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Vol. 55, No. 16           August 8, 2003
[Sandia National Laboratories]

Albuquerque, New Mexico 87185-0165    ||   Livermore, California 94550-0969
Tonopah, Nevada; Nevada Test Site; Amarillo, Texas

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Sandia researchers create nanocrystals nature's way Journey toward improved business systems continues at Sandia



Sandia researchers create nanocrystals nature's way

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By Michael Padilla

Sandia researchers are developing complex nanomaterials that look strikingly similar to the microstructures of diatoms and seashells. Such materials may have potential for a wide range of applications.

Jun Liu (1846) says the ultimate goal is to develop general science and technology for reliable and scalable production of nanoscale materials based on environmentally benign chemical processes.

The research team currently includes Jim Voigt, Zhengrong (Ryan) Tian (1846), Matt McDermott (1846), Randy Cygan (6118), Louise Criscenti (6118), Dianna Moore (1846), Jessica Bickel (1846), and Tom Sounart (1141). The team's intent is to be able to predictively and precisely control a wide range of materials properties that are critical for the materials and device performances. These include composition, particle size and shape, crystalline structure, orientation, particle morphology, surface, and interface chemistry.

Jun says the biochemical processes involved in biomaterials are too complicated for synthetic materials. The team is learning from the physical and chemical principles behind the formation of natural materials, and is developing synthetic routes to achieve similar structural control for the production of nanomaterials.

The project intention is that such extended and oriented nanostructures will find applications in microelectronic devices, chemical and biological sensing and diagnosis, catalysis, and energy conversion and storage including photovoltaic cells, batteries, capacitors, and hydrogen storage devices. These structures could also have potential for light-emitting display, drug delivery, and optical storage.

"We have already demonstrated superior photocatalytic properties and new chemical sensor devices with our new materials," Jun says.

The team has demonstrated complete control of where and how crystals are formed by selectively activating the specific surface they desire to grow and spontaneously producing complicated three-dimensional structures that cannot be formed by other means.

Understanding nature's strategies

"We are not interested in duplicating the mechanisms in natural materials," Jun says. "Nor are we interested in reproducing biominerals."

However, Jun adds, an understanding of nature's strategy is necessary to comprehend how to create similar structures.

The strategies nature uses to produce biomaterials are drastically different from synthetic approaches. Natural materials are produced at low temperature -- mostly room temperature -- and do not produce significant waste. Seashells and diatoms extract calcium and silicate ions from ocean water to form hard tissues to protect the living organisms.

Natural systems use sophisticated protein molecules to precisely control the orientations and morphologies of the biominerals in order to optimize the material's properties such as the mechanical strength. As a result, very complex architectures are formed, such as in diatoms from very simple chemicals such as silicate. Silicate, Jun says, is a very common ceramic material that is frequently experimented on in laboratories.

In general, Jun adds, the proteins play two important tricks. First, the proteins control where the mineral is deposited. Second, they control how the minerals are formed. In red abalone, a marine snail, water-soluble proteins control mineralization of calcium carbonate. Some of these proteins are responsible for the formation of column-like calcite (a natural form of calcium carbonate), while others are for the formation of plate-like aragonite (an unusual form of calcium carbonate). The cooperative action of these proteins produces a highly ordered nanocomposite composed of oriented calcite columns and close-packed aragonite nanoplatelets. This combination gives the best mechanical properties to the hard tissue.

The process

The first step of the process is to understand and control the solution chemistry. Instead of using high temperatures, high concentrations of chemicals, and organic solvents, as widely investigated, the team studies low-temperature -- well below the boiling temperature of water -- and low-chemical-concentration experimental conditions in aqueous environments. Under these conditions the team has better control on how fast the materials grow from the solution and avoid precipitations commonly encountered.

The minerals are controlled where they are formed through chemical and physical means. Modifying of the surface chemistry is often used to stimulate the formation of the minerals on specific locations. Other times nanoparticles are used as the nucleation seeds from which the new minerals will be formed. Using this approach the team can control exactly how the minerals are formed, and potentially align and pattern the minerals for microdevices. The orientation, microstructure, and morphology of the crystals are controlled. Since the roles of mineral-directing proteins are not yet completely understood, and since they cannot be directly applied to synthetic materials, simple organic molecules are used to control crystal growth. Computer modeling is also used to help understand how the organic molecules bind to the crystals.

Overcoming challenges

"Making these kinds of complex nanostructures is a very significant challenge," Jun says. "This is a very important new research area. Not a lot has been understood."

However, Jun says, manufacturing of nanoscale materials in general remains a significant scientific and technological challenge. Most of the approaches currently investigated involve high-temperature processes and complex toxic chemistry.

One challenge now is to fundamentally understand how organic molecules affect crystal growth. Jun says this is not only a challenge for synthetic materials, but also a problem for biomineralization that needs the attention of physicists, chemists, biologists, and material scientists. Another challenge is developing general rules that will guide the production of a wide range of nanomaterials.

Optimistic outlook

Jun says the team is also in the process of developing tools to control the delivery, diffusion, and transport of the chemical species in the reaction chambers.

"We will use Sandia's state-of-the-art microfluidic platforms to provide precise control of the experimental parameters," Jun says. "The microfluidic studies may also lead to methods for continuous manufacturing of tailored nanoscale materials, including nanoparticles, nanowires, and complex nano-structured films."

The team recently published their studies in the Journal of American Chemical Society, Agewandte Chemie, and Nano Letters.

Jun says he hopes to bring visibility to this area and stimulate others to follow. - - Michael Padilla

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Journey toward improved business systems continues at Sandia

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By Chris Burroughs

Journey toward improved business systems continues at Sandia

The journey toward improving business continues at Sandia as two more organizations become ISO (for International Organization for Standardization) certified.

Certified in May was Telecommunications Operations Dept. 9334. In July the International Contracts and Import Export Control Dept. 10257 received notice it has been recommended for ISO 9001:2000 certification.

Two other organizations have been certified in the past several years -- Manufacturing Enterprise Departments 14181, 14186, and 14111 and the Material Processing and Coatings Laboratory.

The organizations sought ISO certification as one way to improve their business management systems -- a fully integrated, well-understood, data-driven system that enables delivery of products and services that meet customer requirements.

ISO was established in 1947 as a nongovernmental worldwide federation of national standards bodies from some 140 countries. It promotes the development of standardization and related activities to aid the international exchange of good and services. It also bolsters cooperation in intellectual, scientific, technological, and economic activity. ISO's work results in international agreements that are published as international standards.

ISO 9001:2000 -- the latest version of ISO 9000 -- is used by companies seeking a management system that provides confidence their products conform to established or specified requirements.

"A robust Business Management System (BMS) that can be certified to ISO 9001:2000 means everyone in the organization understands how their work contributes to successfully addressing customer needs and requirements," says Felipe (Phil) Rivera (12142). "It also acknowledges a system is in place that addresses identified problems or issues to assure sustainable improvements. ISO certification comes at a considerable effort."

He adds, "However, being certified is not the end. It's the beginning of a journey that never ends to improve business. Our philosophy is to offer organizations a method of improving their business by using the criteria of the ISO 9001:2000 standard. As the organization matures and improves, a by-product may be ISO 9001:2000 certification."

Telecommunications

One Thursday in July two people in Media Relations and Communications Dept. 12640 were scheduled to swap offices. A little before 8 a.m. a telecommunications representative was on hand to change phones and take care of networking.

What lies behind such prompt service? Possibly ISO 9001:2000.

Telecommunications Operations Dept. 9334 officially became ISO 9001:2000 certified on May 13, a feat that involved more than two years of documenting and streamlining work methods, trouble shooting, and improving ways of doing work.

"As a result of our efforts, we have greatly improved how we deliver our products," says Mike Gomez (9334). "We can now respond faster to requests and problems."

The concept of adopting ISO 9001:2000 was first mentioned in the department in the summer of 2000. Several department members took an ISO class in December 2000, and over the next two years all 130 employees in the department were bought into the concept.

Mike says that before life with ISO, the department did its work well. Procedures, although written, were not used or valued by the staff.

As part of improving its business management system, the department defined seven processes to document and formalize: change management, trouble resolution, asset management, documentation and communication, quality improvement, design and evaluation, and human resources. They wrote down what the department did in each of these areas and then looked at ways to make improvements by developing a database for tracking corrective and preventive actions. They improved their use of Web FileShare and Sandia's internal web site. During each monthly staff meeting, they discussed how to improve their processes and systems.

"The entire time our focus was on improvement, not certification," Mike says. "We had to make ISO work for us and focus on our goals. We didn't do ISO for the sake of doing ISO."

In November 2002 the department had an internal pre-assessment audit performed by Bob Campbell representing the Performance Review Institute, followed in March 2003 by an official certification audit. It received certification to the 9001:2000 standard on May 13.

Mike says auditors noted that on a scale of 1 to 10, the department rated a 9 in the area of staff commitment. Some of the comments from the auditors at the closing meeting included:

Not bad, Mike says. But the department intends to continue to make improvements and be responsive to its customers. "We will keep seeking new and better ways to do our business."

International Procurement

The International Procurement Team's contracting effort with foreign suppliers around the world means they constantly work within a variety of different systems, regulations, and cultures. As a recognized worldwide quality management standard, ISO 9001:2000 provides the International Procurement Team (IPT) the ability to provide quality assurance to partners and suppliers around the world while meeting or exceeding customer requirements at home.

Aware of this and the opportunities ISO provides for continuous improvement, team members decided to seek ISO 9001:2000 certification.

"We first tried to understand what ISO was all about and how it would apply and help us conduct our business," says Roy Fitzgerald, Dept. 10257 Manager. "We quickly found that ISO would allow us to structure and implement a robust management system that was focused on continual improvement and made good business sense."

Roy and his eight-member team started the ISO journey about a year ago by mapping out existing processes and then determining where there were gaps in their system. They then put together comprehensive business policies and business objectives for their organization.

Roy notes that everyone in the department "became engaged" in developing objectives and procedures and took on ownership of their business management system -- something necessary in order to improve the business and sustain their system.

After formalizing their processes, procedures, and objectives, the team performed a comprehensive internal audit followed by a comprehensive management review. The management review proved particularly beneficial to the team. It gave the team an opportunity to identify and address system deficiencies, customer evaluations, and feedback and then establish action plans and goals for the future. Roy was able to communicate to customers exactly what actions the team would be taking to address any concerns or deficiencies.

After the identification and correction of findings and deficiencies, the team engaged the services of an independent accredited third party registrar for two days to review the organization's operations and business management system.

"They interviewed everyone in our group, reviewed contracts and systems documentation, and talked to our customers," Roy says.

During the exit conference, the registrar commented on the high quality of services the team was able to provide and referenced recent comments obtained from the department's customers: "These people work above and beyond what I have experienced in most private-sector companies. Jet-lagged, working almost all night several nights in a row, and then still being able to negotiate with fresh adversaries on their home turf is exceptional. This doesn't happen on the outside!"

At the end of the two-day visit the registrar notified the team that they would be recommended for certification.

Roy says he is already seeing measurable benefits and anticipates even more in the future as the department adopts corrective actions, preventative actions, and best practices in order to continuously improve IPT services. The benefits will come in the form of cost savings, efficiency, and better customer service. - - Chris Burroughs

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Last modified: August 7 , 2003

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