Optimization of high-quality carbon fiber production from electrospun aligned lignin fibers

In recent years, investigating lignin as an alternative carbon fiber precursor has received immense research attention as a way to reduce the cost and replace the unsustainable conventional petroleum-based precursors for carbon fiber production. The predominant challenge for lignin-based carbon fibers is its low mechanical performance compared to conventional ones. In this work, mechanical properties of electrospun lignin carbon fiber mats were shown to be considerably enhanced via alignment of the submicron fibers. Over 60% of the fibers were aligned via a rotating drum collector utilized during fiber production. The main electrospinning parameters, namely electric field, rotating speed, and flow rate were optimized with the Box-Behnken method to enhance mechanical properties with reduced fiber diameter and improved fiber alignment. The optimal electrospinning process parameter was achieved at 2000 rpm collection speed, 80 kV/m electric field, and 440 nl/s flow rate. The lignin carbon fibers produced under the optimized condition exhibited elastic modulus of 3145.47 +/- 917.75 MPa, tensile strength of 18.78 +/- 6.11 MPa, and average fiber diameter of 697.07 +/- 96.41 nm. The analysis on the interactions between electrospinning parameters has laid a solid foundation for the production of high-quality carbon fibers from lignin precursor.

Automated summary

Investigating the mechanical properties of electrospun lignin carbon fiber mats, researchers found that aligning the submicron fibers significantly enhanced their performance. By optimizing the electrospinning parameters, the elastic modulus, tensile strength, and fiber diameter of the lignin carbon fibers were improved. This study has laid a solid foundation for the production of high-quality carbon fibers from lignin precursor.