Wednesday, 31 January 2018

Once in a (super) blue (blood) moon

Two years ago I viewed my first lunar eclipse from New Zealand but I was unable to capture the moon during the eclipse. Now with the help of friends at the lab and a good camera we have captured a super blue blood moon over Singapore. Here are some of the best images. The blood red colour comes from all of the sunsets from around the world being reflected off the moon. The term blue does not refer to the colour but to it being the second full moon this month and super means it is very close to the earth.

Sunday, 3 December 2017

Describing chemistry at all scales

I recently delivered a presentation on multiscale modelling and experiments in combustion research and generated some plots of the different equations and experiments we employ at different scales. See if you can work out what each equation corresponds to. 

This is a very common plot in many different fields, however often only the bottom-left to top-right diagonal space is populated, whereas in most applications the goal should be to fill the entire space in order to describe all of the physics. 

I have also made a graph of the different modelling techniques we have developed or used in the Computational Modelling (CoMo) group at the University of Cambridge to model soot formation at different scales.

Feel free to suggest any additional experiments or formulas you think I have left out. 

Sunday, 12 November 2017

Nanotechnology right under our noses

Image sources: link, linklink
Nanotechnology conjures up images of tiny machines able to deliver drugs to the body, produce clean energy or take over the world - depending on who you talk to. The reality is that many of the nanostructures that scientists currently use in the lab have already been used for millennia.

In the past, gold nanoparticles were used to produce brilliant reds in stained glass windows and nanoscale tubes were woven into Damascus steel to make strong, sharp swords. These technologies were used without full knowledge of the processes involved, or safety concerns; however, the recent breakthrough in nanotechnology is our understanding and control of nanoscale structures.

My colleagues and I at the Department of Chemical Engineering and Biotechnology have found a common nanostructure that unites a variety of carbon materials, many of which are right under your nose. Water and air filters use activated carbon and vehicles produce soot - even your tennis racket and bike that contain carbon fibres.

You might be familiar with the layered structure of graphite: carbon atoms are arranged hexagonally in sheets that can easily glide past each other. This makes graphite a great material for pencil lead or a solid lubricant, but not as a filter or a bike frame. When graphite starts to become curved and interlinked is when the structure takes on its exceptional and diverse properties.

We ran quantum chemical calculations on the university’s supercomputers to understand what occurs when curvature is integrated into graphitic sheets through the replacement of a hexagonal ring of carbon with a pentagonal ring. This leads to a permanent bend in the structure that shuttles electrons from one side of the sheet to the other. This electric polarisation significantly increases the interaction of curvature-containing carbon material with molecules and itself, explaining how a relatively inert graphite can become strong and porous.

The next step for us is to explore how we can use our discoveries to reduce the emission of soot from vehicles, improve water filtration and improve the many carbon nanostructures that are right under our noses.