Making better materials, one molecule at a time

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[img_inline align=”right” src=”http://padnws01.mcmaster.ca/images/hitchcock_adam.jpg” caption=”Adam Hitchcock”]Imagine being only the second person in the world to have completed a PhD in inner-shell excitation spectroscopy, only to have the director of your doctoral committee ask, “So, what is your research good for?” For some researchers this would discourage them, but not Adam Hitchcock; he has taken his research above and beyond. Today, he has many answers to that question. From designing a better diaper to improving materials for advanced electronics, Hitchcock has made his research good for many things.

Inner-shell excitation spectroscopy involves looking at materials with high energy X-ray or electron beams. When you shine such high energy beams on a material, they transfer energy to the “inner shell” electrons – the electrons that are closest to the nucleus and are held most firmly in place. By measuring the inner shell excitation spectrum, or the energies absorbed by the electrons, Hitchcock and his group can learn what molecules a sample is made of.

Once he knows what a sample is made of, Hitchcock is able to focus on improving the materials themselves. Another part of his research is improving the instrumentation and techniques for materials analysis by inner shell excitation.

Hitchcock's research team currently consists of eight members: three senior researchers, one at McMaster, one in Saskatoon and one stationed in Berkley, California, as well as five graduate students. Hitchcock's team of researchers has become one of the leading groups in the field of X-ray microscopy. “Training new scientists is one of the most important and fulfilling aspects of my research,” says Hitchcock.

In his research, Hitchcock works with samples that are typically much smaller than the diameter of a piece of hair. Through inner-shell excitation spectroscopy, he measures and maps a material's chemical structure and studies how it reacts with other chemicals. From this, he and his collaborators improve the material – whether by making it stronger, more absorbent, or less harmful – thereby making it more practical and useful for society.

In collaboration with other university researchers, as well as government and industry scientists, his work has helped improve materials such as superabsorbent polymers for use in diapers and coatings for advanced electronic devices, such as the latest generation of computer processors.

Hitchcock has had much help bringing his research into focus. The Natural Sciences and Engineering Research Council of Canada (NSERC) funds much of his research. NSERC also funded part of a scanning transmission X-ray microscope located at the Advanced Light Source in Berkley, California. Hitchcock's group, in collaboration with researchers from North Carolina State University and Berkeley Lab, designed and built the microscope, which is widely considered the most advanced of its type in the world. The design is being used in new microscopes in Canada and Switzerland.

NSERC also plays a major role in funding the Canadian Light Source (CLS), which is one of Canada's largest scientific research facilities. The CLS is a machine that is the size of a football field and produces light that is brighter than the sun. The synchrotron is important to Hitchcock's research because it is the only type of X-ray source that can carry out his type of X-ray microscopy.

Hitchcock was a major proponent for CLS, and in 2001 he was appointed the Tier 1 Canadian Light Source – Canada Research Chair for Materials Analysis. He is also the scientific leader of the soft X-ray spectromicroscopy beamline facility at CLS.

Much of Hitchcock's research involves looking at synthetic and natural polymers, for which the X-ray microscope is particularly well suited. “In complex samples, we use the microscope to find what the components are and how they are distributed in space,” he explains. By doing this he can improve materials from a knowledge of their structure, rather than a 'trial and error' approach. One example is a project on improving the absorbency of super absorbent polymers, which are used in many applications, from baby diapers to providing leak protection for the Chunnel.

The common theme of the many different projects Hitchcock has underway is the use of inner shell excitation to look at chemical, physical and material problems. Industrial partnerships play a major role in Hitchcock's research. These partnerships are with large 'raw material' companies like Dow Chemical, and also with much smaller niche companies, such as Chemetics, a manufacturer of water filtration membranes in Vancouver.

Through industrial partnerships, Hitchcock and his research team help develop new materials and sometimes help solve production problems. “We help make sure what the company supplies is useful, and help them understand how to control specific properties of their products such as strength and durability,” says Hitchcock. A goal of his research is to understand the links between the reactions used to make the materials or components of a product and the properties of the final product.

Today when asked what his research is good for Hitchcock says, “Canada must contribute to the well-being of all mankind with its knowledge (and hopefully, some wisdom), not just with exploitation of its natural resources. Synchrotron science in general, and synchrotron-based X-ray microscopy in particular, has much to contribute to improving materials and products, to education, and to being part of a network of advanced science and technology internationally.”

From looking at samples under 'the big light' at synchrotron light sources around North America, to industrial factories, to a store shelf near you, Hitchcock's research 'is good for' many of the efficient, improved materials we use daily in our lives.

(The Natural Sciences and Engineering Research Council SPARK (Students Promoting Awareness of Research Knowledge) program was launched in 1999 at 10 universities across Canada. Through SPARK, students with an aptitude for communications are recruited, trained and paid to write stories based on the NSERC supported research at participating universities.)