Marta Grzesiak-Nowak

Synthesis and investigations of new strontium dicarboxylates

Abstract Using simple methods of synthesis without template agents, 6 new compounds of strontium and dicarboxylic acids have been obtained. The resulting salts are: {1} strontium glutarate pentahydrate, {2} strontium adipate, {3} strontium pimelate monohydrate, {4} strontium suberate, {5} strontium azelate and {6} strontium dodecanedioate hemihydrate. Similarly to the known barium compounds, starting from the salt of azelaic acid, strontium compounds with longer dicarboxylic acids form acidic salts. Metal centers have the coordination number C.N. = 8, and the coordination polyhedra are dodecahedra. Glutaric acid form layered material, whereas with use of longer acids 3D systems are formed. Acids such as dodecanedioic and azealic form systems in which Sr-O polyhedra do not share edges or vertices. Isolated SrO8 polyhedra are joined by carboxylic groups of dicarboxylic acids. Strontium salts {2, 4, 5} are anhydrous, but {1} is pentahydrate, {3} is monohydrate, and {6} is hemihydrate. During thermal decomposition strontium salts of dicarboxylic acids decompose through an unknown intermediate product to strontium carbonate.

X-ray powder diffraction structural studies of lithol red pigments

Lithol reds belong to the group of azo pigments which were popular artists’ pigments at the beginning of the twentieth century. Under the name lithol red pigment, one can find a family of sodium (PR 49), barium (PR 49:1), calcium (PR 49:2), and strontium (PR 49:3) salts of diazotised Tobias (2-naphthylamine-1-sulphonic) acid coupled with 2-naphthol. The colour of the pigment ranges from yellowish red (sodium salt) to bluish red (strontium salt), depending on the metal cation. The main drawback of lithol red is its very poor lightfastness, which has profound implications for its artistic use (e.g. Mark Rothko’s Seagram and Harvard Murals) [1].

On the grounds of icons from National Museum in Krakow

Among various types of cultural heritage objects, icons belong to the most interesting and not too often investigated group. Similarly to the investigations of easel paintings, only tiny amounts of samples taken from icons can be available for scientific studies. In the literature very few technical papers on icons can be found, so there is a shortage of information for comparative studies in this subject.

µ-XRPD investigations of pigments in 17th-century panel paintings from Gdańsk and the northern region of Poland

µ-XRPD investigations of pigments in 17th-century panel paintings from Gdansk and the northern region of Poland

Badania u-XRPD i SEM-EDS pigmentów i zapraw w trzech obrazach z kolekcji Muzeum Pałacu Króla Jana III w Wilanowie

Badania μ-XRPD i SEM/EDS pigmentow i gruntow w trzech obrazach z kolekcji Muzeum Palacu krola Jana III w Wilanowie

The use of XRPD for the investigation of historic pigments and painting materials in works by Henryk Siemiradzki

Precise knowledge of the chemical composition of the pigments used by Henryk Siemiradzki, one of the greatest Polish artists, is important for the enrichment of knowledge concerning his workshop and is essential in choosing the right strategies for the conservation and preservation of his works. An examination of powdered pigments inherited from Siemiradzki, along with an examination of samples taken from his paintings, was part of a research project carried out in the National Museum in Krakow. The aim of the project is to identify the artists painting methods and the palette he used. The X-ray powder diffraction (XRPD) technique, along with other methods of examination, supplemented non-invasive XRF spectroscopy, the starting point of the analyses. None of the applied methods identifies pigments as unequivocally as XRPD analysis, provided the studied material is crystalline. In this article we will present the results of the application of XRPD to investigations of powdered pigments from the collection of historic pigments inherited from Henryk Siemiradzki. We will also present the results of XRPD investigations of paint from several of Siemiradzkis paintings.