Touch-and-go chemistry: development of materials for and demonstration of a contact-initiated polymerization

My graduate research has focused on demonstrating the concept of a contact-initiated, or touch-and-go, reaction. One of the foundational concepts of organic chemistry is that an intermolecular reaction can only occur once two or more reactive molecules come into proximity in the correct orientation. Enzymatic reactions display improved reaction rates because catalytic groups are prearranged in proximity to the substrate. It follows that one can control a reaction rate by controlling the spatial proximity of two reactive groups. To demonstrate this concept, I developed a series of particle sizes that could be functionalized with reactive groups. These particles varied in size from 50 nm to 360 µm in diameter. Particles were then functionalized with N,N-dimethylaniline (DMA) and benzoyl peroxide (BPO) groups which co-initiate free radical polymerizations. The mechanism by which they co-initiate requires contact between the DMA and BPO molecules. When DMA and BPO were conjugated to complementary particles, a free radical polymerization was observed following contact between the particles. However, when the particles were physically separated, no reaction was observed. These experiments demonstrated touch-and-go chemistry, a reaction that could be controlled by controlling contact between two macroscopic objects