An experimental evaluation of non-ionic surfactant Dehypon® LS54

Abstract

Dehypon®
LS45 (LS45) is a common non-ionic surfactant used by UK textile conservators,
however it has very low cloud point of 20 ºC which makes the temperature hard to control
below the cloud point during wet cleaning. This research investigated the critical micelle
concentration (cmc), the detergency and the effect of residues of an alternative surfactant
Dehypon®
LS54 (LS54). The cmc values of LS54 were found to be lower than that of LS45
when measured by Wilhelmy plate method and simplified drop weight method. Artificially
soiled (carbon and olive oil) cotton and wool fabrics were washed with LS45 and LS54 and
their detergency effects on the soils evaluated using colorimetry and visible
spectrophotometry. The most effective concentration of LS54 for removing soils was found to
be 0.3% w/v and its detergency effect was similar to LS45 at the same concentration.
Surfactant residue was detectable on un-rinsed cotton and wool fabrics by Diffuse
Reflectance Infrared Fourier Transform spectroscopy (DRIFTs). DRIFTs analysis also proved
that LS54 is more hydrophilic and has a longer fatty alcohol chain than LS45, which explains
why it has a higher cloud point and cmc than LS45.