Photochemistry and Thermal Chemistry in Polymeric Ceramic Precursors

Area of Science:

• Materials Science
• Chemistry
• Computational Science

Background:

• Pyrolysis is used for ceramic additive manufacturing but is energy-intensive.
• Photochemistry offers a potential low-energy, fast alternative, but mechanisms are unclear.

Purpose of the Study:

• To elucidate the initial reaction mechanisms in silicon-carbide ceramic formation.
• To differentiate photochemical and thermal pathways using multiscale simulations.

Main Methods:

• First-principles nonadiabatic and adiabatic quantum molecular dynamics.
• Semiempirical reactive molecular dynamics simulations.

Main Results:

• Photoexcitation induces rapid Si-C bond scission within 100 fs via hole localization.
• The precursor is thermally stable up to 1800 K without photoexcitation.
• Thermal pathways involve SiCO cluster formation through oxygen-silicon bonding.

Conclusions:

• Distinct photochemical and thermal pathways exist in early-stage ceramic formation.
• Synergistic use of light and heat can enable low-energy ceramic additive manufacturing.
• This research contributes to sustainable materials processing.