Unraveling the Single-Nanometer Thickness of Shells of Vesicle-Templated Polymer Nanocapsules

4 years ago

Unraveling the Single-Nanometer Thickness of Shells of Vesicle-Templated Polymer Nanocapsules

Andrew G. Richter, Yun Liu, Sergey A. Dergunov, Mariya D. Kim, Volker S. Urban, Sergey N. Shmakov, Eugene Pinkhassik, Sai Venkatesh Pingali

Vesicle-templated nanocapsules have emerged as a viable platform for diverse applications. Shell thickness is a critical structural parameter of nanocapsules, where the shell plays a crucial role providing mechanical stability and control of permeability. Here we used small-angle neutron scattering (SANS) to determine the thickness of freestanding and surfactant-stabilized nanocapsules. Despite being at the edge of detectability, we were able to show the polymer shell thickness to be typically 1.0 ± 0.1 nm, which places vesicle-templated nanocapsules among the thinnest materials ever created. The extreme thinness of the shells has implications for several areas: mass-transport through nanopores is relatively unimpeded; pore-forming molecules are not limited to those spanning the entire bilayer; the internal volume of the capsules is maximized; and insight has been gained on how polymerization occurs in the confined geometry of a bilayer scaffold, being predominantly located at the phase-separated layer of monomers and cross-linkers between the surfactant leaflets.

Publisher URL: http://dx.doi.org/10.1021/acs.jpclett.7b01149

DOI: 10.1021/acs.jpclett.7b01149