The December 14 issue of Advanced Materials features our work on carbon fibers on its back cover.

The study presents the “D-loops”, a new type of structural defect in carbon fibers, which may have highly detrimental effect on their mechanical properties and can define a new fundamental upper limit to their strength. These defects form exclusively during polyacrylonitrile (PAN) carbonization, act as stress concentrators in the graphitic basal plane, and cannot be removed by local annealing.

Related:

• Rice News: Study explains strength gap between graphene, carbon fiber
• Futurity.org: Bad ‘zipper’ explains trouble with carbon fibers
•  E. S. Penev, V. I. Artyukhov, B. I. Yakobson, “Basic structural units in carbon fibers: Atomistic models and tensile behavior”, Carbon 85, 72–78 (2015)