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Single-walled zeolitic nanotubes discovered

A new class of nanotube material has been discovered by researchers at Stockholm University together with a research group at the American university GeorgiaTech. The unique mesostructure of nanotube materials provide them with properties that are not available for bulk material. The discovery was recently published in the scientific magazine Science.

Zeolitic nanotube
The single-walled zeolitic nanotube is composed of a microporous aluminosilicate wall encapsulating a hollow mesoporous core. Credit: Tom Willhammar/Stockholm University

The carbon nanotube is the most prominent example known so far and exhibits impressive mechanical properties in terms of strength and stiffness in addition to tailorable electrical, optical and thermal properties.

Through a combination of targeted synthesis and high definition structure elucidation, the zeolitic nanotube has been realized. Analogous to the carbon nanotube this material exhibits an extended one-dimensional structure with an ordered wall structure at the atomic-scale. The zeolitic nanotube is however different both when it comes to chemical composition and in atomic structure. It is composed of a microporous wall, which encapsulates a hollow mesoporous core. The tubular morphology and aluminosilicate composition provide a system with intrinsic multi-lengthscale ordering, creating unique properties.

The zeolitic nanotube was synthesized by a process that simultaneously directs the formation of a ~5nm wide tubular mesostructure and a microporous and crystalline wall. Aberration-corrected transmission electron microscopy imaging provided essential tools to reveal the atomic structure, where information from different projections were used in order to reveal its complete atomic structure.

“Electron microscopy provides a unique opportunity to determine the atomic structure of materials lacking three-dimensional periodicity, such as nanotubes”, says 
Tom Willhammar, researcher at the Department of Materials and Environmental Chemistry (MMK) at Stockholm University.

About the natotube

The unique and well-defined structure of the zeolitic nanotube provides exciting opportunities. Its structure with pores at different lengthscales opens up for controlling chemical reactions, where smaller molecules can diffuse through the micropores to access larger active species inside the tube. The aluminosilicate composition, combined with high stability, provides potential opportunities for the material to be used both in gas separation as well as to make the tube itself catalytically active for use in heterogeneous catalysis.

Find the article “Single-walled zeolitic nanotubes”, published in Science

Read more about Tom Willhammar's research