« This week (19th Oct–24th October) is Real Time Chem Week; as part of it, we’re featuring the RTC Week competition-winning entries of five different chemists here on Compound Interest, with a different feature every day this week.
Today’s feature takes a look at how we can use chemistry to help clean up oil spills – and how the chemicals we use to do so can come from some unlikely sources.
Julian Silverman is currently researching how compounds obtained from fruits and oils can be utilised in a number of applications, including helping to clean up oil spills at sea. Here, he explains the chemistry behind the process and how it works.
“One of the many focuses in the John’s Lab at the City College of New York is to clean up oil spills using chemicals made from renewable resources like fruits and oil. First we do a bit of good old organic chemistry and link fatty acids from edible oils and sugars from raspberries or monkfruits. This creates what we call an ester, a bond strong enough for the applications to come, but not too strong.
We do this using nature’s most efficacious workers (enzymes) to speed things up and make a product that will easily break down after it’s done being used. Here, not only is the product environmentally friendly, but so too is the low energy catalytic process which we use to make it.
Next, we do a little supramolecular chemistry, or to put it another way: Lego with molecules. Because the forces between the molecules we make are so specifically tuned, they are capable of stacking like the bricks into long strings in solution, which then entangle like a sponge to form a gel and trap liquid around it.
While most gels are used to trap water (like Jello), these gels because of their composition are best at turning water-fearing, or apolar liquids into gels. Examples of such liquids include cooking oils for trans-fats replacements, hydrocarbons for next-generation fuels which don’t spill, and, particularly importantly, crude oil. This means they can be used to turn spilled oils and fuels into gels that then can be easily scooped up and taken out of the environment after a devastating oil spill.
Taking this even one step further, these gels can be squeezed or distilled to give you back your spilled liquid, and this should prove to become a much better way to clean up oil spills. By doing a little bit of chemical engineering and materials science we can make sure these gels are strong enough to be taken out of aquatic environment, or in the case of thickened edible oils, soft enough to be spread easily but retain their shape.
By being both the designer of the molecules and also the engineer who tailors them to applications we have a complete control over the design process, which allows us to create sustainable solutions to a variety of problems. As these molecular gels are made of small molecules (not much bigger than table sugar) our work qualifies as nanotechnology, which focuses on systems that are a billionth the size of, for example, yourself. Though this work jumps between sub disciplines in chemistry and engineering, by leveraging out tools in each we can strive to solve the complex problems of today, and perhaps prepare ourselves for those of tomorrow.”
- Functional self-assembled lipid systems derived from renewable resources – J Silverman & others
- Sweet and Sustainable: Teaching the Biorefinery Concept through Biobased Gelator Synthesis (£) – G John, J Silverman & others
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