Throughout history, there have been numerous instances of innovations that completely transformed human civilization. From the development of the printing press to the wheels for cars, technical advancements have significantly improved the standard of living and, in turn, changed society. It is widely accepted that nanotechnology could be the next revolution given its potential to have an impact on practically every industry.
Nanomaterials can be employed for a wide range of applications because of their distinct chemical, physical, and mechanical properties. Almost every industry, including research, engineering, medicine, and health, uses nanotechnology. Perhaps the clearest illustration of the potential of this new technical need is the revolution in communications networks, which is represented by the everyday sight of everyone carrying a cell phone, including the young and old, professionals and students, artisans and scientists. Other applications for nanomaterials include the treatment of water and air pollution, tissue engineering, cosmetics, textiles, healthcare, catalysis, functional coatings, and medical diagnosis and therapies.
Nanochemistry Applications
Some of the major applications of Nanomaterials are listed below:
Nano-Electronics
Electronics has arguably benefited the most from nanotechnology’s intangible effects. Throughout the past few decades, feature size has dramatically decreased while processing performance has increased. Therapeutics, sensors and communication engineering, as well as the remediation of water and air pollution, have all benefited from the transformation from macroscopic to nanoscale transistors in semiconductor electronics technology. The large-scale production of innovative electronic devices has been made possible by advancements in semiconductor technology, including zone refinement, doping by thermal diffusion, and lithography.
Nanoelectronics has benefited the human civilization in terms of:
Metal oxide semiconductor field effect transistor (MOSFET): MOSFETs are currently one of the most widely utilized types of transistors. Source, Drain, and Gate are the three terminals that make up a field effect transistor. The gate of a MOSFET is a metal electrode that is separated from a semiconductor below by an insulating thin oxide barrier.
Solid-state quantum effect devices: The confinement of electrons in at least one of the axes is made possible by the physical dimensions of quantum devices. It plays significant role in terms of quantum dots, resonant tunneling devices, single electrons transistors, and so on.
Hybrid micro–nano-electronic resonant tunnelling transistors: Because to their somewhat complex structure, small size, and the sensitivity of the effects they utilise, nanoscale RTTs are frequently challenging to create in sufficient regularity in large quantities. To maximize the advantages of such nanoscale quantum devices, efforts have been made to create “hybrids” of solid-state quantum effect devices mixed with micron-scale transistors.
In order to create the RTD-FET, a hybrid transistor-like device, small, nanoscale quantum effect RTDs are incorporated into the drain (or source) of a bulk-effect microscale FET. Such a hybrid RTT can display multistate switching behavior similar to that for strictly nanoscale RTTs in the section above. Because of this, a hybrid device on an integrated circuit can represent more logic states than a pure bulk-effect, microelectronic FET.
Molecular electronic devices: Covalently bound components that are electrically separated from a bulk substrate are typically used to make molecular electronic devices. The main benefit of these systems is that they can be made in large quantities using cutting-edge chemical synthesis techniques with a high degree of control and repeatability, ensuring the production of devices with comparable performance.
Micro and Nano-electromechanical systems: Micro-electromechanical systems (MEMS) are employed in a variety of engineering applications, including defense systems, medical devices, automobiles, and environmental monitoring. The use of MEMS is encouraged by a number of features, such as their compact size, decreased weight and power consumption, increased speed and precision, etc. The creation of production technologies that are repeatable, dependable, and affordable is required for the fabrication of MEMS. These technologies must also be able to precisely manage the dimensions of fine features. A few micrometers to a few hundred micrometers is the range of dimension characteristics for MEMS.
Powerful tools for batch processing and miniaturizing electromechanical systems and devices into a dimensional scale that is not possible with standard machining techniques are microfabrication techniques.
Force sensors, chemical sensors, biological sensors, and ultra-high frequency resonators based on NEMS (nano-electromechanical systems), where structures of extremely small mass provide important functionality, have also been developed. NEMS can be made using top-down or bottom-up techniques. The most popular methods right now use lithographic top-down techniques. Bottom-up methods use sequential assembly of atomic and molecular building blocks to fabricate nanoscale devices in a manner similar to how nature creates objects.
Nanosensors
The following are some notable advantages that nanosensors have over their microscale and macroscale equivalents:
- Reduction in the overall size and weight of the associated system
- Cost production
- Mass production
- Low power consumption
- Higher level of integrity
- Utilization of physical phenomena appearing on the nanoscale
- Enhanced sensitivity
Depending on the detecting application, nanoscale sensors can be categorized as physical, chemical, or biological nanosensors. Moreover, nanoscale sensors can be categorized in a manner similar to how conventional sensors are in terms of the energy they transduce. According to the nanostructures used, such as nanotubes, nanowires, nanoparticles, nanocomposites, quantum dots, embedded nanostructures, etc., nanosensors can be categorized specifically. Although there are many different types of sensors, no one sensor can reliably sense all relevant parameters in all conceivable settings. As a result, there is currently interest in expanding sensor arrays to integrate several attributes in various situations.
The human sensory system uses the eyes as the optical sensor, the nose as the gas sensor, the ear as the acoustic sensor, and the tongue as the liquid chemical sensor. Sensor arrays incorporate various combinations of single- and multi-functional sensors to perceive several phenomena simultaneously. The chemical or biochemical industries, among others, employ this to boost data capture and multiplication.
There are numerous areas where nanosensors and nano-enabled sensors are used, including transportation, communications, construction and buildings, healthcare, safety, and national security, which includes both military operations and home defense. Nanosensors are inserted into blood cells to identify early radiation damage in astronauts, and nanoshells are used to detect and eradicate tumors as examples of nanowire sensors that are used, for example, to detect chemicals and biologics.
Nanocatalysts
Catalysts considerably improve chemical reactions. Nanomaterials have a high surface area-to-volume ratio, making them more effective catalysts. In comparison to conventional catalysts, nanocatalysts can be more selective, which can reduce waste and, in turn, the environmental impact. A catalyst is something that modifies the rate of a reaction without getting consumed by it. The catalysts are active participants in the process even though we say they are not eaten, which is true. Typically, a stable complex is formed when the catalyst and reactants interact.
Reactants + Catalyst → Complex
The complex rearranges to yield the products and regenerates the catalyst:
Complex → Products + Catalyst
There is no net catalyst consumption since, as you can see, the catalyst is renewed at the end of the reaction. If a catalyst exhibits high conversion, is selective to the desired products, is stable for an extended period of time, and has strong mechanical strength, it is said to be active in the given chemical process. If the catalysts are made at the nanoscale, it is possible to control the catalyst species at the molecular level. The use of nanostructured materials as catalysts can significantly alter the conversion and selectivity in chemical processes because nanoscale particles have a distinct crystal structure.
For two reason; High surface area and enhanced reactivity, particles in the 1-100 nanometer range are expanding the field of surface chemistry. Nanoparticles with an improved surface-to-volume ratio are anticipated to be particularly effective because the catalytic sites of metal catalysts are located on their surface. The relationship between the fraction of surface atoms and nanoparticle radius is depicted in Figure. The graph demonstrates that the ratio increases with decreasing size. The quantum size of nanoparticles is another distinguishing feature. Although metal in its entirety has a band structure, metal nanoparticles, which are only a few nanometers in size, have relatively distinct electrical energy levels.
Physical and chemical techniques can both be used to generate metal nanoparticles that are rather homogeneous in size. The physical approach, also known as the top-down method, creates metal nanoparticles by breaking down bulk metal by the use of mechanical force, vaporization, laser abrasion, and other processes that can give bulk metal more energy than the metal’s binding energy. The preparation process in the chemical approach, also known as the bottom-up method, begins with the reduction of metal ions to metal atoms, which is followed by aggregation and produces metal nanoparticles. Both approaches offer benefits of their own. Yet, from the perspectives of repeatability, homogeneity, and mass production, chemical procedures are thought to be superior.
Food and agriculture industry
The following are some potential uses for nanoscience in agriculture and food processing:
- Nanosensors for soil quality and plant health monitoring
- Nanocapsules for herbicide delivery
- Food supplements, colour additives and animal feeds
- Nanocomposites for plastic film coatings used in food packaging
- Development of nanobarcodes as labels for food and agricultural items.
- Nano-porous zeolites for the effective and gradual release of nutrients and medications for cattle as well as water and fertilizers for plants.
Food safety and protection from bioterrorism can be guaranteed by the use of nanosensors in agricultural and food packaging. Nowadays, research is being done on photocatalytic degradation as a disinfectant and for wastewater remediation, notably in fruit packaging. It has been discovered that nanocrystalline oxides of metals like Ti, Sn, and Zn make good photocatalytic materials for cleaning packaged foods and agricultural products.
When using nanoparticles for these applications rather than conventional materials, the high surface area-to-volume ratio also becomes favorable. Excited electrons are released during the photocatalytic reaction. By allowing these electrons to infiltrate the bacteria attached to the nanoparticles, disinfection is achieved. Hence, it is believed to be superior in terms of mass manufacturing, homogeneity, and reproducibility.
Research is being done on nano-modified food items to improve the nutritional value of the food by using nano-encapsulated nutrients, nano-modifying fat and sugar molecules to render them inactive, and adding flavor enhancers. Technology has a significant impact on the fast food sector since it can make food less harmful and more appealing to consumers. A significant application for nanotechnology in the food packaging sector is likely to be to extend the shelf life of food goods, among other things.
Cosmetics and Consumer goods
Cosmetics produced with nanomaterials are gaining popularity. There are currently more than a few hundred cosmetics, sunscreens, anti-aging, and personal care items on the market that contain nanomaterials.
Cosmetics: Because of its high absorption coefficient for UV radiation in particular, sunscreens containing particles of titanium dioxide or zinc oxide are often used to prevent skin burn. When applied to the skin, creams containing microcrystalline particles are typically white in color and easily noticeable. These creams are typically opaque, but the nanocrystalline titanium dioxide and zinc oxide particles used in them render them transparent, revealing the skin beneath. These clear creams have no discernible effect on visual appearance. Thus, sunscreen creams containing nanoparticles are gaining in popularity. Nanoparticles included in the cream improve its spreading behavior as well as its absorption, especially of UV light.
Personal care products: Powders, gels, sticks, and sprays designed for use under the arms benefit from the use of nanomaterials to combat bacteria and odor. Additionally, they facilitate a silky, frictionless experience. Nano-sized particles of gold and silver are able to kill bacteria and fungi. This is why you’ll find them in so many beauty aids. Dispersing silver particles smaller than 10 nm in soaps has the dual benefits of killing germs and enhancing the soap’s ability to remove dirt particles from the skin. The use of nano-sized zinc oxide particles in deodorants and antiperspirants is a current research and development focus. The antimicrobial and odor-fighting capabilities of zinc oxide with silver doping are significantly improved.
Anti-ageing products: Vitamin E has long been believed to slow the rate at which cells age by acting as an antioxidant against peroxyl radicals. Antioxidants with greater peroxyl radical-scavenging capacity than the naturally occurring antioxidant α-tocopherol have been the subject of intensive research and development for decades. Increased antioxidation capabilities were observed in trolox-functionalized gold nanoparticles due to an eight-fold increase in their reactivity towards peroxyl radicals. This offers a new and flexible approach to producing superior antioxidants. The anti-aging benefits of these antioxidants extend to the hair and skin as well.
Structure and Engineering
Products with nanotechnology integration are being developed for use in a wide variety of building-related contexts. Here are just a few examples:
- Self-cleaning glass
- Nano-enabled wood
- Fire-resistant coatings
- IR/UV reflecting windows
- Using nanoparticles to strengthen concrete
Nano-silica has been shown to improve the packing density of concrete, which in turn increases its mechanical strength. Integrating sensors to monitor the integrity and safety of the construction could be one of the most significant emerging applications of nanotechnology in civil engineering. This could allow for rapid damage assessment in the event of emergencies or even terrorist disruption. The early detection of wood-destroying fire ants and fungi is another useful application for sensors.
Automotive Industry
Cars of the future will hopefully be more aerodynamic, more fuel efficient, and safer in accidents. Frames with a high strength-to-weight ratio, renewable energy, zero emissions, in-house sensors, and functional nanomaterials are used to improve security and design. Many of these goals, including improved vehicle performance, convenience, and safety, can be substantially aided by the application of nanotechnology in the following ways:
- Coatings and nanopowders can be used to make paint last longer.
- Due to their high strength and low weight, carbon nanotube-based composites are being considered as a replacement for automobile frames.
- Emission gas pollution can be mitigated with the help of nanoscale metal oxide ceramic catalysts.
- The thermal conductivity of fuel will be improved by nanoparticle dispersions.
- The effectiveness of shock absorbers is being worked on by developing magnetic nanofluids.
- Methods for characterizing materials, online sensors for measuring wear and abrasion, and additives for improving part and layer adhesion are all areas of research.
Water treatment and the environment
Nanotechnology-enabled products are anticipated to have a few distinct advantages for large-scale application, to economize, and to perform more efficiently than conventional water treatment technologies such as chemical treatment, mechanical separation, ultraviolet radiation, biological treatment, and desalination. There are numerous ways in which nanotechnology can help with water management:
- Water purification and desalination using nano-membranes and nano-clays
- Nanoparticle-activated wastewater reuse systems
- Nanosensors for detecting pathogens, toxins, and metals in water.
Nano-medical applications
Nanotechnology has the potential to completely transform healthcare systems in a way that benefits patients. Diagnosis, treatment, and even prevention are all finding applications for nanotechnology and nanomaterials. Nanotechnology-enabled targeted drug delivery, cancer therapy, tuberculosis treatment, disease diagnosis, health monitoring biosensors, surgical instruments, implant materials, tissue engineering, molecular imaging, biodetection of disease markers, etc., have all made significant strides in recent years.
Assembly of existing molecular entities; exploration and matching of specific compounds to individual patients for maximum efficacy; and advanced molecular compound delivery systems all fall under the framework of nano-pharmacology, which is the application of nanotechnology in pharmacology. Nanoparticles have the potential to deliver drugs to specific tissues for extended periods of time with minimal systemic effects. Nanoshells can be precisely tuned to scatter or absorb any particular wavelength of light by adjusting the ratio of wall to core dimensions.
Increased and more regulated drug uptake in tissues throughout the body is made possible by nano-pharmaceuticals and nanotechnology drug delivery systems. This is essential for uses in oncology. Drugs can be absorbed through the skin using nano-emulsions applied topically because of developments in nano-pharmacology delivery systems. The use of recently developed contrast dyes allows for molecular level examinations of patients. Damage to the nervous system can also be partially repaired with the help of nanotechnology. As an added bonus, biomimetic scaffolds help damaged nerves regenerate and reconnect.
Textiles
Nanotechnology is used in many unique ways to provide fabrics multifunctional properties. Stain-resistant, water-repellent or absorbent, light-emitting, antimicrobial, fragrance-controlled, etc. Nylon and other polymers with nanoparticles have antimicrobial characteristics. Coating synthetic fibers with nanocrystalline zinc oxide particles gives them antibacterial properties without changing their color or gloss. Plasma technology makes fabrics antibacterial, antifungal, and water resistant by modifying the top few nanometres. Workwear heat resistance, mechanical resilience, ballistic protection, sensors, and camouflage are also of importance.
Paints
Nanoparticles can make paints lighter and change their characteristics, improving their performance. Thinner paint coats reduce weight. Nanopaints also lower solvent content. Since the ecological impact of tributyl tin (TBT) has been recognized, new fouling-resistant marine paints are urgently needed. Anti-fouling surface treatment can save energy in heat exchange processes. Fouling-resistant coatings could be employed in home and industrial water system pipework if they are affordable. Effective anti-fouling coatings may reduce biocide consumption, particularly chlorine.
Nanoparticles may be used in paints that change color with temperature or chemical environment or that reduce heat loss by reducing infrared absorption. Due to concerns about nanoparticle health and environmental implications, nano-engineered paints and coatings must address durability and abrasive behavior so that abrasion products are coarse or microscopic agglomerates rather than individual nanoparticles.
Energy
Nanomaterials will also appear in green energy technologies. Conventional solar cells are inefficient and expensive compared to other large-scale energy sources. Nanomaterial-based solar panels may soon outperform conventional power plants. Scientists are developing cheap, easy-to-apply plastic solar cells made of nanorods in a polymer that can be applied to any surface. Nanorods absorb a wavelength to generate electrons. Though cheaper, their efficiency is only 2%. However, by tuning nanotube dimensions, light energy can be absorbed across a wide range, improving efficiency. A small amount of carbon nanotubes in nanocrystalline TiO2 film almost doubles efficiency. The performance of Li ion batteries has also seen a dramatic improvement as a result of nanotechnology.
Defence and Space applications
Minimizing the bulk, gravity, and energy needs of long-range defense and space systems is a key application of nanotechnology. Future military AI may also benefit from embedded nanosensors connected via wireless networks. The following are some of the potential defense and space applications of nanotechnology:
- Lightweight protective clothes
- Very powerful rocket fuel, like aluminum nanoparticles
- Adapted skin and other features for enhanced temperature regulation.
- Vehicles with a lower curb weight have a greater range per gallon of fuel.
- Anti-ballistic and shatterproof armour
- Using a person’s fingerprint, face, or DNA sequence as a means of identification through biometric sensing.
- Position and motion sensors for tracking and tracing
- Distributed wireless sensor networks for ambient intelligence in surveillance
Structural Applications
Superplastic deformation of nanocrystalline materials would make it more industrially accessible by increasing the rate of forming or decreasing the temperature associated with it. Superplastic deformation allows for the extension of high-speed, large-scale forming processes when applied to nanocrystalline metals. Nanocrystalline superplasticity is thought to be superior to conventional super plastics in situations where the materials chemistry might not be able to be modified. When appropriate processing methods for nanocrystalline materials have been discovered, their superior strength could be put to use in a variety of contexts. When used as reinforcing elements in plastic, ceramic, and metallic matrices, nanotubes may significantly outperform carbon fibers in terms of modulus and strength.
Low ductility in stress has restricted the application of nanocrystalline metallic materials. Yet, the cold rolling of nanocrystalline copper has revealed promising new avenues for exploring the nanocrystalline structure in order to develop novel processing of particular metallic materials.
Nanocrystalline metals provide the potential to greatly simplify the standard deformation-annealing process. The microstructure of a material can be easily modified after heating, allowing for more precise control over the end product’s characteristics.
Nanoenzymes
Nanoenzymes (or nanozymes) have been given special optical, magnetic, electrical, and catalytic capabilities due to their tiny sizes (1-100 nm). In addition, these tiny enzymes have been able to design a complex structure on their surface because of the controllable surface functioning of nanoparticles and their predictable nanostructure.
Watch out this interesting video.
References
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- “Uses of nanoparticles of titanium(IV) oxide (titanium dioxide, TiO2)”. Doc Brown’s Chemistry Revision Notes – Nanochemistry.
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