Phosphor removal from nano iron

A professor at Michigan State University is part of a team developing a new method of removing phosphorus from wastewater; a problem seriously affecting lakes and streams across the world.

Phosphorus is part of all food as well as is in items such as detergents and fertilizer and remains a critical problem as it is always present in human and animal wastes.

Discharge from human and industrial wastewater and runoff into lakes and streams can cause eutrophication, making the water unsuitable for recreational purposes and reducing fish populations, as well as causing the growth of toxic algae.

Researchers have figured out and tested over the past 10 years is how to produce a media, enhanced with nanoparticles composed of iron, that can more efficiently remove larger amounts of phosphorus from water.

Phosphorus that is dissolved in wastewater, like sugar in water, is hard to remove. A nano-media made with waste iron can efficiently absorb it, making it a solid that can be easily and efficiently removed and recovered for beneficial reuse. Their method of phosphorus retrieval is much more cost effective than processing phosphate rock. Research suggests that it is significantly cheaper to recover phosphorus this way.

Molybdenum disulfide (MoS2): New nanomaterial with several advantages

The discovery of graphene, a material just one atom thick and possessing exceptional strength and other novel properties, started an avalanche of research around its use for everything from electronics to optics to structural materials. But new research suggests that was just the beginning: A whole family of two-dimensional materials may open up even broader possibilities for applications that could change many aspects of modern life.

The latest new material, molybdenum disulfide (MoS₂) was first described just a year ago by researchers in Switzerland. But in that year, researchers at MIT who struggled for several years to build electronic circuits out of graphene with very limited results (have already succeeded in making a variety of electronic components from MoS₂. They say the material could help usher in radically new products, from whole walls that glow to clothing with embedded electronics to glasses with built-in display screens.

 Researchers think graphene and MoS₂ are just the beginning of a new realm of research on two-dimensional materials. Like graphene, itself a 2-D form of graphite, molybdenum disulfide has been used for many years as an industrial lubricant. But it had never been seen as a 2-D platform for electronic devices until last year, when scientists at the Swiss university produced a transistor on the material.

 Then MIT researchers found a good way to make large sheets of the material using a chemical vapor deposition process. As there are lots of hindrance in making electronic products out of graphene due to lack of bandgap, MoS₂ just naturally comes with large band gap.

 MoS₂ is widely produced as a lubricant and as others are working on making it into large sheets, scaling up production of the material for practical uses should be much easier than with other new materials. People are able to fabricate a variety of basic electronic devices on the material: an inverter, which switches an input voltage to its opposite; a NAND gate, a basic logic element that can be combined to carry out almost any kind of logic operation; a memory device, one of the key components of all computational devices; and a more complex circuit called a ring oscillator, made up of 12 interconnected transistors, which can produce a precisely tuned wave output.

One potential application of the new material is large-screen displays such as television sets and computer monitors, where a separate transistor controls each pixel of the display. Because the material is just one molecule thick, unlike the highly purified silicon that is used for conventional transistors and must be millions of atoms thick, even a very large display would use only an infinitesimal quantity of the raw materials. This could potentially reduce cost and weight and improve energy efficiency.

Further reading:

arxiv.org/pdf/1208.1078 

 

In the future, it could also enable entirely new kinds of devices. The material could be used, in combination with other 2-D materials, to make light-emitting devices. Instead of producing a point source of light from one bulb, an entire wall could be made to glow, producing softer, less glaring light. Similarly, the antenna and other circuitry of a cellphone might be woven into fabric, providing a much more sensitive antenna that needs less power and could be incorporated into clothing.

 The material is so thin that it's completely transparent, and it can be deposited on virtually any other material. For example, MoS₂ could be applied to glass, producing displays built into a pair of eyeglasses or the window of a house or office.

100,000 Dots-Per-Inch (DPI) image resolution is achieved using metal-laced nanostructures

Researchers from Institute of Materials Research and Engineering (IMRE) have developed an innovative method for creating sharp, full-spectrum colour images at 100,000 dots per inch (dpi), using metal-pattern nanostructures, without the need for inks. In comparison, current industrial printers such as inkjet and laser jet printers can only achieve up to 10,000 dpi while research grade methods are able to dispense dyes for only single colour images. This novel breakthrough using lithographic technique which can potentially revolutionise the way images are printed and be developed for use in high-resolution reflective colour displays as well as high density optical data storage.

 The inspiration for the research was derived from stained glass, which is traditionally made by mixing tiny fragments of metal into the glass. It was found that nanoparticles from these metal fragments scattered light passing through the glass to give stained glass its colours. Using a similar concept with the help of modern nanotechnology tools, the researchers precisely patterned metal nanostructures, and designed the surface to reflect the light to achieve the colour images.

The resolution of printed colour images very much depends on the size and spacing between individual nanodots. The closer the dots are together and because of their small size, the higher the resolution of the image. With the ability to accurately position these extremely small colour dots, the highest theoretical print colour resolution of 100,000 dpi could be achieved.

Instead of using different dyes for different colours, colour information is encoded into the size and position of tiny metal disks. These disks then interacted with light through the phenomenon of plasmon resonances. Nanostructure pattern, size and spacing are then correlated with the database of colour. These nanostructures were then positioned accordingly.