A pure low acyl gellan gum produced from Sphingomonas elodea, a bacterium found on lily pads, for the preparation of rigid gels.

Gelling agent suitable for use with water-sensitive paper objects. Upon contact with the paper surface, water-soluble stains are taken up by the gel. Once prepared it can be used to remove stains on paper, to reactivate adhesive pre-treated tissues, to flatten local creases, and to wash documents.

Model gels are produced by adding Kelcogel CG-LA gellan gum to tap water under shear, heating to 90ºC, adding ions and cooling to set.

Both monovalent and divalent ions can be used: K+, Na+, Ca++ and Mg++.

Sequesting agents such as sodium citrate may be required for hydration in hard water.

Gellan Gum Kelcogel CG-LA" Gel  for use on water-sensitive paper objects:

Removal of water-soluble discolorations through contact with the paper surface, suitable for swelling and peeling off overlays.

Agar and Gellan Gum are gels that are suitable for cleaning art objects made from a wide variety of materials. This cleaning method was developed and tested at the Istituto Centrale per il restauro e la conservazionedelpatrimonio archivistico e librario (ICPAL).

Gellan Gum is preferred over agar because it does not dampen the paper and because of its greater transparency, the work process can be followed more easily. The higher the percentage of gel, the less water is released into the paper.

Recipe and preparation (Gellan Gum)

The gel is made with an alkaline salt solution, which is important for flexibility as well as for the pH value.

0.4 gcalcium acetate in1 ldeionized water, 20–40 g Gellan Gum covered in the microwave at approx. 500 watts warmed up for about 2 minutes. The mixture must reach 85 ° C so that a clear solution is created.

Carefully empty the hot solution into a heat-resistant container (for1 lsolution, the container should measure34 cmx45 cmx1 cm.) When the gel has reached room temperature, it is ready for use and can be placed directly on the back of the object be placed. In order to achieve even moistening, the object is placed in a sandwich of polyester foils and weighted down with a glass plate so that what is happening can be better observed.

Overweighting should be avoided as there is a risk of too much liquid being released onto the paper. The treatment should not last longer than 30 minutes.

Advantages of this cleaning method The gel leaves no residue on the paper. If traces of it stick to the surface, you can easily remove them with a spatula. Due to the consistency and thickness of the gel, it can adapt well to unevenness surfaces.

Degradation products remain in the gel, which is colored yellow-brown by the dirt particles. The gel can be used again on the other side. However, it should not be cleaned and reused.

Clean and unused residues can be reheated and poured out again. The gel can be max. Store in the refrigerator for 1–2 days, covered with foil, as otherwise there is a risk of mold growth.

Other possible uses

The gel is very suitable for softening adhesives made from plants or animals and for removing adhesive backing. Since the gel can also be prepared with water or buffered solutions, options are now being tested to use the gel for deacidification or in combination with enzyme solutions.

Specifications

Appearance:

Off white powder

Composition:

Low acyl polysaccharides

Solution pH

(1% gum in DI water):

4.5 – 6.5