, then K. Eric K. Eric DrexlerDrexler was the prophet. In his book, was the prophet. In his book, Engines of CreationEngines of Creation--the Coming Age of Nanotechnologythe Coming Age of Nanotechnology (1990), (1990), DrexlerDrexler said said ““Nanotechnology is the principle of atom manipulation Nanotechnology is the principle of atom manipulation atom by atom,through control of the structure of matter at atom by atom,through control of the structure of matter at the molecular level. It entails the ability to build molecular the molecular level. It entails the ability to build molecular systems with atomsystems with atom--byby--atom precision, yielding a variety of atom precision, yielding a variety of nanomachinesnanomachines..””

The 1The 1stst International Conference on International Conference on NanoNano--Science and Science and Technology was held in July 1990, Baltimore, U.S.A.Technology was held in July 1990, Baltimore, U.S.A.

Later, three journals (i.e., Later, three journals (i.e., NanostructuredNanostructured Materials, Materials, NanobiotechnologyNanobiotechnology, and Nanotechnology) began to appear. , and Nanotechnology) began to appear.


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NanoNano--science and technology mainly include nanophysics, science and technology mainly include nanophysics, nanochemistrynanochemistry, , nanobiologynanobiology, , nanoelectronicsnanoelectronics, , nanoprocessingnanoprocessing, , nanomechanicsnanomechanics, and , and nanomedicinenanomedicine..

Structural units of Structural units of nanomaterialsnanomaterials: (1) : (1) zerozero--dimensionaldimensional (i.e., (i.e., all three dimensions in all three dimensions in nanoscalenanoscale; e.g., clusters of atoms), (2) ; e.g., clusters of atoms), (2) oneone--dimensionaldimensional (i.e., two dimensions in (i.e., two dimensions in nanoscalenanoscale; e.g., ; e.g., nanowiresnanowires & & nanotubesnanotubes), and (3) ), and (3) twotwo--dimensionaldimensional (i.e., only (i.e., only one dimension in one dimension in nanoscalenanoscale; e.g., ; e.g., nanolayersnanolayers))

The Royal Society (UK),The Royal Society (UK), however, uses a totally different however, uses a totally different way to define nanomaterials. way to define nanomaterials.


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******NanomaterialsNanomaterials----Definitions by dimensionalityDefinitions by dimensionality******(The Royal Society)(The Royal Society)

33--DD: (confined in 3 dimensions) e.g. quantum : (confined in 3 dimensions) e.g. quantum dots, particles, precipitates, colloids, catalysts, dots, particles, precipitates, colloids, catalysts, etc.etc.

22--DD: (confined in 2: (confined in 2--D, extended in 1D, extended in 1--D) e.g. D) e.g. nanotubesnanotubes, , fibresfibres, interconnects/wires, fibrils, , interconnects/wires, fibrils, etc.etc.

11--DD: (confined in 1: (confined in 1--D, extended in 2D, extended in 2--D) e.g. D) e.g. surface coatings, thin films, device junctions surface coatings, thin films, device junctions (diodes etc.), interfaces etc. (diodes etc.), interfaces etc.


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Many unknown processes and phenomena have been noticed Many unknown processes and phenomena have been noticed in various in various nanomaterialsnanomaterials. These . These unique findings cannot be unique findings cannot be explained by traditional theories in physics and chemistry.explained by traditional theories in physics and chemistry.

In the years to come, In the years to come, nanomaterialsnanomaterials will be highly employed will be highly employed in many industries and fields including in many industries and fields including energy, environment, energy, environment, coating, electronics, materials, medicine, and so oncoating, electronics, materials, medicine, and so on..

BenefitsBenefits----Environmental applications of Environmental applications of nanomaterialsnanomaterials might might include catalytic conversion, catalytic degradation, coating, include catalytic conversion, catalytic degradation, coating, adsorption, adsorption, complexationcomplexation, and so on., and so on.

RisksRisks----In addition to the potential benefits indicated above, In addition to the potential benefits indicated above, applications of applications of nanomaterialsnanomaterials could also pose great threats to could also pose great threats to the environment and human health. the environment and human health.


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NanoNano--structural Units (1)structural Units (1)

Atomic clusterAtomic cluster: an aggregate of a few to hundreds of atoms : an aggregate of a few to hundreds of atoms such as Fesuch as Fenn, , CuCunnSSmm (Note: n and m are integers) and carbon (Note: n and m are integers) and carbon clusters (e.g., clusters (e.g., fullerenefullerene CC6060 molecule and other fullerenes)molecule and other fullerenes)

An atomic cluster does not have a fixed shape. Except inert An atomic cluster does not have a fixed shape. Except inert gases, atoms in the atomic cluster are chemically bonded.gases, atoms in the atomic cluster are chemically bonded.

Atomic clusters can be in the forms of monoAtomic clusters can be in the forms of mono--atom, dualatom, dual--atom , atom , polypoly--atom , and cluster compound.atom , and cluster compound.


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NanoparticlesNanoparticles: ultra: ultra--fine particles in the range of 1fine particles in the range of 1--100 nm100 nm

Two approaches to creating Two approaches to creating nanomaterialsnanomaterials: (1) the : (1) the toptop--downdownapproach and (2) theapproach and (2) the bottombottom--upup approach.approach.

Many unique properties exist in Many unique properties exist in nanomaterialsnanomaterials are due to are due to surface effectssurface effects, , quantum size/confinement effectsquantum size/confinement effects, , macro macro quantum tunneling effectsquantum tunneling effects, etc., etc.

Artificial atomsArtificial atoms (also known as(also known as quantum dotsquantum dots): aggregates ): aggregates of a fixed number of atoms having a size smaller than 100 of a fixed number of atoms having a size smaller than 100 nmnm


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Carbon ClustersCarbon Clusters

(1) (1) CC6060 , the 3, the 3rdrd type of carbon crystalstype of carbon crystals, is composed of 20 , is composed of 20 hexagons and 12 pentagons and has a diameter of 0.7nm. hexagons and 12 pentagons and has a diameter of 0.7nm. These soccer ballThese soccer ball--like molecules bind with each other in the like molecules bind with each other in the solid state to form a crystal lattice having a facesolid state to form a crystal lattice having a face--centered cubic centered cubic structure (i.e., 26% of the volume of the unit cell is empty). structure (i.e., 26% of the volume of the unit cell is empty). In In the lattice each Cthe lattice each C6060 molecule is separated from its nearest molecule is separated from its nearest neighbor by 1 nm, and they are held together by van neighbor by 1 nm, and they are held together by van derder Waals Waals forces.forces.

(2) The C(2) The C6060 crystal is an insulator, but crystal is an insulator, but when doped with an when doped with an alkali atomalkali atom it becomes electrically conducting and less it becomes electrically conducting and less magnetic susceptibility (i.e., presence of superconductivity).magnetic susceptibility (i.e., presence of superconductivity).


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Carbon Carbon NanotubesNanotubes (More details will be given(More details will be given in the 4in the 4thth lecture)lecture)

(1) A carbon (1) A carbon nanotubenanotube can be thought as a sheet of graphite can be thought as a sheet of graphite rolled into a tube with bonds at the end of the sheet forming rolled into a tube with bonds at the end of the sheet forming the bonds that close the tube.the bonds that close the tube.

(2) A carbon (2) A carbon nanotubenanotube may consists of one tube of graphite may consists of one tube of graphite (i.e., a (i.e., a singlesingle--walled walled nanotubenanotube, SWNT, SWNT) or a number of ) or a number of concentric tubes, called concentric tubes, called multiwalledmultiwalled nanotubesnanotubes ((MWNTsMWNTs))..

(3) (3) Possible types of carbon Possible types of carbon nanotubesnanotubes: (a) armchair : (a) armchair structure, (b) zigzag structure, and (3) structure, (b) zigzag structure, and (3) chiralchiral structure.structure.


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Size matters: why Size matters: why nanomaterialsnanomaterials are differentare different((RodunerRoduner, 2006), 2006)

Gold is known as a shiny, yellow noble metal that does not tarnish, has a face-centred cubic structure, is non-magnetic and melts at 1336 K. However, a small sample of the same gold is quite different, providing it is tiny enough: 10 nm particles absorb green light and thus appear red. The melting temperature decreases dramatically as the size goes down. Moreover, gold ceases to be noble, and 2–3 nm nanoparticles are excellent catalysts which also exhibit considerable magnetism. At this size they are still metallic, but smaller ones turn into insulators. Their equilibrium structure changes to icosahedral symmetry, or they are even hollow or planar, depending on size.


http://en.wikipedia.org/wiki/Image:Icosahedron.jpg

http://en.wikipedia.org/wiki/Image:Lattice_face_centered_cubic.svg

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Size matters: why Size matters: why nanomaterialsnanomaterials are are differentdifferent ––SummarySummary ((RodunerRoduner, 2006), 2006)

Surface Effects (1) Surface Effects (1) – Atoms at surfaces have fewer neighboursthan atoms in the bulk. Because of this lower coordination and unsatisfied bonds, surface atoms are less stabilised than bulk atoms. The smaller a particle the larger the fraction of atoms at the surface, and the higher the average binding energy per atom.The surface-to-volume ratio scales with the inverse size, and therefore there are numerous properties which obey the same scaling law. Among them are the melting and other phase transition temperatures. Edge and corner atoms have an even lower coordination and bind foreign atoms and molecules more tightly.


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Surface Effects (2) Surface Effects (2) – The coordination number is also limited in narrow pores. The solubility of salts in pore-confined water, the melting point and even the critical point of a fluid are therefore greatly reduced. Phase transitions are collective phenomena. With fewer atoms a phase transition is less well defined, it is therefore no longer sharp. The Gibbs phase rule loses its meaning because phases and components are no longer properly distinguishable. Small clusters behave more like molecules thanas bulk matter. It is therefore useful to think of different isomers which coexist over a temperature range rather than of different phases. There are numerous other concepts of thermodynamics which can break down, in particular when the system of interest consists of a single isolated cluster with a small number of atoms.


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Quantum SizeQuantum Size Effects (1) Effects (1) – In metals and semiconductors the electronic wave functions of conduction electrons are delocalisedover the entire particle. Electrons can therefore be described as ‘particles in a box’, and the densities of state and the energies of the particles depend crucially on the size of the box, which at first leads to a smooth size-dependence. However, when more atoms are added the shells are filled up, and discontinuities occurwhen a new shell at higher energy starts to be populated. Because of these discontinuities there is no simple scaling.Instead, one finds behaviour akin to that of atoms, with filled shells of extra stability. Therefore, such clusters are often called ‘pseudo-atoms’, ‘quantum dots’ or ‘superatoms.”


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Quantum SizeQuantum Size Effects (2) Effects (2) – The HOMO–LUMO band gap of semiconductor particles and therefore their absorption and fluorescence wavelengths become size dependent. Ionisationpotentials and electron affinities are tuned between the atomic values and the work function of the bulk material by variation of the cluster size. These same properties relate to the availability of electrons for forming bonds or getting involved in redox reactions. Therefore, the catalytic activity and selectivity become functions of size.

Quite often, the discontinuous Quite often, the discontinuous behaviourbehaviour of quantum size effects of quantum size effects is superimposed on a smoothly scaling slope which also reflects is superimposed on a smoothly scaling slope which also reflects the size of a the size of a quantisedquantised system. However, it may be difficult to system. However, it may be difficult to distinguish it from the smoothly scaling surface effect.distinguish it from the smoothly scaling surface effect.


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Public Perceptions about Nanotechnology: Risks, Benefits and Trust (1)

In 2004 Michael D. Cobb and Jane In 2004 Michael D. Cobb and Jane MacoubrieMacoubrie of North of North Carolina State University reported data from the first Carolina State University reported data from the first representative national phone survey of Americansrepresentative national phone survey of Americans’’perceptions about nanotechnology (N=1536). perceptions about nanotechnology (N=1536). Public Public opinion about nanotechnology is in its infancy, and opinion about nanotechnology is in its infancy, and knowledge about it is quite limited.knowledge about it is quite limited. Yet, AmericansYet, Americans’’ initial initial reaction to nanotechnology is thus far generally positive, reaction to nanotechnology is thus far generally positive, probably rooted in a generally positive view of science probably rooted in a generally positive view of science overall. Survey respondents expected benefits of overall. Survey respondents expected benefits of nanotechnology to be more prevalent than risks, and they nanotechnology to be more prevalent than risks, and they reported feeling hopeful about nanotechnology rather reported feeling hopeful about nanotechnology rather than worried. than worried.


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(Cobb and Cobb and MacoubrieMacoubrie, 2004 , 2004 )


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(Cobb and Cobb and MacoubrieMacoubrie, 2004 , 2004 )


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Nanotechnology Nanotechnology for the for the EnvironmentEnvironment

Tina MasciangioliAAAS Environmental Science and Technology Policy FellowNational Center for Environmental Research (NCER)

U.S. EPA (2002)

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Nanotechnology and the Environment

“The emerging fields of nanoscience and nanoengineering are leading to unprecedented understanding and control over the fundamental building blocks of all physical things. This is likely to change the way almost everything - from vaccines to computers to automobile tires to objects not yet imagined - is designed and made.”- Interagency Working Group on

Nanoscience, Engineering, and Technology Report (1999)

Nature of nanoparticles themselves.

• As nano-xyz is manufactured, what materials are used?

The bad…

Characteristics of the products made. Manufacturing processes involved.

• What waste is produced?

• Are toxic substances used in the manufacturing of nano-xyz?

• What happens when nano-xyz gets into the air, soil, water, or biota?

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Cd(CH3)2

H2S gas

Cadmium sulfide (CdS) “Quantum dots”

Enter the environment

Bio/Enviro/other applications

+

Avoiding the Negative

Are there more benign precursor materials or synthetic methods that can be used to make the quantum dots?

How are these semiconductor nanoparticles being introduced to their target?

Will it be possible to recover the quantum dots for reuse?

Are there measures that can be taken now to minimize or avoid the negative impact quantum dots (or other nanotechnologies) may have on the environment?

CdS CdS

CdS CdS

CdS

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Nanotechnology has the potential to substantially benefit environmental quality and sustainability through

•Pollution prevention

•Treatment

•Remediation

•Information

Nanotechnology and the Environment

The good…“As EPA looks to the future, it will need to employ innovative approaches and sound science to

investigate complex, interdisciplinary

problems in environmental

protection.”

- EPA FY 2001 Annual Report

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Involved in making a manufacturing process environmentally benign.

An environmentally benign material or manufactured product that replaces toxic substances or minimizes raw materials.

Synthetic or manufacturing processes which can occur at ambient temperature and pressure.

Nanotechnology for pollution prevention

Use of non-toxic catalysts with minimal production of resultant pollutants.

Use of aqueous-based reactions.

Build molecules as needed --“just in time.”

Nanoscale information technologies for product identification and tracking to manage recycling, remanufacture, and end of life disposal of solvents.

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• Biomimetic methods of organizing metal particles 1.5 nanometers in diameter.

Biomolecular nanolithography

J. E. Hutchison and coworkers, Superlattices and Microstructures, Vol. 27, pp. 489-493 (2000)

5µm

• Assembling the particles on a biopolymer template or scaffold stretched out on a surface.

• Nanostructures are organized into well-defined chip architectures, such as lines and grids.

• Process eliminates the current process chemicals that are harmful to the environment.

• Nanoscale assemblies have been made that demonstrate stable, room-temperature electrical behavior that may be tolerant of defects and useful in building nanoscale circuits.

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End-of-pipe management and cleanup of pollution

Treatment & Remediation

Iron Treatment Walls…

Used in groundwater treatment for many years. Iron chemically reduces organic and inorganic environmental contaminants. Currently involves granular or “microscale” iron (≥ 50 µm or 50,000 nm).

and Nanotechnology

Nanosized iron enhances the reaction. Enhanced further by coupling with other metals (Fe/Pd)* on the nanoscale. Nano Fe0 is more reactive and effective than the microscale. Smaller size makes it more flexible --penetrates difficult to access areas.

* Elliot and Zhang, ES&T 2001, 35, 4922-4926

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“Sense and Shoot”Approach to

Pollution Treatment

“Sense and Shoot”Approach to

Pollution Treatment

Nanosized zinc oxide (ZnO) “senses” organic pollutants indicated by change in visible emission signal.

Sensing capability means that the energy-consuming oxidation stage only occurs when the pollutants present.

Dual role of ZnO semicondouctorfilm as a sensor and photocatalyst

>300 nm

UV

The ZnO “shoots” the pollutants via photocatalytic oxidation to form more environmentally benign compounds.

Multifunctionality and “smartness” is highly desirable for environmental applications.

Kamat, P.V, et al. J.Phys.Chem. B 2002, 106,788-794.

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Used for • Process control, compliance

and ecosystem monitoring, and data/information interfaces.

Sensors• Molecules adsorb on surface of micro

cantilever, causes a change in surface stress, cantilever bends.

IBM--Berger et al., Science 1997 June 27; 276: 2021-2024

Single Molecule Detection

• Used to detect chemicals using either a specific reaction between analyteand sensor layer or chem/physisorption processes.

• Applications to bio-toxins as well.

Need to be • Low cost, rapid, precise, and

ultra sensitive.• Operated remotely and

continuously, in situ, and in real time.

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Science and Engineering approaches are needed that offer new capabilities to prevent or treat highly toxic or persistent pollutants, and that result in the more effective monitoring of pollutants or their impact in ways not currently possible.

Conclusions

Nanoscience, engineering, and technology holds great potential for the continued improvement of technologies for environmental protection. The recent breakthroughs in creating nanocircuitry, give further evidence and support the predictions that nanoscale science and engineering “will most likely produce the breakthroughs of tomorrow.”

BUT the environmental implications (nanoin the environment) need to be considered as we consider nano for the environment.

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Environmental and Safety Impacts of Nanotechnology:

What Research is Needed? (1) (Rejeski, 2005)

““As the National Science Foundation (NSF) highlights, the As the National Science Foundation (NSF) highlights, the ability to determine the novel properties of materials and ability to determine the novel properties of materials and systems at this scale implies that nanotechnology eventually systems at this scale implies that nanotechnology eventually could impact the production of virtually every humancould impact the production of virtually every human--made made objectobject——everything from automobiles, tires, and computer everything from automobiles, tires, and computer circuits to advanced medicine and tissue replacementscircuits to advanced medicine and tissue replacements——and and lead to the invention of products yet to be imagined. lead to the invention of products yet to be imagined. Nanotechnology will fundamentally restructure the Nanotechnology will fundamentally restructure the technologies currently used for manufacturing, medicine, technologies currently used for manufacturing, medicine, defense, energy production, defense, energy production, environmental managementenvironmental management, , transportation, communication, computation, and education transportation, communication, computation, and education ((RocoRoco et al., 2000).et al., 2000).””


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Environmental and Safety Impacts of Nanotechnology:

What Research is Needed? (2) (Rejeski, 2005)

““NSF predicts that the world market for goods and services NSF predicts that the world market for goods and services using nanotechnologies will grow to $1 trillion by 2015. using nanotechnologies will grow to $1 trillion by 2015. LuxLux Research calculates that in 2004 there were $13 billion Research calculates that in 2004 there were $13 billion worth of products in the global marketplace incorporating worth of products in the global marketplace incorporating nanotechnology. nanotechnology. Others estimate there are already over 700 products on the Others estimate there are already over 700 products on the market that are made from or with nanotechnology or market that are made from or with nanotechnology or engineered engineered nanomaterialsnanomaterials. . Worldwide about $9 billion annually is being spent by Worldwide about $9 billion annually is being spent by governments and the private sector on nanotechnology governments and the private sector on nanotechnology research and development.research and development.””


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What are the primary concerns about the environmental and safety impacts of

nanotechnology? (1) (Rejeski, 2005)

““One overview of the subject by Günter, Eva, and Jan Oberdörster (2005) notes that laboratory studies have shown that airborne nanoscale materials depositing in the respiratory tract can cause an inflammatory response when inhaled. The small size of engineered nanomaterials also makes it easier for their uptake into and between various cells, allowing for transport to sensitive target sites in the body, including bone marrow, spleen, heart, and brain.Various kinds of nanomaterials, including C-60 fullerenes, single-walled nanotubes, and quantum dots, have been found to mobilize to mitochondria in cells, potentially interfering with antioxidant defenses. However, the translocation rates of these materials are uncertain.””


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What are the primary concerns about the environmental and safety impacts of

nanotechnology? (1) (Rejeski, 2005)

““In addition, Oberdörster et. al. (2005) report that there have been only a few studies looking at the effects of engineered nanomaterials on environmental systems. Water-borne carbon-60 was found to lead to oxidative stress in the brains of largemouth bass, although the mechanisms of action were uncertain. The bactericidal properties of carbon-60 in water have also been reported, and are being used as potential new anti-microbial agents.However, such uses may have unforeseen consequences on delicate ecosystems if materials are released into the environment. Quoting the authors, “During a product’s life cycle (manufacture, use, disposal), it is probable that nanomaterials will enter the environment, and currently there is no unified plan to examine ecotoxicological effects of [nanoparticles].”””


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Environmental Risks of Nanotechnology: National Environmental Risks of Nanotechnology: National Nanotechnology Initiative Funding, 2000Nanotechnology Initiative Funding, 2000--20042004 (1)(1)

((DunphyDunphy--GuzmGuzmáánn, , Taylor, and Taylor, and BanfieldBanfield , 2006), 2006)


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Environmental Risks of Nanotechnology: National Environmental Risks of Nanotechnology: National Nanotechnology Initiative Funding, 2000Nanotechnology Initiative Funding, 2000--20042004 (2)(2)



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Research Outcomes and the Risks of Nanotechnology:Research Outcomes and the Risks of Nanotechnology:Exposure, Environmental Fate, and TransportExposure, Environmental Fate, and Transport (1)(1)


Although concentrations of Although concentrations of incidental incidental nanoparticlenanoparticle aerosolsaerosolshave been shown to decay with distance from the source, it is have been shown to decay with distance from the source, it is unknown if unknown if engineered engineered nanoparticlesnanoparticles, especially those coated , especially those coated to reduce aggregation, will behave similarly.to reduce aggregation, will behave similarly.The exposure and release of The exposure and release of carbon carbon nanotubesnanotubes in a in a manufacturing environment results in low aerosol manufacturing environment results in low aerosol concentrations as a result of handling, but suggests that concentrations as a result of handling, but suggests that dermal exposure may be an issuedermal exposure may be an issue..Exposure assessment studies of engineered Exposure assessment studies of engineered nanoparticlesnanoparticleshave focused on worker exposure, but exposure of the have focused on worker exposure, but exposure of the ecosystem and the public to ecosystem and the public to nanoparticlesnanoparticles, from either , from either manufacturing or the use and disposal of manufacturing or the use and disposal of nanoparticlenanoparticle--based based products, needs to be quantified.products, needs to be quantified.


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Research Outcomes and the Risks of Nanotechnology:Research Outcomes and the Risks of Nanotechnology:Exposure, Environmental Fate, and TransportExposure, Environmental Fate, and Transport (2)(2)


NanoparticlesNanoparticles of CeOof CeO22, a strong oxidant,, a strong oxidant, have recently been have recently been shown to both shown to both decarboxylatedecarboxylate and polymerize some small and polymerize some small organic molecules. These organic molecules. These nanoparticlesnanoparticles have been tested for have been tested for use as use as a gasoline additivea gasoline additive to enhance combustion. to enhance combustion. The The environmental release of CeOenvironmental release of CeO22 may therefore potentially may therefore potentially impact carbon chemistry in soils, water, and organisms.impact carbon chemistry in soils, water, and organisms. The The overall environmental impact of these particles is dependent overall environmental impact of these particles is dependent upon understanding how environmental conditions, such as upon understanding how environmental conditions, such as solution chemistry, solution chemistry, redoxredox potential, heat, pressure, potential, heat, pressure, biochemical reactions over time, and presence or absence of biochemical reactions over time, and presence or absence of coatings, may affect stability and behavior.coatings, may affect stability and behavior.

Transport studiesTransport studies to date have been limited to aerosol to date have been limited to aerosol transport in the atmosphere and transport studies in porous transport in the atmosphere and transport studies in porous media. However, media. However, each ecosystem component must be each ecosystem component must be considered: soil, sediment, oceans, surface waters, considered: soil, sediment, oceans, surface waters, groundwatersgroundwaters, and the atmosphere, with oxygen availability , and the atmosphere, with oxygen availability taken into consideration for these components.taken into consideration for these components.


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Research Outcomes and the Risks of Nanotechnology: Research Outcomes and the Risks of Nanotechnology: ToxicityToxicity (1)(1)


OberdorsterOberdorster et al. (2005) recently published a comprehensive review of et al. (2005) recently published a comprehensive review of toxicology of toxicology of nanoparticlesnanoparticles and discussion of mechanisms, based on and discussion of mechanisms, based on their years of expertise in UFP toxicology. UFP aerosol researchtheir years of expertise in UFP toxicology. UFP aerosol researchsuggests that suggests that some smaller some smaller nanoparticlesnanoparticles show increased toxicity due to show increased toxicity due to their increased surface area; however, particle structure and cotheir increased surface area; however, particle structure and composition, mposition, not only particle size, may play a role in toxicitynot only particle size, may play a role in toxicity..

There may be significant reasons for There may be significant reasons for concern regarding carbonconcern regarding carbon--based based nanomaterialsnanomaterials, given predictions that they will strongly partition into , given predictions that they will strongly partition into cellular hydrophobic compounds such as lipids relative to water,cellular hydrophobic compounds such as lipids relative to water,potentially resulting in significant potentially resulting in significant bioconcentrationbioconcentration. In addition, . In addition, researchers have found researchers have found fullerenefullerene--related related photoinducedphotoinduced damage to lipids, damage to lipids, proteins, and cells, skin inflammation, alteration of biochemicaproteins, and cells, skin inflammation, alteration of biochemical l functions, brain damage, severe organ damage, and distribution ifunctions, brain damage, severe organ damage, and distribution into nto cells and tissues. cells and tissues. Carbon Carbon nanotubesnanotubes are found to be are found to be cytotoxiccytotoxic and to and to induce induce granulomasgranulomas in lungs of laboratory animals. in lungs of laboratory animals.


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Research Outcomes and the Risks of Nanotechnology: Research Outcomes and the Risks of Nanotechnology: ToxicityToxicity (2)(2)


Surface Surface derivatizationderivatization and light exposure are known to greatly and light exposure are known to greatly affect the toxicity of semiconductor affect the toxicity of semiconductor nanoparticlesnanoparticles, TiO, TiO22

nanoparticlesnanoparticles, and fullerenes., and fullerenes. Many believe that surface Many believe that surface coatings have the potential to greatly alter the toxicity, coatings have the potential to greatly alter the toxicity, solubility, reactivity, bioavailability, and catalytic propertiesolubility, reactivity, bioavailability, and catalytic properties of s of underlying underlying nanoparticlesnanoparticles, thus minimizing their health and , thus minimizing their health and environmental impacts. environmental impacts. Unfortunately, these coatings may not Unfortunately, these coatings may not persist indefinitely after release of the underlying persist indefinitely after release of the underlying nanoparticlenanoparticleinto the environmentinto the environment: prolonged exposure to light and oxygen : prolonged exposure to light and oxygen may cause oxidation of either the surface ions to which may cause oxidation of either the surface ions to which coatings are bound or the coating itself, the coating may coatings are bound or the coating itself, the coating may preferentially partition into the local environment, and preferentially partition into the local environment, and microbes may utilize the coating in chemical reaction activity. microbes may utilize the coating in chemical reaction activity.


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Research Outcomes and the Risks of Nanotechnology: Research Outcomes and the Risks of Nanotechnology: ToxicityToxicity ((33))


For example, a study of For example, a study of CdSeCdSe quantum dots with a surface quantum dots with a surface coating found a lack of coating found a lack of cytotoxicitycytotoxicity, likely a consequence of its , likely a consequence of its surface coating. surface coating. In the event that the surface coating does not In the event that the surface coating does not persist, persist, CdSeCdSe (like (like CdTeCdTe and and CdSCdS) is known to be toxic in bulk ) is known to be toxic in bulk form and may be particularly reactive and form and may be particularly reactive and bioavailablebioavailable in in nanoparticulatenanoparticulate form.form. Meanwhile, Meanwhile, waterwater--soluble soluble CdSeCdSe quantum quantum dots without surface coatings can cause DNA damage and can dots without surface coatings can cause DNA damage and can be toxic to cellsbe toxic to cells, although the mechanism for toxicity is still , although the mechanism for toxicity is still being debated in the literature.being debated in the literature.


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Research Outcomes and the Risks of Nanotechnology: Research Outcomes and the Risks of Nanotechnology: ToxicityToxicity ((44))


NanoparticlesNanoparticles such as metals and metal oxides (Cu, Co, TiOsuch as metals and metal oxides (Cu, Co, TiO22, , and SiOand SiO22) have also been shown to have inflammatory and toxic ) have also been shown to have inflammatory and toxic effects on cells, and TiOeffects on cells, and TiO22 nanoparticulatesnanoparticulates have also been shown have also been shown to induce DNA damage and chromosomal aberrations.to induce DNA damage and chromosomal aberrations.HydroxyapatiteHydroxyapatite nanoparticlesnanoparticles, a substance closely related to the , a substance closely related to the mineral component of bones and teeth, mineral component of bones and teeth, were found to induce were found to induce cell death.cell death.

Other factors affect toxicity, such as Other factors affect toxicity, such as concentrations of concentrations of nanoparticlesnanoparticles. The concentrations likely to be seen in . The concentrations likely to be seen in environmental contexts environmental contexts are intrinsically linked to the exposure are intrinsically linked to the exposure studies, which, unfortunately, are incompletestudies, which, unfortunately, are incomplete. . Studies should Studies should also encompass toxicity to microorganisms, larger animals, also encompass toxicity to microorganisms, larger animals, and plants. and plants.


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Research Outcomes and the Risks of Nanotechnology: Research Outcomes and the Risks of Nanotechnology: Global Impact and Life CyclesGlobal Impact and Life Cycles((DunphyDunphy--GuzmGuzmáánn, , Taylor, and Taylor, and BanfieldBanfield , 2006), 2006)

GlobalGlobal--scale impact of scale impact of nanoparticlesnanoparticles should also be considered, should also be considered, as small particles have been shown to have atmospheric impact as small particles have been shown to have atmospheric impact ((cloud propertiescloud properties).).NanoparticulateNanoparticulate oxides such as TiOoxides such as TiO22, used to degrade , used to degrade pollutants and for disinfection, may have the potential to pollutants and for disinfection, may have the potential to induce other organic transformations and impact induce other organic transformations and impact photochemical reactions in the atmosphere.photochemical reactions in the atmosphere. NanoparticlesNanoparticles are are key components in many biogeochemical processes; any globalkey components in many biogeochemical processes; any global--scale impact of engineered scale impact of engineered nanoparticlesnanoparticles on elemental cycles on elemental cycles should be considered. should be considered. Finally, Finally, life cycle analyses of life cycle analyses of nanoparticlesnanoparticles, incorporating , incorporating results of the studies discussed above to determine the overall results of the studies discussed above to determine the overall impact of these particles, will be critical to discussing the riimpact of these particles, will be critical to discussing the risks sks involved with each new involved with each new nanoproductnanoproduct as it is developed.as it is developed.


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Nanoparticles: Health Effects-Pros and Cons((Gwinn and Vallyathan, 2006), 2006)

In conclusion, there is no doubt that nanotechnology will profoundly impact into a wide range of applications and many aspects of human life including environmental decontamination, water purification, cheaper electricity and better disease treatment modalities. One of the major challenges facing industry and government is the lack of information concerning possible health effects resulting from exposure to different nanomaterials. Development of safety guidelines by government for industry in manufacturing, monitoring of worker exposure, ambient release, and risk evaluations are mandatory to promote nanotechnology for its economic incentives and medicinal applications.


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As a nanoAs a nano--science and engineering science and engineering student, what and how you do sure will student, what and how you do sure will make a difference toward human being make a difference toward human being and the globe.and the globe.

Be a responsible nanotechnologist!Be a responsible nanotechnologist!

Campus ofCampus of


introduction to environmental nanotechnologyfy.chalmers.se/~fogelstr/gordonyang/lecture1.pdf ·...

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