Chemical News | Actualité chimique
Law and Policy
Toban Black
Turning Up the Heat on Chemical Valley Ada Lockridge and Ron Plain have had enough. The longtime members of the Aamjiwnaang First Nation near Sarnia, Ont. have been trying for eight years to change the way air pollution is regulated in their area. Now they’ve teamed up with the environmental law organization Ecojustice to file a lawsuit against the Ontario government. The suit challenges the government’s decision last April to grant an approvalto Suncor Energy Products Inc. to expand its refinery operations in Sarnia. The applicants argue that the decision does not account for what happens when Suncor’s pollutants interact with those of other emitters across the region, which is colloquially known as “chemical valley.” The cumulative emissions can exceed healthy levels of various pollutants, and even produce new ones by reacting with each other. Failure to recognize this, they argue, is a violation of section 7 of the Charter of Rights and Freedoms, which guarantees life, liberty, and security of the person. Graffiti in downtown Sarnia Although the suit focuses on a specific approval, the general goal is to force government to re-examine its environmental regulations. “What we’re hoping for is a change to how pollution is regulated in hot spots, places like Hamilton and Sarnia, where there are multiple polluters,” says Justin Duncan a lawyer for Ecojustice working on the case. “This is what’s done in the U.S., but there aren’t really any good examples in Canada.”
Nanotechnology
Beep, beep, beep. The chips are done! There’s a new tool in the quest to design ever-smaller silicon circuits: the microwave oven. Researchers at the University of Alberta’s National Institute of Nanotech nology are using microwave heat to speed up the self-assembly of certain block copolymers. The ability to do these reactions quickly offers an alternative method of making the intricate templates used in semiconductor manufacturing. Computer chips are typically made by photolithography. Light is used to burn patterns into polymer films which then serve as templates for etching silicon. Certain
features in these patterns can be as thin as 50 nanometres. But the process is becoming prohibitively expensive as scientists try to make even smaller features with more finely focused light. Block copolymers bypass light entirely. These mixtures of two different plastics selfassemble into intricate patterns in much the same way as the two complimentary strands of a DNA molecule. They’ve been shown to be capable of producing the intricate features in chip templates, but the problem is speed. “The time in which these things will spontaneously self-assemble normally takes hours to days at high temperature,” says Jillian Buriak, lead researcher on the project. “We do it in a microwave in a minute.” Not only is the process fast and cheap, but Buriak believes it could make even smaller templates, right down to the limits of nature. “People are talking about sub-10 nanometre patterns using self-assembly,” she says. “A nanometer is about four to five atoms. At a certain point, you’re just coming up against numbers of atoms. It’s amazing.”
Climate change
Raining on the Carbon parade Modeling global CO2 cycles, already notoriously difficult, just got a little harder. New research indicates that under certain conditions, even common processes like rain can significantly alter carbon exchange rates in the oceans. Oceanographer Daniela Turk of Dalhousie University and her team used a giant tank to simulate the effects of wind and rain on carbon exchange. She found when lots of rain falls without much wind, it dilutes the ocean surface, lowering the partial pressure of CO2. As it falls, it also absorbs carbon from the air and influences mixing conditions at the air-water interface. Taken together, these effects can be enough to change parts of the ocean from net sources of carbon to net sinks. Turk then looked at data from meteorological buoys in a place called the western equatorial warm pool, near Papua New Guinea. Sure enough, the carbon-sinking effects of rain were measurable during tropical storms. While she cautions that more work needs to be done, she is confident that her work will change our understanding of carbon cycles. “Rain effects mostly were ignored in the climate models,” she says. “This pilot study shows that we might need to consider these effects, especially in the tropical areas.”
January 2011 CAnadian Chemical News 9