Electrospun Lignin-Based Phase-Change Nanofiber Films for Solar Energy Storage

Functional materials for solar energy collection, conversion, and storage need to be developed to address the global energy crisis. In this study, phase-change nanofiber films [PCNFs, sodium lignosulfonate (SLS)/polyvinyl alcohol (PVA)/polyethylene glycol (PEG)], which maintain their shape, were developed for solar-to-thermal energy conversion and storage. The films were constructed by electrospinning with PEG as the phase-change material, SLS/PVA mixture as the supporting matrix, and SLS as the photothermal material. SLS effectively improved the supporting property of the PCNFs owing to sturdy hydrogen bonds and electrostatic entanglement between its macromolecule chains and PVA/PEG, which prevented the leakage and transfer issue for PEG. Moreover, the PCNFs showed excellent solar-to-thermal energy conversion and storage ability, attributed to the π–π stacking of SLS molecules and the phase-change process, respectively. The SLS/PVA/PEG film with a PEG content of 32.43% exhibited a diameter of 465 ± 109 nm and a latent heat of fusion of 42.16 J·g–1, with a phase-change temperature of 45.20 °C. The film showed favorable stability over 50 heating–cooling cycles, thermal stability below 220 °C, good shape stability, and a solar-thermal energy conversion and storage efficiency of 18.03%. This study demonstrates a potential route to improve the utilization of lignin and solar energy and promotes the development of sustainable energy

Dually Prewetted Underwater Superoleophobic and under Oil Superhydrophobic Fabric for Successive Separation of Light Oil/Water/Heavy Oil Three-Phase Mixtures

Remediation of oil spills requires new technologies to separate light oil/water/heavy oil mixtures. Low-cost, biological, and environmentally friendly materials are needed to treat water pollution caused by oils. In this study, a corn straw powder (CSP)-coated fabric (CSPF) was fabricated by spraying waste CSP and polyurethane onto amphiphilic cotton fabric, and thus, the wettability of CSPF is enhanced by taking advantage of the hierarchical structure and increased surface roughness. Therefore, the CSPF could be dually prewetted (DCSPF) with both water and oil, and it showed underwater superoleophobic and under oil superhydrophobic properties without any further chemical modification. When applied to light oil/water/heavy oil separation, the DCSPF could be used to successively separate light oil/water/heavy oil three-phase mixtures under gravity with a high separation efficiency and flux. In addition, the DCSPF showed excellent structural and chemical stability according to repeated cycling and corrosive solution/oil separation experiments. The results of this study are of value in providing a simple, low-cost, and environment-friendly approach for application in the field of successive separation of light oil/water/heavy oil three-phase mixtures