NEON Art Conservation decided to make a preliminary assessment on the use of two commercial brands of tea as possible adsorbents of volatile organic compounds (VOCs). A historical polyethylene (PE) object showing severe degradation such as crazing, fractures and strong odour release was used as a case study. Two varieties of tea - black tea and one infusion of orange and ginger - were used as adsorbents. This PE object was releasing a strong acid odour, also verified by an A-D strip (acidic vapour indicator) changing from blue to green in just one day. This strip was put inside a plastic film bag along with an object fragment. To assess the efficacy of the two teas, other fragments of the same object were also stored in plastic bags with A-D strips. Great results were obtained with the infusion of orange and ginger, as the A-D strip remained blue even after one week. Curiously, the black tea was apparently not capable of adsorbing such acid VOCs, as the A-D strip changed to green in less than 24 hours.
Visual assessment after 24 hours of the fragments of a polyethylene historical object inside plastic bags with: A-D strip (left), A-D strip and orange and ginger infusion (centre) and AD strip and black tea (right). As observed, only in the presence of the orange and ginger infusion did the A-D strip remained blue. This suggests the absence of acid compounds being released from the PE fragments. Credit: NEON Art Conservation Lda.
Still, other VOCs might have been adsorbed, launching this line of research as a possible promising topic in sustainable conservation practice. NEON Art Conservation is a recently formed studio based in Lisbon (Portugal), dedicated to the conservation of modern and contemporary cultural heritage including works on paper, photography, paintings and plastic. The company was founded by five conservators who ambitioned to develop their activity in the safeguarding of modern and contemporary art. It is a spin-off company of NOVA School of Science and Technology, which is committed to applying scientific research and knowledge of materials as a base for the development of this rigorous and demanding work.
We would like to thank SiC for the inspirational post and to Julianne Bell, Mick Newnham and Petronella Nel for their research paper with such promising results .
The full title of the SiC article inspiring this one is: