Characterization of Langmuir monolayer, Langmuir-Blodgett and Langmuir-Schaefer films formed by POSS compounds

The properties of Langmuir monolayers and Langmuir-Blodgett as well as Langmuir-Schaefer films formed by two open-cage polyhedral oligomeric silsesquioxanes (POSS): 1,3,5,7,9,11,14-hepta-isooctyltricyclo [7.3.3.15,11] heptasiloxane-endo-3,7,14-triol (TSiO-POSS) and 1,3,5,7,9,11-octaisobutyltetracyclo [7.3.3.15,11] octasiloxane-endo-3,7-diol (DSiB-POSS) were studied. Both compounds were shown to form stable monolayers at the air/ water interface. The morphology of the monolayers was visualized with a Brewster Angle Microscopy (BAM). The results obtained indicated that TSiO-POSS molecules formed dimers whereas in the case of DSiB-POSS was found the network structure, which was seen on the water/air interface as well as on L-S and L-B thin films. The difference in the interfacial behavior of POSS considered results from alkyl chains length and number of hydroxyl groups in the POSS molecule. The formation of network structure and presence of POSS dimers after transfer of the films on the solid substrates were reported. (C) 2014 Elsevier B.V. All rights reserved.