0D.docx

September 21, 2017 | Author: Mohd Azman Suwandi | Category: Carbon Nanotube, Photolithography, Graphene, Sintering, Fullerene
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WEEK 4: CLASSIFICATION OF NANOMATERIALS: CLASSIFICATION OF NANOMATERIALS 0D 1D 2D 3D 1 dimension of the Nano-dimensions in 2 dimensions are All dimensions are nanostructure will be all the three outside the outside the Nano outside the directions nanometer range meter range nanometer range Nano films such as Nanowires and Quantam dots coatings and Nano Bulk materials nanotubes. sheets Long (micrometer in large (several square Spherical in size, length), but with micrometer),but the Blocks which are in Diameter of these diameter of only a thickness is always the nanometer scale particles (1-50 nm) few nanometer. in Nano scale range 0D NANOMATERIALS : QUANTUM DOTS Quantum dots are small devices that contain a tiny droplet of free electrons. Typical dimensions are between nanometers to a few microns. A quantum dot can have anything from a single electron to a collection of several thousands. The size ,shape and number of electrons can be precisely controlled Just as in an atom, the energy levels are quantized due to the confinement of electrons. The 3D spatial confinement is observed in the quantum dots. In quantum dots even if one electron leaves the structure there is a significant change in the properties. Unlike atoms however, quantum dots can be easily connected to electrodes and are therefore excellent tools to study atomic-like properties. The potential of nearby metal gate is changed. The atomic structure might behave as a lead one minute and gold next minute The fanciful idea of designer materials might be realized 0D Dendrimers 0D Fullerenes Dendrimers are spherical polymeric In the mid-1980s carbon 60 (C60) was discovered. C60 is spherical molecules about molecules, formed through a nanoscale 1nm in diameter, comprising 60 carbon hierarchical self-assembly process. There are atoms arranged as 20 hexagons and 12 many types of dendrimer; the smallest is pentagons: the configuration of a football. several nanometres in size. Dendrimers are The C60 species was named used in conventional applications such as ‘Buckminsterfullerene’. In 1990, a technique coatings and inks, but they also have a range to produce larger quantities of C60 was developed by resistively heating graphite of interesting properties which could lead to rods in a helium atmosphere. Several useful applications. For example, dendrimers applications are envisaged for fullerenes, can act as nanoscale carrier molecules and as such as miniature ‘ball bearings’ to lubricate such could be used in drug delivery. surfaces, drug delivery vehicles and in Environmental clean-up could be assisted by electronic circuits. dendrimers as they can trap metal ions, which could then be filtered out of water with ultra-filtration techniques. 1D NANOMATERIALS: CARBON NANOTUBES Carbon nanotubes (CNTs) were first observed by Sumio Iijima in 1991. CNTs are extended tubes of rolled graphene sheets. There are two types of CNT: single-walled (one tube) or multi-walled (several concentric tubes) Both of these are typically a few nanometres in diameter and several micrometres (10-6m) to centimetres long. CNTs have assumed an important role in the context of nanomaterials, because of their novel chemical and physical properties. They are mechanically very strong (their Young’s modulus is over 1 terapascal, making CNTs as stiff as diamond), flexible (about their axis), and can conduct electricity extremely well (the helicity of the graphene sheet determines whether the CNT is a semiconductor or metallic). All of these remarkable properties give CNTs a range of potential applications: for example, in reinforced composites, sensors, nanoelectronics and display devices. 1D NANOMATERIALS: NANOWIRES Nanowires are ultrafine wires or linear arrays of dots, formed by self-assembly. They can be made from a wide range of materials. Semiconductor nanowires made of silicon, gallium nitride and indium phosphide has demonstrated remarkable optical, electronic and magnetic characteristics. Nanowires have potential applications in high-density data storage; either as magnetic read heads or as patterned storage media, and electronic and opto-electronic nanodevices, for metallic interconnects of quantum devices and nanodevices. The preparation of these nanowires relies on sophisticated growth techniques, which include self-assembly processes, where atoms arrange themselves naturally on stepped surfaces, chemical vapour deposition (CVD) onto patterned substrates, electroplating or molecular beam epitaxy (MBE). “One-dimensional” structure Exhibits crystal structure Many different materials Diameter: 1-100 nanometers  Unlike quantum “dots” (0-  Metals, semiconductors, (10-9 m) dimensional) oxides Length: microns (10-6 m) 2D THIN FILM, LAYERS AND SURFACES Two-dimensional nanomaterials, such as thin films and engineered surfaces, have been developed and used for decades in fields such as electronic device manufacture, chemistry and engineering. In the silicon integrated-circuit industry, for example, many devices rely on thin films for their operation, and control of film thicknesses approaching the atomic level is routine. Monolayers (layers that are one atom or molecule deep) are also routinely made and used in chemistry. The formation and properties of these layers are reasonably well understood from the atomic level upwards, even in quite complex layers (such as lubricants). Advances are being made in the control of the composition and smoothness of surfaces, and the growth of films. 4B: GRAPHENE WHAT IS GRAPHENE? Graphene is a one-atom-thick planar sheet of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. APPLICATIONS BASED ON GRAPHITIC CARBON Steel company: Coke Rubber/plastic: Carbon black Pencil: graphite + clay Graphite refractory Graphite electrode GRAPHITIC COMPOSITION MATERIALS: CARBON FIBER Weigh ~ ¼ of aluminium Strength ~ 10 times of steel Electrical conductor Thermal conductor HOW THICK IS IT? A million times thinner than paper HOW STRONG IS IT? Stronger than diamond. HOW CONDUCTIVE IS IT?

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Better than copper. PROPERTIES OF GRAPHENE electronic properties, thermal properties, mechanical properties, optical properties, relativistic charge carriers anomalous quantum hall effect ELECTRONIC PROPERTIES High electron mobility (at room temperature ~ 200.000 cm2/ (V·s), carbon nanotube: ~ 100.000 cm2/(V·s), organic semiconductors (polymer, oligomer): 1200C) 2. Other hydrocarbon compounds such as ethane and acetylene are not suggested due to rapid decomposition at high temperature; 3. Other transition metal such as Fe, Co, and Ni are not preferred for mono or bilayer graphene growth due to their higher-than-desirable capacity to decompose hydrocarbons. 4. The low decomposition rate of methane on Cu allows the possibility of controlling the number of graphene layers. Analysis (II): Decomposition of hydrocarbon 1. Cu foil: Cu foil is usually not single crystal possessing grain boundaries and steps; 2. The sites have much higher chemical activation energy than those of the flat regions of Cu; as a result, hydrocarbons prefer to decompose on the sites to form nucleation centers; 3. Cu foil with smooth surface is preferred: pre-polish and in-situ polish. EPITAXIAL GROWTH Production of EG on diced (3 mm by 4 mm) commercial SiC wafers. Steps: hydrogen etching to produce atomically flat surfaces; (2) vacuum graphitization to produce an ultrathin epitaxial graphite layer; (3) application of metal contacts (Pd, Au), (4) electron-beam patterning and development; (5) oxygen plasma etch to define graphite structures; (6) wire bonding. When SiC substrates are annealed at high temp., Si atoms selectively desorb from the surface and the C atoms left behind naturally form FLG (few-layer graphene) Advantage: Patterned graphene structure Drawback: Ultra-high vacuum, high cost

Based on the theoretical analysis, stability of the C atoms on SiC substrate was investigated. At a C coverage of 8/3 MLs, corresponding to 8 C atoms on three SiC unit cells, C atoms form a graphenelike two-dimensional sheet and are strongly [email protected] When more C atoms are added, they become highly unstable on the buffer layer and prefer to reside between the buffer layer and SiC substrate. At a C coverage of 16/3 MLs, a new buffer layer is formed at the interface and the original buffer layer loses bonds with the substrate. GRAPHENE NANORIBBONS (FROM CARBON NANOTUBE)

Figure 3(a)-(d) Figure 3(e) Electrons have wave-like properties, and their kinetic energy determines the wavelength, as shown in Fif. 3(a). Electrons reflected from the graphene surface and graphene/SiC interface can interfere, which causes the electron reflectivity to change periodically as a function of the electron energy and FLG thickness. The LEEM image intensity corresponds to the electron reflectivity. From LEEM images sequentially obtained while the electron beam energy was changed, we obtained the energy dependence of the electron reflectivity from regions 1 to 8, as shown in Fig. 3(e).** Growth processes After annealing at 1060ºC, preferential nucleation of the buffer layer occurred at the atomic steps on the SiC surface, where 1/3 of the ML of Si adatoms(@1) was periodically arranged (Fig. 4(a)). After annealing at a higher temperature (Fig. 4(b)), the whole surface was covered with the buffer layer and the surface steps eandered widely(@2).

At the initial stage of graphene growth, ML graphene preferentially formed near the substrate steps (Fig. 4(c)). When the annealing temperature was further increased, bilayer (BL) graphene appeared before the buffer layer completely disappeared (Fig. 4(d)). This means that uniform ML graphene is difficult to grow in UHV.

1. The nanogap probe contains two Pt electrodes with a gap of 30 nm fabricated at the tip of the cantilever of an atomic force microscopy (AFM) apparatus. 2. An electrical conductivity map of BL graphene is shown in Fig. 5(c). Linear contrasts, which correspond to the substrate steps, reveal that the substrate steps modify the electrical conductivity. 3. The TEM image (Fig. 5a) depicted that FLG covered the substrate steps like a carpet. FLG was locally bent near the steps, and this bending could affect the carrier transport.

Fig. 1. Graphene films. (A)Photograph (in normal white light) of a large multi-layer graphene flake on top of an oxidized Si wafer. (B) AFM image of 2 µm by 2 µm area of this flake near its edge. Colors: dark brown, SiO2 surface; orange, 3 nm height above the SiO2 surface. (C) AFM image of single-layer graphene. Materials: HOPG Preparation: 1. prepared 5 mm-deep mesas on top of the platelets (mesas were squares of various sizes from 20 mm to 2 mm). 2. Pressed the structured surface on a 1-mm-thick layer of a fresh wet photoresist spun over a glass substrate. After baking, the mesas became attached to the photoresist layer, which allowed us to cleave them off the rest of the HOPG sample. Then, using scotch tape to repeatedly peel flakes of graphite off the mesas 3. Thin flakes left in the photoresist were released in acetone. 4. Dipping a Si wafer was in the solution and then washed in plenty of water and propanol, some flakes became captured on the wafer’s surface (chose thick SiO2 with t =300 nm). 5. Used ultrasound cleaning in propanol to remove mostly thick flakes. Thin flakes (d < 10 nm) were found to attach strongly to SiO2, presumably due to van der Waals and/or capillary forces.

(Left) Optical photograph in white light of a large Hall bar made from multilayer graphene (d »5nm). The central wire is 50mm long. (Right) A short (200 nm) wire made from few-layer graphene. Advantages : Production of single layer graphene is feasible Drawbacks : Limited quantity Chemical synthesis through oxidation of graphite The most promising methods for large scale production of graphene are based on the exfoliation and reduction of GO. The commonly adopted method for producing GO is the Hummers method in which graphite is oxidized using strong oxidants such as KMnO4, KClO3, and NaNO2 in the presence of nitric acid or its mixture with sulfuric acid. GO is composed of graphene oxide sheets stacked with an interlayer spacing between 6 and 10 A ° depending on the water content. The model describes GO as built of pristine aromatic “islands” separated from each other by aliphatic regions containing epoxide and hydroxyl groups and double bonds GO contains ketones, 6-membered lactol rings, and tertiary alcohol in addition to epoxide and hydroxyl groups. GO has an approximate C/O/H atomic ratio of 2/1/0.8. Although GO can be readily dispersed in water and in organic solvents after chemical modification, graphene oxide is electrically insulating and thermally unstable. Therefore, at least partial reduction of graphene oxide is necessary to restore electrical conductivity. A number of different methods currently exist for the exfoliation and reduction of GO to produce chemically modified graphene. Stable colloids of graphene oxide can be obtained using solvents such as water, alcohol, and other protic solvents combined with either sonication or long stirring. Alternatively, GO can be exfoliated in polar aprotic solvents by reacting with organic compounds. Colloidal graphene oxide or the organically treated version can be chemically reduced producing chemically reduced graphene (CRG) using hydrazine. Potential application of graphene Single molecule gas detection, Graphene transistors, Integrated circuits Transparent conducting electrodes for the replacement of ITO, Ultracapacitors, Graphene biodevices -Reinforcement for polymer nanocomposites: Electrical, thermally conductive nanocomposites, antistatic coating, transparent conductive composites..ect WEEK 5D: (CARBON NANOTUBE) WAYS TO SYNTHESIS CNT: • Arc Discharge • Laser Ablation • Chemical Vapor Deposition (CVD) • Ball Milling ARC DISCHARGE: • A direct current creates a high temperature discharge between two electrodes • Atmosphere is composed of inert gas at a low pressure • Originally used to make C60 fullerenes • Cobalt is a popular catalyst • Typical yield is 30-90% Advantages Disadvantages • Simple procedure Requires further purification • High quality product Tubes tend to be short with random sizes • Inexpensive LASER ABLATION: Vaporizes graphite at 1200 ⁰C Helium or argon gas A hot vapor plume forms and expands and cools rapidly Carbon molecules condense to form large clusters Similar to arc discharge Yield of up to 70% Types of laser ablation: • Pulsed -Much higher light intensity (100 kW/cm2) • Continuous-Much lower light intensity (12 kW/cm2) Advantages Disadvantages • Good diameter control • Costly technique, because it requires • Few defects expensive lasers and high power • Pure product requirement CHEMICAL VAPOR SEPOSITION (CVD) • Carbon is in the gas phase • Energy source transfers energy to carbon molecule • Common Carbon Gases (Methane, Carbon monoxide, Acetylene) • After energy transfer, the carbon molecule binds to the substrate • Temperature between 650 – 900 ⁰C • Yield is usually about 30% • One of the most common methods of carbon nanotube synthesis Advantages Disadvantages • Easy to increase scale to industrial Defects are common production • Large length • Simple to perform • Pure product BALL MILLING • Powder graphite is placed in a stainless steel container • Argon gas is used • Process occurs at room temperature • Powder is then annealed Combining Ball Milling and Vapor Deposition • Arkema France developed the process • Process generates the highest carbon purity • Products have improved dispersion GROWTH MECHANISM • Electronic and Mechanical Properties are closely related to the atomic structure of the tube. • Essential to understand what controls the size, number of shells, helicity & structure during synthesis. • Mechanism should account for the experimental facts: metal catalyst necessary for SWNT growth, size dependent on the composition of catalyst, growth temperature etc. • MWNT Growth Mechanism: - Open or close ended? - Lip Lip Interaction Models SWNT Growth Mechanism • • • • • •

Is uncatalyzed growth possible? Simulations & Observations  No! Spontaneous closure at experimental temperatures of 2000K to 3000K. Closure reduces reactivity. Catalytic Growth Mechanism • Transition metal surface decorated fullerene nucleates SWNT growth around periphery. • Catalyst atom chemisorbed onto the open edge. Catalyst keeps the tube open by scooting around the open edge, ensuring and pentagons and heptagons do not form. APPLICATION 1. Electrical: Field Emission Display ( FED) Uses electron beam to produce color images (FED) Traditionally cathode ray tubes are used but recently more focus on using carbon nanotubes NASA is researching this technology to use in space exploration 2. Energy Storage: a) Lithium Battery - Nanotubes have the highest reversible capacity of any carbon material for use in Lithium ion batteries - Nanotubes have intrinsic characteristics desired in material used as electrodes in batteries and capacitors - Nanotubes are outstanding materials for super capacitor electrodes - They also have a number of properties including high surface area and thermal conductivity that make them useful as electrode catalyst supports in Polymer Electrolyte Membrane (PEM) fuel cells 2 b) Hydrogen Storage Single-walled carbon Nanotubes can store hydrogen Nano tube technology will meet the challenge of storing hydrogen and releasing them adequately in hydrogen fuel car in future Physisorption and chemisorption e mechanisms used for hydrogen storage in carbon nanotubes 3. Biological. a) Sensors Many spherical Nano-particles have been fabricated for biological applications. Nanotubes offer some advantages relative to Nano-particles by the following aspects: a) Larger inner volumes – can be filled with chemical or biological species. b) Open mouths of Nano tubes make the inner surface accessible. c) Distinct inner and outer surface can be modified separately. 3b) AFM tips Carbon nanotubes as AFM probe tips: Small diameter – maximum resolution 3c) DNA sequencing Nanotubes fit into the grove of the DNA strand Apply voltage across CNT, different DNA base-pairs give rise to different current signals With multiple CNT, it is possible to do parallel fast DNA sequencing 4. Paper Battery Could easily be mistaken for a sheet of black paper Functions as both a lithium-ion battery and a supercapacitor Lightweight, thin, flexible Can function at a wide range of temperatures 5. Nanotube speaker Thin carbon nanotube films can act as speakers New generation of cheap, flat speakers Transparent, flexible, stretchable, and magnet free 6. Artificial Muscles Aerogels made from carbon nanotubes (CNTs) can serve as electrically powered artificial muscles Sheet becomes 220% wider and thicker when voltage is applied Flexes about 3 orders of magnitude faster and generates more than 30 times the force than human muscles of the same size 7. Nanotube Thermocell uses multiwalled carbon nanotubes as electrodes 3 times efficient than conventional Converts waste heat from industrial plants, pipelines into electricity 8. Nanotube Catalyst Carbon nanotubes doped with Nitrogen Reduce oxygen more effectively than platinum catalysts Not susceptible to carbon monoxide poisoning, known to deactive platinum catalysts WEEK 6: CHARACTERIZATION AND DISADVANTAGES OF NANO MATERIALS WHAT IS CHARACTERIZATION? Characterization refers to study of materials features such as its composition, structure, and various properties like physical, electrical, magnetic, etc. WHY IS CHARACTERIZATION OF NANOPARTICLES IMPORTANT? - Nanoparticle properties vary significantly with size and shape - Accurate measurement of nanoparticles size and shape is, therefore, critical to its applications SCANNING PROBE MICROSCOPE  Atomic Force Microscope  Scanning Tunneling Microscope Atomic force microscope:  Operation: see figure  Modes of operation: i. Contact mode ii. Non-contact mode iii. Tipping mode

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Limitations Advantages Probe tip radius, high resolution microscope, capable of producing 3d images, image processing speed, pre-treatment of samples is not necessary, vacuum chamber not small image size required for some mode of operation Contact mode Used for scanning hard samples and resolution > 50 nanometres are required. The cantilever may be constructed from silicon or silicon nitride. Resonant frequencies of contact cantilevers around 50 KHz and the force constant are below 1N/m. Non-contact mode The cantilever is oscillated slightly above its resonant frequency; oscillation 103 metric tons annually in the next 4-7 years. Major use – electronics and composites.(Enhanced strength, stiffness and toughness without added weight, Improved durability, increased functionality and reduced flammability) Probes for microscopy and chemical ranging Coatings – Organic Projected to make up 73 % of nanocomposites market by 2010. Thin film, clear nanocomposites for improved scratch and mark properties. Antimicrobial, self-cleaning surfaces. Smart coatings: Sense pressure, impact, damage, chemicals, heat, light, etc. Coatings – Inorganic Self-cleaning glass Nano-TiO2 coated Photovoltaics Predominant photovoltaic material is silicon, but an emerging technology involves the use of dye-sensitized nano-TiO2. Large surface area of nano TiO2 greatly increases photovoltaic efficiency. Also has potential for lower material and processing costs relative to conventional solar cells. Nanoadditive Fire Retardants Use of nanoadditive fire retardants prompted by bans on halogenated flame retardants enacted in many states. Polymer nanocomposites filled with clay, CNTs, etc., possess improved flammability resistance while maintaining or improving mechanical properties. Reduces heat release rate during fire event by formation of surface char which insulates underlying material. Challenges Techniques for dispersing nanofillers AND measuring degree of dispersion. Measurement of adhesion and interfacial properties. Chemical and mechanical measurements at the nanoscale. Prediction of nanocomposite properties and service life over a wide range of length scales. Unknown health and environmental effects – virgin, released material. OTHER APPLICATIONS Liposome Liposomes are currently investigated for a variety of additional therapeutic agents; anticancer drugs such as paclitaxel, camptothecin, cisplatin; antibiotic such as amikacin, vancomysin, ciprofloxacin; biologics such as antisense oligonucleotides, DNA. Pharmacy on A Chip The drug released from the implanted microchip demonstrated similar measures of safety and therapeutic levels in blood to what is observed from standard, recommended multiple subcutaneous injections. Process of Drug Delivery The first drug delivery microchip. Microchip-based implant wirelessly programmed to release drugs inside the body. 1. Reservoirs are filled with drugs. - Prior to implanting. Drugs are stored in an array of sealed microreservoirs. 2. Device is implanted. - Device with microchip is implanted under skin. 3. Device is activated.- When electrical current is applied, the membrane sealing the microreservoir melts. 4. Drug is released.- Releasing drug from reservoir. 5. Ongoing drug administration.- When drug reservoir is empty, the next dose can be delivered from another reservoir. Ceramic in Bonds The European Commission reports that ceramic nanocomposites developed in BIOKER could solve the problem of fracture failures in artificial joint implants. This would extend patient mobility and eliminate the high cost of reparative surgery. Point of Care Testing (POCT) POCT can augment the capabilities of disaster medical assistance teams, and provide minimally-invasive monitoring in critical and emergency care environments. ENERGY Sun is natural energy. Energy Source Nanotechnologies provide essential improvement potentials for the development of both conventional energy sources (fossil and nuclear fuels) and renewable energy sources like geothermal energy, sun, wind, water, tides or biomass. Energy Distribution Researchers at Rice University are working to develop wires containing carbon nanotubes that would have significantly lower resistance than the wires currently used in the electric transmission grid. The so-called armchair quantum wire would be composed of carbon nanotubes woven into a cable. Energy Storage adding Li to H2 increase storage

• If we add small amounts of lithium to hydrogen and if we keep the pressure at about one-fourth of a pressure (on which hydrogen turns into a metal) hydrogen transforms into a metal with superconductivity properties. NANOBIOTECHNOLOGY • Genetic Engineering • Enzyme/Cell Engineering • Nanotechnology • Bioinformatics Nanobots Nanobots swims in blood it is provided with microcamera,capacitor,payload and swimming tail. It reaches the targeted area and finds the unwanted growth or any tumor cell and ruputes the particular diseased area.

Gene Therapy (Viral Vector) Viral vectors are a tool commonly used by molecular biologists to deliver genetic material into cells.

Genetherapy (By Non Viral Vector) Synthetic or non-viral gene delivery vectors typically consist of DNA (usually plasmid DNA produced in bacteria) or RNA which may be delivered to the target cell.

Gene Delivery (By Direct Injection) In the direct injection method a blood sample is taken from patient , cell isolation and expansion is done it is placed on matrix. As a result new tissue is created and it is implanted into the patients body.

ANTIMICROBIAL ACTIVITY Panel A 1. Concentrations of Ag+ ions built up by elution from the silver nanoparticle coating were high enough to kill bacteria. 2 and 3: Possible killing of bacteria by contact-dependent transfer of Ag+ ions following collision with the silver nanoparticle-containing surface.

Panel B 1. Ag+ ions from the silver nanoparticle coating did not result in Ag +concentrations high enough to activate blood platelets. 2 and 3. Activation of blood platelets by contact-dependent transfer of Ag+ ions following collision with the silver nanoparticle-containing surface

ENVIRONMENT Global Warming Polymers like thermosets, thermoplastics and elastomers reinforced with colloidal silica, nanoclay and nanotubes are promising candidate materials. Employing nano composites can lead to reduced energy consumption in cars, with the impact of their use being likely to be even more dramatic in the aerospace sector. Hence the global warming can be reduced. Percentage of Global Warming Caused by Various Sector

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Transporation (Diesel Truck, Jet Airplane, Petrol Car) 28% Industrial (Cement Plant, Chemical Factory) 20% Residential and Commercial 11% Electrio Power 34% Agriculture 7% Pollution (Water) Nanoparticles is used to clean industrial water pollutants in ground water through chemical reactions that render them harmless, at much lower cost than methods that require pumping the water out of the ground for treatment. Researchers have developed a nanofabric "paper towel," woven from tiny wires of potassium manganese oxide, that can absorb 20 times its weight in oil for cleanup applications. Cleaning Up Organic Polluting Ground Water Iron nanoparticles can be effective in cleaning up organic solvents that are polluting groundwater. The iron nanoparticles disperse throughout the body of water and decompose the organic solvent in place. This method can be more effective and cost significantly less than treatment methods that require the water to be pumped out of the ground. Food and Agriculture (Food Contaminant Detection) In 2008, thousands of people, especially children, got sick as a result of melamine contamination in dairy products from China. A quick and easy way to detect melamine in milk using gold nanoparticles. In the presence of melamine, the mixture changes from pink to blue. Agriculture Use of new biopesticides, sensor to monitor soil condition and agrichemical delivery the agriculture productivity can be increased.

INFORMATION AND COMMUNICATION Memory Storage Memory storage before the advent of nanotechnology relied on transistors, but now reconfigurable arrays are formed for storing large amount of data in small space. For example, we can expect to see the introduction of magnetic RAMs and resonant tunnel elements in logical circuits in the near future. Every single nanobit of a memory storage device is used for storing information. Molecular electronics based on carbon nanotubes or organic macromolecules will be used. Semiconductors Nano amplification and chip embedding is used for building semiconductor devices which can even maintain and neutralize the electric flow.

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