Mechanical Strength, Thermal Stability, and Hydrophobicity of Fiber Materials after Removal of Residual Lignin

The carbon materials with diverse morphologies and structures have attracted much interest for various applications. In this work, by introducing lignosulfonate with PEO-PPO-PEO triblock copolymer P123 as soft templates, unique yolk shell structure with pollen-like surface of carbon microspheres were innovatively synthesized using xylose as the carbon precursor under hydrothermal carbonization. A mechanism for the yolk shell carbon microspheres formation was proposed. The associations between lignosulfonate and P123 led to the formation of mixed micelles. Owing to the highly branched structure and steric hindrance effect of lignosulfonate, lignosulfonate preferentially assembled at the outer position of double layers of micelles, while linear structure P123 located at the inner position.