A. Masuyama et al., Ozone-cleavable gemini surfactants. Their surface-active properties, ozonolysis, and biodegradability, LANGMUIR, 16(2), 2000, pp. 368-373
A series of bis(sulfonate) or bis(carboxylate) types of double-chain surfac
tants (gemini surfactants) containing carbon-carbon double bond(s) in their
lipophilic chains and/or the connecting part were prepared with the intent
ion of developing high-performance surfactants having a decomposition chara
cter toward ozone. Some profiles with respect to the structural effect of t
he double bond(s) on the surface-active properties of these gemini types of
surfactants were revealed as follows: (1) the displacement of a C-C bond b
y a C=C bond in the connecting part made a positive contribution both to mi
cellar formation and to the effectiveness and efficiency of adsorption on t
he surface; (2) in contrast to this, a C=C bond in the lipophilic chains of
gemini surfactants made a negative contribution to these properties. Ozono
lysis of these gemini surfactants was easily accomplished by passing ozone
through their micellar aqueous solutions followed by successive reduction o
f the resulting mixtures with NaBH4. A remarkable change in foaming propert
ies was observed before and after the ozonolysis; that is, foam stability o
f all examined ozonolytic products was extremely low. Finally, biodegradabi
lity of some gemini surfactants and their ozonolytic product by activated s
ludge was estimated. Their degradabilities were much higher than that of so
dium dodecyl-benzenesulfonate and were comparable to that of sodium 1-dodec
anesulfonate under the same conditions.