Heritage Science Laboratory Ljubljana
PhD and MSc Projects
PhD and MSc projects
If you’re interested in a PhD with us, please do get in contact. We have a range of supervision expertise, from analytical chemistry and materials characterisation, to evaluation of conservation methods, data modelling and visualisation. Most PhD research projects are highly collaborative and you will develop a wide personal network internationally, helping you to jump-start a career in heritage science, or in any of the related fundamental science disciplines. All of our past PhD students work in industry, public institutions or academia, and many have continued to do research in collaboration with our Lab.
Ongoing MSc Theses
Historic artifacts are a vital part of our cultural heritage, so they need to be protected from substances that could harm them – the ones in museums are particularly endangered, especially if the buildings are not (well-)ventilated. The project focuses on characterization of sorbents that could be suitable for the protection of artifacts by absorbing harmful compounds, which would otherwise degrade (decompose) them. First, a general test of sorbents is done with the Oddy test, where we can superficially assess whether the sorbent is suitable to be placed near the artifacts, as it could also emit harmful compounds. Sorbent analysis is continued by SPME sampling. Identification of the resulting compounds is done by GC / MS.
Supervisor: Irena Kralj Cigić
The work focuses on the development of a model for reversed-phase chromatographic separations based solely on thermodynamic parameters and minimal experimental retention data. The parameters used in the model include Hansen solubility parameters and analyte molar volumes, both of which are estimated using various theoretical calculations. Initially, the experimental investigation of retention processes of selected phthalates will be carried out. This will be followed by the development of a theoretical model that enables the prediction of retention factors for the larger group of analytes under investigation.
Phthalates are a key component in many polymeric heritage materials and serve as plasticizers. Often, they do not mix well with the base polymer and may migrate out of the polymer matrix under various environmental conditions, and form surface deposits, contribute to changes in the specific volume of the material and thus promote cracking and loss of mechanical properties. The study will contribute to our understanding of the solubility of phthalates in polymeric matrices.
Supervisors: Irena Kralj Cigić and Matija Strlič
Various metals originating from catalyst residues, stabilizers and some additives such as flame retardants, antimicrobial reagents, plasticizers and pigments can be found in synthetic fibers and plastic materials of everyday use. Excessive concentrations of these metals can adversely affect the properties of such materials, so the quantitative determination of metals is important for the identification of impurities, for the assessment of the quality of polymer production, and also from the point of view of understanding the effect of metals on the durability of the material. In the case of poly(vinyl chloride), during the decomposition of the polymer, organometallic compounds, metal oxides or carbonates, which are added as stabilizers, react with the resulting hydrochloric acid, which is eliminated from the polymer chain, and thus prevent decomposition. In my master’s research, I optimized the microwave decomposition of PVC and subsequently determined the metals in the resulting solution using ICP-OES. I checked the results for some samples using SEM-EDS. The goal of the master’s research is primarily to find meaningful connections between the presence of various metals and the properties of PVC and to determine how these metals affect the durability of the material.
Copper-based green pigments promote the deterioration of many valuable historical manuscripts. Verdigris was often used, from antiquity to the 19th century, as a green or green-blue pigment. Despite the fact that it is very unstable, as the color changes with time and depending on atmospheric conditions, it was widely used for manual coloring of printed material, as it is semi-transparent and does not cover the printing ink. It was mainly used on illuminations, book illustrations and maps.
The aim of the project is to study the degradation of different papers with the application of verdigris pigment under the conditions of thermal accelerated degradation, which is comparable to the natural degradation. Model samples will be analysed by AAS, SEC, FTIR and colorimetry. The influence of two antioxidants on the stability of verdigris paper will also be evaluated under the same conditions and with the same methods. Part of the samples will be treated with tetrabutylammonium bromide, which has an antioxidant effect in the pseudo-Fenton reaction system on verdigris paper. The second part will be treated with 1H-benzotriazole (BTA), which has also been shown to slow down the degradation of verdigris paper, but the research was conducted under thermally accelerated degradation conditions that are not comparable to natural pigment degradation processes.
Ongoing PhD Theses
Museums and galleries have large collections of plastic objects from the late 19th and 20th century, as well as collections of contemporary art based on plastic materials. The degradation of plastics in museums and galleries does not result solely in the loss of integrity and value of the object itself but can also lead to deterioration of objects in the vicinity due to the formation of harmful volatiles. This project will focus on PVC degradation research to develop a damage function for PVC materials. Degradation of PVC occurs due to HCl elimination from the polymer chain, which leads to the formation of polyene sequences resulting in colour change of the material. Development of damage functions will allow us to determine an artefact’s degradation state and help to determine the optimal management to prolong the object’s lifetime. So far damage functions were established only for certain traditional polymeric materials, such as paper. The laboratory work will focus on non-destructive analytical techniques such as passive and active sampling of emitted HCl, VOCs determination by TD-GC-MS and spectrocolorimetry of model PVC samples exposed to accelerated aging at different T and RH.
The research is part of the APACHE Project.
Duration: 1. 10. 2019 – 31. 9. 2023
Supervisors: Irena Kralj Cigić and Matija Strlič
Compared to other senses, the sense of smell has currently only a minor role in the way heritage and history are communicated. Recently, olfactory exhibitions enhancing the role of smell have been displayed in museums and galleries without exploring the effect of these volatile organic compounds towards the objects in the vicinity. This project will focus on the characterisation of VOCs emitted by perfumes belonging to olfactory exhibition as well as VOCs emitted by different type of museum objects. The laboratory work will focus on determination of object aroma and identification of volatile compounds constituting the odour. VOCs will be sampled both in passive and active mode, on a sorbent in the shape of a thin wire (SPME), or in narrow tubes filled with a sorbent material such as Tenax®, followed by TD-GC-MS with olfactory detection.
The research is part of ODOTHEKA project.
Duration: 1. 11. 2021 – 30. 10. 2025
Supervisor: Matija Strlič
Completed MSc Theses
Plastic objects and art from 19th century and later, which are stored in museums and galleries, undergo visible change in the time they are kept there. This presents a problem for the institutions, as in how to store them so they remain in their original state. One of the processes that occur is migration and subsequently loss of PVC plasticizers. The aim of this work will be to obtain the information about how the type of phthalate plasticizer, moisture, airflow and air temperature affect migration and content of plasticizers in PVC. The techniques which will be used are GC-FID and FT-IR. The results of this projects will be helpful in creating guidelines for preservation of plastic heritage objects and art [COBISS.SI-ID 108508675].
Supervisor: Matija Strlič
Sara Moreno Castaño
Many extraordinary examples and illustrations of coloured paper from the islamic medieval era have been preserved in heritage institutions around the world. In this research, 17 islamic samples from 18th to 19th centuries are analyzed to detect some natural dyes.
The techniques used are related to Raman spectroscopy such as conventional Raman, portable Raman and surface-enhanced Raman spectroscopy (SERS). Using these techniques, a dye spectral reference database of the most used dyes in the Islamic era (henna, madder, weld, saffron, safflower, lac and curcuma) is built and used as a reference when analyzing the historic islamic samples. In islamic coloured paper can be present direct dyes or mordant dyes, thus some pretreatment prior analysis of Raman spectroscopy (using techniques such as the hydrolysis with hydrofluoric acid) are tested on dyed reference paper to find the one that best extracts the dye from the paper.
The research will contribute to achieve a better knowledge about the composition of the islamic paper and the dyes on it, as well as knowledge about how to preserve and handle this historical paper.
Completed PhD Theses
Vibrational spectroscopy for characterization of inks and their interaction with paper, 2014 [COBISS.SI-ID 271462656] Supervisor: Matija Strlič
Characterisation of paper using spectroscopic methods and chemometric data analysis, 2014 [COBISS.SI-ID 271461120] Supervisor: Matija Strlič
New analytical methods in studies of parchment degradation, 2013 [COBISS.SI-ID 36922373] Supervisor: Matija Strlič
Use of chemiluminometry in cellulose degradation studies, 2007 [COBISS.SI-ID 28554757] Supervisor: Matija Strlič
Synthesis, characterisation and study of antioxidative properties of selected myo-inositol phosphates, 2007 [COBISS.SI-ID 28555781] Supervisors: Boris Pihlar and Jana Kolar
Vid Simon Šelih
Determination and role of selected transition metals during oxidative degradation of cellulose, 2007 [COBISS.SI-ID 28769285] Supervisor: Matija Strlič
The influence of selected antioxidants on the stability of cellulose, 2005 [COBISS.SI-ID 221355520] Supervisors: Slovenko Polanc and Matija Strlič