Method for Producing Graphene from Lignin Awarded Patent

Forest Products Laboratory (FPL) researcher Zhiyong Cai, with industrial and academic partners from Domtar Corporation and Mississippi State University, was granted a patent on June 2, 2020 for their method of synthesizing graphene from lignin.   

Zhiyong Cai – Supervisory Materials Research Engineer

Graphene is one of the most promising materials of the future. Its potential to be implemented in tech manufacturing is huge, from medicine to medical devices, electronics to batteries, environmental protection equipment to devices used for clean-energy, and more.

One barrier to realizing the vast capabilities of this material is finding a low-cost, largely available source for graphene. The ability to produce graphene from lignin, as the patent describes, breaks down that barrier.

“Lignin is a primary component of the plant cell wall in most terrestrial plants and the second most abundant biopolymer in nature,” explained Cai. A byproduct of the pulping and papermaking process, most lignin has been used as a low-value material for fueling power and heat. Cai and his collaborators’ process now provides a higher value use for lignin. Importantly, the synthesizing method is not just limited to lignin but can be used to produce graphene from other solid carbon resources as well, especially biomass.

This novel method of synthesizing graphene allows for high-volume production. Cai best explained this now patented process:

“Few-layer graphene materials are produced through a molecular cracking and welding (MCW) method. The MCW technique is a single step process with two stages, i.e., graphene-encapsulated core–shell nanoparticles are first formed by catalytic thermal treatment of solid carbon materials. Then these core–shell structures are opened by ‘cracking molecules’ in the second stage and the cracked graphene shells are self-welded and reconstructed to form high quality multilayer graphene materials at a heating temperature with selected welding reagent gases.”

The formation of a graphene-based material from graphene-encapsulated core–shell nanoparticles. (a) Graphene-encapsulated metal nanoparticles; (b) cracked core–shell nanoparticles; (c) graphene sheets

This new and innovative method has been proven “to be a scalable process for the production of low-cost, high-purity nanoscale graphene materials from renewable resources,” bringing the fabrication of tomorrow’s technologies one step closer.

To find out more about the amazing advancements our scientists are making, visit the Forest Products Laboratory at: https://www.fpl.fs.fed.us/

Spectroscopy Research Challenges a Deadly Tree Fungus

Loblolly pine ranges from Georgia and the Carolinas to Texas but a destructive fungus is threatening this common southern softwood. Fusiform rust, Cronartium quercuum f.sp. fusiforme, is one the most destructive forest diseases in the South. With its complex life cycle, this fungus infects both loblolly and slash pine causing canker formation that frequently kills the infected branch.

The pine infection cycle occurs in Georgia in April and early May. Elongated swelling of the branches is the result of individual attacks on different parts of a tree. Many of the infected trees are unsuitable for later use as forest products, causing millions of dollars to be lost annually. Trees with large galls on the main stem are also unsuitable for many products.

Most of the photos in the above slideshow are by Robert L. Anderson, US Forest Service.

Changes in wood chemistry resulting from fungal decay of Scots pine have been studied directly using spectroscopy, the study of interactions between matter and radiated energy. A 2003 study by Pandey and Pitman exposed Scots pine sapwood to brown rot, selective white rot, and nonselective white rot fungi. In this study, the decay process was followed using Fourier Transform Infrared Spectroscopy (FTIR). After 12 weeks, the wood exposed to the brown rot fungus resulted in progressive increase in lignin content relative to cellulose and hemicellulose, whereas the lignin content of the wood exposed to the selective white rot decreased as decay proceeded. For the wood exposed to the nonselective white rot wood, both occurred.

A recently published FPL study applied both FTIR spectroscopy and Nuclear Magnetic Resonance Spectroscopy (NMR) to determine whether the pathogen caused any structural modifications to the chemical composition of lignin. A new FPL paper, Effect of Fusiform Rust (Cronartium quurcum f.sp. fusiforme) on the Composition of Loblolly Pine Lignin by Roderquita K. Moore, Allisha N. Blood, and Cherrelle I. Esekie discusses the results.