Cloud-free distribution

As an eight-year-old who had just received the second dose of the Pfizer vaccine, I was interested in the article on Asel Sartbaeva’s use of silica layers to prevent vaccines from spoiling at room temperature.

Many years ago I was involved in research into silica hydrogels to prevent lager beers from becoming cloudy when chilled. This led to the development of the commercial product Lucilite, which to my knowledge is still in use today. It does this by adsorbing the proteinaceous material that is causing the cloudiness onto the silica, which could then be filtered out.

Although they look powdery, these silica hydrogels contain up to 80% water. An alternative line of research showed that such hydrogels can be tabletted or extruded under pressure and dried if necessary, leaving the silica matrix intact and stable.

It occurred to me that this could be investigated to see if such stable and inorganic silica hydrogels could be used as carriers to bring vaccines cheaply and safely to poorer parts of the world.

Tom Griffiths FRSC
By email

Mineral plastics in war

Your article on mineral plastics reminds me of the work of my former supervisor Peter Plesch from Keele University. At the beginning of World War II, there was a shortage of balsa wood because of the submarines – a threat to the production of the Mosquito combat bomber. He developed an alternative by gelling aqueous sodium alginate with calcium ions and drying the resulting hydrogel. The program was a success but was not needed as the B24 naval bomber closed the mid-Atlantic submarine gap. He then worked on synthetic rubber for Michael Polanyi in Manchester, but was beaten by the much better-funded Americans.

I guess the postwar necessity was to sell olefin and polyester polymers to the customer, but hopefully his work will be cited against modern patents.

John Cooper MRSC
Ayr, Scotland

Living with hearing problems

I am a person with hearing problems. As the Royal Society of Chemistry (RSC) is trying to make chemistry more accessible to people with disabilities, I thought I should try to share my experience in the hopes that people with good hearing can understand the problem.

The first thing I thought was to suggest an experiment. Firmly press your index fingers into each of your ear canals and let someone speak to you at a normal volume. If you can still understand what is being said, ask two or three people to speak to you on the same level and at the same time. Then try to imagine what it is like to be like this 24 hours a day.

My hearing became problematic in my early 30s and I was one of the first people to have a stapedectomy in 1974 in Adelaide, Australia. I had a cochlear implant in 2019 the RSC does not offer any assistance in using these digital aids, but prefers to use social media for its communication.

There have been some remarkable people who have learned to deal with their problems. Sir John Cornforth is the first chemist I met. He was fortunate that his hearing problems didn’t come until after he’d completed his formal training. He was also fortunate to have married a very selfless chemist who was willing to subordinate her career to him.

There was another remarkable woman who went blind and deaf at the same time and that was Helen Keller. She is said to have been asked what was worse and replied that she thought it was a hearing loss. She went on to say that blindness separates you from things, but hearing from people.

David Hamon MRSC
Adelaide, Australia

Details, details

Reading Emma Pewsey’s article on the importance of publishing full experimental details reminded me of a case early in my career. At the time in our group, the preferred method of carbonizing a Grignard reagent was to pour it onto crushed dry ice in a large flask (in one batch) for later workup, usually the next morning. Most of our Grignards were in tetrahydrofuran (THF), and I was unaware that aside from the sheer convenience of the method, it avoided the reaction of the magnesium intermediate with the reagent which in THF tends to be a ketone as the major product. In a publication we just talked about “carbonation with CO.”2‘. This led to a pointed letter from another chemist.

I also noticed the article by Chemjobber, in which nitrogen is referred to as an inert gas – which is normally the case in organic chemistry. In my later career in industry, we did a process where the first stage was the reaction of lithium with triphenylphosphine, again in THF. Our final product was contaminated with difficult to remove nitrogenous contaminants. This was solved by switching to argon as the inert atmosphere. Nitrogen is definitely ‘ert’ for lithium metal!

Anthony Webb CChem FRSC
By email

Miracle of the deep

In connection with the structure of hydrazoic acid, it is appropriate to recall another remarkable compound that is unique among natural products and has not received much advertising: 6-azidotetrazole[5,1-a] Phthalazine. This is the product of a toxic marine dinoflagellate that was isolated in 1958. It has a unique tetrazole ring and a very rare phthalazine ring. Structural confirmation of this excessively rich (52.8%) nitrogen compound came later.

A varvoglis, MRSC
Thessaloniki, Greece

A serious mistake

The article “New magnesium alloy exhibits exceptional corrosion resistance” states that magnesium is widespread “due to its low weight …”. Low density please!

Dr. Peter B. Baker CChem FRSC
Prestwood, UK

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