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.

A new article from Ning Yan’s lab has been published in the Carbohydrate Polymers written by Sanming Hu, Zhijun Shi, Kun Chen, Xiao Chen, Hongfu Zhou, Ning Yan, Guang Yang,

You can find the paper here.

Abstract

The proliferation of electronic devices has led to a substantial increase in non-degradable electronic waste (e-waste), posing significant environmental challenges. Consequently, biodegradable natural polymers have garnered considerable attention as sustainable alternatives to conventional non-degradable materials in electronic applications. Bacterial cellulose (BC), a natural polymer characterized by abundant hydroxyl groups and a three-dimensional (3D) nanonetwork structure, exhibits exceptional properties including high purity, superior mechanical strength, excellent water retention capacity, non-toxicity, renewability, and complete biodegradability. These unique attributes, coupled with its distinctive structural features, render BC as a promising green matrix material for developing functional composites in eco-friendly electronic devices. This review provides a systematic analysis of various eco-friendly composite materials derived from BC, covering conductive, piezoelectric, magnetoelectric, and thermoelectric composites. Additionally, the fabrication methodologies for BC-based composites, including in-situ chemical synthesis, ex-situ incorporation, and biosynthesis techniques, are comprehensively analyzed. Furthermore, the applications of BC-based composites was explored in diverse fields such as sensors, energy storage systems (batteries and supercapacitors), and energy harvesting devices (nanogenerators). Finally, we deliver a critical evaluation of the current challenges and future research directions for BC-based composites in the development of sustainable electronic devices.

A new article from Ning Yan’s lab has been published in Materials Horizens written by Kaiwen Chen, Luyao Chen, Xianfu Xiao, Cheng Hao, Haonan Zhang, Tongtong Fu, Wei Shang, Hui Peng, Tianyi Zhan, Jianxiong Lyu and Ning Yan.

You can find the article here.

Abstract
Inspired by cactus spine and desert beetle back structures, we developed a wood-based wedge-shaped surface with gradient wettability for efficient and controlled spontaneous directional liquid transport. Utilizing the natural anisotropic and porous structure of wood, the wedge-shaped surface exhibited a continuous gradient wettability after chemical treatments combined with UV-induced modifications. The resulting surface enabled highly efficient directional liquid transport with transport rates reaching up to 8.9 mm s−1 on horizontal placement and 0.64 mm s−1 on vertical surfaces against gravity. By integrating geometric curvature and surface energy gradients, the innovative design achieved synergistic Laplace pressure-driven and wettability-driven liquid motions. To further demonstrate its potential for practical application, a fog-driven power device constructed using the gradient wettability wood with cactus spines not only enhanced water harvesting and energy conversion capabilities but also offered an environmentally friendly system. This study expanded the design toolbox for bioinspired liquid management surfaces, offering promising applications in water resource management, energy harvesting, and microfluidic devices.

A new article from Ning Yan’s lab has been published in npj Clean Water written by Kaiwen Chen, Jianyi Zhu, Cheng Hao, Haonan Zhang, Yujing Tan, Xianfu Xiao, Fengze Sun, Xuewen Han, Hui Peng, Tianyi Zhan, Jianxiong Lyu & Ning Yan.

You can find the article here.

Abstract

Global climate change has exacerbated water scarcity, while traditional water treatment technologies are often unsustainable due to high energy consumption and negative environmental impacts, posing an urgent need for a sustainable solution. This study developed a novel wood-based flexible Janus membrane coupled with a spine structure for efficient oil-water emulsion separation and fog harvesting. The Janus wood membrane showed high separation efficiency (> 99.6%), high filtration flux (water-in-oil and oil-in-water emulsions exceeded 810 L/m²·h and 747 L/m²·h, respectively), and good reusability. Additionally, the introduction of spine and conical pores significantly enhanced fog collection efficiency (19.23 kg/m²·h), expanding the application potential of Janus membranes. Moreover, this Janus wood membrane offered excellent mechanical properties, dimensional stability, mildew resistance, and environmental benefits. This study underscored the potential of Janus membranes in water management and liquid separation, providing a sustainable solution to water scarcity.

A new article from Ning Yan’s lab has been published in Carbohydrate Polymers written by Nicole Tratnik, Nicolas R. Tanguy, Daniel J. Davidson, Ning Yan.

You can find the article here.

Abstract

Bio-based epoxy vitrimers are gaining attention as sustainable alternatives to traditional epoxies due to renewable starting materials and recyclability, enabling material circularity. Transesterification, a dynamic bond reaction mechanism in vitrimers, relies on ample hydroxy and esters groups in the polymer network to rearrange under moderate conditions. To reduce reliance on petroleum we investigated starch, a natural feedstock rich in hydroxy groups. Ester bond densities were adjusted with an ester containing crosslinker (pentaerythritol tetrakis(3-mercaptopropionate) (PETMP)) at various epoxy to crosslinker molar ratios (1:0.7, 1:1, 1:1.25 and 1:1.5) with TEMPO as the catalyst. The reformation efficiency of the vitrimer increased to 239 % from 31 % when the ratio changed from 1:1 to 1:1.5. Essential dynamic behavioral parameters (dynamic bond exchange activation energy (E_a(d)), Arrhenius prefactor (τ₀), and freezing transition temperature (T_v)) were analysed. Adding excess amount of crosslinker decreased the T_g, crosslink density, E_a(d) and T_v of the starch-based epoxy vitrimer. Adhesion tests on birch veneer found that a 1:1.5 ratio had the highest adhesion performance at 3.02 ±0.7 MPa with an adhesion recovery as high as 91 % averaging 61 +/− 23 %. These insights into density of dynamic bonds and active functional groups will contribute to developing new bio-based vitrimers with designed circularity.