Mh. Huang et al., In situ probing by fluorescence spectroscopy of the formation of continuous highly-ordered lamellar-phase mesostructured thin films, LANGMUIR, 14(26), 1998, pp. 7331-7333
Continuous highly-ordered mesostructured lamellar-phase thin films are form
ed by a rapid dip-coating method. The films are made by a dip-coating proce
ss from a sol consisting of tetraethoxysilane and the surfactant sodium dod
ecyl sulfate (SDS). XRD patterns give sharp peaks extending to 14 orders, i
ndicative of a highly-ordered structure. Film thickness is measured in real
time by using interferometry; interference fringes remain constant in heig
ht above the sol on the continuously-moving silicon substrate. In situ fluo
rescence spectra of probe molecules were recorded to trace both the formati
on of the micelles and the solvent composition of the films as they are pul
led in real time. Micelles are formed, break up, and re-form to produce the
final structure in 12 s, and the water content smoothly increases from 2%
to 60% in the same amount of time.