What links self-heating drinks and the D-day landings?


The imposing cliffs of Pointe de Hoc overlook the Normandy beaches where Allied troops landed on June 6 1944. The assaults marked the beginning of the liberation of German-occupied Europe. And the cliff tops were the perfect spot for artillery pieces capable of devastating any troops who tried to attack the Omaha and Utah beachheads.

The Allied command knew this and so, to shore up the attack, the navy bombarded Pointe de Hoc. Afraid this might not be enough, they also had a backup plan. A team of US Rangers scaled the 30-metre cliffs and, after locating the weaponry, deployed grenades, destroying the guns. The key to success was the choice of thermite-based charges. Yup, just good old iron oxide and aluminium.

 

 

Ok, so what this got to do with self-heating cans?

Link number 1:  Some of the same troops who were landing on the Normandy beaches that day had self-heating soap cans.

These were essentially a stove and can rolled into one, with a tube of cordite (more typically used as the propellant in small arms ammunition) running through the centre of the can to act as fuel. The cans were quick and easy to use and could be lit with a cigarette, allowing troops to prepare a hot meal in under five minutes. Unfortunately, they also had a tendency to explode, showering the assembled squaddies with piping hot soup.

Self-heating cocoa. University of Cambridge

Since then, there have been numerous attempts to make self-heating cans into a mainstream product. Most relied on a rather less volatile reaction to provide the heat, although some have still struggled with explosive issues.  Calcium oxide heats up rapidly when mixed with water. But it’s not particularly efficient, producing about 60 calories of energy per gram of reactant.

The upshot is that, to heat the drink by 40℃, you need a heating element that takes up nearly half the packaging. That’s just about OK if you want a small drink on a warm day, but in the depths of winter, when you might really want a hot drink, you only end up with a tepid coffee.

More powerful cans

What’s needed is a much more efficient reaction. Something, like thermite perhaps? As crazy as packing a can with a reaction capable of disabling an artillery gun may seem, that’s just what HeatGenie is planning. Over the last ten years, the firm has filed numerous patents describing the use of thermite within self-heating cans. It turns out the reaction used by the US Rangers is still too hot to handle, so they’ve dialled things back a bit by replacing the rust with a less reactive but no less familiar material, silicon dioxide. So the latest generation of heated cans is fuelled on aluminium and ground-up glass.

When this reaction is triggered it still kicks out a whopping 200 calories per gram of reactant and can achieve 1,600℃. Given the troubled history of self-heating packaging, releasing this much energy from the can in your hand might be a bit of a concern, so several of HeatGenie’s patents cover safety issues.

These include a complex arrangement of “firewalls” that can block the so-called “flamefront” should things get too hot, and energy-absorbing “heatsinks” to ensure the heat is efficiently transmitted around the drink, as well as vents to let off any steam. With all that is place, the company claims just 10% of the packaging is taken up by the heating elements, which can still produce a warm coffee in two minutes (although the exact temperature hasn’t been revealed).

A US technology firm is hoping to make a very old idea finally work by launching self-heating drinks cans. HeatGenie recently received US$6m to bring its can design to market in 2018, . Yet the principles behind the technology go back much further – to 1897, when invented the first self-heating can. So how do these cans work, why has no one has managed to make them a success, and what’s HeatGenie’s new approach? To answer that, we have to go back to World War II.

The ConversationSo, well over a century on fromRussian engineer Yevgeny Fedorov first attempts to make self-heating cans and more than 15 years after Nestle abandoned a similar idea, has HeatGenie final cracked it? Judging from the patents and investments, the firm might have sorted out the technical side, but whether it really has a hot product on its hands is another thing entirely.

This article was originally published on The Conversation. Read the original article.

By June 22, 2018 4 comments general chemistry, science news

Graduating My First PhDs

It’s been far too long since I’ve written a blog post, but I think I have a good excuse: I’ve been focusing on getting tenure. It’s been a 5-year, assistant professor roller coaster ride. But the ride is nearly over. Weirdly, it feels like just yesterday, but also a lifetime ago, that I shared my experience during the job search, wrote my memoir of a first year assistant professor, and captured our first year in lab with a time-lapse camera. My tenure package is submitted and my external letter requests are out. Thankfully, my group has been very productive and we’ve published some really solid science. I’m optimistic about tenure and it is honestly a relief to have my portion of the process behind me.

My tenure timeline also coincides with the bittersweet experience of graduating my first PhD students. While I am not a fan of ceremonies for the sake of ceremonies, I can get behind the pomp and circumstance surrounding a PhD graduation. I sat through two different 3-hour graduation ceremonies, one for the College of Arts & Sciences and one for the College of Engineering, and it was worth it. It isn’t every day that you get to be a central part of a centuries-old tradition. I hooded my students, just as my advisor hooded me, and his advisor before him, in a chain that dates back to the earliest Ph.D.’s over 500 years ago. While the thesis defense is typically anticlimactic, the Ph.D. hooding ceremony has a formal grandiosity that’s well-earned following 5 years of dedicated effort.


I have mixed emotions about losing (err…graduating) my first students:

Pros:
• My students certainly earned their ‘Dr.’ title
• I’ve contributed the growth and development of some truly exceptional scientists and I look forward to seeing what they accomplish next
• I got to hood my first PhDs!
• I got to wear my most expensive outfit (hood + gown = ~$1,000)
• My lab now has room for more new students
• I have several new connections entering the academic and industrial communities
• It’s time. There isn’t much more they can learn from me
• Now that I have academic progeny, I’m more motivated to add my information to my graduate and postdoc advisors’ academic family trees

Cons:
• I lost fifteen years of combined practical lab knowledge in a weekend
• Now that they are especially good at writing papers, they are leaving
• I had more time with these students while creating our lab than I will probably have with any others. I am going to miss them
• I am not entirely sure that all of our instrument and account logins and passwords have been handed down
• They each have their own unique skills. While some of these skills will be replaced by new students, others are irreplaceable

 

In preparation for their departure I contemplated two questions:

1) How do I commemorate my students time in lab?

I really wanted to do something tangible and long lasting to commemorate their time in my group.

Approximately five years ago we started Photo Friday by sharing one photo of our research every week on our Twitter and Instagram accounts. Since then, my group has captured some truly remarkable images. One was selected as C&EN’s 2015 Chemistry in Pictures photo of the year. This included a spread in an issue of C&EN and a grand prize award of a DSLR camera.

My wife and I liked the photos so much that we decided to incorporate them into our home decor. We found an online printing company to create 8” x 12” metal prints of our favorite photos. The number of prints grew and below is a photo of our current collection.

Each photo has its own story. For example, the second photo down on the far right was included in the TOC image of our first corresponding author paper.

So, in a kind of wonderful but unintentional way, we happened upon a way to commemorate my students: we asked them to sign their work. On the back of their photo is I asked the students to write their name, signature, degree, and year of graduation.

2) How do I keep track of them after they leave FSU?

Two years ago, at the Fall 2016 ACS meeting, I organized a special symposium to celebrate the 75th birthday of my postdoc advisor, Thomas J. Meyer. The event included three days of presentations and a dinner for both the speakers and all Meyer group alumni (AKA The Meyer Mafia). Part of my organizing duties involved contacting and inviting as many alumni as I could find. Thankfully, Prof. Meyer’s secretary had an excel spread sheet containing over 150 names spanning more than four decades. While it was not comprehensive, and some of the email addresses and webpages had long-since died, the list was impressive and very helpful nonetheless. The symposium and birthday party were ultimately a huge success. The proceedings even helped populate a book, aptly titled The Ru(bpy)3 Legacy, commemorating Prof. Meyer’s impact on the research community and his students. The book also included a list of all his academic children and their current affiliations.

The symposium allowed me to meet, face-to-face, the people behind the papers I had read for years. It also made me very reflective. How was I going to keep track of my students? Over the course of 4 or 5 years you spend hundreds of hours in meetings together, exchange thousands of emails, and learn a hundred little details that you might not even recognize. For example, I can identify who’s about to enter my office based on the rhythm of the steps coming down the hallway. The advisor / student relationship can sometimes be a love-hate but hopefully it is still deeply rooted in mutual respect. And while we (mentors/advisors/professors) don’t always show the impact students have on us (I for one am an emotionless robot) the bonds of a quality mentor-mentee relationship run deep.

It is for this reason that I am going to do my best to collect private email addresses and current affiliations. My hope now is that they will continue to contact me and update me on their major milestones. It is always a pleasure to hear from Hanson Research Group undergraduates who’ve moved on (even though they have only been gone for a few years). In the future I will look forward to hearing from my newly minted PhD students too.

By June 18, 2018 0 comments Chemistry Art, fun

2050 – A world without plastics


An experimental bit of writing – be nice 😉

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The 20th centuries wonder material had turned into a blight of biblical proportions. The world was awash with plastic. From obvious fragments of polystyrene packaging, to polyethene shopping bags, and discarded PVC furniture to the microscopic micro-fibres shed from our polyester clothing during every wash. It accumulated in great, becalmed garbage patches in the middle of our oceans or washed up as vast invasions of flotsam, where it was consumed by wildlife, mistaking our discarded packaging for food.

Meanwhile the currents and geological forces abraded the jet-sum into tiny fragments that found their way into, well everything. Our cheap, durable and omni-present material had reached every corner of the globe, it had became part of the very fabric of the planet. Geologists coined a new type of sedimentary rock; plastiglomerate – part plastic pollution part stone.

For decades the litter had been building. The obvious detritus featured on every street corner, beach and country park. It became part of the scenery, we got used to it, ignored it, or mildly complained, whilst making sure we kept hydrated by sipping from our water bottles, that we clutched like life-support systems.

Then almost two decades into the 21st century the zeitgeist shifted. Seemingly triggered by the haunting image of pilot whale grieving her dead cub. The narrator blamed plastics. Our blinkers fell away, and we noticed the plastic as if it had just been dumped on our doorsteps. Unlike the invisible carbon dioxide, ravishing the climate and the oceans, we could point at this culprit.

Almost overnight plastic packaging became universally distasteful. Shoppers curled their lips when offered a plastic punnet of mushrooms and then stripped of the useless artificial skins from their purchases before dumping them in front of the supermarkets. Companies raced to see who could strip the plastic from their products the quickest. Listicle blogs sprang up providing tips on how to throw the ultimate plastic free dinner party. And, much to children’s dismay, drinking straws disappeared from cafes across the land.

Politicians were as quick to jump on the bandwagon, keen to cash in on the voters’ new plastic outrage, they vilified cotton buds, toothpicks and wet wipes.

But all this outrage, bans and boycotts was just tinkering around the edges. One small island’s war on drinking straws did little more than remove a mole hill from the mountain of the world’s plastic waste. Something much more radical was needed.

Gaia had the beginnings of an answer. She was used to cleaning up detritus. Over millions of years the myriad of micro-fauna have found biochemical ways to harness the resources from organic dead matter. But plastics had only been around for a few decades. So microorganisms simply hadn’t had enough time to evolve the necessary biochemical tool kit to latch onto the plastic fibres, break them up and then utilise the resulting chemicals as a source of energy and carbon that they need to grow.

Or so we thought.

But deep within a Japanese rubbish tip, devoid of organic matter on which to feed, evolutionary pressure had selected an organism with a new feeding strategy. Nature it seemed, had quietly made a start on tackling our plastic plague. Somewhen, in the recent past, a bacteria had undergone a random mutation and a protein that normally allowed the bug to feed on fats had been converted into one that empowered it to digest plastics.

Not that the plastic waste was noticeably decomposing. The bacteria wasn’t up to the scale of the job. After all, it was a mere evolutionary infants, taking the first tentative bites of a new food, still unequipped to make full use of it. It might have been decades or longer before anyone noticed the rubbish was rotting. Or maybe some other natural pressure may have been to much for the new species. It could so easily have gone extinct before anyone ever became aware of its existence.

But for Prof Yoshiharu Kimura’s eureka moment. Struck by an inspiration particle, it occurred to him that the obvious place to look for a plastic eating organism was in the heaps of rubbish. For five years he hunted through 100s of samples of soil, sludge and stagnant water seeping out of tips and recycling plants. Then, back in the lab, he painstakingly tried to grow something, anything, by feeding his soup of organisms little more than ground up polythene bottles. Miraculously, in just one dish a single bacteria flourished, multiplied and thrived. Soon he had a viable culture. Professor Kimura had found the needle in the plastic stack. He called it Ideonella sakaiensis.

For a while people were mildly interested, there was a flurry of pressproclaiming the solution to the plastic problem may have been found. But soon the excitement died down, for this was still two years before the dead whale cub was beamed into homes around the world. And so the newly discovered I. sakeienis slipped from the folk mind. That was until, a second breakthrough came. Perfectly timed, on this occasion, coinciding with the new anti-plastic movement. Professor Kimura had been happily sharing his cultures with scientist far and wide, and and one group had accidentally genetically engineering the protein that empower I. sakeienis to be a much more efficient plastic digester. In those 24 months they had done what nature might have taken centuries to achieve. The bacteria hit the headlines. They showed the world that by taking what Gaia started and combining it with 21st century biotechnology we could at last tackle the plastic problem of our own making.

Genetically modification of organism, vilified for decades as the technology that would destroy our ecosystems, suddenly became the answer to all our worries. Folks who had ripped up experimental GM crops, fell over each other in their efforts to support genetically enhanced plastic munching microbes. After all, the plastics were unnatural and evil. And so, they reasoned, it was perfectly acceptable (at least in this case) to utilise GM bugs to clear up our mess. It might even be that we were just giving nature a helping hand, it was possible that some organisms might even have made a start on the plastics in the oceans.

The great cleanup began. Governments and eco-charities around the world throw money at the problem. What started with the odd publication here and there became a torrent of papers describing newly discovered and genetically enhanced bacteria, fungi and even worms. All equipped with an arsenal of plastic eating enzymes. Soon concerned citizens got in on the act. School science fairs featured projects dreamt up by keen children attempting to breed plastic-eating creatures, the maker movement got involved, as they discovered home bio-hack kits could be used to tinker with microbes molecular machinery.

By 2022 we had identified thousands of organisms, both naturally evolved and artificially enhanced, equipped with the molecular and mechanical machinery required to set to work on our poly-materials. In just a few more years the impact was tangible. Recycling plants quickly harnessed the new biotech boom to turn rubbish into fuel and chemical feedstocks used to create, amongst other things, fresh virgin plastics. Plastics production and recycling had at last become a truly circular economy. It even became economically viable, with the help of solar powered drone barges, to sweep up the great ocean garbage patches.

The oceanic rubbish rafts shrank, plastics slowly rotted on our beaches, reports of plastiglomerate dwindled. There was a collective sigh of relief.

Except it wasn’t just the rubbish the new breed of bugs were eating. Once out in the wild they were unable to distinguish between refuse and infrastructure. Whether the plastic-munching organisms escaped from the recycling plants, the amatuer bio-hackers’ sheds, or just naturally evolved, we can’t be sure.

The world was once crisscrossed with polythene pipes delivering gas and water to homes and industry. PVC insulated electrical cables and sheathed the world’s fibre optic communication networks. The many uses of plastics were incalculable. At its peak 350 million metric tonnes of plastic materials produced annually had formed the fabric of not just our single use packages, that we so quickly discarded, but also the very structure of our civilisation. And now that fabric rots like so much soft-wood.

By May 8, 2018 4 comments opinion, science news

Chemistry Blog needs you!

Poor old chemistry-blog, its being going since 2006, but its been a bit neglected of late. So as it approaches it’s teenage years, (13 in May!) we felt it could do with a new lease of life.

So we’re blowing the dust off the old thing and inviting a new generation of writers, chemists and chemistry enthusiast to join the venerable network.

If you fancy contributing to the site then drop us a line (email, twitter or the comments are fine) and let us know why you’d like to write for the blog and a little bit about your background (280 characters will do!).

Over the years we’ve covered  everything from data manipulation, plagiarism to a fair bit of larking around.  In case you need any reminders here’s a few of our highlights (in no particular order, and having polled exactly one person).

Over to you!

The Rules

Alleged Data Manipulation in Nano Letters and ACS Nano from the Pease group

What’s in Lemi Shine? – UPDATED

Something Deeply Wrong With Chemistry

By April 21, 2018 4 comments Uncategorized