Coupling of liquid crystals to silica nanoparticles

Liquid crystal (LC) molecules were functionalized with alkoxysilane groups and grafted on silica nanoparticles by the sol-gel process, requiring condensation of hydrolyzed molecules with silanol groups at the surface of molecules. The grafting ratio was precisely quantified from a very simple procedure using in situ recording of ¹ H NMR spectra. We showed that LC-grafted nanoparticles can be dispersed at high concentration in organic solvents such as pure LC. They were used as nucleation centers to prepare polymer-dispersed liquid crystal (PDLC) samples with nanometric LC droplets and a complete phase separation between LC and polymer.