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1. Thinnest Nonvolatile Memory Based on Monolayer h‐BN

   https://doi.org/10.1002/adma.201806790  

   Wu, Xiaohan; Ge, Ruijing; Chen, Po‐An; Chou, Harry; Zhang, Zhepeng; Zhang, Yanfeng; Banerjee, Sanjay; Chiang, Meng‐Hsueh; Lee, Jack_C; Akinwande, Deji (February 2019, Advanced Materials)

   Abstract 2D materials have attracted much interest over the past decade in nanoelectronics. However, it was believed that the atomically thin layered materials are not able to show memristive effect in vertically stacked structure, until the recent discovery of monolayer transition metal dichalcogenide (TMD) atomristors, overcoming the scaling limit to sub‐nanometer. Herein, the nonvolatile resistance switching (NVRS) phenomenon in monolayer hexagonal boron nitride (h‐BN), a typical 2D insulator, is reported. The h‐BN atomristors are studied using different electrodes and structures, featuring forming‐free switching in both unipolar and bipolar operations, with large on/off ratio (up to 10⁷). Moreover, fast switching speed (<15 ns) is demonstrated via pulse operation. Compared with monolayer TMDs, the one‐atom‐thin h‐BN sheet reduces the vertical scaling to ≈0.33 nm, representing a record thickness for memory materials. Simulation results based on ab‐initio method reveal that substitution of metal ions into h‐BN vacancies during electrical switching is a likely mechanism. The existence of NVRS in monolayer h‐BN indicates fruitful interactions between defects, metal ions and interfaces, and can advance emerging applications on ultrathin flexible memory, printed electronics, neuromorphic computing, and radio frequency switches. 

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2. Electrospun Silk-Boron Nitride Nanofibers with Tunable Structure and Properties

   https://doi.org/10.3390/polym12051093  

   Xue, Ye; Hu, Xiao (May 2020, Polymers)

   null (Ed.)

   In this study, hexagonal boron nitride (h-BN) nanosheets and Bombyx mori silk fibroin (SF) proteins were combined and electrospun into BNSF nanofibers with different ratios. It was found that the surface morphology and crosslinking density of the nanofibers can be tuned through the mixing ratios. Fourier transform infrared spectroscopy study showed that pure SF electrospun fibers were dominated by random coils and they gradually became α-helical structures with increasing h-BN nanosheet content, which indicates that the structure of the nanofiber material is tunable. Thermal stability of electrospun BNSF nanofibers were largely improved by the good thermal stability of BN, and the strong interactions between BN and SF molecules were revealed by temperature modulated differential scanning calorimetry (TMDSC). With the addition of BN, the boundary water content also decreased, which may be due to the high hydrophobicity of BN. These results indicate that silk-based BN composite nanofibers can be potentially used in biomedical fields or green environmental research. 

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3. Atomically resolved interfacial water structures on crystalline hydrophilic and hydrophobic surfaces

   https://doi.org/10.1039/d1nr00351h  

   Uhlig, Manuel R.; Benaglia, Simone; Thakkar, Ravindra; Comer, Jeffrey; Garcia, Ricardo (March 2021, Nanoscale)

   null (Ed.)

   Hydration layers are formed on hydrophilic crystalline surfaces immersed in water. Their existence has also been predicted for hydrophobic surfaces, yet the experimental evidence is controversial. Using 3D-AFM imaging, we probed the interfacial water structure of hydrophobic and hydrophilic surfaces with atomic-scale spatial resolution. We demonstrate that the atomic-scale structure of interfacial water on crystalline surfaces presents two antagonistic arrangements. On mica, a common hydrophilic crystalline surface, the interface is characterized by the formation of 2 to 3 hydration layers separated by approximately 0.3 nm. On hydrophobic surfaces such as graphite or hexagonal boron nitride (h-BN), the interface is characterized by the formation of 2 to 4 layers separated by about 0.5 nm. The latter interlayer distance indicates that water molecules are expelled from the vicinity of the surface and replaced by hydrocarbon molecules. This creates a new 1.5–2 nm thick interface between the hydrophobic surface and the bulk water. Molecular dynamics simulations reproduced the experimental data and confirmed the above interfacial water structures. 

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4. Fire‐Resistant Structural Material Enabled by an Anisotropic Thermally Conductive Hexagonal Boron Nitride Coating

   https://doi.org/10.1002/adfm.201909196  

   Gan, Wentao; Chen, Chaoji; Wang, Zhengyang; Pei, Yong; Ping, Weiwei; Xiao, Shaoliang; Dai, Jiaqi; Yao, Yonggang; He, Shuaiming; Zhao, Beihan; et al (January 2020, Advanced Functional Materials)

   Abstract Fire retardant coatings have been proven effective at reducing the heat release rate (HRR) of structural materials during burning; yet effective methods for increasing the ignition temperature and delay time prior to burning are rarely reported. Herein, a strong, fire‐resistant wood structural material is developed by combining a densification treatment with an anisotropic thermally conductive flame‐retardant coating of hexagonal boron nitride (h‐BN) nanosheets to produce BN‐densified wood. The thermal management properties created by the BN coating provide fast, in‐plane thermal diffusion, slowing the conduction of heat through the densified wood, which improves the material's ignition properties. Compared with densified wood without the BN coating, a 41 °C enhancement in ignition temperature (T_ig), a twofold increase in ignition delay time (t_ig), and a 25% decrease in the maximum HRR of BN‐densified wood can be achieved. As a proof of concept for scalability, the pieces of the BN‐densified wood are fabricated with a length larger than 25 cm, width greater than 15 cm, and thickness more than 7 mm. The improved thermal management, fire resistance, mechanical strength, and scalable production of BN‐densified wood position it as a promising structural material for safe and energy‐efficient buildings. 

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5. A tale of two minerals: contrasting behaviors and mitigation strategies of gypsum scaling and silica scaling in membrane desalination

   https://doi.org/10.1007/s11783-025-1923-9  

   Tong, Tiezheng; Park, Shinyun; Yao, Yiqun (January 2025, Frontiers of Environmental Science & Engineering)

   Abstract Mineral scaling represents a major constraint that limits the efficiency of membrane desalination, which is becoming increasingly important for achieving sustainable water supplies in the context of a changing climate. Different mineral scales can be formed via distinct mechanisms that lead to a significant variation of scaling behaviors and mitigation strategies. In this article, we present a comprehensive review that thoroughly compares gypsum scaling and silica scaling, which are two common scaling types formed via crystallization and polymerization respectively, in membrane desalination. We show that the differences between scale formation mechanisms greatly affect the thermodynamics, kinetics, and mineral morphology of gypsum scaling and silica scaling. Then we review the literatures on the distinct behaviors of gypsum scaling and silica scaling during various membrane desalination processes, examining their varied damaging effects on desalination efficiency. We further scrutinize the different interactions of gypsum and silica with organic foulants, which result in contrasting consequences of combined scaling and fouling. In addition, the distinctive mitigation strategies tailored to controlling gypsum scaling and silica scaling, including scaling-resistant membrane materials, antiscalants, and pretreatment, are discussed. We conclude this article with the research needs of attaining a better understanding of different mineral scaling types, aiming to inspire researchers to take scale formation mechanism into consideration when developing more effective approaches of scaling control in membrane desalination. 

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