Mater Dei College Tubigon, Bohol GE 07 – SCIENCE, TECHNOLOGY, AND SOCIETY 1st Semester AY 2020-2021 NANOTECHNOLOGY _______________________________________________________________________________________________ __ Intended Learning Outcomes At the end of this section, the students should be able to: 1. Discuss the antecedents of nanotechnology and its importance to society; 2. Enumerate the positive and negative impacts of nanotechnology on the environment and society; and 3. Identify the moral and ethical questions and concerns surrounding nanotechnology. Nanotechnology is the branch of technology that deals with the manipulation and study of matter at the nanoscale. It covers all types of research and technologies that deal with the special properties of matter on an atomic molecular and supramolecular scale. Scientist in the field of chemistry, biology, physics, materials science, and engineering are all involved in studying matter on the nanoscale. Nanotechnology is “convergent” because it brings together various fields of science through its innovations, e.g., DNA silicon chips, converging between semiconductor science (inorganic chemistry) and biology, with applications in the medical industry. It also involves design, characterization, production, and application of structures, devices, and systems by controlling shapes and sizes at the nanometer scale. This technology is “enabling” in the sense that it provides the platform and the tools to produce innovations. To decipher how nanotechnology works, three dimensions must be considered. The first dimension involves tangible objects which include materials, devices, and systems. The second dimension deals with the passive and static objects i.e., nanoparticles that have properties different bulk objects, even if they have the same composition; the active devices, i.e., those that can store information, induce energy, or change their state; and the nanofacture, which refers to atomically precise manufacturing (APM), i.e., collection of instruments and procedures. The third dimension is direct nanotechnology which refers to materials structured at nanoscale components. This also extends to indirect nanotechnology, which starts with nanoparticles but can be used in huge applications i.e., hugely powerful information processors with individual nanoscale components (Ramsden, 2009). Why Nano? The term “nano” refers to a unit meaning one billionth or ten raised to negative nine (10 -9). For example, a nanometer is one billionth of a meter. Hence, “nano” expresses a very tiny amount or size. Figures 3.9 and 3.10 compare objects of different sizes. A particle of beach sand is almost ten times larger than a pollen grain. Nanostructures can be found in nature. Catalysts, minerals, and other particles are measured on a nano scale. A single strand of DNA is about three nanometers wide. Nanoscience, therefore, deals with materials that are very small using specialized microscopes and other nanodevices. Just as we are aware of the air we breathe or the molecules constantly feeding our cells at every second, we are also not conscious of these very little particles. Since the nano world cannot be seen by the naked eye, it was only recognized and identified after technology has allowed for the discovery of nanostructures. Without the microscope and its attendant technology, people would not even be aware of how this tiny world surrounds and affects us. But what is the purpose of dealing with such small entities? STS | 1T20 VMBacolot Mater Dei College Tubigon, Bohol GE 07 – SCIENCE, TECHNOLOGY, AND SOCIETY 1st Semester AY 2020-2021 NANOTECHNOLOGY _______________________________________________________________________________________________ __ Nanotechnology refers to the manipulation of matter on an atomic or subatomic scale. Some innovations developed in this field include microprocessors and strain-resistant fabrics. In the future, as nanoscience and nanotechnology progress, more breakthroughs are expected to arise in the different fields of science, hopefully resolving problems in health, environment, and security, among others. Applications of Nanotechnology With scientists and engineers continuously finding ways to make materials at the nanoscale, more and more uses of nanotechnology arise. In medicine, nanotechnology has numerous applications in the development of more effective drugs. Assisted by the view of molecules afforded by X-ray lasers, biological mechanisms can be simulated to destroy a cancer cell while it is treated by drug-bearing nanoparticles. Nanobots, or molecular-scale workers can employ molecular processes within cells, which can deliver drugs to specific molecular sites or even carry out surgery (Biercuk, 2011). It is now possible to diagnose prevalent contagious disease like HIV/AIDS, malaria, tuberculosis, among others, with screening devices using nanotechnology (Maclurcan, 2005). Water purification systems containing nanomaterials and utilizing new membrane technologies containing variable pore-sized filters (i.e., the forward-osmosis membrane technology of Hydration Technologies) are now available (Jadhawar, 2004). Nanoparticles are also used to prepare heat-resistant and selfcleaning surfaces, such as floors and benchtops. Nanoparticles of silicon dioxide or titanium dioxide can also make a surface repel water, thus preventing stains. Detergent molecules self-assemble into a sphere to form a micelle that allows the detergent to trap oils and fats within the cavity of the sphere that aids in washing surfaces. Zeolites are silicon oxides and aluminum oxides that have specific nanoporous cage-like structures that are used as molecular sieves. In agriculture, novel techniques of nanotechnology applications are applied to breed crops with higher levels of micronutrients to detect pests and to control food processing (Heckman, 2005). Ultra-small probes on earth surfaces for agricultural applications and control of soil, air, and water contamination are also developed using nanotechnology (Zhang et al., 2011). A simple, cheap, and effective way of removing arsenic in soil and water is through the use of TiO2 nanoparticles. (Pena et al., 2005). A nanotechnology-inspired detector from Washington, which can sense the smallest amount of radiation, located a nuclear leak faster and more accurately at the Fukushima Daiichi Nuclear Power Plant (Zhang et al., 2011). Chlorinated compounds (i.e., chlorinated solvents and pesticides, polychlorinated biphenyls (PCBs), and brominated compounds) are major environmental contaminants that can be reduced using nanoscale metal particles, such as FeO and Fe-Ni in conjunction with iron filings [Fe(O)] (Dayrit et al., 2008). Silver (Ag) has long been known to exhibit strong antimicrobial properties. Its activity has been enhanced with the discovery that the bactericidal properties of Ag nanoparticles (1—100 nm) are dependent on both their size and shape. Bionanotechnology can support cleaner production methods and provide alternative and renewable energy sources to enhance the sustainability of factories (Colvin, 2003). Nanotechnology helps in energy consumption like in the use of grapheme into a coating material resulting in the need for only one layer, which STS | 1T20 VMBacolot Mater Dei College Tubigon, Bohol GE 07 – SCIENCE, TECHNOLOGY, AND SOCIETY 1st Semester AY 2020-2021 NANOTECHNOLOGY _______________________________________________________________________________________________ __ does not require a multifunctional film coating. Nanoscale chemical reagents or catalysts are smaller yet they increase the rate of chemical reactions, thus lessening the input of raw materials (Zhang et al., 2011) In the Philippines, nanotechnology can be applied in making sources of renewable energy accessible to many, developing medicine that would address serious diseases, improving the state of agriculture, and more. There are also existing and ongoing research studies funded by the Department of Science and Technology (DOST) on the possible application of technology, as well as on Nano-Metrology and Education and Public Awareness. Challenges of Nanotechnology The advantages brought by innovations in nanotechnology come with a price. With rapid developments in nanotechnology, its adverse effects become more visible. The environmental effect of mineral-based nanoparticles found in cosmetics, paints, clothing, and other products are questioned as they go through sewerage treatment plants untreated due to their undetectable size. They can be carried down by fine silts or microplastics with both inorganic and organic pollutants. Thus, these may affect water source (Biercuk, 2011). For instance, in the 1980s, a semiconductor plant contaminated the ground water in Silicon Valley, California (Zhang et al., 2011). Carbon nanotubes used in the manufacture of memory storage, electronics, batteries, etc. were found to have unknown harmful impacts to the human body by inhalation into lungs comparable to asbestos fiber 11. A pulmonary toxicological evaluation of single-wall carbon nanotubes indicated that it is more toxic than carbon black and quartz. Due to its size, a nanoparticle is not easy to analyze. Lack of information and methods of characterizing nanomaterials makes it a challenge to detect its concentration in air or in any matrix of the environment. Predicting the toxicity of a nanomaterial relies heavily on information about its chemical structure since minor changes in its chemical function group could drastically change its properties. Point-to-point risk assessment at all stages to human health and environment. Risk assessment should include the exposure risk and its probability of exposure, toxicological analysis, transport risk, persistence risk, transformation risk, and ability to recycle (Zhang et al., 2011). This is which is quite expensive due to the difficulty of detecting nanoparticles. Ethical Dilemmas of Nanotechnology With the identified potential hazards that nanoparticles can bring to human health and the environment, should people disregard the benefits that nanotechnology provide them? Issues raised regarding nanotechnology should be further studied, and nanotechnology methods should be modified. For example, altering the composition of grapheme, known to be one of the most advanced materials for structural improvements, replacing silicon in electronic devices, and thermal transferring nanomaterials can be done to diminish environmental hazards of nanotechnology. Some studies also found microorganisms that can decompose graphene to make it less toxic for the environmental (Zhang et al., 2011). STS | 1T20 VMBacolot Mater Dei College Tubigon, Bohol GE 07 – SCIENCE, TECHNOLOGY, AND SOCIETY 1st Semester AY 2020-2021 NANOTECHNOLOGY _______________________________________________________________________________________________ __ It is imperative, therefore, that experts and governments support themselves with enough knowledge on how nanomaterials work for the benefit of society. STS | 1T20 VMBacolot
