Nanoscale Ampoule Fabrication by Capillary Autoclosing

An approach for fabricating nanoscale containers, termed 'nanoampoules', which have the characteristics of ideal delivery agents, was reported. Titania NTs (oxide nanotubes) were fabricated by atomic layer deposition (ALD) on track-etched PC membranes. The polycarbonate (PC) templates were first treated with octadecyltrichlorosilane (OTS) self-assembled monolayers for reasons of release. A mixture of Sylgard 184 A and B polydimethylsiloxane (PDMS) prepolymer, with a volume ratio of 10:1 was prepared and then poured into Petri dishes. After bubbles were degassed out of the mixture, followed by curing in a convection oven at 65°C for 1 h, PDMS stamps with a flat surface were obtained. After loading of the desired materials, both holes of the NTs were closed by means of atmospheric chemical vapor deposition in humid conditions. The nanoampoules were released from the template by dissolving the template in chloroform for more than 1 h. The TEM images and elemental analysis results showed the successful encapsulation of the oxide NTs by autoclosing with silica.