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Nanotechnology Spotlight

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Showing Spotlights 89 - 95 of 95 in category Green Nanotechnology (newest first):

 

Green nanotechnology: Synthesizing nanoparticles with sunlight

While the first reported fullerenes and nanotube structures were composed of carbon, it was soon recognized that a plethora of comparable inorganic candidates should also exist. A rich assortment of IF (inorganic fullerene-like structures, or IF for short) nanostructures have been synthesized, and are finding practical uses in tribology, photonics, batteries, and catalysis. On such inorganic molecule that can achieve fullerene-like nanostructures, cesium oxide, is particularly useful for a multitude of applications in photoemissive systems. Unfortunately, it is extremely reactive in the ambient atmosphere, so its production and handling require high vacuum and very pure inert conditions; which translates into problematic and expensive manufacturing and handling, which in turn limits its technological scope and device lifetime. In their quest for a relatively uncomplicated high-yield synthesis method for chemically stable cesium oxide IFs, scientists succeeded in exploiting highly concentrated solar radiation (ultrabright incoherent light) toward that end. This resulted in a simple, inexpensive, and reproducible photothermal procedure for synthesizing IF nanoparticles.

Posted: Nov 29th, 2006

Nanomaterials made from apricots and cashew nuts could replace petrochemicals

The use of renewable resources (biomass) as an alternate source for fuel and the production of valuable chemicals is becoming a topic of great interest and a driving force behind research into biorefinery concepts. In the early parts of the 20th century, most nonfuel industrial products such as medicines, paints, chemicals, dyes, and fibers were made from vegetables, plant and crops. During the 1970s, petroleum based organic chemicals had largely replaced those derived from plant materials, capturing more than 95% of the markets previously held by products from biological sources. By then, petroleum accounted for more than 70% of our fuel. However, recent developments in biobased materials research show prospects that many petrochemical derived products can be replaced with industrial materials processed from renewable resources. Researchers continue to make progress in research and development of new technologies that bring down the cost of processing plant matter into value-added products. Rising environmental concerns are also suggesting the use of agriculture and forestry resources as alternative feedstock. Being able to develop soft nanomaterials and fuel from biomass will have a direct impact on industrial applications and economically viable alternatives. Researchers already have used plant-derived resources to make a variety of soft nanomaterials, which are useful for a wide range of applications.

Posted: Oct 31st, 2006

Biomechanical nanoswitches open door to green bioelectronics

The ability to generate functional nanoswitches might ultimately allow the integration of nano-components into electronic components. Single molecule switches using scanning tunneling microscope (STM) manipulation have been demonstrated before. Mostly these switches are based on single atoms or small molecules and operate between two distinct states. Researchers now realized the first multi-step switching process by STM manipulation on a single molecule. Instead of small organic molecules they used a large plant molecule which is environmentally friendly and abundant in nature.

Posted: Sep 18th, 2006

Non-toxic nanolithography using pure water

Conventionally, the fabrication of thin film nanostructures is primarily done by using selective etching or templating growth on a prepatterned resist and then performing lift-off. The solvents used in developing resist are typically toxic and add to the cost of lithographic processing. Recently, many environmentally friendly lithographic processes have been designed using either a water-based solution or supercritical carbon dioxide to develop the resist. A novel pure water developable spin-coatable lanthanum strontium manganese oxide (LSMO) resist has been developed by scientists in Taiwan. The use of pure water instead of organic or alkaline solvents would undoubtedly be not only environmentally desirable but also could greatly simplify the imaging process.

Posted: Aug 22nd, 2006

A green synthesis technique for fabricating carbon-coated magnetic nanoparticles

Encapsulating metal nanoparticles inside carbon shells is of considerable significance but fraught with high manufacturing cost due to high energy consumption and intensive use of hardware. This cost issue limits their practical applications. Researchers in China have developed a novel, simple, efficient, and economical synthesis technique for the fabrication of carbon-encapsulated nanostructures where the carbonization is conducted at a relatively low temperature of 160C in water and no toxic reagents are added. This new technique is facile and versatile, and suitable for the coating of other transition metal with carbon.

Posted: Aug 15th, 2006

Nanosensors in environmental analysis

A comprehensive overview of the main concepts behind the development of nanosensors and the most relevant applications in the field of environmental analysis.

Posted: Mar 22nd, 2006