Direct laser writing (DLW) is an unconventional technique for producing porous graphene from various carbon precursors using a laser as an energy source. Biomass with higher lignin content appears to be a suitable feedstock for graphene formation by DLW, but the underlying mechanisms of lignin production from biomass for laser-induced graphene (LIG) production are not well understood. Furthermore, the mechanisms involved in lignin conversion into graphene under laser-induced reaction conditions also remain unclear. The proposed research aims to develop fundamental understanding of lignin transformation into graphene via DLW and develop a new process for upgrading waste lignin produced by paper mills and biorefineries into porous graphene for energy storage applications.
The proposed research will investigate how lignin chemistry and structure affect LIG properties in terms of porosity, composition and degree of graphitization. Photothermal and photochemical effects of lignin-laser interactions will be studied to identify key laser parameters (e.g., power, scanning speed, image density) governing LIG properties. Transient chemical and physical processes of lignin-to-LIG will be studied at the atomic level by reactive force field molecular dynamics (ReaxFF MD) simulations. The lignin-derived LIG will be explored as active electrode material for supercapacitors. The project will train graduate and undergraduate students in research, with a focus on recruiting members of underrepresented and minority groups to join the research team. A new upper level undergraduate/graduate course will be developed based on the knowledge generated from the proposed research. There is also a plan for developing teaching modules for K-12 students to stimulate their interest into pursuing STEM careers.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.