In situ GISAXS monitoring of Langmuir nanoparticle multilayer degradation processes induced by UV photolysis

In continuation of our previous studies on Langmuir nanoparticle films we prepared well-ordered bilayer film on the air–water interface in the Langmuir–Blodgett trough. The distance of neighboring nanoparticles was adjustable by shortening the carbon chain length by UV–ozone irradiation. Kinetics of the nanoparticle reassembly in multilayer structure was monitored in time by grazing-incidence small angle X-ray scattering (GISAXS) technique. The interparticle distance determined from the first lateral peak positions decayed exponentially with characteristic time of 102 ± 13 s. The final GISAXS pattern proves nanoparticle multilayer collapse and multilayer agglomeration at the end of the UV exposition.