Nanotechnology Notes
11. The Nano World
Overview
Nanotechnology: Exploration and manipulation of matter at the atomic and molecular scale, generally 1 to 100 nanometers.
Chapter topics:
Detailed background of nanotechnology, exploring its historical roots and evolution.
Comprehensive overview of microscopy tools essential for nanoscale observation and manipulation.
In-depth analysis of carbon nanomaterials, including fullerenes, carbon nanotubes, and graphene.
Examination of the issues and concerns surrounding nanotechnology, including environmental, health, and ethical aspects.
Current status and future prospects of nanotechnology in the Philippines.
Specific Objectives:
Provide a precise definition of nanotechnology and describe its key characteristics.
Compare and contrast various microscopy tools used in nanotechnology, highlighting their strengths and limitations.
Explore diverse applications of nanotechnology across various fields.
Discuss the potential risks and challenges associated with nanotechnology.
Evaluate the current state of nanotechnology research, development, and application in the Philippines.
11.1. Background of Nanotechnology
Nanoscale: Dimensions typically ranging from 1 to 100 nanometers, where materials exhibit unique properties.
Nano: Derived from the Greek word \"nanos,\" meaning dwarf.
One nanometer (nm): Equivalent to one billionth of a meter or meter, providing a scale for atomic and molecular manipulation.
Analogy: To comprehend scale, imagine a marble as a nanometer; on this scale, Earth would be about 1 meter.
Human eye can see objects down to 105 nm: Human vision is limited to seeing objects at a scale larger than 105 nm, necessitating advanced tools for nanoscale observation.
Properties change dramatically below 100 nm, dependent on particle size: At the nanoscale, materials exhibit unique properties influenced by quantum mechanical effects and increased surface area.
Examples of property changes: These include alterations in conductivity, electrical behavior, thermal properties, mechanical strength, and chemical reactivity.
Pure silicon: A material that is an insulator in bulk form becomes a conductor at the nanoscale due to quantum confinement effects.
Nanoscience: The interdisciplinary field dedicated to the study of phenomena and manipulation of materials at the nanoscale.
Nanotechnology: Focused on the design, production, and application of nanoparticles and nanoscale structures to create novel materials and devices.
National Nanotechnology Initiative (NNI) Definition: Encompasses the control of matter at the atomic and molecular levels, specifically within the range of 1-100 nm.
Includes imaging, measuring, modeling, and manipulating matter at this scale: Involves advanced techniques for imaging, measuring, modeling, and manipulating materials at the atomic and molecular levels.
Nanoscale particles existed in nature and science prior to the formal field: Nanoscale phenomena and materials existed long before the formal establishment of nanotechnology as a distinct field.
Richard Feynman: Delivered the groundbreaking speech \"There's Plenty of Room at the Bottom\" on December 29, 1959.
Introduced manipulating things on a small scale: Feynman's visionary ideas laid the foundation for nanotechnology by proposing the manipulation of matter at the atomic and molecular levels.
Question: \"Why cannot we write the entire 24 volumes of the Encyclopedia Britannica on the head of a pin?\": Feynman challenged the scientific community to explore the possibilities of miniaturization and information storage at the nanoscale.
Proposed shrinking computing devices with wires of 10-100 atoms in diameter: Feynman envisioned the creation of ultra-compact computing devices using nanoscale wires.
Samsung in 2009: Achieved large-scale production of electronic devices using 30-nanometer technology, demonstrating the feasibility of nanoscale manufacturing.
Feynman's Nobel Prize (1965): Awarded for his theoretical physics research on the interaction of light and matter, which laid the groundwork for understanding nanoscale phenomena.
Norio Taniguchi (1974): Coined the term \"nanotechnology\" at Tokyo University of Science.
Description of semiconductor processes involving nanometer control: Taniguchi's definition emphasized the precision control of materials at the nanometer scale in semiconductor manufacturing.
Nanomaterials: Utilized in various applications across electronics, communications, optical systems, and biological systems, offering enhanced performance and novel functionalities.
Nanotechnology: Achieved a global valuation of $4.4 trillion by 2018, reflecting its widespread adoption and economic impact across diverse industries.
Nanotechnology Consumer Products Inventory (CPI): Established in 2005 to monitor and track the proliferation of nanoproducts in the consumer market.
2013 survey: Identified 1814 consumer products from 622 companies in 32 countries, showcasing the global presence of nanotechnology-enabled products.
Health and fitness category: Dominated the nanoproduct market, accounting for 42% of consumer products.
Nanoparticle metal silver: Emerged as the most frequently used nanomaterial, found in 24% of nanoproducts due to its antimicrobial properties.
Composition not provided: Remained undisclosed for 49% of products, raising concerns about transparency and regulatory oversight.
Nanotechnology research started in November 1996: Significant milestones in nanotechnology research marked the beginning of focused efforts to explore and develop nanoscale technologies.
Interagency Working Group on Nanotechnology (IWGN): Officially adopted under the National Science and Technology Council (NSTC) in September 1998, facilitating collaboration and coordination among government agencies.
U.S. National Nanotechnology Initiative (NNI): Established in 2000 by President Bill Clinton, marking a formal commitment to advancing nanotechnology research and development at the national level.
Federal government effort in nanotechnology: The NNI represents a coordinated effort involving over 20 US departments and independent agencies to promote nanotechnology innovation.
Involves over 20 US departments and independent agencies: These agencies collaborate on research, development, and regulatory activities related to nanotechnology.
Focus on research on nanomaterials: The NNI prioritizes research on nanomaterials, including their synthesis, characterization, and application in various fields.
United States: Emerged as a leading country in nanotech research based on publications and citations from 2003 to 2013, demonstrating its scientific prominence.
China: Surpassed the United States in nanotechnology research, holding a 39% share of publications as of 2018, reflecting its growing influence in the field.
11.2. Microscopy Tools in Nanotechnology
Nanotechnology requires visualizing and controlling individual atoms and molecules: Essential for manipulating and engineering materials at the nanoscale.
Electron Microscope:
Bombards sample with electrons: Uses a beam of electrons to illuminate the sample, enabling high-resolution imaging.
Monitors transmission or scattering effects: Detects changes in the electron beam as it interacts with the sample, providing information about its structure and composition.
Two Types:
Transmission Electron Microscopy (TEM): Produces 2D images that require careful interpretation; offers higher resolution capabilities for examining internal structures.
Scanning Electron Microscopy (SEM): Generates 3D images of particle surfaces, providing detailed topographical information about the sample.
Ernst Ruska: Developed the first TEM in 1931, revolutionizing the field of microscopy and paving the way for nanoscale imaging.
Scanning Tunneling Microscope (STM):
Applies voltage bias between electrical probe tip and sample surface: Utilizes quantum tunneling to probe the surface of conductive materials at atomic resolution.
Measures distance based on tunneling current: Measures the tunneling current between the tip and sample surface to determine the distance and create an image.
Gerd Binnig and Heinrich Rohrer: Developed the first working STM in 1981, opening new possibilities for surface science and nanotechnology.
Won Nobel Prize in Physics in 1985: Recognized for their groundbreaking invention of the STM, which enabled atomic-scale imaging of surfaces.
Atomic Force Microscope (AFM):
Overcomes limitation of STM--only works on conducting/semiconducting surfaces: Extends nanoscale imaging capabilities to both conductive and non-conductive materials.
Resolves images of almost any surface: Enables high-resolution imaging of a wide range of materials, including polymers, ceramics, and biological samples.
Uses atomic scale force sensor (cantilever) to measure forces between tip and sample: Measures the forces between a sharp tip and the sample surface, providing information about its topography and material properties.
Gerd Binnig and Calvin Quate: Put forward the initial ideas of AFM in 1986, expanding the toolkit for nanoscale imaging and characterization.
11.3. Carbon Nanomaterials
Widely used nanomaterials with promising applications: Carbon-based nanomaterials offer exceptional properties and versatile applications across various sectors.
Carbon can bond to itself and other elements, forming nearly 10 million compounds: Carbon's unique bonding capabilities enable the formation of diverse molecular structures and materials.
Additional forms of carbon discovered (beyond graphite and diamond): Research has revealed novel allotropes of carbon, including fullerenes, carbon nanotubes, and graphene.
Classes of nanomaterials:
Carbon-based
Carbon nanotube: These are cylindrical molecules that consist of rolled-up sheet of single-layer carbon atoms (graphene).
Fullerene: These are molecules of carbon atoms that take the form of a hollow sphere, ellipsoid, tube, and many other shapes
Graphene: A single layer of carbon atoms arranged in a hexagonal lattice.
Inorganic-based
Silver nanoparticle: Silver nanoparticles have unique optical, electrical, and antibacterial properties and they also have application in catalysis, sensing, and imaging.
Gold nanoparticle: Gold nanoparticles are used in various applications, including drug delivery, medical imaging, and electronics.
Titanium dioxide: This is a widely used compound because of its photocatalytic activity, high refractive index, and other special properties.
Organic-based
Dendrimer: Artificial molecules built up from branched units called monomers. The name comes from the Greek word dendron, which translates to "tree."
Polymer nanoparticle: Organic nanoparticles are made especially from polymers. A naturally sourced polymer is a polysaccharide, a peptide (protein) or another biopolymer.
Composite-based
Hybrid nanofiber: Hybrid nanofibers combine different materials at the nanoscale to create structures with enhanced properties and functionalities.
Metal-organic framework: Metal-organic frameworks (MOFs) are a class of compounds consisting of metal ions coordinated to organic ligands to form one-, two-, or three-dimensional structures.
11.3.1. Fullerenes
Commercial manufacture started in 1985 after fullerene discovery: This marked the beginning of their exploration for various applications.
Spherical carbon-caged molecules with sixty (C60) or more carbon atoms: These molecules have a distinctive structure resembling a soccer ball.
Diameter: Typically ranging from 0.7 to 1.5 nm.
Unusual properties: Exhibiting exceptional heat resistance and superconductivity under certain conditions.
High tensile strength: They are capable of withstanding significant mechanical stress.
Bounce back to original shape after high pressure: Fullerenes demonstrate remarkable resilience and structural integrity.
Buckminsterfullerene (C60) or buckyball: Discovered by Harold Kroto, Sean O'Brien, Robert Curl, and Richard Smalley (Rice University).
Stable molecule with 50-500 carbon atoms in a ball: They are among the most stable carbon structures.
Named after Buckminster Fuller for geodesic dome resemblance: Inspired by the architectural designs of Buckminster Fuller.
Kroto's team awarded 1996 Nobel Prize in Chemistry: Recognized for their groundbreaking discovery of fullerenes.
Production Techniques: Involves vaporizing graphite using a short-pulse, high-power laser and then depositing the resulting carbon vapor; however, this process is relatively inefficient.
Applications:
Antioxidants: React with up to 34 methyl radicals, earning them the nickname 'radical sponge' due to their scavenging abilities.
Antiviral agents: Suppress replication of HIV, offering potential in delaying the onset of AIDS by interfering with viral processes.
11.3.2. Carbon Nanotubes
Cylindrical shape (not spherical): Possessing a unique tubular structure.
Carbon atoms linked in hexagonal shapes: Forming a honeycomb lattice.
Diameter: Ranging from single to tens of nanometers.
Length: Extending over several micrometers.
High tensile strength (6-7 times that of steel): Offering exceptional mechanical robustness.
Stiffest fibers known: Carbon nanotubes exhibit remarkable rigidity and resistance to bending.
Sumio Iijima (Research Development Corporation of Japan): Credited with discovering carbon nanotubes, marking a major advancement in nanotechnology.
Shared Kavli Prize in Nanoscience in 2008: Acknowledged for his pioneering work in carbon nanotube research.
Two Types:
Cylindrical shape with open ends: Allowing for the encapsulation of molecules and materials.
Closed ends with pentagons: Altering their electronic and chemical properties.
Electrical Properties: Exhibiting either conducting or semiconducting behavior depending on their chirality and structure.
Production Method:
Graphite powder immersed in HNO3 and H2SO4 with KCIO3: Involving chemical treatments to exfoliate and disperse carbon nanotubes.
Heat treatment up to 70°C and air drying: Stabilizing and purifying the carbon nanotubes.
Potential Uses:
Reinforced composites: Enhancing the mechanical properties of materials.
Nanoelectronics: Enabling the development of nanoscale electronic devices.
Sensors: For detecting various chemical and biological species.
Nanomechanical devices: Creating nanoscale actuators and machines.
Lightweight spacecraft: Reducing the weight of spacecraft components.
Space elevator (Japan): A futuristic concept for accessing space.
11.3.3. Graphene
Flat one-atom thick sheet of carbon atoms in a hexagonal honeycomb lattice: Consisting of a single layer of carbon atoms arranged in a repeating pattern.
Layers form graphite: Stacking together to form the common material graphite.
Thinnest compound discovered: Graphene represents the ultimate limit in thinness for materials.
Lightest material known ( at 0.77 mg): Exhibiting an extremely low density.
Strongest compound discovered (100-300 times stronger than steel): Offering unparalleled mechanical strength.
Best conductor of heat and electricity (150 times more conducting than silicon): Enhancing thermal and electrical conductivity in devices.
Pliable (stretch up to 120%): Demonstrating exceptional flexibility.
Impermeable to liquid and gas: Creating barriers for various applications.
Discovered in 2004 by Sir Andre Geim and Sir Kostya Novoselov (University of Manchester).
Won Nobel Prize for Physics in 2010: Recognized for their groundbreaking experiments with graphene.
Production Methods:
Mechanical exfoliation (tape method): Involving the use of adhesive tape to peel off single-layer graphene from graphite.
Chemical vapor deposition (CVD): Growing graphene films on metal substrates at high temperatures.
Applications:
Fast charging lithium-based batteries: Improving the efficiency and performance of energy storage devices.
11.4. Issues and Concerns in Nanotechnology
Nanotechnology may cause dramatic and sweeping changes in human life: Presenting both opportunities and challenges for society.
Nanoproducts expected to improve materials but may have risks: Balancing the benefits and risks associated with nanomaterials.
Nanoproducts may bring improvement in health and medicine but may also bring certain toxicity and negative health effects: Considering both the potential benefits and adverse effects.
Nanomaterials may help clean certain environmental wastes but can also contaminate the environment in other ways: Addressing the dual nature of nanomaterials in environmental applications.
Special regulations needed: Ensuring responsible development and use of nanotechnology.
Consumer Product Safety Commission: Serving as a member agency of the National Nanotechnology Initiative to ensure the safety of nanotechnology in consumer products.
Nanomaterials in food industry: Used as nutritional additives, flavoring & coloring, anti-caking agents, antibacterial ingredients for food packaging, raising potential health concerns.
Nanomaterials present in some baby milk and baby products: With potential implications for infant health and development.
Nanoparticles can penetrate biological membranes and cells more readily than larger particles: Increasing their potential for interactions with biological systems.
They may enter the organs like the heart, brain, liver, kidneys, bone marrow, etc. and eventually interfere with normal cellular function, which may cause cell death: Highlighting the potential for systemic toxicity.
Limited and inconsistent environmental effects and risks: Creating uncertainties in assessing the long-term consequences.
11.4.1. Environmental Concerns
Zhang et al. (2019) summarizes potential risks of nanotechnology:
Lower recovery and recycling rates: Impeding the sustainability of nanomaterials.
Lack of trained engineers and workers causing further concerns: Indicating a need for workforce development in nanotechnology.
Environmental implications of other life cycle stages not clear: Highlighting the need for comprehensive lifecycle assessments.
Dissemination of toxic, persistent nanosubstances originating environmental harm: Pointing to the potential for long-term environmental contamination.
High-energy requirements for synthesizing nanoparticles causing high-energy demand: Addressing the energy footprint of nanotechnology production.
Buckyballs can interact with water and form nano-sized clumps that can harm soil bacteria: This poses risks to soil ecosystems.
11.4.2. Health Concerns
Aerosolized form of a protective sealant (contains nanoparticle) for glass and ceramics experienced breathing problems and coughing: Demonstrating the potential for respiratory irritation.
Women in China working directly in a paint factory that uses nanoparticles fell ill with serious lung disease: Underlining the occupational health risks associated with nanomaterials.
11.4.3. Ethical and Social Concerns
Nanotechnology is not a single technology; it may become pervasive: Necessitating comprehensive ethical and social considerations.
Nanotechnology may introduce new efficiencies and paradigms, which may make some natural resources and current practices uncompetitive or obsolete: Disrupting traditional industries and economies.
Nanotechnology may be very difficult to detect its presence unless one has the specialist tools of nanotechnology: Which creates challenges for regulation and monitoring.
Nanotechnology raises ethical and social justice concerns, which must be addressed in its regulation: Ensuring equitable access to the benefits of nanotechnology.
Nanobots (also called nanorobots, nanoids, nanites or nanomites):
Researchers at the University of California San Diego (UCSD) have developed nanobots, which are capable of cleaning the blood of toxins generated by bacteria in experimental stage.
11.5. Nanotechnology in the Philippines
Significant government funding on research and development in nanotechnology: Supporting scientific innovation and economic growth.
2008: DOST convened interdisciplinary group to craft nanotechnology roadmap.
1. Nanostructured solar energy devices: Harnessing nanotechnology for renewable energy solutions.
2. Nanosensor technology to food, agriculture, and environment: Enhancing food safety, agricultural productivity, and environmental monitoring.
3. Environmental remediation and water: Applying nanotechnology for pollution control and water purification.
4. Nanocomposite materials using local minerals and biological resources: Promoting sustainable use of indigenous materials.
11.5.1. Nanostructured Solar Devices
Collaborative research program between Ateneo de Manila University, De La Salle University and the University of the Philippines supported by DOST.
Development of solar cells based on solid-state nanomaterials and dye-sensitized materials, including the use of graphene as low-cost and environment-friendly alternative energy sources.
11.5.2. Nanocomposite Materials
DOST and ITDI team led by Dr. Blessie A. Basilia developed food packaging material using organoclay (nanoclay) from local bentonite blended with thermoplastic starch made from cornstarch.
11.5.3. Nanoparticle in Commercial Paint
2008: Pacific Paint (Boysen) Philippines, Inc., conducted