MCP mixing surfactant: Sodium Deoxycholic acid

Sodium Deoxycholate acid is a surfactant (detergent) that can be used as a component for both cleaning and removal of old varnish and is part of my MCP set (Modular Cleaning Programme). I love mixing this surfactant that consist of the components Deoxycholate acid and Sodium hydroxide 10%. During the process it goes through various stages that look wonderful. You need patience for it but you will be rewarded. It starts with adding the white powdery deoxycholic acid in demineralised water, slowly wetting the powder on the stirring plate. A creamy white substance is formed. Sodium Hydroxide 10% is added and the following hours a slimy substance is formed. But finally the acid is solved and the solution is cleared!
adding DOA in demiwater
stir well with patience
adding NaOH
the last stage: it becomes transparent

 

  Properties of Sodium deoxycholic acid:

  • Alternative Names: Sodium deoxycholic acid; deoxycholate, sodium salt
  • Chemical Name: 3, 12-α-Dihydroxy-5β-cholan-24-oic acid, monosodium salt
  • Molecular Weight: 414.6g
  • Detergent Class: Ionic (anionic)
  • Aggregation Number: 5 (average)
  • Micelle Molecular Weight: 2000g (average)
  • Critical Micelle Concentration (CMC): 2 to 6mM (0.083 to 0.249%, w/v)
  • Cloud Point: Unknown
  • Dialyzable: Yes

Modular Cleaning Programme in practice

Recently a colleague, Judith Bohan who is an interior conservator, called for help. She is working on a project at Haarlem Station. Here the third class waiting room is to be conserved. I was asked for my expertise on cleaning and removing old yellowed and cracked varnish on the beams. I did tests using my Modular Cleaning Programme. In less than two hours we had tested both cleaning and removal and knew what were the best steps to take. We could do a great job, in removing varnish  without damaging the red band. My newest challenge is to calculate how much mixture we need.
testing

final result by Judith Bohan

Modular Cleaning Program practical cours by Chris Stavroudis

After the theoretical part of September 1 and 2 (see publication below’, 16 restorers of all disciplines came together at the SRAL in Maastricht, to learn how the MCP programme works in practice. Kate Bangerter and Marjan de Visser took their home/made MCP kit and tested it on the spot with the aid of Chris.

Besides that we all made new mixtures to make a kit for everybody. It was a hard working four days….in which we got divided in groups and mixed the five orthogonal components. They are water, pH buffer, chelating agent, surfactant and gelling agent. Besides that we mixed a solvent set and a Pemulen set.
During the workshop we tested the system of the set, and discussed the results.
We all went home with our own sets and can get started.
I was exhausted but satisfied, right now I already feel very confident with this method. I helps you in speeding up cleaning tests and making the recipe you chose, in every amount you want.

All restorers togehter. Chris is at the back row right behind Marjan in the blue-white stripe shirt.
putting the mixture in bottels and label them…
 

The Modular Cleaning Program (MCP) lecture by Chris Stavroudis, September 2011 Amsterdam


For the Aqueous Cleaning Method byRichard Wolbers,painting restorer Stravoudis developed a computerized Modular Cleaning Program (MCP) to make the method efficient and accessible.
On the first and second of September Chris gave lectures on how to use the computer program and the aqueous chemistry.
Next week a small group of restorers of different disciplines will start
making their own MCP cleaning test sets and take the first steps in using it.
Kate Bangerter and Marjan de Visser are participating.
Chris Stavroudis explains the MCP, September 2, 2011
To be continued…