The photothermal heating of nanoparticles has been shown to enhance the reactivity for certain thermally initiated reactions. This effect allows for the reaction to occur at much lower bulk temperature and efficiently utilize the energy from the light. This study has undertaken experimentation to test carbon black nanoparticles’ ability to photothermally activate a thermal initiator for radical vinyl polymerization. The initiator used was dibenzoyl peroxide and the vinyl monomer was styrene. These were combined with THF and nanoparticles and illuminated while stirring. The resulting mixture is filtered and then analyzed afterwards via gas phase chromatography and NMR. Because the radical resulting from thermal decomposition goes on to initiate vinyl polymer chains, we can use the degree of monomer conversion and length of polymer chains to extrapolate the rate of thermal decomposition. Through this extrapolation significant enhancement in reactivity over bulk heating has been shown. Additionally, the molecular weight distribution of polymers resulting from this process show distinct deviation from the polymers formed through bulk heating. The results indicate that nanoscale heating performed by the nanoparticles uniquely interacts with the bulk system, and elucidates how they may be used to manipulate the resulting distribution of polymers. These findings pave the way for future research for unique applications of photothermal heating.

Photothermal heating of nanoparticles for activation of initiators for radical polymerization

253rd National Meeting (2017)

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