Investigation of Materials used by Edvard Munch

The pigments and paint binders used by Edvard Munch have been investigated in several studies. Munch used a mixture of media in his works of art. The two versions of The Scream studied here were found to include oil paints and oil paints thickened with beeswax and also oil crayons containing beeswax and Japan wax, as well as casein pastels, a paraffin wax crayon and at least one gum-bound paint. His sketches on canvas make use of oil paints and tempera paints including egg and casein, as well as casein pastels in at least one instance. His oil paintings on canvas seem to have been executed using a more conventional technique, with most having one or a few paint layers bound with linseed oil on a ground formed from lead white in oil on top of a ground made of chalk in glue. Munch's palette is not extensive, though he was reasonably willing to introduce new materials, such as his use of a petroleum-based wax crayon in 1893, oil pastel - possibly as early as 1893 and certainly by 1910, and his use of cadmium red by 1927-1929. The identification of materials has informed conservators who are planning and carrying out conservation treatment

Substitution of nanoclay in high gas barrier films of cellulose nanofibrils with cellulose nanocrystals and thermal treatment

International audienceThe aim of this study is to design a nanocellulose based barrier film. For this purpose, cellulose nanofibrils (CNFs) are used as a matrix to create an entangled nanoporous network that is filled with two different nanofillers: nanoclay (reference), i.e. the mineral montmorillonite (MMT) and the bio-based TEMPO-oxidized cellulose nanocrystal (CNC-T), to produce different types of nanocelluloses and their main physical and chemical features were assessed. As expected, films based on neat CNFs exhibit good mechanical performance and excellent barrier properties at low moisture content. The introduction of 32.5 wt% of either nanofiller results in a significant improvement of barrier properties at high moisture content. Finally, thermal treatment of a dried CNF/CNC-T film results in a decrease of the oxygen permeability even at high moisture content (> 70 %). This is mainly attributed to the hornification of nanocellulose. A key result of this study is that the oxygen permeability of an all-nanocellulose film in 85 % relative humidity (RH), is similar to CNF film with mineral nanoclay (MMT), i.e. 2.1 instead of 1.7 cm(3) A mu m m(-2) day(-1) kPa(-1), respectively