22 November 2017
Green metal organic frameworks
Published online 6 July 2017
Scientists have developed an eco-friendly material that can be used as a biodegradable pesticide carrier.
Metal organic frameworks (MOFs) are porous crystalline hybrids of metal ions and organic linkers. To date, more than 20,000 MOFs have been developed for purposes such as gas separation, storage and catalysis. But the majority of these materials are based on toxic transition ion metals and organic linkers derived from petrochemical origins.
Now, a team led by Omar M. Yaghi, researcher at the King Abdulaziz City of Science and Technology (KACST), Saudi Arabia, has successfully made two MOFs based on calcium ion centers and lactate and acetate linkers, publishing their findings in the Journal of the American Chemical Society1.
The team established the ability of the new material to form permanent pores and demonstrated its promise as a replacement to liquid pesticides.
Traditionally, liquid pesticides are applied by injection or drip irrigation causing air and groundwater pollution. Porous solids that adsorb the pesticide then release it slowly into the ground have gained traction recently, but the materials used, such as activated clay and activated alumina, are not biodegradable and tend to accumulate.
The team showed that their MOF acts as a carrier for the pesticide known as cis-1,3-dichloropropene and releases it 100 times slower than liquid pesticides. As well, the MOF can decompose in water to its components leaving behind calcium as a nutrient into the soil.
- Yaghi, O. M. et al. Calcium L-lactate frameworks as naturally degradable carriers for pesticides. J. Am. Chem. Soc. 139, 8118–8121 (2017)