Tag Archives: Frank Ko

Creating nanofibres from your old clothing (cotton waste)

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Researchers at the University of British Columbia (UBC; Canada) have discovered a way to turn cotton waste into a potentially higher value product. An October 15, 2019 UBC news release makes the announcement (Note: Links have been removed),

In the materials engineering labs at UBC, surrounded by Bunsen burners, microscopes and spinning machines, professor Frank Ko and research scientist Addie Bahi have developed a simple process for converting waste cotton into much higher-value nanofibres.

These fibres are the building blocks of advanced products like surgical implants, antibacterial wound dressings and fuel cell batteries.

“More than 28 million tonnes of cotton are produced worldwide each year, but very little of that is actually recycled after its useful life,” explains Bahi, a materials engineer who previously worked on recycling waste in the United Kingdom. “We wanted to find a viable way to break down waste cotton and convert it into a value-added product. This is one of the first successful attempts to make nanofibres from fabric scraps – previous research has focused on using a ready cellulose base to make nanofibres.”

Compared to conventional fibres, nanofibres are extremely thin (a nanofibre can be 500 times smaller than the width of the human hair) and so have a high surface-to-volume ratio. This makes them ideal for use in applications ranging from sensors and filtration (think gas sensors and water filters) to protective clothing, tissue engineering and energy storage.
Ko and Bahi developed their process in collaboration with ecologyst, a B.C.-based company that manufactures sustainable outdoor apparel, and with the participation of materials engineering student Kosuke Ayama.

They chopped down waste cotton fabric supplied by ecologyst into tiny strips and soaked it in a chemical bath to remove all additives and artificial dyes from the fabric. The resulting gossamer-thin material was then fed to an electrospinning machine to produce very fine, smooth nanofibres. These can be further processed into various finished products.

“The process itself is relatively simple, but what we’re thrilled about is that we’ve proved you can extract a high-value product from something that would normally go to landfill, where it will eventually be incinerated. It’s estimated that only a fraction of cotton clothing is recycled. The more product we can re-process, the better it will be for the environment,” said lead researcher Frank Ko, a Canada Research Chair in advanced fibrous materials in UBC’s faculty of applied science.

The process Bahi and Ko developed is lab-scale, supported by a grant from the Natural Sciences and Engineering Research Council of Canada. In the future, the pair hope to refine and scale up their process and eventually share their methods with industry partners.

“We started with cotton because it’s one of the most popular fabrics for clothing,” said Bahi. “Once we’re able to develop the process further, we can look at converting other textiles into value-added materials. Achieving zero waste [emphasis mine] for the fashion and textile industries is extremely challenging – this is simply one of the many first steps towards that goal.”

The researchers have a 30 sec. video illustrating the need to recycle cotton materials,

You can find the researchers’ industrial partner, ecologyst here.

At the mention of ‘zero waste’, I was reminded of an upcoming conference, Oct. 30 -31, 2019 in Vancouver (Canada) where UBC is located. It’s called the 2019 Zero Waste Conference and, oddly,there’s no mention of Ko or Bahi or Ayama or ecologyst on the speakers’ list. Maybe I was looking at the wrong list or the organizers didn’t have enough lead time to add more speakers.

One final comment, I wish there was a little more science (i.e., more technical details) in the news release.

Goats, spider silk, and silkworms

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A few years ago (2008), I attended the Cascadia Nanotech Symposium organized by the now defunct, Nanotech BC (British Columbia, Canada) and heard Dr. Frank Ko speak. He is a Canada Research Chair at the University of British Columbia (UBC) who leads the Advanced Fibrous Materials Laboratory and, in his talk, he mentioned that he had added spider genes to goats with the intention of easing the process of spinning goat’s milk thereby exploiting spider silk’s properties.

I’m never especially comfortable about mixing genes between species that, as far as I know, would never have occasion to mingle their genetic material together. It’s a little too close to ‘The Isle of Dr. Moreau’ (Victor Hugo’s novel which I have never read but have heard about). But there were people who had some similar concerns about electricity, which I take for granted, violating the natural order of things as per Carolyn Marvin’s book, When old technologies were new. Consequently, I’m willing to think about it but not terribly happy to do it.

Getting back to spider silk and Dr. Ko’s work, he and others are very interested in exploiting the strength inherent in spider silk. Here’s a description of that strength from an article by David Zax on Fast Company,

Oftentimes, nature is better at building stuff than we are. Spider silk is an example. The tiny threads spun by our eight-legged friends has a tensile strength comparable to high-grade steel. If humans could harness the spider and turn it into a manufacturing agent, the industrial and commercial potentials could be immense. One problem, though: Spidey hasn’t been cooperating. Spiders just don’t spin the stuff in great quantities, and there is no commercially viable way of mass-producing spider silk.

In looking at Dr. Ko’s webpage I see that adding a spider gene to goats may have been his solution to the problem of producing more spider silk (and perhaps other issues as well),

An internationally recognized expert in 3-D complex fiber architecture for structural toughening of composites Professor Ko’s pioneering work on the development of continuous nanocomposite fibrils by co-electrospinning has provided a new pathway to connect nanomaterials to macrostructural design. With an objective to understand the structural basis for the outstanding combination of strength and toughness in spider silk Professor Ko has played a leading role in the study of nanocomposite fibrils from recombinant spider silk. It was demonstrated that 10X increase in strength and 5X increase in modulus were attainable with the addition of 1-3 weight % of carbon nanotube to the recombinant spider silk. Research has been extended to various filler geometry that include graphite nanoplatelet (GNP); nanoparticles such as nanodiamonds and various functional particles.

Zax’s article highlights a different approach to producing greater quantities of spider silk,

There is, however, already a silkworm industry, which yields most of the silk–less strong than the spider’s–that we’re familiar with. A few scientists got a bright idea: what if you could make the silkworm, which is already equipped for industry, spin spider silk?

Notre Dame, the University of Wyoming, and Kraig Biocraft Laboratories, Inc. joined heads, and recently announced that they had succeeded in genetically engineering silkworms so that they produce artificial spider silks. Several biologists teamed up to splice certain DNA from spiders into the genomes of silkworms. The altered silkworms now spin cocoons that are a mixture of silkworm silk and spider silk. Though the tensile strength of the altered silk still falls well short of that of pure spider silk, it’s a step in the right direction.

I can certainly see benefits to this but I sometimes wonder if humans have enough humility and foresight as we embark on ever more subtle manipulations of life.

ETA October 29, 2010: If you are interested in the goat/spider issue, take a look at Andrew Manard’s October 27, 2010 posting on his 2020 Science blog. He’s running a poll on the question,

… why not take the gene responsible for making spider silk, and splice it into a goat [to produce more spider silk]?

Be sure to take a look at the comments, if you’re interested in the history of the technique, which apparently stretches back to the 1950s!