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A Greener Approach to Developing Gels

UBC researcher’s serendipitous discovery could influence a greener method in the gel production industry.

Graduate student Lev Lewis of the Department of Chemistry at the University of British Columbia unexpectedly developed a simple method to form gels from cellulose nanocrystals.

First off, let’s break down what a cellulose nanocrystal (CNC) actually is. Cellulose is one of the most, if not the most abundant molecule produced by plants. It is responsible for the strength, structure, and form that allows you to hold a flower up by its stem. Next in order, a nanocrystal is basically a small crystal. Now how small are we talking? A nanocrystal, is a crystal smaller than 200 nanometers. To put this value in perspective, the diameter of a hair is roughly 100,000 nanometers across. In other words, these CNCs that Lev is working with are really really small crystals.

Graphic representing the molecular structure of CNCs which is composed of chains of individual cellulose molecules. Image courtesy of yalescientific.org via the Keten lab.

Lev found that by simply heating a CNC-water mixture under high pressure, this would yield the liquid to thicken into a gel.

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Gel made using CNCs under high pressure and high temperature. Picture courtesy of Lev Lewis.

He attributes this unexpected formation of gel to the desulfation of CNCs (or the removal of sulfur groups) which causes the crystals in the mixture to become unstable, thus forming a gel. The following audio clip describes the process of desulfation using a candy analogy we all can understand.

Constructing gels using this method is an attractive objective because it’s easy, it’s green, and it uses cellulose which is renewable resource. These gels are used in a wide variety of products including diapers, contact lenses, insulation, and tissue scaffolds to list a few. Perhaps one of the most possibly important applications of these gels is in drug delivery. Lev explains that gels could be used to treat cancer instead of the traditional method of chemotherapy. Due to the physical properties of a gel, we could inject them into the cancerous area of the body needing treatment and expect them to stay put. This allows treatment to be localized as opposed to chemotherapy that wreaks havoc on the entire body. The following video elaborates on CNCs and their applications.

VIDEO HERE

Currently, CNCs can be obtained from wood pulp. Seeing as the world is increasingly making the shift from paper to digital, there’s a lot of wood pulp, which is used to make paper, going to waste. Due to the ease and accessibility of materials of Lev’s method of gel formation, large scale industries that use gels in their products could adopt this method, thus providing an outlet for all the unused wood pulp being produced.

~Lindsey Belsher, Jennifer Jung, Uzair Ahmed

 

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Disappearing Glaciers

Glaciers are consistent bodies of moving ice sheets that usually exist in high latitude areas and high mountain areas. They are formed by huge amounts of high-density ice that have been condensed and refrozen. 97% of total glaciers and 99% of total ice amount on earth are contained in the Antarctic ice sheet and the Greenland ice sheet that are located in the Polar regions. The ice contained in these ice sheets is the largest fresh water bank on earth such that it has the ability to change the climate throughout our world.

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Credit: http://www.onlyonesolution.org/albedo.html

 

The melting ice sheets throughout the world have drawn much attentions from the news media in recent years. The public has noticed that climate change has become one of the major troubles that human beings are facing. Also, it has been reported that the average thickness of glaciers on earth has decreased by 11.5 meters since 1980, and this phenomenon is caused by people using fossil fuels recklessly. Additionally, energy companies are still searching and drilling for more oil and gas in the Arctic and this will make the climate issue worse.

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Credit: http://climatechangeconnection.org/

Now you see it, now you don't - Climate 365 graphic

Credit:NASA Climate 365 project, http://climate.nasa.gov/climate_resources/4/

Scientists have been collecting temperature data since the 18th century. According to those data, our planet is getting warm constantly since the industrial revolution. Many people still hold the viewpoint that the increasing density of greenhouse gases is the main reason for Global Warming. However, scientists have found that the change of greenhouse gases’ density does not match the exponentially increasing trend of the average temperature. Meanwhile, glaciologists have claimed that the ice contained in the Polar regions has the ability to affect the global climate. In fact, as so much ice sheets have disappeared in the past few decades, lots of area on the surface of earth have turned from bright color of ice into dark color of water. Since dark colors can absorb heats faster than bright colors, our earth is now absorbing much more heats than in the past. Consequently, the melting glaciers have much greater influence on the climate than the greenhouse gases.

Credit:NASA, http://www2.sunysuffolk.edu/mandias/global_warming/global_cooling.html

Last but not the least, the melting glaciers can result in much more serious consequences than just higher temperature. Melted sea ice produces a huge amount of water as ice sheets are the biggest water bank in the world. Also, it has been reported that about 40% of total glaciers have melted in the past four decades and the sea levels is rising slowly since 19th century by 0.1-0.15 m every 100 years. Many people still think that it does not matters since rising sea levels seems not so dangerous and it’s coming very slow. However, the rising sea levels may destroy many cities throughout the world.

Credit: The daily conversation from Youtube

In my opinion, the melting glaciers is just the start of  the disaster that may cause human’s extinction. Also, the masses have not fully realized the trouble that mankind is facing. Our planet will survive in extreme weathers as it has survived for 4.6 billion years. But we may be the generation that decides if human being can still live on earth. Therefore I suggest that everyone should start to think the changes that people need to make in order to protect our world.

 

Yitao Gu

 

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