A new article from Ning Yan’s lab has been published in the Advanced Functional Materials written by Kaiwen Chen, Cheng Hao, Wenjuan Zhao, Haonan Zhang, Jianxiong Lyu and Ning Yan.

You can find the article here.

Abstract
Efficient and intelligent membranes that can overcome the inherent trade-off between flux and selectivity while providing real-time process monitoring are highly desirable for advanced oil/water separation. This work reported a smart conductive Janus wood membrane (CJW) that integrated high-efficiency oil/water separation with in situ real-time monitoring. A bio-inspired modular design strategy fully exploited wood’s natural anisotropy: transverse wood with vertically aligned macrochannels acted as a high-flux transport layer, while longitudinal wood with an inherent micro/nano-capillary network served as a high-precision sieving layer. Asymmetric wettability was established by grafting hydrophilic poly(DMAEMA) on one side and immobilizing hydrophobic fluorosilane-modified nano-SiO₂ on the other side. A continuous GO/PPy conductive network distributed throughout the hierarchical pores enabled in situ electrical sensing during separation. The resulting membrane achieved separation efficiencies > 93.1% over 30 cycles for immiscible oil/water mixtures, with a maximum flux of 8001 L/m²·h. For oil/water emulsions, efficiencies remained > 92.3% after 10 cycles with sustained fluxes of 540-760 L/m²·h. The electrical response of the conductive network provided real-time feedback on membrane status. Additionally, a threshold-based early-warning mechanism using the coefficient of variation (CV) of resistance predicted degradation 3-18 cycles in advance. This work presents a novel paradigm for intelligent separation materials with self-monitoring capabilities.

A new article from Ning Yan’s lab has been published in the Chemical Engineering Journal written by Cheng Hao, Daniel Davidson, Haonan Zhang, Alper Alper, Shawn Prevoir and Ning Yan.

You can find the article here.

Abstract

The flammability of polycarbonate/acrylonitrile butadiene styrene (PC/ABS) significantly restricts its use in safety-critical applications, despite its desirable mechanical and thermal properties. Bio-based, halogen- and PFAS-free flame retardants have gained interest as sustainable alternatives to conventional halogen-based flame retardants for engineering thermoplastics, yet most exhibit insufficient thermal stability for the demanding processing temperatures (>250 °C) required by high melting point engineering thermoplastics, such as PC/ABS. To overcome this fundamental thermal stability bottleneck, in this study, a reactive compatibilization strategy was developed to tailor a thermally robust and compatibilized lignin-derived flame-retardant system for PC/ABS. Nitrogen and phosphorous modified lignin was pre-compounded with styrene-maleic anhydride copolymer (SMA), which not only significantly raised the onset decomposition temperature (T_d5 = 293 °C) to withstand the high-temperature compounding, but also ensured uniform dispersion within PC/ABS. This strategy enabled, to the best of our knowledge, for the first time, effective incorporation of a bio-based flame retardant into engineering-grade PC/ABS at industrial relevant loadings. With the addition of 5 wt% LNP and 10 wt% SMA, the PC/ABS blends achieved the UL-94 V-0 rating with an increased limited oxygen index (LOI) and a 51.5 % reduction in peak heat release rate, while significantly enhancing heat deflection temperature and maintaining tensile strength of the PC/ABS samples. Mechanistic investigations revealed a synergistic condensed-phase barrier effect from crosslinked phosphorus-rich char and a gas-phase radical-quenching effect to suppress flame propagation. This work aligns with current regulatory drivers to replace halogenated and PFAS-based additives, showing a viable pathway for developing sustainable and high-performance flame retardants for engineering thermoplastics with high melting temperatures.

A new article from Ning Yan’s lab has been published in the Chemical Engineering Journal written by Mohammad H. Mahaninia, Keerti Rathi, Ning Yan, Mohini Sain, Colin van der Kuur.

You can find the article here.

Abstract

To enhance the performance and durability of lithium-ion batteries, the development of effective binder materials in the anode is crucial, with eco-friendliness being an additional consideration. This study presents a bio-based and self-healable polymeric binder designed for use in graphite-based anodes to achieve enhanced battery performance. The binder was synthesized via a Schiff base reaction between chitosan and a vanillin-derived linker, forming imine bonds that establish a self-healable 3D network. The bio-based binder effectively holds the graphite particles together while also providing excellent mechanical strength, thermal stability, and strong adhesion to the copper foil. Notably, it demonstrated self-healing behavior, with mechanical recovery exceeding 90 % after damage. Thermogravimetric analysis confirmed high thermal stability up to 300 °C, while the binder exhibited excellent tensile adhesion strength (ca. 21 kPa). Both coin and pouch cells fabricated with the bio-based binder achieved a specific capacity of 161.2 mAh g⁻¹ and retained 81 % of their capacity after 250 cycles. Coulombic efficiency remained consistent at above 92 % even after 250 cycles, indicating no side reactions. Even at a high current density of 1.0C, the cells maintained approximately 50 % of their original capacity measured at 0.3C, showcasing excellent rate capability. Electrochemical impedance spectroscopy revealed low interfacial resistance, further validating the stability of the chitosan-based binder. We anticipate that this class of bio-based binders will not only extend the service life of lithium-ion batteries but also make a significant contribution to greener, safer energy storage technologies.

A new article from Ning Yan’s lab has been published in the Journal of Cleaner Production written by Kaiwen Chen, Cheng Hao, Luyao Chen, Fengze Sun, Yujing Tan, Wenjuan Zhao, Hui Peng, Tianyi Zhan, Jianxiong Lyu and Ning Yan.

You can find the article here.

Abstract

Wood-based membranes offer a promising, sustainable platform for oil/water separation due to their intrinsic porosity, renewability, and structural anisotropy. However, current approaches often require complex chemical modifications and lack a systematic understanding of how structural and processing parameters govern separation performance. This study introduced a simple yet robust strategy leveraging intrinsic structural anisotropy of natural wood to fabricate high-performance membranes without synthetic coating or surface functionalization. By altering the cutting direction, two distinct membrane architectures were obtained: cross-section membranes with longitudinal channels enabled the gravity-driven separation of light oil/water mixtures, while longitudinal membranes with interconnected transverse pores facilitated vacuum-assisted separation of oil-in-water emulsions. Quantitative analysis revealed that delignification time and thickness jointly governed wetting and transport behavior. Increasing delignification reduced the water contact angle from ∼115° to <40°, enabling tunable flux (∼90–1000 L m⁻²·h⁻¹) and efficiency (75–99.9 %). For CW membranes, flux decreased and efficiency increased with thickness—thinner samples (0.5–1 mm) exhibited the highest flux (∼995 L m⁻²·h⁻¹) but moderate efficiency (85–95 %), while thicker ones (∼3 mm) achieved up to 99.8 % efficiency at lower flux. For LW membranes, a similar trade-off was observed: thinner membranes (0.5–1 mm) offered higher flux (75–95.9 % efficiency), intermediate thickness (1–2 mm) balanced both (up to 99.1 %), and thicker membranes (∼3 mm) provided the highest efficiency (98.9–99.9 %) but reduced flux. Through systematic characterization, this study established a clear structure–property–performance relationship, revealing how processing parameters (cutting orientation, thickness, and lignin content) govern key structural features and, in turn, separation efficiency and flux. This work not only provides a sustainable route for fabricating high-performance membranes using natural materials but also delivers quantitative mechanistic insights and predictive design principles for liquid–liquid separation, with broad relevance for environmental remediation and resource recovery.

A new article from Ning Yan’s lab has been published in the Advanced Functional Materials written by Qin Chen, Araz Rajabi-Abhari, Tongtong Fu, Haonan Zhang, Siqi Huan, Liang Chen, Jinchao Li, Cheng Hao, Yaping Zhang and Ning Yan

You can find the paper here.

Abstract

Atmospheric water harvesting has emerged as a sustainable solution for overcoming water and energy shortages. Herein, an entirely biobased bionic spider silk (chitosan–sodium alginate filament [CSF]) is prepared using an interfacial, aqueous, and straightforward polyelectrolyte complexation with a continuous drawing technique, simultaneously harvesting water and triboelectric energy from ambient humidity. CSF exhibits a periodic spindle-shaped structure resembling spider silk, with surface roughness conducive to atmospheric water harvesting. The success of the electrostatic complexation technique for CSF is confirmed by water solubility, Fourier-transform infrared spectroscopy, and thermogravimetric analyses. The production yield of CSF reaches the maximum of 99.36% by controlling the substrate type and polyelectrolyte mass ratio. Moreover, fog-harvesting efficiency peaks at 1552.83 mg cm⁻¹ h⁻¹ (1.0 wt.% polyelectrolyte concentration), demonstrating concentration-dependent performance. Subsequently, CSF is woven into a bionic spider web (CSW) for simultaneous water and energy harvesting. Through parametric optimization, the CSW-based droplet triboelectric nanogenerator system achieves 180 V and 72.25 µW output. When deployed in a high-humidity greenhouse, the system powers 80 light-emitting diodes, a hygrometer (thermometer), and a stopwatch. This study presents a straightforward, effective, and green strategy for simultaneously harvesting water and energy from the ambient environment, providing fresh water and renewable energy to enhance sustainability.