Applications of Nanotechnology in Polymers
Nanotechnology contributes significant advantages to plastics applications today and will bring even more advances in the future. Nanocomposites that enhance the properties of thermoplastic resins, making them tougher, more heat-, dent- and scratch-resistant, can be processed using the same equipment and methods as “traditional” resins. Nanotechnology promises to bring about new products that would have been impossible with macro-sized materials, for example, postage-stamp sized memory chips capable of holding 25 DVDs’ worth of data, or completely scratch-resistant auto body paints.Here are a few examples of how nanotechnology is changing plastics product manufacturing today:
Nanoclays or nanocarbon fillers, including layered silicate nanoclays, nanotalcs, carbon nanotubes and graphite platelets in a polymeric matrix. Nanoscale reinforcing materials are used in a variety of thermoplastics, such as polypropylene, thermoplastic olefins, polyethylene terephthalate, polyethylene, polystyrene and nylon. Nanocomposites outperform standard fillers and reinforcements in raising heat resistance, dimensional stability, stiffness, flame retardancy and electrical conductivity. Typical applications include automotive parts, including body side molding, fuel-line components and interior center consoles. In electronics, polycarbonate and polyetherimide components of hard drives have been reinforced with nanotubes to give them better conductivity. Nanocomposite concentrates are being evaluated in films for enhancing barrier properties and controlling the release of additives such as biocides and dyes. Nanoclays in nylons are used as barrier layers in multi-layer PET bottles and films for food packaging.
Electrically Conductive Polymer Nanocomposite Materials
Scientists and engineers at the Materials and Manufacturing Directorate, working with the University of Dayton Research Institute, have developed polymer nanocomposite materials capable of carrying or dissipating significant electrical charge. Nanotubes on the order of 50 to 150 nm (nanometers) in diameter, that are remarkably flexible and have the current carrying capacity of copper, are dispersed into a supporting polymer matrix. Electrically condcutive polymer nanocomposite materials offer substantial weight savings, flexibility, durability, low-temperature processability and tailored reproducible conductivity compared to conductive metal-filled systems. Applications could include conductive paints, coatings, caulks, sealants, adhesives, fibers, thin films, thick sheets and tubes for use the in aerospace, automotive and chemical industry markets.
The U.S. Department of Energy’s Lawrence Berkeley National Laboratory and The University of California-Berkeley have developed a hybrid semicondctor-polymer photovolatic device which will be cheaper and easier to make than conventional solar panels and could be molded into the same nearly infinite variety of shapes as pure polymers. Semiconductor nanorods are be used to fabricate readily processed and energy-efficient hybrid solar cells together with polymers. The use of solar, or photovoltaic, cells — devices that can absorb and convert light into electrical power — has been limited because production costs are so high.
Ohio State University engineers have found a way, using nanocomposites, to make dense plastic foam that may replace solid plastic in the future. The foam products are lighter than solid plastics, but appear the same to the eye. Potential applications include seat cushions, carpet padding, home insulation, disposable diapers, fast food container, coffee cups and packaging material.
Nanotechnology in the Construction Industry
The use of nanotechnology materials and applications in the construction industry should be considered not only for enhancing material properties and functions but also in the context of energy conservation. This is a particularly important prospect since a high percentage of all energy used (e.g., 41% in the United States) is consumed by commercial buildings and residential houses by applications such as heating, lighting, and air conditioning.
According to an economic assessment, nanotechnology has a significant impact in the construction sector. Several applications have been developed for this specific sector to improve the durability and enhanced performance of construction components, energy efficiency and safety of the buildings, facilitating the ease of maintenance and to provide increased living comfort. Though self-cleaning feature has been possible to attain using micron sized coatings and surface treatments e.g. Teflon™, polysilazane based coatings, etc. now this feature has become a marketing tool / motto for nanotechnology applications, especially for consumer markets like construction, textile, etc.
Nanomaterialsused in construction
Carbon nanotubes – Expected benefits are mechanical durability and crack prevention (in cement); enhanced mechanical and thermal properties (in ceramics); real-time structural health monitoring (NEMS/MEMS); and effective electron mediation (in solar cells).
Silicon dioxide nanoparticles – Expected benefits are reinforcement in mechanical strength (in concrete); coolant, light transmission, and fire resistance (in ceramics); flame-proofing and anti-reflection (in windows).
Titanium dioxide nanoparticles – Expected benefits are rapid hydration, increased degree of hydration, and self-cleaning (in concrete); superhydrophilicity, anti-fogging, and fouling-resistance (in windows); non-utility electricity generation (in solar cells).
Iron oxide nanoparticles – Expected benefits are increased compressive strength and abrasion-resistant in concrete.
Copper nanoparticles – Expected benefits are weldability, corrosion resistance, and formability in steel.
Silver nanoparticles – Expected benefits are biocidal activity in coatings and paints.
Quantum dots – Expected benefits are effective electron mediation in solar cells.
One particular area for nanotechnology in the construction industry is concrete, specifically research on how to reinforce concrete to improve its mechanical performance . The video below shows how researchers are using nanosilica to strengthen concrete: