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Nanoscale Trends, Opportunities and Emerging Markets Christopher C. Ibeh Pittsburg State University (PSU), Pittsburg, KS 66762 Abstract Nanotechnology has attained the status of currency but is predominantly an emerging and trendy technology. This is desirable as it is poised for growth and sustainability. At the 2010 Nanotechnology Entrepreneurship Forum, there was a consensus among the guest speakers and panelists for the need to move beyond the “Forbes.Com” top ten nanotechnology products to achieving its true potential in the aerospace, naval and homeland security infrastructure development. In order to achieve this potential that is currently estimated at 20 Billion ($1,085 Billion in 2015) Dollars, the challenges posed by nanotechnology need to be addressed and leveraged. A concerted approach of research and education at Pittsburg State University is leveraging the opportunities at the nanoscale. Introduction Background There is a school of thought that contends that “nanotechnology” is not really new despite the 1991 invention of carbon nanoubes (CNTs) that is attributed to Iijima and NEC, Japan 1-2 . Recent molecular structure studies have found carbon nanotubes (CNTs) and carbon nanowires 3-8 in a sample of a 17th century sword made from “Damascus steel.” The Damascus steel were first made in the 8 th century and last manufactured in the 18 th century. Sabers and swords made from the Damascus steel had extraordinary strength, extremely sharp cutting edge and the characteristic wavy “damask” banding pattern. These characteristics of the Damascus steel sabers and swords posed challenges to the Crusaders of those times. The contention is that the sabres and swords [Figure 1] forged from Damascus steel may have Figure 1: The Sabres and Swords made from Damascus Steel (circa 1700s and prior) [Courtesy: Alexander Dietsch, NatureNews, November 15, 2006] gotten their strength from nanoscale structures in Wootz steel that contains iron ores from India and Sri Lanka 9-13 . The Indian iron ores contain transition metal impurities that could have facilitated and catalyzed the formation of the nanotubes (CNTs) from burning wood and
Transcript

Nanoscale Trends, Opportunities and Emerging Markets

Christopher C. Ibeh

Pittsburg State University (PSU), Pittsburg, KS 66762

Abstract

Nanotechnology has attained the status of currency but is predominantly an emerging and trendy technology. This is desirable as it is poised for growth and sustainability. At the 2010 Nanotechnology Entrepreneurship Forum, there was a consensus among the guest speakers and panelists for the need to move beyond the “Forbes.Com” top ten nanotechnology products to achieving its true potential in the aerospace, naval and homeland security infrastructure development. In order to achieve this potential that is currently estimated at 20 Billion ($1,085 Billion in 2015) Dollars, the challenges posed by nanotechnology need to be addressed and leveraged. A concerted approach of research and education at Pittsburg State University is leveraging the opportunities at the nanoscale. Introduction

Background There is a school of thought that contends that “nanotechnology” is not really new despite the 1991 invention of carbon nanoubes (CNTs) that is attributed to Iijima and NEC, Japan1-2. Recent molecular structure studies have found carbon nanotubes (CNTs) and carbon nanowires3-8 in a sample of a 17th century sword made from “Damascus steel.” The Damascus steel were first made in the 8th century and last manufactured in the 18th century. Sabers and swords made from the Damascus steel had extraordinary strength, extremely sharp cutting edge and the characteristic wavy “damask” banding pattern. These characteristics of the Damascus steel sabers and swords posed challenges to the Crusaders of those times. The contention is that the sabres and swords [Figure 1] forged from Damascus steel may have

Figure 1: The Sabres and Swords made from Damascus Steel (circa 1700s and prior) [Courtesy: Alexander Dietsch, NatureNews, November 15, 2006] gotten their strength from nanoscale structures in Wootz steel that contains iron ores from India and Sri Lanka9-13. The Indian iron ores contain transition metal impurities that could have facilitated and catalyzed the formation of the nanotubes (CNTs) from burning wood and

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leaves during the high temperature, annealing and forging manufacturing process of the Damascus steel. Asbestos is another case in point in the nanotechnology timeline. It is a known carcinogen and a discontinued material in most industries14-16. Asbestos is a naturally occurring silicate mineral with long, thin fibrous crystals; the rupture or damaging of asbestos releases fibrous asbestos particles into the air. Susceptibility to asbestos and the development of cancerous conditions such as mesothelioma (malignant lung cancer), asbestosis (non-cancerous, pneumoconiosis), etc arise from exposure to airborne fibrous asbestos particles. Figure 2 shows two of the many types of asbestos. The typical dimensions of asbestos are 3.0 - 20.0 µm length and 0.01µm thickness (10*10-9 m). In 1989 US Environmental Protection Agency (EPA), banned the commercial manufacture, importation, processing and distribution of most asbestos-containing products. The original 1989 EPA ban was vacated and remanded by the 1991 U.S. Fifth Circuit Court of Appeals but the upgraded EPA ban remains in effect under

A B C Figure 2: Some of the Many Different Forms of Asbestos [Courtesy: US Geological Survey] A = Serpentine Asbestos [(Mg,Fe)3Si2O5(OH)4, Magnesium/Iron Silicate Hydroxide)] B = Tremolite Asbestos; C = Presence of Asbestos in the Lung. the 1999 Clean Air Act and the Toxic Substances Control Act (TSCA). Asbestos manufacturing has been discontinued in the US since 2002, and importation has decreased from 2530 tons in 2005 to 715 tons in 2009. The nano-size dimension of asbestos implies that it is a nanomaterial; this highlights the need for safety that is of paramount importance in nanotechnology. In addition, the diminished but continued usage of asbestos in the US despite the EPA rule on it suggests a realization of its efficacy and indispensability in certain formulations and applications. Nanotechnology is generically defined as the creation, processing, characterization, and utilization of materials, devices, and systems with dimensions less than 100 nanometers. A nanometer is one billionth of a meter or 10-9 m. Nanoscale-sized systems exhibit novel and enhanced physical, mechanical, chemical and biological properties/functions. Figure 3 is an FE-SEM micrograph of a sparse network of isolated individual Single Wall Carbon Nanotubes (SWCNT), prepared by CVD with cobalt nanoparticles as catalyst and alcohol as the carbon source and grown on silicon/silica chips 17-19. Figure 3A shows the nanoscale size of CNTs; CNTs are 50,000 to 70,000 times smaller than a typical hair strand.

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The US National Nanotechnology Initiative has identified four major generations of nanotechnology development: passive nanostructures, active nanostructures, nanosystems and molecular nanosystems. Passive nanostructures, circa 2000, include dispersed and contact

A B

Figure 3: A. Carbon Nanotube Network Compared to a Hair Strand (Dark Gray) [Courtesy: Jirka Cech, http://www.jirkacech.com/blog/]; B. Atomic Force Microscope Image of ECSA Nanosensor [Courtesy: CNCMM-PSU].

nanostructures such as aerosols and colloids, and nanostructures-based products such as nanoparticles reinforced composites, etc. Active nanostructures, circa 2005, include bioactive, targeted drugs and biodevices, and physico-chemically active nanostructures such as actuators, amplifiers, 3D transistors and adaptive structures. Nanosystems, circa 2010, include hierarchical/hybrid architectures, controlled assembling, 3D networking, robotics, etc. The fourth generation, molecular nanosystems, circa 2015 – 2020, includes molecular and sub-atomic designed devices20-22, etc.

The objectives of this paper are to discuss: the current trends, challenges, opportunities and emerging markets of nanotechnology. The current trends in nanotechnology are highlighted via the relevant literature approach. The different types of nanomaterials are explored, and their associated challenges including safety are specified; the mechanisms for overcoming these challenges are proposed. The nanotechnology research and education at Pittsburg State University and partner institutions are utilized to illustrate some of the emerging opportunities and markets at the nanoscale.

Relevant Literature: Current State of the Nanotechnology Industry

In 2007, there were more than 370 nanotechnology companies23. Of these, 78 were nanoparticles’ companies; the complete demographics include: fabrication equipment (50), inspection/analysis (49), carbon nanotubes (46), semiconductors (21), sensors (21), coatings (17), batteries (12), solar cells (12), displays (12), and others (85). Figure 4 shows the market share of the projected $1085 Billion nanotechnology industry by segments; materials, electronics and pharmaceuticals are ranked numbers 1, 2 and 3 at 31%, 28% and 17% respectively. It is important to note that nanotechnology is also slated to play a role in sustainability. Figure 5 indicates that the projected growth of nanotechnology depicted by Figure 4 is in line with the nanotechnology hype index, and impacts every segment of society.

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Figure 4: 2005 – 2015 Market Share of the Nanotechnology Industry [Courtesy: NSF]

The Nanotechnology Hype Index [Data: Lux Corp.]

0

0.5

1

1.5

2

2.5

3

1 2 3 4 5 6 7

Years: 1=1995; 4=1998; 7=2001

Num

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of A

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itin

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Years: 1=1995 & 7 =

2001

Figure 5: The Nanotechnology Hype Index [Courtesy: Lux Corporation ] Josh Wolfe, Forbes/Wolfe Nanotech Report, January 12, 2005, “Forbes.Com Top Ten

Nanoproducts”

Forbes.com “Top Ten Nanotech Products” include24 a fullerene-based golf driver by Tokyo-based Maruman & Co that out-classes the conventional titanium-based 366c golf driver in bending stiffness, hardness, resilience and flight distance (15 extra yards); a nano-based golf ball by Buffalo, NY-based NanoDynamics Inc. that has the capability for flight path correction as it is able to absorb and channel the energy from the driver head; washable

Potential Impact of Nanotechnology - Market Share

Materials

31%

Electronics

28%

Pharmaceuticals

17%

Chemical

Manufacture

9%

Aerospace

6%

Sustainability

4%

Enhanced

HealthCare

3%

Tools

2%

Materials

Electronics

Pharmaceuticals

Chemical Manufacture

Aerospace

Sustainability

Enhanced HealthCare

Tools

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mattress; nanosilver dressing for burn wounds that cleans and disinfects in one step; aerogel footwarmer; 3M dental adhesive, etc.

Figure 6: NanoDynamics Nano-based Golf Ball that has flight path correction. Subhasish Mitra, Philip H. S. Wong, “Nanotechnology-Carbon Nanotube (CNT)

Electronics,” Stanford Nanofabrication Lab25-26

This research effort epitomizes some of the best practices in nanoelectronics as it leverages fundamental research in CNT science into useful nano-chip technology for high speed computing based on quarter-size CNT chips. CNTs are highly electrically conductive, and their small, nanometer size allows for wafer scale, smaller circuits than the conventional silicon circuits. In this, CNT instead of silicon is grown on quartz wafer facilitated by catalyst nanoparticles at 900 oC for 17 hours. This growth process is carried out at optimal conditions of density, length and uniformity to marginalize the problem of misalignment that plagues nanoelectronic manufacturing and logic gate design. 100-nm gold is evaporated on the grown CNT to embed the CNT in gold. A special tape that looses its adhesiveness at 120 oC is applied over the gold-CNT wafer. The tape is removed to lift the gold and CNT; the tape with gold and CNT is applied to a new substrate. The gold is chemically dissolved away. Standard lithography and photoresist techniques are applied to the system for pattern printing. CNT logic gates design is a challenge due to CNT misalignment. Logic gates are used to produce circuits and circuits give systems. Eric K. Drexler, Nanorex Inc., “Molecular Machinery Gallery,”27-28

A B C

Figure 7: K. Eric Drexler’s 4th Generation Molecular Designs of Gear s and Bearing . A. The MarkIII(k), a nanoscale planetary gear; B. The SRG-III Gear - the third parallel-shaft speed reducer gear; C. Small Bearing. Animated videos of fourth generation molecular designs of gears and bearings by Eric Drexler are available on the websites of References 27 – 28. The MarkIII(k) is a nanoscale planetary

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gear design; it couples an input shaft via a sun gear to an output shaft through a set of planet gears. The planet gears roll between the sun gear and a ring gear on the inner surface of a casing. This animation was implemented with QuteMol29 by reading PDB files from a NanoEngineer-1 molecular dynamics simulation. A section of the casing atoms is hidden to expose the internal gearing assembly. QuteMol is an open source (GPL), interactive, high

quality molecular visualization system. QuteMol exploits the current OpenGL shaders’ GPU capabilities to provide innovative visual effects. QuteMol visualization techniques enhance clarity and understanding of the 3D shape and structure of large molecules especially complex proteins. The SRG-III is the third parallel-shaft speed reducer gear; it is the first molecular gear train ever designed. The SRG-III has 15,342 atoms, and is the second largest nanomechanical device modeled in atomic detail. The Small Bearing was also modeled and simulated via the NanoEngineer-1 software. Peter Lillehei, "Quantifiable Assessment of SWNT Dispersion in Polymer Composites,"

Nanotechnology Entrepreneurship Forum, April 23, 2010.30-32

Figure 8: A. NASA Subsonic Fixed Wing Program; (B). NASA Sample #1; (C). NASA Sample #5 A NASA nanoscale initiative sponsored by the Subsonic Fixed Wing program focuses on the development and characterization of lightweight and multifunctional nanomaterials that will enable cost-effective, aerospace cargo transportation [Figure 8a]. In addition to lightweight, other desirable attributes in this application include radiation protection, electrical conductivity for lightening strike protection, actuation, thermal conductivity, sensing, health monitoring, self healing, energy generation, energy storage, etc. This effort emphasizes the fundamental understanding of the underlying science33-34 of how the bulk properties are influenced by such nano-attributes as dispersion, aspect ratio, interfacial phenomena, structure (primary, secondary and tertiary), purity, defects, etc. Transition of nanotechnology to aerospace and aircraft applications will be facilitated via such factors as technology readiness, verifiable distribution and orientation of nanoparticles, quality assurance and quality control tools and methodologies, certification plan, and the need for industry-academia-government collaboration. This NASA effort has resulted in the development of new tools that enable the generation and collection of relevant and useful data. The “Poly-transparent” imaging, one of the newly developed analysis tools, enables “one to see through the polymer as if it” is clear and transparent, and to truly observe the nanotube network deep within the sample. The contrast mechanism is currently not well understood but it allows the quantitative

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representation of nanomaterials dispersion. Figure 8 depicts the quantitative distinction between the ordinarily mixed sample of 8B and the in-situ polymerized and sonicated sample of 8C. The study employs the use of Minkowski functionals, volume (ν), surface (s) and connectivity (χ) to validate experimental data. The dispersion of nanoparticles is one of the challenges of nanotechnology, and a key element in achieving the potential of nanotechnology. Fujitso Corp., SemiConducting Leading Edge Technologies, “Novel Carbon Nanotube-

Graphene 3D Composites,” Nanotech 2009

This joint project between Fujitso Corporation and SemiConducting Leading Edge Technologies35 leverages the 2D graphene planar structure and the 1-D CNT cylindrical structure to produce a 3D Composite that conducts electricity in all directions.. The 2-D graphene conducts electricity in the horizontal direction whereas the 1-D CNT conducts electricity in the vertical direction. The produced 3D composite also conducts heat. It also has free control of structure, and extremely flat surface that makes it amenable to joining with other materials unlike CNT by itself. This new material makes it possible to enhance wafer technology with variety of carbon nanomaterials. Christopher C. Ibeh, Nanjia Zhou, Andrey Beyle, “Lightweight nanocomposite

hierarchical structures for blast mitigation,” Plastics Research Online, June 2009, The

SPE36-38

A B C Figure 9: (A)&(B). Nanoparticles (silicon carbide, nanoclay, carbon nanofiber, and nanographene) used in CNCMM's development of nanocomposite hierarchical structures. (B). A VibraCell Sonicator for nanoparticle infusion and dispersion of nanocomposite matrices. The Center for Nanocomposites and Multifunctional Materials (CNCMM), Pittsburg State University (PSU) uses an energy-absorption approach for the development and characterization of polymeric nanocomposites-based protective panels that can withstand high dynamic loads, fire, smoke, and toxicity. CNCMM’s nanocomposite hierarchical materials have properties and characteristics—particularly with respect to energy absorption and dissipation—that make them suitable for mitigation of high dynamic loads. Infusion of nanoparticles in polymeric matrices confers enhanced stiffness and the ability to absorb energy. Current efforts focus on real-time, blast- and ballistic-impact testing of fabricated panels. Additional and potential applications of CNCMM's nanocomposite hierarchical structures include39-40 cryogenic storage tanks (e.g., helium, hydrogen), storm-proof structures and sympathetic detonation mitigation (insensitive munitions).

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Nanotechnology: Major Types of Nanoparticles

Data of Figure 4 indicate that nanoparticles represent a major segment of nanotechnology market. Three major types of nanoparticles41 are distinguishable based on the number of dimensions that are in the nanometer range, and these are:

i. Iso-dimensional nanoparticles, ii. Nanotubes, and iii. Nanoplatelets.

Iso-dimensional nanoparticles such as carbon black, silica, aluminum oxide, titanium dioxide, zinc oxide, silicon carbide, polyhedral oligomeric sislesquioxanes (POSS), etc have three dimensions (X, Y and Z) in the nanometer scale. Iso-dimensional nanoparticles tend to have spherical and quasi-spherical shapes. Figure 9A depicts the in-lab, aerogel process (AP) synthesized strontium-titanium dioxide by Professor Dilip Paul’s research group at PSU. Viscoelasticity studies suggest that the spherical configuration of iso-dimensional nanoparticles make them more amenable to infusion in 3D glass fabrics employed as reinforcements in the design of CNCMM’s nanocomposite hierarchical structures38. Nanotubes42-48 such as carbon nanotubes (CNTs), carbon nanofibers, cellulose whiskers, boron nitride nanotubes, boron carbon nitride tubes, gold nanotubes, silver nanotubes, etc have two dimensions are in the nanometer range, and the third dimension is more than nanoscale. Nanotubes form elongated structures; Figure 10 shows some of the different types of nanotubes. Nanotubes, like other nanoparticles, exhibit multifunctional characteristics. CNTs are currently the most studied nanomaterials primarily due to their exceptional mechanical and electrical properties. CNTs exhibit mechanical properties about 100 times higher than those of steel, and electrical conductivity properties 1000 times higher than that of copper. CNTs are graphene sheets formed in tube shape. The MWCNTs are concentric SWCNTs linked together by secondary van der Waal bonds. Interests in the other nanotubes

A B C D Figure 10: Different Types of Nanotubes. (A). Single Wall Carbon Nanotube (SWCNT) [Courtesy: Dakota Systems];.B. Multiwall Carbon Nanotube (MWCNT); (C). Scanning Electron Microscope of Silver Nanotube [Courtesy: Advanced Materials]41 (D). Schematic of a Theoretical Hollow Gold Nanotube Consisting of 42 Gold Atoms [Courtesy: Liu et al, J. Chem. Phys]42

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are growing due to their enhanced biocompatibility, optical characteristics, etc. Boron nitride nanotubes have better oxidation resistance properties than CNTs, and are currently being considered as competition for CNTs in aerospace and space applications. Nanoplatelets38,49-51 such as layered silicates, layered graphite flakes and layered double hydroxides are the third major type of nanoparticles. They have only one dimension in the nanometer range, and are characterized by their occurrence in sheets of one to a few nanometers thickness and hundreds to thousands nanometers length. Figure 11 depicts some of the different forms of nanoplatelets.

A B C D

Figure 11: Different Types of Nanoplatelets; (A) & (B). Graphite Flakes; (C). Nanographene Sheet (carbon atoms shown in black, hydrogen atoms shown in light gray); (D). Layered Silicate Montmorillonite (MMT) Clay [stacks of plate-like structures, or platelets]. Nanographene, a polycyclic aromatic hydrocarbon, was first described in 2004 by two groups of investigators from the University of Manchester (UK) and the Institute for Microelectronics Technology, Chernogolovka (Russia). They produced 2D graphene sheets of carbon that are one atom thick from graphite, the form of carbon that is commonly used in pencil. Chemically pure graphene structure contains 60, 78, 120, or 222 carbon atoms in plane hexagonal lattice sheet with hydrogen atoms on the peripheral edges (Figure 11B). Nanographene has enhanced mechanical, electrical and thermal properties. It is currently manufactured by Angstron Materials, LLC, and is touted as a cost-effective alternative to

A B

Figure 12: (A) Atomic Force Microscope (AFM) and (B)Transmission Electron Micrsocope (TEM) Images of Nanographenes (NGPs)[Courtesy: Angstron Materials].

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CNTs and carbon nanofibers (CNFs); NGPs have exceptional51-52 thermal conductivity, in-plane electrical conductivity, stiffness (Young’s Modulus), specific surface area, and low density values of 5,300 W/(mK), 20,000 S/cm, 1,000 GPa, 2,675 m2/g and 2.25 g/cc respectively. NGP’s specific thermal conductivity is twenty times higher than that of copper. NGP’s specific surface area is twice that of CNTs, and implies higher reactivity than CNTs. Figure 12 shows the AFM and TEM images of nanographenes; AFM and TEM are two of the few microscopy technologies that can be utilized for characterizing nanosystems. Of all the nanoparticles, the nanoclays are the most commonly used because of their cost-effectiveness and flammability resistance characteristics. Figure 11C is a depiction of the plate-like (platelet) structure of Montmorillonite (MMT) clay with stacking of layers. Stacking of layers results in the occurrence of regular van der Waals spaces between the layers referred to as gallery. Efficacy of Nanoparticles Nanoscale materials or nanoparticles intrinsically have new properties and characteristics that are not typically present in conventional, micro and macro-materials. In most cases, nanoparticles exhibit more than one of these new properties, and are referred to as being multifunctional. These properties are mostly attributable to the nanoparticles’ high surface area-volume ratio. The changes in particle diameter, layer thickness and diameter from micrometer to the nanometer range, changes the surface area-volume ratio by about three orders in magnitude. At the nanoscale, there is distinct size dependence of the material properties as there is increase in interfacial area, and consequent high reactivity and interactivity. Data of Table 1 shows the effect of process-type and size on surface area and interactivity of nanoparticles. Nano-sized , commercial strontium-titanium dioxide materials have higher surface area-volume ratio (m2/g) than commercial, non-nanosized strontium-titanium dioxide materials. In addition, in-lab, aerogel process (AP)-synthesized versions of the nanomaterial have higher surface area-volume ratio (m2/g) than the commercially available versions.

Table 1: Textural Properties of In-Lab Synthesized, Mixed Metal Oxide Nanoparticles [Courtesy: Prof. Paul’s Research Group, PSU]

SrTiO3 Sample Crystallite Size

(nm) Surface Area (m2/g)

Total Pore Volume (cc/g)

Avg Pore Size (d), Å

CM-SrTiO3 145 1.0 0.003 93 NCM-SrTiO3 25 17 0.12 290 SrTiO3 (methanol)

25 82 0.58 280

SrTiO3 (ethanol)

8 159 0.62 150

AP-SrTiO3 (isopropanol)

20 121 0.59 190

* CM – commercial; NCM – commercial nanosized, AP – aerogel process samples

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Nanotechnology: Processing Challenges

Nanotechnology is a trendy technology with currency; this status is accompanied by the understanding and consensus of the challenges encountered with nanoscale activities. These challenges include: alignment, dispersion, interfacial bonding, purity or absence of defects and contaminants, processing technology, safety, etc. of the nanoparticles in applications. Regardless of the challenges, what is needed are the appropriate processing and safety technologies from synthesis, to characterization/validation and to fabrication. Nanoparticles are typically produced via chemical vapor deposition (CVD), laser ablation, aerogel and other techniques. Characterization and validation techniques are currently limited to atomic force microscopy, x-ray diffraction and transmission electron microscopy techniques. New validation techniques including the NASA “Poly-transparent” imaging technique30-32 are finding their place in the industry. Variety of fabrication techniques are available including, vacuum infusion, compression molding, casting, and many in-house developed processes. The alignment problem experienced with carbon nanotubes (CNTs) arises because CNTs occur as ropes or bundles due to their inherent van der Waals interactions. Alignment and purity problems are addressed via a couple of functionalization techniques including:

i. oxidation by acid treatment, ii. functionalization via fluorination and pyrolysis, iii. plasma functionalization and coating, etc.

Disentanglement and purification of nanotubes53 are generally carried out via acid treatment during which low reactivity nanotubes are made more reactive by oxidation. Oxidation involves treatment of nanotubes with proper ratio of nitric and sulfuric acids to open up their end caps and introduce carbonyl, carboxyl and hydroxyl groups. These introduced end groups enhance CNTs reactivity with other functional groups and miscibility with polymeric matrices. Figure 13 shows some of the end groups that can be introduced into CNTs’ end caps via oxidation. Figure 14 is a

CHR

O

Aldehyde

CR'R

O

Ketone

COR'R

O

Ester

C

O

OHR

Carboxylic Acid

C

O

R NR" C

R'

O

ORC

O

R'

Carboxylic Acid Acid Anhydride

Figure 13: Carbonyl-Type Compounds

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schematic representation of the case of the reaction between the acid anhydride end group and expoxy matrix. Opening of the anhydride ring is facilitated by the presence of hydroxyl (OH-) and other active hydrogen groups in the reaction system. These also facilitate opening of the epoxy oxirane ring, and the ultimate high level reactivity of all these functional groups to form a crosslinked network structure that is characteristic of thermoset polymeric matrices. Surface area-volume ratio (m2/g) data of Table 1 suggest an ultra-high level reactivity of the functionalized, nano-sized particles as represented by Figure 14.

C

C

O

O

O

HOH

C

C

OH

OH

O

O

ROHC

C

O

OH

O

OR

+

O

CC C

O

O C C

OH

Epoxy Oxirane Ring Epoxy Crosslink

NetworkAcid Anhydride

Figure 14: Reactivity of CNT's End Groups; Case of Acid Anhydride The fluorination and pyrolysis process for the functionalization of CNTs involves the treatment of CNTs with fluorine; the partially fluorinated CNTs are pyrolyzed to remove the fluorine. The deflourinated CNT is disentangled and chemically active on its covalent side walls. Plasma functionalization of nanotubes involves the coating of their surface with a monomeric material such as styrene; this results in enhanced dispersion and mechanical properties. Functionalization modification is also applicable to the other nanoparticle-types. Iso-dimensional nanoparticles have metal-OH (silanol)groups on their surface41, 51, 54. The bifunctional nature of silane coupling agents lend them to use for the surface treatment of these nanoparticles. The bifunctional nature of coupling agents make them capable of reacting with the silanol groups on nanoparticle surface and the functional groups of the polymeric matrix. Coupling agents and compatibilizers are considered similar but are distinguished by their medium of action. Compatibilizers facilitate adhesion between two immiscible polymers by reducing their interfacial tension whereas coupling agents accomplish this between a polymer and filler. Regular clay platelets are much larger than one nanometer in all dimensions, and are naturally hydrophillic. This makes them unsuitable for creating polymeric composites as they would form agglomerates that inhibit dispersion. Treatment of clay with surfactants gives it

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hydrophobic-organophobic characteristics and larger interlayer spacing that makes for intercalation and exfoliation or favorable dispersion. In general, functionalization via acid treatment, fluorination, plasma coating, treatment with coupling agents, surfactants and others facilitate dispersion and interfacial bonding of nanomaterials. Dispersion and interfacial bonding are critical for the efficacy and cost-effectiveness of nanoparticles. Figures 8B and 8C show the difference in dispersion of two NASA LaRC CNT samples. The sonication mixed sample 8C has smaller CNT bundle sizes, straighter tubes and theabsence of agglomerates that plague the ordinarily mixed sample 8B. A graduate thesis study of the effect of sonication on the dispersion of nanoparticles in polymeric matrices, performed under the auspices of the Center for Nanocomposites and Mutifunctional Materials (CNCMM) used a 2-level, 3-factorial DOE (Table 2) to verify the parameters that are important in the use of sonication (Figure 9C) for the dispersion of nanoparticles and the creation of polymeric nanocomposites. This study was conducted using

Table 2: Two-Level Three-Factor Factorial Design of Experiment (DOE)

Study of Sonication Infusion of Polymeric Matrices

Time: 10min; 40min Temperature: 45oC, 85 oC

Concentration: 1%, 6%

Young’s Modulus

Yield Strength

Ultimate Strain

Main value a00 0.362 0.483 2.073

Sonication Time x1 1.628 1.696 -1.509

Sonication Temperature x2 -0.229 -0.418 -1.011

Concentration of Nanoclay x3

-0.291 -0.183 -0.307

Combination of Time and Temperature x1x2

-1.145 -0.745 1.065

Combination of Time and Concentration x1x3

-0.057 -0.762 0.249

Combination of Temperature and Concentration x2x3

1.54 1.384 0.05

vinyl ester and nanoclay, and found that nanoparticle concentration has the major influence on nanocomposites creation via sonication. In addition, the duration of sonication or higher sonication time yields higher stiffness and higher strength properties. The combination of time and temperature parameter facilitates attainment of enhanced strain properties that are desirable in the energy absorption characteristics that are of interest in this study. Similar studies show that peak structural integrity properties are achieved at the 4% - 5% nanoparticle level36,38,41. For some systems, this peak can occur at the 2 – 3% level. Figure 15 shows the use of X-Ray Diffraction to validate the dispersion of nanoparticles; dispersion is good at the 2% and 4% levels whereas the 6% nanoclay level is showing agglomeration in the epoxy

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matrix of this study. For ideally or completely well dispersed nanoparticles, there is no peak at 3 degrees. With aggregation or agglomeration, the peak appears; the peak corresponds to the Figure 15: X-Ray Diffraction Patterns of Epoxy-Clay Nanocomposites [Courtesy: CNCMM] small distance between two parallel platelets of nanoclay in the aggregate that can be detected at 3 degrees. Intensity of the peak of the aggregate is proportional to the number of aggregates. At low nanoclay concentration, the probability of creation of aggregates is also low but at high nanoclay concentration, this probability increases. Data of Figure 15 indicates that the 2% and 4% concentration levels have low peak levels. The 6% concentration level however exhibits a significant increase in peak level indicating that the 6% concentration is higher than the optimal nanoparticle concentration. Data for the pure nanoclay sample provides the reference point for this analysis, and exhibits a very sharp at the 3 degrees. Experimental data for mechanical properties tests also show that samples with 6% of nanoparticles have lower properties than the samples with 2% and 4% of nanoparticles (Figure 16).

Figure 16: Flexural Property Data for a Epoxy-Carbon Nanofiber (CNF) Nanocomposite [Courtesy: CNCMM].

0%1%

2%

3%

0

500

1000

1500

2000

2500

3000

3500

4000

Tangent M

odulu

s o

f E

lasticity in B

end

ing

,

EB

(M

Pa)

(Error for 95% confidence)

No break for CNF-epoxy nanocomposites

Epoxy-CNF Nanocomposites

0%

1%

2%

3%

0

20

40

60

80

100

120

140

160

Fle

xu

ral str

en

gth

(M

Pa)

(Error for 95% confidence)

No break for CNF-epoxy nanocomposites

Epoxy-CNF

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Modeling

Figure 17. CNCMM’s Conceptual Design of the Energy Absorbing, NanoSyntactic foam-Impregnated Honeycomb Hierarchical-Hybrid Structure. The 3D Fabric Facesheet is also Nanocomposite Impregnated. Some of our graduate students’ thesis efforts involve the use of the Elastic Support Model, Three Phase Model and others to study the synergism of impregnation of honeycomb cores with nanocomposites and nanocomposite-syntactic foams. From the 3-phase model55-58, the effective density

Fρ of syntactic foam is related to the total volume concentration of solid

phase ( mc ) in the syntactic foam as per equation 1.

F Scmρ ρ= ……………………………..………………… Eq. 1.0

The density of the solid phase (S

ρ ) is usually known; for example, the density of S2 glass

(3M Corp.) is 2,460 kg/m3. The presence of voids V

c significantly affects properties of

syntactic foam and voids concentration (V

c ) must be taken into account. Void concentration

(V

c ) is determined from the difference between real density of the syntactic foam and density calculated from the mixture rule as per equation 2.

1 M B

V F

M B

cµ µ

ρρ ρ

= − +

…………………………………. Eq. 2.0

Where (

Mµ ) and (

Bµ ) are the mass concentrations of polymer matrix and microspheres

respectively, and are typically known from the syntactic foams manufacturing process, and (

Mρ ) is the density of polymer matrix (≈ 1,300 kg/m3). Correct determination of the density

of the pure polymer matrix requires that the polymer matrix be degassed and compressed during sample preparation to minimize the effect of voids. Correct determination of all the above-mentioned parameters is important for the comparison of analytical and experimental data. The 3-phase model (Figure 18) is used to study and analyze the epoxy and vinyl ester-based nano-syntactic foams. Syntactic foams typically have higher strength on compression than on tension. Consequently, the flexural strength is determined by tensile failure on the stretched side of the sample, and it is lower than the compression strength. Similar results are

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obtained for the vinyl ester foams of this study but not for the epoxy-based foams. This can be attributed to the very high adhesive properties of epoxy resins with respect to the glass microspheres. Epoxy resins typically have high adhesiveness due to the polar nature of the oxirane ring when opened (Figure 14). This results in high tensile and flexural strength values of the syntactic foam. The flexural Young’s Modulus was found higher than that of the

Figure 18. Three-phase model used for calculations of the effective properties of syntactic foams; the case of unidirectional tension is shown. compressive version, and is consistent with the expected higher tensile Young’s Modulus of the syntactic foams. Efforts to maximize the effects of the microspheres are not encouraging as higher volume fractions of the microspheres yield higher porosities of approximately 30% porosity for 60% volume fractions as opposed to about 15% porosity for the 50% volume fractions. Experimental data actually suggest that the 30% microsphere level maybe optimal. [Figures 19; Table 3].

A B Figure 19. A. Influence of the porosity

Vc in matrix (in volume fractions from the whole

syntactic foam volume) on the decrease of the Effective Bulk Modulus K in comparison

with ideal syntactic foam having zero porosity and Effective Bulk Modulus i

K .

B. Influence of the porosity Vc in matrix (in volume fractions from the whole syntactic foam

volume) on the decrease of the effective Young’s Modulus E in comparison with ideal

syntactic foam having zero porosity and effective Young’s Modulus iE .

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Figure 20: Relative Bulk Modulus of Syntactic Foam [S2-Glass/Vinyl Ester] Vs. Volume Concontration of Microsphere (C) for Varying Wall Thickness (m = Volume of Solid Phase of Microsphere) Table 3 has some of the benchmark study data of the mechanical properties of vinyl ester and epoxy-based syntactic foams, and shows that vinyl ester resin can be formulated as a cost-effective alternative to epoxy resins with regards to structural attributes. Nanotechnology Safety and Ethics59-61

The emergence and the trendy high growth rate (Figures 4 and 5) of the nanotechnology industry have resulted in interest and concerns about the health, safety and ethical ramifications of nanotechnology-related endeavors. Efforts are being made to understand these ramifications but in the interim, the experiences with asbestos-type materials and the realization of the high reactivity associated with the high surface areas of nanomaterials imply that the safety concerns be handled with utmost urgency by the nanotechnology industry. Surprisingly, nanomaterials do not only occur from engineered endeavors; they can occur naturally and anthropogenically. Volcanoes, fires and ocean spray activities are some natural sources of nano-sized particles. Combustion processes, industrial coal burning, power plants, transportation systems such as trains, etc are sources of anthropogenically generated nanomaterials. Nanoparticles have high diffusivity62-65 due to their very small size, and tend to stay airborne for longer periods of time; this increases their potential for exposure in the workplace and other source areas. Table 4 has data on the different uptake routes of nanoparticles that

Table 3: Benchmark Study of Mechanical Properties of Epoxy and Vinyl Ester Nanosyntactic Foams With Different

Microspheres

Property S-32, 60% Epoxy

S-60, 61% Epoxy

QC-300, 50% ;VE

QC-6028, 50%; VE

QC-6028, 30%; VE

FlexEnergy Absorbed (KJ/m3)

20.7 10.2 31.7 29.7 71.6

Frac Tough (Mpa.m1/2)

0.934 0.910 1.39 1.01 1.83

Comp Str (Mpa)

42.2 43.8 41.5 29.0 56.7

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Table 4: Uptake Routes For Nanoparticles

Exposure Medium

Uptake Pathway Translocation and Distribution

Excretory Pathways

Air, water, clothes

Skin Lymph to blood; Blood to bone marrow, Nervous system*

Sweat*

Drug delivery Blood Kidney, Bone marrow, other sites

Urine*

Air Respiratory Tract – nasal, tracheobronchial, alveoli, blood, lymph

Kidney, Spleen, Heart, Bone marrow, other sites

Urine, Breast milk*

Food, Water GI Tract, lymph*, liver*, blood*

Spleen, Heart Urine, Breast milk*

*Potential, unconfirmed route include but not limited to: inhalation by the respiratory system, ingestion of contaminated food and groundwater, and the skin via laboratory activities and consumer products such as cosmetics, toothpaste, etc. Figure 21 is a schematic of the respiratory pathway. Atmospheric air passes through the nasal pathway to the alveoli where the respiratory gas exchange takes place via diffusion through its semi-permeable membrane. The alveoli respiratory walls are only one cell thick and its respiratory surface is about 70 m2. The pulmonary artery of the

Figure 21: The Respiratory Pathway consisting of the mouth, nose, larynx, trachea, bronchi, bronchial tubes, alveoli (tiny sacs), lungs , diaphragm and intercostal muscles [Courtesy: S. West, http://www.ambulancetechnicianstudy.co.uk/respsystem.html]

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the alveoli’ microscopic capillaries bring carbon dioxide (CO2) from the heart and delivers oxygen (O2) back to the heart via the pulmonary vein. The inspired air consists of 79% N2, 20% O2, 0.04% CO2 and trace water vapor and other gases whereas the expired air consists of 79% N2, 16% O2, 4% CO2 and trace water vapor and other gases.

The presence of nanoparticles in the body, and their ability to penetrate key body tissues and organs have been studied and confirmed by several studies. In one such study carried out by researchers from Empa and the University Hospital in Zurich, the scientists determined that nano-sized polystyrene can penetrate the placenta from the mother to the child. One of the functions of the placenta is to ensure that the circulatory systems of the mother and child do not mix; evidently, nanoparticles can bridge this divide. It was determined though that the nanoparticles have to be less than 300 nm in diameter67 to be able to abridge the placenta barrier. The smaller nano-sized particles can penetrate deeper into the body cells. Scary as this may appear, it does present the potential for the manufacture of delivery drugs targeted to the placenta and foetus, and other tissues and organs. Nanoparticles can be similar in size as the biomolecules of the human body such as proteins. Proteins have unique characteristics, and are essential for the structure, function and regulation of cells, tissues and organs. Inside the body, nanoparticles can attach to the molecules of the tissue or organ via adsorption. The attachment or adsorption process depends on the nanoparticle’s profile with regards to size, shape, chemical composition, surface characteristics, etc. The toxicity of a nanoparticle or its ability to cause adverse or hazardous effect is related to its exposure dose, absorption dose, solubility and bioaccumulation. Bioaccumulation represents the increase in concentration of the nanoparticle in an organism with time. Bioaccumulative nanoparticles are fat-soluble; they are not biodegraded by the organism, and are considered to pose the greatest toxicity69-70 to the human body. The nano-size dimensions of nanoparticles confer on them higher surface area-volume ratio and higher reactivity than larger-sized counterparts. The complexity of the chemical composition of nanoparticles include components such as organics, metals, etc. that can result in enhanced reactivity. Metallic iron is known to induce oxidative stress in carbon black; oxidative stress is the occurrence of excessive levels of highly reactive free radicals in the cell, and the deficiency of antioxidants that are capable of mitigating free radicals. Oxidative stress can result in reduced immunological function and increased risk of chronic conditions. Health conditions that are attributable to the presence of nanoparticles in the body include but not limited to:

i. inflammation of the lung and surrounding tissues, ii. lung tumor, iii. damage to DNA, and subsequent increase in cancer risk, iv. pre-clotting of blood v. damage of the nervous system and inducing of mutation, vi. cardiovascular diseases, vii. skin inflammation, damage and itching, etc.

Nanoparticles can also pose fire and “dust explosion” hazards under certain conditions such as the accumulation of metallic particles that are extremely pyrophoric.

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Rules and guidelines from governmental agencies and others such as NIOSH, EPA, NIST, OSHA, TSCA are available. Other agencies and organizations that are active in this arena include the EU Commission (Health and Consumer Protection Directorate-General) , SCENIHR (Scientific Committee on Emerging & Newly Identified Health Risks), PEN (Project on Emerging New Technologies), etc. Mitigation guidelines for nanoparticles include but not limited to:

a. coating and encasing of manufacturing vessels to avoid leakage b. use of clean laboratories to isolate generation of nanoparticles where applicable, c. maintenance and test local exhaust ventilation systems as recommended by the

American Conference of Governmental Industrial Hygienists (ACGIH), d. use high-efficiency particulate air (HEPA) filter media for exhaust ventilation systems,

including respiratory masks, e. use of disposable lab coats, f. use of HEPA vacuum and wet wiping methods for cleaning work areas at end of each

work shift, g. Separation of consumption and storage of food or beverages from areas where

nanomaterials are handled, etc.

Figure 22: Pictorial Representation of Effective Nanoparticles Mitigation Practices By CNCMM-Sponsored Students @ Pittsburg State University. Figure 22 shows effective use of the ventilation hood for the ASTM flammability test of blast mitigation panels made of nanocomposite hierarchical materials. The students are required to wear disposal lab coats, gloves and HEPA respiratory masks even during training of high school REACH-RS workshop participants, and especially when implementing the cone calorimetry experiments. The nano-sized particles are not very amenable to visualization by the naked eye, and tend to linger in air and eventually settle on surfaces including the lab coat of the researcher or worker. The worker may falsely believe that the nanoparticles are non-existent in the workspace but only to discover that his or her lab coat is saturated with nanoparticles. Disposable lab coats are preferred to marginalize the accumulation effect of nanoparticles on lab coats, and contact thereof. The effort to get students to implement safety practices when working in nanotechnology laboratories is an ethical responsibility for program and research administrators. The prevention and mitigation of exposure to nanoparticles is a first and very critical step in the safe handling of these ultra-fine and reactive materials.

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Nanoscale Emerging Opportunities and Markets

The segment of this paper entitled: “Relevant Literature: Current State of the Nanotechnology Industry” is a very good marker of the current trends in the nanotechnology market. Figure 4, entitled: “2005 – 2015 Market Share of the Nanotechnology Industry” indicates that this market is projected to be worth $1,085 Billion by 2015, and confirms that the nanotechnology market includes all major segments of society from materials to electronics, pharmaceuticals, chemical manufacture, aerospace, sustainability, healthcare, tools, and others.

The fourth generation, molecular nanosystems exemplified by Eric Drexler’s “Molecular Machinery Gallery”of sub-atomic designed devices, and others that are projected to be the norm circa 2015 – 2020, symbolize the right strategy for the emerging nanotechnology market. Molecular simulation is not new but this technique is being applied to the design of nanostructures and systems27-28,72. It is possible to utilize already empirically proven mathematical models to theoretically predict the performance of a desired material or device via simulation and computer modeling. This is a cost-effective and productive approach as nanomaterials and systems can be designed and developed without rigorous, resource consuming experimentation. Of particular importance, is that simulation and computation at the nanoscale level make it possible to study phenomena at extreme environmental and physiological conditions that are of relevance to the space, aerospace and medical industries.

The synthesis of nanomaterials and the fabrication of nanodevices will always be part of the nanotechnology market and landscape. Desirable nanomaterials will transition from the design models to the laboratory models, and ultimately, production models require modification. Understanding of the science, chemistry and physics of these nanomaterials facilitate their synthesis. NanoScale Corporation, Manhattan, KS, a provider of a suite of quality management nano-based products and technologies started as an off-shoot of the laboratory work of Professor Klabunde73-74 on nano-synthesis. Consumer product is another strong segment of the nanotechnology market, and will continue to be a high growth rate market. Manufacturers24 are discovering the efficacy of nanomaterials in consumer products and are also becoming knowledgeable on the safety requirements of these high reactivity materials. They are taking advantage of already established in-house manufacturing infrastructure to improve already exist products using nano-sized components of their products’ formulation and recipes. Sometimes these endeavors do not require patenting activities as the manufacturer considers the trade secret route a much faster and profitable market entry route. The nanoelectronics industry, currently with about 28% of the nanotechnology market is another growth area for nanotechnology. Use of CNTs permits the fabrication of wafer scale, smaller circuits and faster computing power than the conventional silicon circuits. Spintronics or spin electronics, is one of the emerging areas of nanoelectronics. Spintronics involves the development of devices based on quantum physics and the spin properties of electrons at the atomic and sub-atomic levels 75-78. Unlike conventional electronics that use the electrical charge of the electron, spintronic devices utilize both the spin and electrical charge of the electron, and achieve enhanced performance. Spintronics is poised to facilitate the

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A B C

Figure 23: Nanographenes in Spintronics Application - (A). Graphene with Predicted Electron Spins (Courtesy: Oleg V. Yazyev, EPFL); (B). Ferromagnetic Graphone Sheet. (Courtesy: Puru Jena/VCU); (C). Nanographene Host-Guest Materials

development of new techniques for smaller, faster, more robust and more versatile computer chips. Spintronic devices are prospects for magnetic sensors, memory storage and quantum computing. Virginia Commonwealth University scientists and their Chinese and Japanese partners have successfully used theoretical computer modeling to design a new material called graphone that is grapheme-based. Graphone (Figure 23 B) has confirmed magnetic properties; this a step further than the theoretical prediction of Figure 23A. The magnetic79-81 properties of graphone are achieved by controlling the level of hydrogen coverage of graphene. This semi-hydrogenation technique makes it possible to customize graphene’s magnetic characteristics. Other researchers82 are achieving magnetic properties in nanographene by using it as a host material (Figure 23C). Nanographene’s unique electronic properties facilitate unique properties in the guest atom or molecule such as is the case for potassium atoms, molecular oxygen, helium atoms, etc. Potassium guest atom becomes magnetic whereas oxygen molecule creates high magnetoresistance for spintronic applications. On the other hand, helium atoms can be detected via their interaction with the nanographene edge. The medical industry is another growth area for nanotechnology. The small size, reactivity and selectivity of nanomaterials is being leveraged to develop targeted drug delivery systems, cancer curing drugs, antibacterial drugs, etc. Silver nanoparticles83 have demonstrated high efficacy in antibacterial drugs. They are also effective against multiple strains of bacteria due to their attack mechanism. This makes nanosilver suitable in anti-bacterial implants and wound dressings. NanoGold coated carbon nanotubes84-85 are less toxic, more efficient and environmentally-friendly than carbon nanotube for targeted detection of cancer cells and bacteria. Sound waves emitted by CNTs due to heat generation and expansion, when subjected to laser pulses, facilitate the detection of cancer cells. CNT’s toxicity is a known drawback for this technology. The addition of a gold coating reduces the toxicity of CNT,

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increases the absorption of laser pulses and reduces the amount of nanotube required for this diagnosis and therapy. The gold coated CNT for cancer detection, nanographene host material for spintronics, novel carbon nanotube-graphene 3D composites35 and others are some of the newer nanosystems regarded as composite nanotubes. These group of nanomaterials make it possible to design new nanosystems based on hybridization of already existing nanotubes and nanomaterials.

The use of nanomaterials in structural and infrastructure applications is an area of interest to government agencies and laboratories. The use of nanomaterials can facilitate the design and development of lightweight hybrid materials for aerospace, naval, defense and homeland security infrastructure. This author and several of his partners30-34, 36-38 are currently engaged in the development of these systems. The use of other nanomaterials including boron nitride, silicon carbide, nanoclay have shown efficacy in structural and flammability resistance properties that are desirable in the aforementioned infrastructures.

The energy and sustainability markets are showing a lot of interest in the use of nanomaterials. Fuel cells, solar cell, wind turbines, energy storage systems are some of the areas of activity. This author is currently involved in an “ECoTIES” (environmentally compliant, transformative and integrated energy system) project that use hydrogen produced from a solar-based and nano-catalyzed splitting of water, to operate a fuel cell. In another effort, researchers at the University of Wisconsin86 have developed a new nanotechnology-based technique for producing hydrogen gas for fuel cells. Conclusion

This paper has demonstrated the currency of nanotechnology, its challenges, opportunities and emerging markets. Already established organizations are leveraging nanotechnology innovations to gain larger market shares for their products. Laboratory stage innovations in nanotechnology are poised for market entry. Safety is of critical importance in the leveraging of nanotechnology innovations; the implementation of sound safety practices makes it possible to cost-effectively optimize the impact of nanotechnology. Of critical importance in the emerging nanotechnology markets is the fundamental understanding of the science, engineering and technology of these new systems. This paper has highlighted the link between the nano-size of these materials and their inter-reactivity, efficacy and applications.

Acknowledgment

The author acknowledges the support of Pittsburg State University (PSU), the Office of Naval Research (ONR) and the NCIIA for their sponsorship of the Center for Nanocomposites and Multifunctional Materials (CNCMM) and its activities. This paper was partially inspired by the collaborations entered into by the author, and particularly by the guest speakers of the 2010 Nanotechnology Entrepreneurship Forum.

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68. Phillip Moos et al, “Zinc Oxide Nanoparticles Used in Sunscreen are Toxic to Colon Cells,” Nanotoxicology, June 24, 2010 69. K. Donaldson, V. Stone, et al, “Toxicology of Nanoparticles,” Occup Environ Med, 2004; 61:727-728 doi:10.1136/oem.2004.013243 70. L. C. Renwick, D. Brown, et al, “Increased Inflammation and Altered Macrophage Chemotactic Responses Caused by Two Ultrafine Particulate Types,” Occup Environ Med 2004;61:442-447 doi:10.1136/oem.2003.008227 71. Risk Assessment Synthesis Report http://ec.europa.eu/health/ph_risk/committees/04_scenihr/docs/scenihr_o_003b.pdf 72. E. Mockensturm, V. Crespi, “Research: Computation and Modeling,”Nanoscale Computation and Simulation, Penn State, http://www.gonano.psu.edu/research/computation.asp 73. O. Koper, „Innovation and Entrepreneurship: NanoScale – thinking big in a small Science,” Nanotechnology Entrepreneurship Forum, April 27, 2007, www2.pittstate.edu/cncmm/documents/07_entrepre_forum/OKoper_Forum%2004-27-07.pdf 74. O. Koper, NanoScale, http://www.nanoscalecorp.com/ 75. John Shlueter et al, “Magnetic Polymers May Advance Spintronics,” Chemical Communications, December 21, 2006 Issue (accessed January 31, 2009), http://www.rsc.org/Publishing/Journals/cc/index.asp 76. O. V. Yazyev, Swiss Federal Institute of Technology in Lausanne (2008, February 15). “Graphene Holds Promise For Spintronics.” ScienceDaily. (accessed February 1, 2009) http://www.sciencedaily.com/releases/2008/02/080210124107.htm 77. I. Zutic, J. Fabian, S. Das Sarma, “Spintronics: Fundamentals and Applications,” Reviews of Modern Physics, Volume 76, April 2004, Pages 322 – 410. 78. W. J. Gallagher , S.S. P. Parkin, “Spintronics,” IBM Journal of Research and Development, Volume 50, Number 1, 2006, (accessed February 1, 2009) www.research.ibm.com/journal/rd50-1.html 79. “Graphene Holds Promise for Spintronics,” ScienceDaily (Feb. 15, 2008) http://www.sciencedaily.com/releases/2008/02/080210124107.htm 80.‘Magnetic correlations at graphene edges: Basis for novel spintronics devices’, Physical Review Letters 100, 047209 (2008) http://link.aps.org/abstract/PRL/v100/e047209

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81. J. Zhou, X. Chen, Y. Kawazoe, “New Graphene-Based, Nanomaterial Has Magnetic Properties,” ScienceDaily (Sep. 5, 2009), http://www.sciencedaily.com/releases/2009/09/090902122841.htm 82. T. Enoki, K.Takai, “Nanographene host-guest materials,” Dalton Trans., 2008, 3773, http://www.rsc.org/Publishing/Journals/DT/article.asp?doi=b800138n 83. EMPA, http://www.empa.ch/ 84. World Gold Council, “Gold Nanotubes in the Deyection of Cancer,” http://www.science.gold.org/news/2009/08/26/story/12811/gold_nanotubes_aid_detection_of_cancer_cells/, Wednesday, 26th August 2009 85. J. Wan, J. Ding, M. Wang, “Preparation of Gold Nanotube by Direct Electrodeposition for Biosensors,” J. Clust. Sci., April 07, 2010. 86. Gold Nanotube Catalytic Process Removes carbon Monoxide from Hydrogen Gas for Fuel Cells, Elliminates Need for Water Gas Shift and captures Energy in Carbon Monoxide for More Power, Nanopatents and Innovations, http://nanopatentsandinnovations.blogspot.com/2010/01/gold-nanotube-catalytic-process-removes.html Key Words: Nanoscale, Nanotechnology, Nanocomposites, Damascus Steel, National Nanotechnology Initiative (NNI), Carbon Nanotubes (CNTs), SCENIHR (Scientific Committee on Emerging & Newly Identified Health Risks), PEN (Project on Emerging New Technologies), Hybrid, etc. Biographical Information

CHRISTOPHER C. IBEH

Dr. Chris Ibeh is a professor of plastics engineering technology at Pittsburg State University, KS. He is the director of the Center for Nanocomposites and Multifunctional Materials (CNCMM). Professor Ibeh has a doctorate from the department of chemical engineering at Louisiana Tech University, and MS and BS degrees in Natural Gas Engineering from Texas A & M University, Kingsville, Texas. He is the author of the textbook entitled: “Thermoplastic Materials: Properties, Manufacturing and Applications,” CRC-Taylor and Francis Publications. Dr. is the organizer of the Nanotechnology Entrepreneurship Forum.


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