Tag Archives: internship

17th Century Modern Materials

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The six samples as they were given to me – these are nice big samples too, sometimes we get ones much much smaller!

A while back I was given six small samples to analyse – nothing unusual about this till I looked at the images of the object that the samples had come from and immediately had grand notions of treasure hunting for the Holy Grail with Indiana Jones! These thoughts were soon followed by me humming ‘knights of the round table’ down the back of the lab…

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17th Century cup (Museum no: 659-1904). On the right hand side of the image you can clearly see on segment that had a number of different cracks – I also think the cup looks like something from Indiana Jones… (c) Victoria and Albert Museum, London.

We do a lot of analysis of this type in the lab – a conservator will come to us looking to identify the materials used in a past conservation treatment. In this case the amber cup had been treated a long time ago to join the broken sections back together. Depending on the type of material used, the length of time since the treatment and the storage/environmental conditions, old conservation treatment can be in various conditions. The material used in the previous treatment of this object had become discolored and was also beginning to fail; the joints were starting to crumble away. This impacted the object in two ways – the failing joints meant the cup was structurally vulnerable and the discoloration impacted the interpretation of the object.

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This image shows where the conservator took samples. They are all along joint lines, where the adhesive is failing and where samples were easily taken. (c) Victoria and Albert Museum, London.

Now you might be wondering what the intern for modern materials is doing anywhere near an object from 17th century Prussia! When we analysed, via FTIR, the samples they mostly turned out to be amber (shocking considering the cup is made from amber and is also is used in conservation treatments) and some pigment (probably burnt sienna).

Image of one sample under magnification, showing what looks like two substances joined together. The red substance is most likely burnt sienna, while the glassy substance was amber

Image of one sample under magnification, showing what looks like two substances joined together. The red substance is most likely burnt sienna, while the glassy substance was amber. (c) Victoria and Albert Museum, London.

The main issue with FTIR, the scientific method we use to identify materials of this kind, is that in the resulting spectrum we see everything that was present in the sample. I spoke a little about FTIR in a previous post but didn’t delve in the world of mixtures.

If we look at the image below of two spectra from the same sample we can see that they don’t quite match up (don’t mind that the peaks have different heights this could be due to other issues like thickness of the sample used) . There are a few extra peaks in the Blue spectrum compared with the Red.

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Spectrum from different area in same sample showing the sample is a mixture. The peak at 1 has a larger shoulder in Blue than in Red; A peak at 2 is found in Blue spectrum and not in Red; The ratio of peaks at 2 &3 are different in Blue than in Red; Formation of new peaks at 4 and 5.

One of the easier ways we can try and distinguish mixtures is to subtract one spectrum from the other using computer software. This method isn’t perfect and a certain amount of skepticism is required – luckily this particular mixture was very straight forward. The image below shows the resulting subtraction in Red. The Purple and Green spectrum are the closest matching spectrum from our database; both are aged Cellulose Nitrate.

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Top spectrum (in red) is resulting subtraction. The two other spectra are the nearest match from the database. Both of the nearest matches are from aged Cellulose Nitrate.

Cellulose nitrate was the first semi-synthetic “modern material” to be produced and mass marketed. In the beginning it was mostly associated with shirt collars and cuffs, and then later with film negatives; it was also used in conservation treatments and industry. However, it has a tendency to discolor, disintegrate and spontaneously catch on fire. Outside of traditional objects we commonly find cellulose nitrate used as a protective coating and adhesive in past conservation treatments. The issue conservators have is with their removal as sometimes one needs to used harsh solvents – this could have implications for the object material. The manner in which cellulose nitrate degrades can also affect the object as nitric acid is formed and this can speed up the decay of surrounding objects.

Beginnings…

I suppose it’s best to begin at the beginning – My name is Mark Kearney and until a short time ago I was living the idyllic (yet unemployed) country life on the west coast of Ireland. That was until I moved over to London to start work at the Victoria and Albert Museum. I have been lucky enough to be chosen to be the Institute of Conservation/Heritage Lottery Fund intern for Modern Materials (Plastics) at the V&A. The move over hasn’t been as smooth as I’d have liked and I have discovered the joys of house hunting in London! But that has finally been sorted and I’ve a place to live!

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Sunset on the Northwest of Ireland – Not exactly my backyard, but not far from me either.

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Cherry blossoms at South kensington tube station the week I started work.

My background is in Astrophysics – a subject many think is light years away from conservation. I spent a lot of my time in physics looking at fancy images of the sun with the help from the lovely people over at Solar Monitor.

I got into conservation because I have always loved museums, art, design and old things in general! When it was coming to the end of my undergraduate and careers had to be picked, I wanted to find something where I could combine all the science I’d learnt with my interests in art and design. Conservation was an obvious choice for me (I’m also nosy and I wanted to find a way round the ‘do not touch’ signs you see in museums).

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One of the many “Do Not Touch” signs here at the V&A. (c) Victoria and Albert Museum, London.

This internship is going to be mostly focused on the conservation of plastics, a material that most people think lasts forever, but some, in reality have a very short life. I will pepper the blog with images, analysis spectra and as many interesting things as I can find. The blog is going to be a record of the work I do over the coming year and I’m going to try and keep it as informal as I can. I will post links to websites where you can go into a bit more detail if you wish, but I will try keep this blog as easy to read, yet with as much real substance, as I can.

I started the internship a little over a month ago and thanks to the fall of bank holidays, some long meetings and a training day I’ve only had one full weeks work yet! (Talk about soft landings!). So far, a lot of time has been spent getting all the ducks in line for some of the work I want to do during the year. I have also been getting used to some of the high-tech gadgetry the Conservation Science department has. Over the next year you’re going to hear me talk a lot about FTIR spectroscopy.

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The FTIR machine we use here with its fancy microscope attached. (c) Victoria and Albert Museum, London.

Spectra

A typical FTIR specta for a polymer. (c) Victoria and Albert Museum, London.

This is the analysis mostly used when dealing with plastics. The department has an especially nice FTIR machine – I say nice because it has a microscope attached to it (more on that in a later post…). I am also lucky because the department has the facility for Raman spectroscopy, which is a bit like FTIR, but isn’t as widely used in conservation – mainly due to the historic high cost of the machine, but it’s thankfully coming down.

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The Raman machine. (c) Victoria and Albert Museum, London.

Over the year I will also be helping out with some of the other people in the Conservation Science department. Ill will get a chance to see how the Pest Management systems works and how we keep track of the environment we store the objects in. This is a great opportunity for me to learn as much as I can about the conservation of plastics and about large museums, so if some day you see a post about moths or the UV levels in a gallery, don’t worry you haven’t ended up at the wrong interns blog!

And lastly… It’s not all high tech here at the Victoria and Albert! Sometimes the simplest method is the best, and nowhere is that better demonstrated than in the way objects are carried, short distances, internally within the museum.

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The little baskets that objects come to the lab in – the simplest and safest way for them to travel short distances! (c) Victoria and Albert Museum, London.