Svetsare nanopartiklar
Nya material kan förstås även innebära nya risker för miljön och vår hälsa.
Nanopartiklar är oftast mer reaktiva än större partiklar och har därför en potential att påverka organismer i omgivningen mer. De senaste åren har vi sett flera exempel på hur en ny teknologi från början verkar riskfri, men senare visade sig vara. Green nanotechnology refers to the use of nanotechnology to enhance the environmental sustainability of processes producing negative externalities. It also refers to the use of the products of nanotechnology to enhance sustainability.
It includes making green nano-products and using nano-products in support of sustainability. On one hand it describes the environment friendly technologies utilized to synthesize particles in nano scale; on the other hand it refers to the nanoparticles synthesis mediated by extracts of chlorophyllus plants. It also encourages replacement of existing products with new nano-products that are more environmentally friendly throughout their lifecycle.
Green nanotechnology has two goals: producing nanomaterials and products without harming the environment or human health, and producing nano-products that provide solutions to environmental problems. It uses existing principles of green chemistry and green engineering [ 3 ] to make nanomaterials and nano-products without toxic ingredients, at low temperatures using less energy and renewable inputs wherever possible, and using lifecycle thinking in all design and engineering stages.
In addition to making nanomaterials and products with less impact to the environment, green nanotechnology also means using nanotechnology to make current manufacturing processes for non-nano materials and products more environmentally friendly. For example, nanoscale membranes can help separate desired chemical reaction products from waste materials from plants. Nanoscale catalysts can make chemical reactions more efficient and less wasteful.
Sensors at the nanoscale can form a part of process control systems, working with nano-enabled information systems.
Extracellular vesicles versus synthetic nanoparticles for drug delivery
Using alternative energy systems, made possible by nanotechnology, is another way to "green" manufacturing processes. The second goal of green nanotechnology involves developing products that benefit the environment either directly or indirectly. Nanomaterials or products directly can clean hazardous waste sites, desalinate water , treat pollutants, or sense and monitor environmental pollutants. Indirectly, lightweight nanocomposites for automobiles and other means of transportation could save fuel and reduce materials used for production; nanotechnology-enabled fuel cells and light-emitting diodes LEDs could reduce pollution from energy generation and help conserve fossil fuels; self-cleaning nanoscale surface coatings could reduce or eliminate many cleaning chemicals used in regular maintenance routines; [ 4 ] and enhanced battery life could lead to less material use and less waste.
Green Nanotechnology takes a broad systems view of nanomaterials and products, ensuring that unforeseen consequences are minimized and that impacts are anticipated throughout the full life cycle. Research is underway to use nanomaterials for purposes including more efficient solar cells , practical fuel cells , and environmentally friendly batteries.
Nano på gott och ont: möjligheter och risker med nanoteknologi
The most advanced nanotechnology projects related to energy are: storage, conversion, manufacturing improvements by reducing materials and process rates, energy saving by better thermal insulation for example , and enhanced renewable energy sources. One major project that is being worked on is the development of nanotechnology in solar cells. The price per watt of solar energy is lower than one dollar. Research is ongoing to use nanowires and other nanostructured materials with the hope of to create cheaper and more efficient solar cells than are possible with conventional planar silicon solar cells.
Materials with small nanosized pores may be suitable for hydrogen storage. Nanotechnology may also find applications in batteries , where the use of nanomaterials may enable batteries with higher energy content or supercapacitors with a higher rate of recharging. Nanotechnology is already used to provide improved performance coatings for photovoltaic PV and solar thermal panels. Hydrophobic and self-cleaning properties combine to create more efficient solar panels, especially during inclement weather.
PV covered with nanotechnology coatings are said to stay cleaner for longer to ensure maximum energy efficiency is maintained. Nanotechnology offers the potential of novel nanomaterials for the treatment of surface water, groundwater , wastewater , and other environmental materials contaminated by toxic metal ions, organic and inorganic solutes, and microorganisms. Due to their unique activity toward recalcitrant contaminants, many nanomaterials are under active research and development for use in the treatment of water and contaminated sites.
The present market of nanotech-based technologies applied in water treatment consists of reverse osmosis RO , nanofiltration, ultrafiltration membranes. Indeed, among emerging products one can name nanofiber filters, carbon nanotubes and various nanoparticles. Nanotechnology is expected to deal more efficiently with contaminants which convectional water treatment systems struggle to treat, including bacteria, viruses and heavy metals.
This efficiency generally stems from the very high specific surface area of nanomaterials, which increases dissolution, reactivity and sorption of contaminants. Nanoremediation is the use of nanoparticles for environmental remediation. Some nanoremediation methods, particularly the use of nano zerovalent iron for groundwater cleanup, have been deployed at full-scale cleanup sites. This process typically involves a pump-and-treat process or in situ application.
Other methods remain in research phases. Scientists have been researching the capabilities of buckminsterfullerene in controlling pollution, as it may be able to control certain chemical reactions. Buckminsterfullerene has been demonstrated as having the ability of inducing the protection of reactive oxygen species and causing lipid peroxidation. This material may allow for hydrogen fuel to be more accessible to consumers.
This patented nanotechnology uses a high pressure and temperature chamber to separate isotopes that should by nature not be in drinking water to pure drinking water, as to the by the WHO ´s established classification. This method has been developed by among others, by professor Vladimir Afanasiew, at the Moscow Nuclear Institution. This technology is targeted to clean Sea, river, lake and landfill waste waters.
It even removes radioactive isotopes from the sea water, after Nuclear Power Stations catastrophes and cooling water plant towers. By this technology pharmaca rests are being removed as well as narcotics and tranquilizers. Bottom layers and sides at lake and rivers can be returned, after being cleaned.