Jam or marmalade? Whichever you prefer on your toast in the morning, it’s the pectin that’s stopping it dripping off the slice! Find out about this networker par excellence in this week’s Chemistry in its element podcast.

                  

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Recommendation and review posted by G. Smith

A Dartington glassblower uses a newspaper paddle to shape a piece of blown glass

A letter in the Financial Times about a month ago piqued my interest. It stated that the characteristic salmon pink pages of the FT play a unique role in producing hand-made crystal glass at Dartington crystal. Since I was about to go on holiday to Devon, and had planned a trip to the Dartington factory anyway, I decided to do a bit of investigating myself.

In the FT letter, the correspondent says that the  reason for using the pink pages of the FT is so that no trace elements are transferred to the crystal ‘when the protective newsprint is peeled away’, as they might be with other, bleached, newspaper.

This sounded a little implausible to the chemist in me. If the newspaper was only being used for protection, surely any interaction with the crystal glass would be confined to the ink, or any contaminants left from the paper processing, rubbing off on the surface? The possibility of significant chemical reaction between the glass and the newsprint at room temperature seemed remote at best.

A tour of the factory quickly confirmed my hunch. The role of the newspaper is much more than simply protective, but perhaps quite surprising. It is an integral tool in shaping blown glass. The yellow-handled paddle in the picture is actually made up of a wad of newspaper.

This yellow handled paddle is actually a stack of newspapers

As the glassblower blows and shapes a globule of molten glass into a tumbler (in this case) or any other object, part of the process involves dipping that paddle into a bucket of water and holding it up to the red hot glass. At the same time he rolls the blowpipe backwards and forwards to ensure the glass is the right shape and consistent thickness.

Newspaper is absorbent and cheap to replace, making it ideal for making these paddles. However, being in contact with glass at several hundred degrees means the paper does burn away slowly, so it’s important it doesn’t transfer contaminants to the glass in its semi-molten state, which could then create imperfections in the final product.

So that begs the question, what is it about the FT that makes it the preferred choice of glassblowers? Is it something to do with the chemical processing of the paper? Is the paper bleached less ferociously than its white cousins? Or does the dyeing process mean any residues from the bleaching are washed out more thoroughly? Or is it simply tradition with little scientific backing? Speaking to some of the Dartington staff I got some vague answers about the ‘quality of the paper’, but it would be interesting to know if any of our readers have more insight.

If you have never watched a glassblower at work, it is quite an amazing experience. The apparently effortless skill of a master glassblower is breathtaking. No wonder it takes around 10 years to reach that level. But, as with glassblowing for chemistry equipment, it is a skill that is slowly dying out – Dartington is one of the last commercial-scale producers of hand-blown glass in the UK.

Phillip Broadwith

                  

Source:
http://prospect.rsc.org/blogs/cw/?feed=rss2

Recommendation and review posted by G. Smith

I picked it for you! © Wiley

That’s exactly what George Whitesides and his team at Harvard have achieved. By using silicone elastomer tubing and pressurised air, they produced a ‘tentacle’ that can be used for picking up delicate or complicated objects such as flowers or horseshoes. Published in Advanced Materials this month, this is the latest in a series of developments in the ‘pneumatic network’ method over the past few years. Previously, the group developed a starfish-like gripper that could pick up an egg, but the gripping motion was the limit of its movement. Whitesides’ groups have also used this soft robotics technology to develop a crawling robot.

This new tentacular system has hard polymer tubing running through the centre which can bend easily – but resists stretching – surrounded by a highly elastic polymer with channels running through it to allow pressurised air to enter. By controlling which channel the air enters, the tentacle can be manipulated to twist and turn in three dimensions. The construction of the tubing might be simple, but controlling it looks a lot more difficult!

Describing the new system as a tentacle is selling it short — it can do so much more. Just like an elephant’s trunk, it can use the central tubing for suction, either to lift objects or suck up liquids and powders. Just like the best robots (or colonoscopes), it can even have a video camera attached to the end.

As well as being cheaper than conventional ‘hard’ robots, this soft tubing has other advantages. The nature of the system allows for an even pressure spread across the object, rather than the ‘pincer’ method that we use with our fingers and that many robots try to emulate. Also, the stiff links and fixed structure of most robotic arms mean that they have difficulty in situations that they are not specialised for. The flexibility of the tubing allows it to grip in various ways and adapt as is needed.

The long list of innovations coming from the lab of George Whitesides have led to him having his name on nearly 1000 academic papers and over 100 patents. He is a co-founder of a dozen companies, including Genzyme which was the third largest biotech company in the world before it was acquired by Sanofi for $20 billion in 2011. With the level of development in this technology, I imagine it won’t be long before we see these tentacles going commercial.

Ian Le Guillou

                  

Source:
http://prospect.rsc.org/blogs/cw/?feed=rss2

Recommendation and review posted by G. Smith

— Nanoparticles for colouring

Wondering how to keep yourself amused this weekend, or worried how to keep the kids amused on a rainy day? May I suggest this new colouring-in book full of images from the nanoscale world. If you’ve ever felt that that false colour electron microscope images could really be more eye catching this is the book for you.

Founded perhaps for less suspicious reasons than Terry the Fracosauraus‘ colouring-in book, each image comes with scale bars and a short explanatory paragraph explaining what exactly it is you’re colouring in. The explanations are aimed at a US fifth grader, so about 10 years old, and also asks questions to be filled in along the way.

My only concern, and maybe that’s because I’m a fun killing, literal scientist type, is that rather than use real photographs the book uses line-drawn approximations. That makes sense for DNA perhaps, but wobbly fractals? I think if I were going to lose myself in the crazy complexity I’d want it to be accurate.

However, I applaud the idea of communicating nanoscience early – get them hooked young, I say. And if you’re into stretching yourself, or introducing languages early to your children, the pages are also available in French. Amusez-vous bien!

Laura Howes

                  

Source:
http://prospect.rsc.org/blogs/cw/?feed=rss2

Recommendation and review posted by G. Smith