David Kirkpatrick

November 4, 2010

Transparent solar panels?

A very real possibility. This sounds like very promising technology.

The release:

Transparent Conductive Material Could Lead to Power-Generating Windows

Combines elements for light harvesting and electric charge transport over large, transparent areas

November 3, 2010

conjugated polymer honeycombClick on the image to download a high-resolution version.Top: Scanning electron microscopy image and zoom of conjugated polymer (PPV) honeycomb. Bottom (left-to-right): Confocal fluorescence lifetime images of conjugated honeycomb, of polymer/fullerene honeycomb double layer and of polymer/fullerene honeycomb blend. Efficient charge transfer within the whole framework is observed in the case of polymer/fullerene honeycomb blend as a dramatic reduction in the fluorescence lifetime.

UPTON, NY — Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Los Alamos National Laboratory have fabricated transparent thin films capable of absorbing light and generating electric charge over a relatively large area. The material, described in the journal Chemistry of Materials, could be used to develop transparent solar panels or even windows that absorb solar energy to generate electricity.

The material consists of a semiconducting polymer doped with carbon-rich fullerenes. Under carefully controlled conditions, the material self-assembles to form a reproducible pattern of micron-size hexagon-shaped cells over a relatively large area (up to several millimeters).

“Though such honeycomb-patterned thin films have previously been made using conventional polymers like polystyrene, this is the first report of such a material that blends semiconductors and fullerenes to absorb light and efficiently generate charge and charge separation,” said lead scientist Mircea Cotlet, a physical chemist at Brookhaven’s Center for Functional Nanomaterials (CFN).

Furthermore, the material remains largely transparent because the polymer chains pack densely only at the edges of the hexagons, while remaining loosely packed and spread very thin across the centers. “The densely packed edges strongly absorb light and may also facilitate conducting electricity,” Cotlet explained, “while the centers do not absorb much light and are relatively transparent.”

Mircea CotletClick on the image to download a high-resolution version.Mircea Cotlet, Ranjith Krishna Pai, and Zhihua Xu (seated at the microscope).

“Combining these traits and achieving large-scale patterning could enable a wide range of practical applications, such as energy-generating solar windows, transparent solar panels, and new kinds of optical displays,” said co-author Zhihua Xu, a materials scientist at the CFN.

“Imagine a house with windows made of this kind of material, which, combined with a solar roof, would cut its electricity costs significantly. This is pretty exciting,” Cotlet said.

The scientists fabricated the honeycomb thin films by creating a flow of micrometer-size water droplets across a thin layer of the polymer/fullerene blend solution. These water droplets self-assembled into large arrays within the polymer solution. As the solvent completely evaporates, the polymer forms a hexagonal honeycomb pattern over a large area.

“This is a cost-effective method, with potential to be scaled up from the laboratory to industrial-scale production,” Xu said.

The scientists verified the uniformity of the honeycomb structure with various scanning probe and electron microscopy techniques, and tested the optical properties and charge generation at various parts of the honeycomb structure (edges, centers, and nodes where individual cells connect) using time-resolved confocal fluorescence microscopy.

The scientists also found that the degree of polymer packing was determined by the rate of solvent evaporation, which in turn determines the rate of charge transport through the material.

“The slower the solvent evaporates, the more tightly packed the polymer, and the better the charge transport,” Cotlet said.

“Our work provides a deeper understanding of the optical properties of the honeycomb structure. The next step will be to use these honeycomb thin films to fabricate transparent and flexible organic solar cells and other devices,” he said.

The research was supported at Los Alamos by the DOE Office of Science. The work was also carried out in part at the CFN and the Center for Integrated Nanotechnologies Gateway to Los Alamos facility. The Brookhaven team included Mircea Cotlet, Zhihua Xu, and Ranjith Krishna Pai. Collaborators from Los Alamos include Hsing-Lin Wang and Hsinhan Tsai, who are both users of the CFN facilities at Brookhaven, Andrew Dattelbaum from the Center for Integrated Nanotechnologies Gateway to Los Alamos facility, and project leader Andrew Shreve of the Materials Physics and Applications Division.

The Center for Functional Nanomaterials at Brookhaven National Laboratory and the Center for Integrated Nanotechnologies Gateway to Los Alamos facility are two of the five DOE Nanoscale Science Research Centers (NSRCs), premier national user facilities for interdisciplinary research at the nanoscale. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE’s Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge and Sandia and Los Alamos national laboratories.

 

February 3, 2009

Nanotech facing additional oversight

I do think public safety ought to be a priority, but I’d also like to make sure regulatory actions are not unnecessary overkill. It would be a shame to stifle innovation in nanotechnology.

The release from this evening:

Risk-Management Policies Needed Now in Nanotechnology, Insighter Piece Concludes; FDLI Sponsors Nanotechnology Meeting, Publishes Book on FDA-Regulated Products

WASHINGTON, Feb. 3 /PRNewswire-USNewswire/ — Companies that manufacture products containing nanomaterials must immediately institute high-quality risk management and product stewardship measures to limit potential liability exposure in the future, assert attorneys Jesse Ash, Antony Klapper and James Wood.

This issue will be thoroughly explored at FDLI’s 2nd Annual Conference on Nanotechnology Law, Regulation and Policy, February 18-19, 2009, in Washington, D.C., and discussed in a book to be published by FDLI February 17, Nanotechnology & FDA-Regulated Products: The Essential Guide. At the conference, six top officials of the Food and Drug Administration will answer questions about how the new Administration intends to regulate nanotechnology products.

In their Insighter article on the Food and Drug Law Institute’s website (www.fdli.org), Ash, Klapper and Wood, part of a team of more than two dozen attorneys involved in nanotechnology issues at the law firm of Reed Smith, note that while there has not been a single lawsuit filed where someone claimed injury because they were exposed to engineered nanomaterials, many scientists are raising questions regarding the manufacturing of nanomaterials and its effects on workforces, researchers and consumers.  “For example,” they write in the Insighter piece, “some scientists wonder whether engineered nanomaterials will become the next asbestos.”

The attorneys point out that a recent study indicated that certain types of carbon nanotubes, graphite-based structures commonly used in nanotechnology applications, both resemble and behave like asbestos fibers.  Because they are as light as plastic and stronger than steel, carbon nanotubes will likely see use in a variety of new applications, including medical nanodevices.  Based on toxicity studies, scientists found that inhaling long, thin multi-walled carbon nanotubes had the potential to cause lung disorders similar to those caused by exposure to asbestos.  Because there are many unanswered questions regarding risk, it is essential that companies follow the principles of good product stewardship activities and good risk management strategies in the design and manufacturing of products made with engineered nanomaterials, the authors conclude.

To register for the conference, order the book or view the entire Insighter article, visit www.fdli.org

Source: Food and Drug Law Institute

July 29, 2008

Nanotech faces local regulation

Because nanotech and nanomaterials face little, or no, Federal government oversight, state and local government is stepping into the void.

The press release:

Local officials move toward monitoring nanotechnologies

Massachusetts city health officials urge adoption of unique voluntary program

Washington, DC — State and local officials have taken steps to begin monitoring the manufacture and storage of nanomaterials, a major step for a cutting-edge technology that has yet to be regulated by the federal government.

On July 28, the Cambridge (Mass.) Public Health Department recommended to the city manager that Cambridge take several steps to gain a better understanding of the nature and extent of nanotechnology-related activities now underway within the city. In addition, news outlets are reporting that a key member of California State Assembly Committee on Environmental Safety and Toxic Materials is holding meetings around the state in advance of introducing legislation next year that may grant state regulators landmark oversight of nanomaterials.

In 2006, Berkeley, Calif., passed the first local ordinance in the nation by requiring handlers of nanomaterials to submit toxicology reports on the materials to the city government.

The efforts by state and local officials come as the Project on Emerging Nanotechnologies (PEN) recently released a report that discusses possible options for state and local governments to follow for oversight of potential negative impacts of nanotechnology – including local air, waste and water regulations, as well as labeling and worker safety requirements.

“In the absence of action at the federal level, local and state governments may begin to explore their options for oversight of nanotechnologies,” says Suellen Keiner, the author of Room at the Bottom? Potential State and Local Strategies for Managing the Risks and Benefits of Nanotechnology.

Another recent PEN report, Application of the Toxics Release Inventory To Nanomaterials, addresses the potential application of local “right-to-know” laws concerning nanotechnologies.

The Cambridge Public Health Department, in collaboration with the Cambridge Nanomaterials Advisory Committee, in its new report does not recommend the city manager enact a new ordinance regulating nanotechnology, but it does recommend that the city take the following steps:

 

  • Establish an inventory of engineered nanoscale materials that are manufactured, handled, processed, or stored in the city, in cooperation with the Cambridge Fire Department and the Local Emergency Planning Committee. 

 

  • Offer technical assistance, in collaboration with academic and nanotech sector partners, to help firms and institutions evaluate their existing health and safety plans for limiting risk to workers involved in nanomaterials research and manufacturing. 

 

  • Offer up-to-date health information to residents on products containing nanomaterials and sponsor public outreach events. 

 

  • Track rapidly changing developments in research concerning possible health risks from various engineered nanoscale materials. 

 

  • Track the evolving status of regulations and best practices concerning engineered nanoscale materials among state and federal agencies, and international health and industry groups. 

 

  • Report to the city council every two years on the changing regulatory and safety landscape of the nanotechnology sector. 

David Rejeski, the director of PEN and a member of an advisory committee that oversaw the public health department’s document, says that while the recommendations are encouraging and important, there is still a need for federal oversight of nanotechnology and an increase in research concerning the risks posed by nanomaterials.

“Today, there are more than 600 manufacturer-identified consumer products available on the market that contain nanomaterials and countless other commercial and industrial applications the public and policymakers are not aware of,” Rejeski says. Unfortunately, federal agencies currently have to draw on decades-old laws to ensure the safe development and use of these technologically advanced products — many of which are woefully out of date. Federal officials need 21st century tools for cutting-edge technologies. Anything short of that is unacceptable.”

Meanwhile, California Assemblyman Mike Feuer (D), a member of the Assembly’s Committee on Environmental Safety and Toxic Materials, is holding meetings at major state universities and research centers with representatives from industry, government, environmental groups and others in an effort to craft legislation for introduction in 2009 that would establish a state nanotechnology regulatory program, according to an April article in Inside Cal/EPA.

 

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The Cambridge recommendations are available here: http://www.cambridgepublichealth.org/policy-practice/nano_policy.php

Room at the Bottom? Potential State and Local Strategies for Managing the Risks and Benefits of Nanotechnology is available here: http://www.nanotechproject.org/publications/archive/room_at_bottom/

Application of the Toxics Release Inventory To Nanomaterials is available here: http://www.nanotechproject.org/publications/archive/toxics/

About Nanotechnology

 

Nanotechnology is the ability to measure, see, manipulate and manufacture things usually between 1 and 100 nanometers. A nanometer is one billionth of a meter; a human hair is roughly 100,000 nanometers wide. In 2007, the global market for nanotechnology-based products totaled $147 billion. Lux Research projects that figure will grow to $3.1 trillion by 2015.

The Project on Emerging Nanotechnologies (www.nanotechproject.org) is an initiative launched by the Woodrow Wilson International Center for Scholars and The Pew Charitable Trusts in 2005. It is dedicated to helping business, government and the public anticipate and manage possible health and environmental implications of nanotechnology.