12 Nov

Mechanochemical Synthesis

High frequency milling may be an alternative to the bulk use of solvents in chemical synthesis.  This would contribute greatly to the greening of the chemical synthesis industry.  A good example is the production of Zeolitic imidazolate frameworks.  ZIFs are composed of transition metal ions such as Fe, Co, Cu, Zn linked by imidazole.  The framework resembles zeolites and the ZIFs behave like zeolites.  ZIF-8 can capture 83 liters of CO2 for every Liter of ZIF-8.  As it is stable at high temperature it is a promising candidate for stack scrubbers in power plants.  Ironically the current production method for ZIF-8 requires bulk amount of solvents; does this make ZIF-8 a zero sum game if used in carbon capture?  Not if it can be made with mechanochemical production from simpl non-toxic components.  Mechanical forces such as in a ball mill can produce chemical reactions between reagents and catalysts.  The chemical reaction occurs at the point where the balls collide.  This reaction has been studied recently  at the European Synchrotron Radiation Facility using high energy X-Rays.  This technique for studying the reactions have revealed reaction kinetics and reaction intermediates.  Knowledge of the chemical processes in the ball mill will enable researchers develop other procedures for mechanochemical synthesis and aid in the optimization of these procedures.

Robin Prymula

1McGill University. “A better way to make chemicals? Technique for observing ‘mechanochemical’ synthesis could boost green chemistry.” ScienceDaily, 2 Dec. 2012. Web. 4 Dec. 2012.