From soufflés to seashells to intelligent ink

Creative researcher receives DOE’s E.O. Lawrence Award for innovations in nanostructured materials

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Sandia news media contact

Neal Singer
nsinger@sandia.gov
505-845-7078

ALBUQUERQUE, N.M. — C. Jeffrey Brinker will be one of seven scientists awarded the Department of Energy’s E.O. Lawrence award in a ceremony on Oct. 28 in Washington, D.C.

Jeff Brinker
Jeff Brinker observes the structures of submicroscopic spheres created by his team at the nanometer scale. (Photo by Randy Montoya)

The award — one of the highest honors bestowed upon researchers by the DOE — was announced by Secretary of Energy Spencer Abraham.

Brinker is a senior scientist at Sandia National Laboratories and professor of chemical and nuclear engineering and chemistry at the University of New Mexico.

He will be honored for innovations in materials science that created nanostructured materials with applications in energy, manufacturing, defense, and medicine.

The award, established in 1959, includes a citation, gold medal, and a $25,000 prize. It is offered in seven categories of science for outstanding contributions in the field of atomic energy, broadly defined. It is named in memory of physicist Ernest Orlando Lawrence who invented the cyclotron, a particle accelerator, and received the Nobel Prize in physics in 1939.

Encomiums
“We are all enriched by the contributions researchers [such as Brinker] have made,” Secretary Abraham said.

Said Sandia President Paul Robinson, “In addition to his pioneering work in sol-gel technology, which made possible the lowest density structures ever created, Brinker’s leadership in mastering nature’s secrets are extraordinary. His development of materials that mimic the structure of abalone seashells makes it possible to build tough, lightweight structures or coatings that, because of their inherent microstructures, can resist cracking.

“Brinker mentors graduate students at the University of New Mexico, combines research interests with practical applications, and produces technical papers that are models of insight and clarity. His innovations in nanotechnology will only grow in importance as the United States launches what is the most ambitious scientific research program in decades.”

Says Al Romig, VP for Science-Technology & Partnerships, “I’ve seen him move from more traditional inorganic to organic chemistry and from sol-gel to nanotechnology, migrating and evolving his ideas along the way. He’s been a prolific author in Science and Nature; the first person we had to formally hold a full tenured professorship [at UNM] and be employed as a Sandia scientist at the same time. And he’s worked diligently to develop the next generation’s cadre of scientists through his university work. He’s been a major organizer of symposiums and conferences, an engine of intellectual properties, and one of our most prolific generators of patents.”

From Jell-O to soufflés
Brinker’s first work at Sandia involved sol-gels — Jell-O-like solutions heated at relatively low temperatures until they solidify into a glass-like material. The material is important (among other uses) in forming glass-like coatings over substrates too sensitive to be exposed to the temperatures needed to make real glass flow. This early work culminated in 1990 in the publication of Sol-Gel Science (with co-author George Scherer), a book that — though he and George never found the time to revise — remains the most highly cited reference in the field.

In the 1990s, Brinker moved from creating sol-gels into creating aerogels — materials extremely light because they are extensively penetrated by cave-like tunnels. He devised room-temperature techniques that were simple and inexpensive. The resultant concoctions — a kind of material scientist’s soufflé — are the world’s lightest solids. Brinker’s group created them in collaboration with UNM researchers using a simple chemical trick that caused shrinkage by drying to be reversible, rather than by conventional high-temperature/pressure autoclaving with its hazards and costs.

The work overcame the 60-year-old barrier to commercial aerogel production and enabled the first preparation of aerogels as thin films.

Aerogels, because of their extraordinarily low thermal conductivities, were used on NASA’s Pathfinder mission to insulate the Rover that explored Mars.

Aerogel films are also of interest for coatings needed for future generations of microelectronic devices.

The holes in grandma’s blanket
But it wasn’t enough merely to have an inexpensive aerogel; Brinker wanted better control over the size of its interior chambers, or pores. In the mid-1990s he devised techniques to cheaply, easily, and precisely control the pore size of films for use as membranes, adsorbents, concentrators, and electrically insulating materials called dielectrics. Here he used simple evaporative methods to organize two-sided detergent-like molecules into intricate patterns as regular as the knitting on grandma’s blanket (only more so). This pattern served as a mold around which silica solidified. Removal of the detergents then created a predictable series of holes — where strands of grandma’s blanket used to be.

The precise periodic porosity of these films has enabled the development of inorganic membranes with the best reported combination of selectivity and permeability. In addition, the small pores, regular distribution, and fully connected framework architecture has made these films attractive for low-dielectric-constant films for the next several generations of microelectronics.

These seashells not sold at the seashore
But why settle merely for inorganic soufflés? Brinker then extended his techniques to organic materials. He created nanocomposites that mimicked the hard/soft laminated construction of natural materials like sea shells, which due to their hardness, toughness, and strength have obvious advantages for materials design and construction. In a process akin to washing dishes, he used surfactant assemblies called micelles to organize both organic and inorganic precursors simultaneously.

But that still wasn’t enough. Why have a simply created organic/inorganic composite mass with defined interior nanostructure — including controlled pore size, shape, and regularity — and not control the overall architecture of the material?

Ship-in-a-bottle constructions
The starting point for overall architectural control is a solution or colloidal suspension like that used to form films. Evaporation of the aerosolized droplets (like those formed using a simple humidifier) causes self-assembly to proceed radially inward. Any additives introduced into the solution are inevitably incorporated within the self-assembling droplet, enabling ship-in-the-bottle constructions. This approach has significant implications in a diverse range of technologies like drug delivery, cosmetics, catalysis, chromatography, and custom-designed pigments.

Intelligent ink
During the past several years, Brinker demonstrated the direct writing of functional self-assembled nanostructures applied through computer-driven pens and ink-jet printers. This approach, dubbed “intelligent ink,” formed functional hierarchically organized structures in seconds and established the first link between computer-aided design and self-assembled nanostructures. Second came the self-assembly of photosensitive films that incorporated ultraviolet-sensitive molecules compartmentalized within periodic nanostructures. Varying the intensity of a simple ultraviolet light shone upon the material enabled researchers to control its wetting behavior, pore volume, pore size, and refractive index. This capability should enable standard lithographic procedures to be used both to pattern and define the structure and function of nanomaterials.

Nanostructured hosts
Most recently, Brinker used polymerizable surfactants to incorporate conjugated polymers in nanostructured hosts, enabling control of their charge and energy transfer necessary to advance the field of organic electronics.

Brinker has won five DOE Basic Energy Sciences Awards. In February 2002 he was elected to the National Academy of Engineering.

 

Sandia National Laboratories is a multimission laboratory operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration. Sandia Labs has major research and development responsibilities in nuclear deterrence, global security, defense, energy technologies and economic competitiveness, with main facilities in Albuquerque, New Mexico, and Livermore, California.

Sandia news media contact

Neal Singer
nsinger@sandia.gov
505-845-7078