We report on studies of composite Langmuir films containing lignin (ex
tracted from sugar cane bagasse) and cadmium stearate and their subseq
uent transfer as Langmuir-Blodgett (LB) films. Pure lignin was found t
o form non-monomolecular films at the air-water interface. Composite m
onolayers of lignin and cadmium stearate with varying compositions hav
e been obtained and characterized by surface pressure and surface pote
ntial isotherm studies which essentially indicated the formation of a
meta-stable composite monolayer at the air-water interface. Neverthele
ss, these composite monolayers could be uniformly transferred onto sol
id substrates under optimized deposition conditions. Transferred multi
layer LB films were characterized by UV-vis and Fourier transform infr
ared spectroscopy (FTIR), X-ray diffraction (XRD) and surface potentia
l measurements. FTIR studies confirmed the transfer of lignin along wi
th cadmium stearate. W-vis results revealed a layer-by-layer transfer
of the composite monolayer. In the composite him, both cadmium stearat
e and lignin were present as separate domains and the stacking order i
n the cadmium stearate domains was found to be influenced by the incor
poration of lignin, as evidenced from XRD. Surface potential measureme
nts indicated a good film uniformity. (C) 1998 Elsevier Science S.A. A
ll rights reserved.