Subject: Hydrogen peroxide as cleaning agent
Daniel-Harry Steward <posterdoctor [at] msn__com> writes >I use a solution of hydrogen peroxide to clean paper surfaces. The >paper is usually printed posters and the inks are not affected by >the cleaning wash. I have done numerous tests and the papers appear >to have no residual damage from the peroxide solution. Does anyone >have other input with this procedure. This is in response to the discussion of the use of Hydrogen Peroxide as a cleaning agent. The use of Hydrogen Peroxide in bleaching is discussed by Alexander Scott in his many publications (1921, 1923 and 1926 especially). Writers on this topic are correct that its action is largely due to oxidation, but there are other chemical interactions which take place in the presence of H2O2 as paper manufacturers and the cleaning industry have long recognized. The nature of the action of Hydrogen Peroxide is aptly explained by W. Schumb, C. Satterfield and R. Wentworth, in Hydrogen Peroxide, Reinhold, 1955. Clearly Ms. Carrol is correct that the effect of washing must be separated from that of H2O2 and what we perceive as "bleaching" action on the cellulose. Plenderleith was aware of the effect when he discussed the difference between sun "bleaching" and the use of oxidants and H2O2 in his The Conservation of Prints, Drawings and Manuscripts (1937). I discussed this with Keiko Keyes in the 1980s asking why conservation had abandoned sun bleaching. Keiko felt (and she was an avid fan of Plenderleith, his later book on conservation having inspired her to a career) that Plenderleith failed to provide a proper description of how sun bleaching was attained. In traditional use wet sheets of fabric and paper had been exposed to the sun and bleaching resulted. What was apparent (and clear from Schumb, et al.) is that bleaching only occurs in association with moisture and that it is essentially due to the production of micro-environments of H2O2 produced by light energy from water. James W. Rice (in his wonderful series of articles in the Textile Museum Journal which I keep as a workbook) noted that water ionizes into H+ and OH-. The hydrogen in some cases impedes cleaning while the OH- ion acts to support some cleaning processes. Under light energy more H+ is given off in micro-environments as a gas liberating areas for accelerated cleaning and H2O2 involvement. Some conservators had associated exposure to light with browning and the obvious association with accelerated aging and other chemical action. Certainly other species of peroxides can be produced as degradation products in light from organic materials. These can cause degradation cycles themselves. The action of H2O2 in the case of cellulose is interesting, and we found that we could potentiate its "cleaning and bleaching" by the use of alcohol which allows H2O2 to penetrate deeper into bundles of the cellulose structure. We published our results in Restaurator, v. 13, 1992:1-22. Thus I agree with Ms. Carroll, the action of H2O2 in this case is not due to washing but to the chemical action of H2O2 on cellulose as both a "cleaning" agent and a "bleaching" agent. Niccolo Caldararo Director and Chief Conservator Conservation Art Service P.O. Box 77570 S.F., Ca. 94107 415-453-9064 *** Conservation DistList Instance 16:8 Distributed: Wednesday, July 24, 2002 Message Id: cdl-16-8-002 ***Received on Friday, 19 July, 2002