The discovery of zeolite nanotubes

Zeolites are crystalline porous minerals that are frequently employed in the manufacture of chemicals, fuels, materials, and other items. Zeolites have only been manufactured as 3D or 2D materials so far. Researchers from the Georgia Institute of Technology, Stockholm University, and Penn State University recently discovered crystalline zeolites in a nanotubular (1D) structure. The findings were reported in Science.

Sankar Nair, main investigator and professor in Georgia Tech's School of Chemical and Biomolecular Engineering, said, "A discovery like this is one of the most exciting portions of our study." "We're becoming more accustomed to conducting research with a clear end goal in mind, so this serves as a reminder that fundamental discoveries in materials science are still interesting and vital."

Scientists and engineers have used the varied sizes, shapes, and connections of the pores in zeolites to discriminate between molecules of different sizes, allowing for the production of chemicals suitable for plastic production, or for the separation of undesired molecules from desired molecules, for example.

The group was working on syntheses to put together 2D zeolite materials. Some of the results revealed that a new type of assembly process was taking place, which was an unexpected turn of events. One such instance led to the development of a new 1D zeolite material with a tube-like structure and perforated porous walls. This one-dimensional substance, known as a zeolitic nanotube, was unlike any zeolite ever manufactured or discovered in nature.

"Zeolite nanotubes might be used to create totally new types of nanoscale components that govern mass, heat, and charge movement not just along the length of the tube or pipe, but also in and out through the perforated walls," Nair said.

The Georgia Tech researchers collaborated with zeolite crystallography experts from Stockholm University and Penn State to resolve the exact arrangement of the atoms in the zeolite nanotube. They discovered that the nanotube walls had a unique atom arrangement not found in 3D or 2D zeolites. The zeolite is forced to form as a 1D tube rather than a 2D or 3D material due to the similar layout.

"This is the first example of a new class of nanotubes, and its distinctive and well-defined structure offers fascinating ideas and potential for designing zeolite nanomaterials," said co-investigator and researcher Tom Willhammar of Stockholm University. "We intend to obtain diverse zeolitic nanotubes with changes in pore size, shape, and chemistry through additional research."

Simply put, a nanometer-scale tube manufactured from a one-dimensional material with regular, perforated holes on the sides is now available for investigation. In addition to being a groundbreaking scientific finding that has the potential to transform the way we think about porous materials design, the researchers believe there are numerous practical implications.

"These materials' unique structural characteristics will allow for a wide range of possible applications in membrane separations, catalysis, sensing, and energy devices where mass or energy transmission is critical," said Christopher W. Jones, co-principal investigator and professor at Georgia Tech. "The materials could have unique mechanical properties and, like carbon nanotubes, could be used in composite materials. At this point, the sky is the limit, and we hope that researchers will come up with innovative methods to use these materials for the greater good."

Reference:

Akshay Korde, Byunghyun Min, Elina Kapaca, Omar Knio, Iman Nezam, Ziyuan Wang, Johannes Leisen, Xinyang Yin, Xueyi Zhang, David S. Sholl, Xiaodong Zou, Tom Willhammar, Christopher W. Jones, Sankar Nair. Single-walled zeolitic nanotubes. Science, 2022; 375 (6576): 62 DOI: 10.1126/science.abg3793