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.