D. Dunne et al., 2ND-HARMONIC GENERATION FROM LANGMUIR-BLODGETT MULTILAYERS ASSEMBLED FROM ACTIVE NON-POLYMERIC AMPHIPHILES AND INACTIVE POLYMERIC AMPHIPHILES, Journal of materials chemistry, 8(6), 1998, pp. 1391-1397
Alternating Langmuir-Blodgett (LB) multilayers have been prepared from
a non-polymeric hemicyanine and a poly(4-vinylpyridine) 66% quaternis
ed with docosyl bromide, and from a non-polymeric azobenzene and the s
ame pyridinium polymer. With both types of multilayer the intensity of
the SHG signal increased as the square of the number of layers up to
a thickness of ca. 60 bilayers. The slopes of the plots correspond to
second order susceptibilities of 17.5 and 9 pm V-1 respectively,Althou
gh these properties and the stabilities of the films over time compare
favourably with many other LB films described in the literature, thes
e films prepared from 'active' non-polymeric amphiphiles and a 'passiv
e' polymeric amphiphile are not as satisfactory as the closely related
all-polymeric films described previously.