Conservation Research
and Development
Instrumental analysis in conservation
science, especially identification of pigments and binder materials |
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Resources
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Conservation-related IR
spectra (Old page) |
In this page a selection
of IR spectra of various paint and coating materials registered at UT Institute of Chemistry
and UT Testing Centre
can be found. The spectra have been acquired over the last couple of years in
the course of various projects on historic, industrial and construction
paints and coatings. |
Research Results
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Cross sections of shells
of the Furongian lingulate
brachiopod Ungula ingrica from Estonia were studied
using the Attenuated Total Reflectance - Fourier Transform Infrared
(ATR-FTIR) microspectroscopic and energy dispersive
spectroscopic (EDS) mapping. For the first time it was shown that different structural
laminae of the shell have different chemical
compositions. Compact laminae are rich in PO43-,
Na, Mg and poor in F and Ca. Porous (baculate) laminae are rich in carbonate anions, Ca and F, but
contain less Na and Mg. The ATR-FTIR spectra show further differences in the
nu(2) carbonate region, where the IR band at 872 cm(-1) in compact laminae is replaced by a strong band at 864 cm(-1) in baculate laminae. The changes
in shell apatite suggest different origins of the apatite phases. Compact laminae are likely chemically less altered and could
potentially carry more reliable palaeoenvironmental
or geochemical information than the apatite in baculate
laminae, which is mostly authigenic
in its origin. |
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The applicability of
ATR-FTIR spectroscopy with partial least squares (PLS) data analysis was
evaluated for quantifying the components of mixtures of paint binding media
and pigments, and alkyd resins. PLS methods were created using a number of
standard mixtures. Validation and measurement uncertainty estimation was
carried out. Binary, ternary and quaternary mixtures of several common
binding media and pigments were quantified, with standard measurement
uncertainties in most cases below 3 g/100 g. Classes of components aromatic
anhydrides and alcohols - used in alkyd resin synthesis were also
successfully quantified, with standard uncertainties in the range of 2-3
g/100 g. This is a more demanding application because in alkyd resins
aromatic anhydrides and alcohols have reacted to form a
polyester, and are not present in their original forms. |
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ATR-FT-IR spectroscopy in the region of 550-230 cm-1 for identification of inorganic pigments (presentation
given at the ACS Spring
meeting 2011 in Anaheim, CA) |
An analytical method for
recording ATR-FT-IR spectra of inorganic pigments in the low wavenumber range
(550-230 cm-1) is presented. Due to the nature of the ATR
phenomenon poor-quality spectra are generally obtained from pure pigments.
For obtaining good-quality spectra the pigments are mixed with linseed oil
matrix and spectra are recorded from the mixtures. It is demonstrated on the
example of 47 inorganic pigments widely used in historical paintings that
this spectral range, essentially devoid of absorption peaks of the common
binder materials, can be well used for identification of inorganic pigments
in paint samples. This markedly extends the possibilities of pigment
identification/confirmation by ATR-IR spectroscopy. In some cases the method
can be used alone for pigment identification and in many cases it provides
useful additional evidence for pigment identification using other
instrumental techniques. Several case studies of pigment identification of
real paint samples using the developed method are presented. |
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ATR-FT-IR spectroscopy in
the region of 550–230cm−1 for identification of |
A comprehensive study of
ATR-FT-IR spectra of 40 inorganic pigments of different colours
widely used in historical paintings has been carried out in the low wave
number spectral range (550–230cm−1). The infrared spectra
were recorded from mixtures of pigment and linseed oil. It is demonstrated
that this spectral range – essentially devoid of absorption peaks of the
common binder materials – can be well used for identification of inorganic
pigments in paint samples thereby markedly extending the possibilities of
pigment identification/confirmation by ATR-IR spectroscopy into the realm of
pigments having no absorptions in the mid-IR region. The paper contains a
collection of reference IR spectra of pigments that is expected to be a
useful reference for conservation practitioners. |
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Paper about a method of pigment
determination by low wavenumber ATR-FT-IR spectra (wavenumber region between ), applied to red pigments (red lead, cinnabar,
cadmium lead, different ochres). All investigated pigments absorb IR
radiation in the range of 500-230 cm-1 and can be identified. |
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Determination of iron in
ink writing by SEM-EDS |
Determination of iron in
ink writing on paper manuscripts using electron probe microanalysis
(SEM-EDS). Novel calibration approach is introduced. Detailed analysis of
uncertainty sources and their quantification is done. |
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The conservation and
restoration of the historic Jaani church in Tartu.
Final report of the project. |
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Conservation and Preservation of Parchment
Collection in Estonian Historical Archives |
Master thesis of Eve Keedus (in Estonian) |
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Master thesis of Herki Helves (in Estonian) |
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Master thesis of Jaan Lehtaru (in Estonian) |
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Education
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Training of Conservators and restaurers at University of Tartu |
An overview about
training conservation specialists at University of Tartu |
Last modified: 28.02.2016