Dual internal functionalization of imogolite nanotubes as evidenced by optical properties of Nile red

Hybrid imogolites have been prepared by combining methyltrimethoxysilane with various organosilanes (Si-R) to obtain nanotubes with a bi-functional internal cavity. With an initial doping ratio Si-R/Si of 5%, nanotubes remain the major product in the samples and their diameter is not modified compared to pristine methyl imogolite (Imo-CH3). The nanotube wall's internal polarity and reactivity is significantly changed as evidenced by using a solvatochromic dye (Nile red). This research opens many possibilities to bring selectivity to the internal cavity or to manipulate the properties of trapped organic molecules.