I love to hear about different
experiences with textile deacidification from list members.
There are a number of studies looking
into the effects/benefits of deacidification on textiles (see list below
for a few examples). But I am not aware of textile conservators using
deacidification routinely as a treatment for acidic textiles. While
the benefits of deacidification for paper is well established, there are
a few reservations (not all are proven risks under treatment conditions)
for use on textiles that has kept the treatment from being use routinely.
Deacidification are used on acidic
textiles to neutralize the acids in hope of prolonging their useful lives
- so it is not always needed, many textiles that have been laundered in
the past (eg. tablecloths and pillow cases) are already neutral or slightly
alkaline in pH. Or if a textile is already very brittle or powdering
from acid hydrolysis, deacidification is not going to add to its useful
life, therefore in my opinion, it is not needed.
Deacidification is typically used
on cellulosic textiles only, because of reservations about using alkaline
solutions or leaving alkaline buffering agents on protein fibres. If
there are any colourants or silk embroidery etc on the textile, there are
always concerns of colour change with deacidification, or its effect on
silk. For very degraded/weak cellulosic textiles, other than the
fact that deacidification would not reverse its physical state, there is
the added risk of further damage caused by high alkaline hydroxide solutions.
Some have suggested that introducing calcium and magnesium ions to
the textile may attract dust. So for all or some of these reasons,
deacidification of textiles is not routinely used.
If deacidification is required,
magnesium bicarbonate would be a safer reagent than calcium hydroxide mainly
because of the pH of the aqueous solution. Hydroxides have a much
higher pH and there are higher risk of colour change of alkaline sensitive
colourants on the textiles, also for degraded cellulosic textiles. Bicarbonate
solutions are more laborious to prepare but the solutions are not alkaline
- even though the final magnesium carbonate buffer remaining on the textile
is alkaline.
Some articles related to deacidification
of textiles:
1. Nancy Kerr and her co-authors
have studied the effect of calcium hydroxide and magnesium bicarbonate,
morpholine, and non aqueous methoxy magnesium methyl carbonate (WeiT'o
spray) on cellulosic textiles.
Kerr, N.; Jennings, T.; Méthé,
E.; "Long-term stability of cellulosic textiles: effect of alkaline
deacidifying agents on naturally aged cellulosic textiles" Historic
Textile and Paper Materials II: Conservation and Characterization. Developed
from a symposium sponsored by the Cellulose, Paper and Textile Division
at the 196th National Meeting of the American Chemical Society, Los Angeles,
California, September 25-30, 1988 Zeronian, S. Haig; Needles, Howard L.
(Editor); (ACS Symposium Series 410) Washington: American Chemical Society,
1989 Pp.143-158
Kerr, Nancy; Hersh, Solomon; Tucker,
Paul A., "The use of alkaline-buffering agents to retard the degradation
of cotton textiles" Science and technology in the service of conservation.
Preprints of the contributions to the Washington congress, 3-9 September
1982 (1982) Pp.100-103
2. Ira Block included calcium hydroxide
in his research
Block, Ira, "The effect of
an alkaline rinse on the aging of cellulosic textiles. Part IV" Science
and technology in the service of conservation. Preprints of the contributions
to the Washington congress, 3-9 September 1982 (1982) Pp.96-99
3. Peacock, Elizabeth E, "Deacidification
of degraded linen" Studies in conservation Vol.28 No.1 (1983) Pp.8-14
4. At CCI we have studied extensively
the effect of washing and deacidification on paper and cellulosic textiles.
For textiles we didn't use deacidification chemicals to neutralize
acids but rather to see if adding low concentrations of magnesium bicarbonate
and the neutral magnesium sulphate salts to wash water would benefit cotton
and linen textiles.
Tse, Season "Wash water quality
requirements for textile conservation: an overview of Canadian Conservation
Institute research" Strengthening the bond: science & textiles.
Preprints of the North American Textiles Conference 2002, Philadelphia:
North American Textile Conservation Conference, 2002 Pp.143-151
- Low concentrations of magnesium
sulphate and magnesium bicarbonate in wash water to improve washing. The
article also summarizes the results from CCI's washing and deacidification
research.
Season
Season Tse
Senior Conservation Scientist/Chemist
Conservation Research
Canadian Conservation Institute
Canadian Heritage
1030 Innes Rd.
Ottawa, ON
Canada
K1A 0M5
Tel: (613) 998-3721 x-187
Fax:(613) 998-4721
email: season_tse@xxxxxxxxx
Websites: www.cci-icc.gc.ca & www.preservation.gc.ca
Jennifer Hadley <hadleyj@xxxxxxxxxxxxx> Sent by: Textile Conservators <TEXCONS@xxxxxxxxxxxxxxxxxx>
10/07/2007 04:44 PM
Please respond to
Textile Conservators <TEXCONS@xxxxxxxxxxxxxxxxxx>
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TEXCONS@xxxxxxxxxxxxxxxxxx
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Subject
Re: deacidification
Hello everyone,
I was talking to our paper conservator today about the deacidification
of
paper. He was wondering if textile conservators use similar chemicals
to
deacidify textiles. They use Calcium Hydroxide or Magnesium Bicarbonate.
I had
never heard of using these chemicals with textiles. Does anyone know
if these,
or similar chemicals are ever used in the treatment of textiles?
Thanks,
Jennifer
Jennifer Hadley
Collections Care
Museum of Church History and Art
(801) 240-0297
hadleyj@xxxxxxxxxxxxx
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