No abstract

High value utilization of renewable biomass materials is of great significance to the sustainable development of human beings. For example, because biomass contains large amounts of carbon, they are ideal candidates for the preparation of carbon nanotube fibers. However, continuous preparation of such fibers using biomass as carbon source remains a huge challenge due to the complex chemical structure of the precursors. Here, we realize continuous preparation of high-performance carbon nanotube fibers from lignin by solvent dispersion, high-temperature pyrolysis, catalytic synthesis, and assembly. The fibers exhibit a tensile strength of 1.33 GPa and an electrical conductivity of 1.19 × 105 S m−1, superior to that of most biomass-derived carbon materials to date. More importantly, we achieve continuous production rate of 120 m h−1. Our preparation method is extendable to other biomass materials and will greatly promote the high value application of biomass in a wide range of fields.

Piezoresistive nanocomposite fibers are essential elements for smart wearables and have recently become a research hotspot because of their high sensitivities at large deformations in the plastic regime. However, little attention has been paid to the electromechanical properties of such fibers at low strains where the resistance−strain (R−ε) relationship is reliably linear. In addition, prediction of the resistance signal stability for these materials during cyclic loading remains unreported. Here, we studied these two aspects using wet-spun piezoresistive nanocomposite fibers from polyether block amide (PEBA) composed of a hybrid conductive filler network of carbon black (CB) and carbon nanotubes (CNTs) in which the CB loading in the PEBA matrix was varied at a constant volume fraction of CNTs. We found the R−ε linear relationship (working factor, W) to increase with CB filler loading from 0.01 to 0.058. In addition, the gauge factors of these fibers varied inversely with W from 16.89 to 3.81. Using fatigue theory, we predicted the endurance limit of PEBA/CB-CNT fibers in the elastic regime to be ∼34.9 cycles. Although our fibers were extremely deformable, up to 500% strain, as is the case for most piezoresistive nanocomposite fibers, this work reveals the working range to be actually very small, comparable to rigid conventional strain gauges. We believe with PEBA/CB-CNT fibers' robust mechanical properties and the ease with which the electromechanical signal can be quantified with the fatigue model, they would be ideal materials to be integrated into textiles to perform as tough, finely tuned strain sensors for a range of rigorous bodily monitoring such as low-strain impacts and joint movements.

No abstract

The high value‐added application of lignin is of great significance for the effective utilization of biomass and environmental protection. In this work, TiO2‐loaded lignin‐derived carbon nanofibers (TiO2@LCNFs) are developed by the process of electrospinning, per‐oxidation, and carbonization. The effects of TiO2 content, carbonization temperature, initial RhB concentration, and solution pH value on the photocatalytic efficiency are systematically studied. Up to 86% photocatalytic efficiency and excellent cycling stability of the TiO2@LCNFs to rhodamine B under optimized conditions are achieved. The superior catalytic property of the TiO2@LCNFs can be attributed to the synergistic effect of the uniform distribution of TiO2 on the fiber surface and the good electrical conductivity of LCNFs. It is expected that this work will provide some guidance for the preparation of efficient photocatalytic materials, especially those based on biomass‐derived fiber materials.