One of the difficulties of conservation & the internet is that conservators
tend to have historic issues & the internet only current ones. So at
http://www.uniqema.com there's information "A guide to the Replacement of
Nonyl phenol ethoxylates" and nothing on Synperonic N. It's really important
to keep those old technical information sheets! Vincent Daniels reported on
Synperonic N and NDB being phased out in Europe--by 1995 for domestic use &
2000 for industrial use in Conservation News UKIC #68 (March, 1999):6. V.
Daniels joined other authors in an article "Finding Substitute Surfactants
for Synperonic N" in JAIC vol 43 (2004):55-73. Their experimental CMC for
Synperonic N was 0.190gr/l. Part of the reason for the ban on Synperonic N
is that it may have pseudoestrogenic effects and it does have a very slow
breakdown (the degree of breakdown like the level of pseudoestrogenic effect
remain in discussion in the US). Textile conservators will have noticed that
nonionic ethoxylates maintain their detergency in solution long after
anionic surfactants have broken down.

Mary W. Ballard
Senior Textiles Conservator
Smithsonian Center for Materials Research & Education
4210 Silver Hill Road, Suitland MD 20746 USA
tel: 301-238-1210 fax: 301-238-3709
email: [log in to unmask]

>>> [log in to unmask] 04/27/05 02:54PM >>>
Assuming room temperature, what is the critical micelle concentration of
the
non-ionic surfactant Synperonic N?  Timar-Balazsy and Eastop give a range
for non-ionics of .05g/L to 0.5g/L; an internet search has not yielded
much
specific info.  I am curious what concentration people are using. Thanks,
Anne Peranteau
Mellon Fellow in Textile Conservation
Philadelphia Museum of Art