Presenting Author Name/s

Richard Chen and Mehmet Kerem Gokus

Faculty Advisor

Silvina Pagola

Presentation Type

Poster

Disciplines

Materials Chemistry

Description/Abstract

The mechanical processing of solids, such as milling or grinding powders, often leads to mechanochemical reactions. Mechanochemistry affords “green” synthetic routes avoiding or reducing the use of solvents, thus providing environmentally friendly and cost-effective synthetic alternatives for many materials. The solid-state reactants are usually ground together with small quantities of organic solvents, called “liquid assisted grinding” (LAG). LAG increases the reaction rates, it can yield products from otherwise unreactive mixtures, it increases the products crystallinity, and it selectively leads to crystal structures (polymorphs) of the products, depending on the quantities and physicochemical properties of the liquids used in LAG.

Mechanochemistry has been increasingly used in academia during recent years. However, the overall features of the mechanochemical reaction mechanisms are poorly understood, and only starting to be unraveled often by using in-situ synchrotron X-ray powder diffraction and Raman spectroscopy measurements. In particular, the reasons underlying the above liquid roles in LAG are unknown.

Our objectives are: (1) To test an experimental procedure to study the kinetics of two – four mechanochemical reactions for the synthesis of organic charge transfer complexes, using laboratory X-ray powder diffraction. (2) To determine the rate laws and the orders of the reaction with respect of each reactant and the LAG liquid. (3) To determine whether polar LAG liquids must be present in the rate laws for the conditions leading to ionic charge transfer complexes, or not; and (4) To provide research experience to two undergraduate students as part of a PURS project.

Session Title

Poster Session

Location

Learning Commons, Northwest Atrium

Start Date

2-2-2019 8:00 AM

End Date

2-2-2019 12:30 PM

Full Text of Presentation

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Feb 2nd, 8:00 AM Feb 2nd, 12:30 PM

Toward Unraveling the Mechanisms of “Green” Mechanochemical Reactions

Learning Commons, Northwest Atrium

The mechanical processing of solids, such as milling or grinding powders, often leads to mechanochemical reactions. Mechanochemistry affords “green” synthetic routes avoiding or reducing the use of solvents, thus providing environmentally friendly and cost-effective synthetic alternatives for many materials. The solid-state reactants are usually ground together with small quantities of organic solvents, called “liquid assisted grinding” (LAG). LAG increases the reaction rates, it can yield products from otherwise unreactive mixtures, it increases the products crystallinity, and it selectively leads to crystal structures (polymorphs) of the products, depending on the quantities and physicochemical properties of the liquids used in LAG.

Mechanochemistry has been increasingly used in academia during recent years. However, the overall features of the mechanochemical reaction mechanisms are poorly understood, and only starting to be unraveled often by using in-situ synchrotron X-ray powder diffraction and Raman spectroscopy measurements. In particular, the reasons underlying the above liquid roles in LAG are unknown.

Our objectives are: (1) To test an experimental procedure to study the kinetics of two – four mechanochemical reactions for the synthesis of organic charge transfer complexes, using laboratory X-ray powder diffraction. (2) To determine the rate laws and the orders of the reaction with respect of each reactant and the LAG liquid. (3) To determine whether polar LAG liquids must be present in the rate laws for the conditions leading to ionic charge transfer complexes, or not; and (4) To provide research experience to two undergraduate students as part of a PURS project.