Reactive oligo(dimethylsiloxane) mesogens and their nanostructured thin films.

K. Nickmans,J. Lub,A. P. H. J. Schenning,D. J. Broer,Ph. Leclère

doi:10.1039/c7sm00673j

Abstract

Oligo(dimethylsiloxane)-based reactive mesogens were prepared and shown to form room-temperature smectic phases which were 'frozen-in' by photopolymerization. Homeotropically aligned, nanostructured thin films were obtained by spincoating, and micropatterning was demonstrated. These hybrid reactive mesogens are suitable for the preparation of aligned nanostructured polymer thin films with potential applications ranging from stimuli responsive coatings to nanoporous membranes.

Highlights

Oligo(dimethylsiloxane)-based reactive mesogens were prepared and shown to form room-temperature smectic phases which were ‘frozen-in’ by photopolymerization
ODMS has been incorporated into calamitic,30–33 discotic,34–36 and bent-core mesogens,[21,37] but anisotropic thin film coatings consisting of ODMS reactive mesogens (RMs) have not been reported
Reactive mesogens RM-3Si and RM-4Si (Scheme 1) were synthesized according to Scheme 2. 4-(Allyloxy)phenyl acetate 1 was prepared by acetylation of 4-(allyloxy)phenol.[38]

Summary

Introduction

Oligo(dimethylsiloxane)-based reactive mesogens were prepared and shown to form room-temperature smectic phases which were ‘frozen-in’ by photopolymerization. Scheme 1 Molecular structures of the reactive ODMS mesogens RM-3Si and RM-4Si. and polymerization in thin films is crucial for smart coating applications. The reactive mesogens were aligned in thin films driven by the low surface energy of oligo(dimethylsiloxane), and photo-polymerized into nanostructured polymer films.

Results

Conclusion