Porous Molecular Crystals: Applications in Storage, Recycling and Sensing

NSF Grant Funds Analysis and Development

A three year, $456K grant from the National Science Foundation will fund the development and analysis of materials that can store, release and sense different chemicals. These materials, called porous molecular crystals, are scaffold-like structures which contain hollow pores.

Ognjen Miljanic
Ognjen Miljanic, professor of chemistry, works on developing and analyzing porous molecular crystals, which have a number of useful properties.

“Porous molecular crystals have a wide range of useful properties,” said Ognjen Miljanic, University of Houston professor of chemistry and principal investigator of the grant.

Porous Molecular Crystals: Can Absorb and Release Different Molecules

Porous molecular crystals are assembled like LEGOs, with discrete building blocks being ‘snapped’ together to form a scaffold-like structure. This assembly means the connections between individual pieces are strong enough to build a durable structure, but weak enough to disassemble when needed.

“Because these are built from individual molecules, you can engineer their properties more precisely,” Miljanic said.

The defining property of these crystals is that each building block contains a hollow pore. Similar to the way a sponge absorbs and releases water, the pores contained within these crystals can absorb and release different types of molecules. Depending on its properties, a pore can have affinities for specific molecules.

Properties Include Energy Storage, Molecule Sensing, and Molecule Storage and Recycling

Different types of porous molecular crystals have applications ranging from energy storage and material recycling to chemical sensing.

Porous molecular crystals can absorb pressure and store energy. They can also trap and release different types of molecules, which can be used to recycle materials such as anesthetics, or to sequester harmful chemicals. Some porous molecular crystals also have sensing properties, where the color changes based on whether or not molecules are contained within the pores.

For this latest grant, which builds upon previous work, Miljanic’s research group will be analyzing and modifying the properties of materials they previously synthesized.

“We will be studying the response of these porous molecular crystals to pressure,” Miljanic said.

Given the flexibility of the bonds between the building blocks of these crystals, these pressure-based changes could have useful properties.

- Rachel Fairbank, College of Natural Sciences and Mathematics