Tag Archives: iridescent beetles

Mark MacLachlan talks about beetles, biomimcry, and nanocrystalline cellulose

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After mentioning the Café Scientifique talk coming up on Tuesday, March 29, 2011 at Vancouver’s (Canada) Railway Club in my March 24, 2011 posting (http://www.frogheart.ca/?p=3171), I’m happy to say that Mark MacLachlan, the featured speaker, has answered a few questions about himself, his work and what he plans to talk about. Here he is,

(a) Could you tell me a little bit about yourself and why you’re giving a talk for Café Scientifique?

I grew up in Quesnel then obtained my BSc degree at UBC and my PhD at the University of Toronto. After a 2 year post-doc at MIT, I returned to UBC where I have been a chemistry professor since 2001.

My research is in materials chemistry – we develop new materials that “do things”. That might include materials that change properties when exposed to another chemical (i.e., sensing) or light, or materials that can store gases in their interior. We are excited about developing new materials with unusual properties.

(b) How did you decide on your topic? Are people demanding to know about biomimcry?

I was invited to give a talk on our work we published in Nature on the coloured glasses. As these materials mimic the structures of beetle shells, I thought that would be an interesting angle for a more general talk.

(c) The description for your upcoming talk in common with the description of a paper you and your team published Nov. 2010 in Nature mentions irridescent beetle exoskeletons. Which came first, an interest in irridescence or an interest in nanocrystalline cellulose (or is nanocrystals of cellulose)? And, how was the connection between the two made?

An interest in NCC came first. We were working with NCC to develop composites of NCC/glass when we discovered the iridescent materials. It was then a few months later that we made the connection to beetle exoskeletons.

(d) What can your audience expect? Will you be singing about biomimicry and/or nanocrystalling cellulose or offering a mixed media show as part of the talk?

I will be talking about biomimicry a little and mostly about the materials. I plan to take a few samples with me.

e) Is your talk connected to the Nano Days events which run from March 26 – April 3, 2011 or is it coincidence?

Just a coincidence – this is the first I’ve heard of Nano Days!

f) Is there anything you’d like to add?

I’ve never been to Café Scientifique before and I am looking forward to this opportunity to share some science!

Thank you Mark MacLachlan. If you want to know more, check out the Railway Club at 579 Dunsmuir St. The event starts at 7:30 pm on Tuesday, March 29, 2011.

Glass and cellulose nanocrystals at the University of British Columbia

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I got a news release from the folks at the University of British Columbia (UBC) about nanocrystals of cellulose (I imagine this is a another of sayng nanocystalline cellulose, a topic I’ve posted about a number of times,  most recently in my Aug. 27, 2010 interview with Dr. Richard Berry of FPInnovations).

From the UBC news release,

Using nanocrystals of cellulose, the main component of pulp and paper, chemistry researchers at the University of British Columbia have created glass films that have applications for energy conservation in building design because of their ability to reflect specific wavelengths of light, such as ultra violet, visible or infrared.

These nanoporous films, described in a paper published in today’s [November 17, 2010] issue of Nature, may also be used in optical filters, sensors, or for molecule separation in the pharmaceutical industry.

“This is the first time that the unique, helical structure of cellulose has been replicated in a mineral,” says Mark MacLachlan, associate professor in the chemistry department at UBC and co-authour of the paper. “The films have many applications and we created them from an exciting new product derived from our wood processing industry right here in British Columbia.”

At the molecular level, the films have the helical structure of nanocrystalline cellulose, a building block of wood pulp, explains MacLachlan.

MacLachlan and PhD student Kevin Shopsowitz, post-doctoral fellow Hao Qi and Wadood Hamad of FPInnovations, stumbled upon this discovery while trying to create a hydrogen storage material. [emphasis mine]

The UBC researchers mixed the cellulose from the wood pulp with a silica, or glass, precursor and then burned away the cellulose. The resulting glass films are composed of pores, or holes, arranged in a helical structure that resembles a spiral staircase. Each hole is less than 1/10,000th of the diameter of a human hair.

“When Kevin showed me the films and they were red, blue, yellow and green, I knew we’d been able to maintain the helical structure found in the cellulose.”

“The helical organization we produced synthetically mimics the structure of the exoskeletons of some iridescent beetles,” says Shopsowitz.

The pores in the helix give the films a wide range of applications. When certain liquids are added to the film, the liquid gets trapped in the pores and changes the optical properties of the films.

“By functionalizing the pores to make them more selective to particular chemicals, we may be able to develop new sensors that are very sensitive for detecting substances in the environment,” says Shopsowitz.

To reduce the energy needed to cool buildings, windows could be treated with the transparent films that reflect infrared light – the light that heats up a building. Right now, metal particles are often used to do this but they tint the windows brown.

This research was done in partnership with FPInnovations, an organization dedicated to developing new products from the forest sector, and with funding from the Natural Sciences and Engineering Research Council of Canada.

I hope to hear about this soon as it feeds into my fascination with windows and, if I read this rightly, this discovery may lead to products that are both useful and aesthetically pleasing.