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81.
One of the most fascinating properties of materials in nature is the superhydrophobic and self‐cleaning capabilities of different plant surfaces. This is usually achieved by the hydrophobic cuticles that are made of cutin and contain wax crystals both within them and on their surfaces. Here, bioinspired n‐hexatriacontane wax films are deposited via thermal evaporation and it is shown that the surface evolves in time via self‐assembly. This leads to a dramatic change in the wetting properties with a transition from hydrophobic to superhydrophobic characteristics, which takes place within several days at room temperature. This phenomenon is investigated and strain‐induced recrystallization is proposed to be the mechanism for it. This work could become the basis for the inspiration and production of tuned, time‐dependant, temperature‐sensitive, variable‐wettability surfaces. 相似文献
82.
Wonyoung Lee Hee Joon Jung Min Hwan Lee Young‐Beom Kim Joong Sun Park Robert Sinclair Fritz B. Prinz 《Advanced functional materials》2012,22(5):965-971
The role of grain boundaries on oxygen surface exchange in an oxide ion conductor is reported. Atomic‐scale characterization of the microstructure and chemical composition near the grain boundaries of gadolinia‐doped ceria (GDC) thin films show the segregation of dopants and oxygen vacancies along the grain boundaries using the energy dispersive spectroscopy in scanning transmission electron microscopy (STEM‐EDS). Kelvin probe microscopy is employed to verify the charge distribution near grain boundaries and shows that the grain boundary is positively charged, indicating a high concentration of oxygen vacancies. AC impedance spectroscopy on polycrystalline GDC membranes with thin interfacial layers with different grain boundary densities at the cathodes demonstrated that the cells with higher grain boundary density result in lower electrode impedance and higher exchange current density. These experimental evidences clearly show that grain boundaries on the surface provide preferential reaction sites for facilitated oxygen incorporation into the GDC electrolyte. 相似文献
83.
84.
对比传统的平面型晶体管,总结了三维立体结构FinFET器件的结构特性。结合MOS器件栅介质材料研究进展,分别从纯硅基、多晶硅/高k基以及金属栅/高k基三个阶段综述了Fin-FET器件的发展历程,分析了各阶段FinFET器件的材料特性及其在等比缩小时所面临的关键问题,并着重从延迟时间、可靠性和功耗三方面分析了金属栅/高k基FinFET应用于22 nm器件的性能优势。基于短沟道效应以及界面态对器件性能的影响,探讨了FinFET器件尺寸等比缩小可能产生的负面效应及其解决办法。分析了FinFET器件下一步可能的发展方向,主要为高迁移率沟道材料、立体型栅结构以及基于新原理的电子器件。 相似文献
85.
Xiaoding Lou Yu Huang Xian Yang Hai Zhu Liping Heng Fan Xia 《Advanced functional materials》2020,30(10)
Surfaces with controllable liquid wettability and related functions have gained increasing attention from interfacial scientists due to the high demand of fundamental research and practical applications. Inspired by pitch plant's excellent liquid repellency, external stimuli responsive lubricant‐infused surfaces switching between slippery state and nonslippery state under external stimuli (E‐LIS) have been developed by introducing external stimuli responsive materials as substrates, lubricants, or repellent liquids. This progress report is focused on recent development of E‐LIS. First, design strategy and fabrication of E‐LIS upon external stimuli exposure, including stress, electrical field, magnetic field, and temperature, is summarized. Then, emerging interfacial applications of E‐LIS, such as microreactors, pipetting devices, fog collection devices, and so on, are highlighted. In addition, remaining challenges and future prospects are provided. 相似文献
86.
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88.
Zinc oxide (ZnO) nanograin and nanorod films were prepared by magnetron sputter deposition and an aqueous solution growth
method. Their surface wettability was studied in relation to their surface morphologies. While the surfaces of both films
were hydrophobic, the nanorod films exhibited higher surface hydrophobicity. A superhydrophobic surface was obtained on a
ZnO nanorod film with a water contact angle of 151 deg. Results have shown that their surface wettability was influenced by
the morphology of ZnO nanostructures, including the grain size, the length, and density of nanorods. Both types of ZnO films
showed switchable wettability under ultraviolet irradiation and dark storage. 相似文献
89.
Samuel Jayaraj Richard Prabakar Amol Bhairuba Ikhe Woon-Bae Park Docheon Ahn Kee-Sun Sohn Myoungho Pyo 《Advanced functional materials》2023,33(29):2301399
Crystalline water-free β-phase Ca0.14V2O5 is reported for the first time as a viable cathode material for calcium-ion batteries (CIBs). In contrast to layered α-V2O5 and δ-CaxV2O5·nH2O, which have limited capacity, the β-phase delivers a reversible capacity of ≈247 mAh g−1, which corresponds to the insertion/extraction of Ca2+ between Ca0.14V2O5 and Ca1.0V2O5. The process of Ca2+ insertion process and the accompanying structural relaxation are theoretically and experimentally verified. The initial insertion of Ca2+ into Ca0.14V2O5 causes a slight shift of oxygen atoms surrounding hepta-coordination sites, creating penta-coordinated sites that are then partially filled up to Ca0.33V2O5. Further insertion occurs through the stepwise occupation of up to 50% of neighboring hexa- and tetra-coordination sites to form Ca0.67V2O5 and Ca1.0V2O5, respectively. The rearrangement of oxygen atoms in Ca0.14V2O5 also minimizes dimensional changes, leading to high cyclic stability during repeated charge/discharge cycles. The remarkable electrochemical performance of full cells containing a Ca0.14V2O5 cathode and a K metal anode in Ca2+/K+ hybrid electrolytes, is also demonstrated, thanks to the inertness of K+ insertion into Ca0.14V2O5 and the absence of calcium plating/stripping. The cyclic stability and high capacity of Ca0.14V2O5 is not compromised in hybrid electrolytes, making it a viable CIB cathode. 相似文献
90.
采用直流磁控溅射的方法在普通玻璃上制备了低价的氧化钒薄膜,在氧气和氩气混合气氛中,对所制备的薄膜进行不同时间的热处理,得到具有相变特性的VO2薄膜。分别利用X射线衍射(XRD)和场发射扫描电镜(SEM)分析了薄膜的组分、结晶结构和表面形貌,利用四探针法测试了薄膜的电阻。结果表明:热处理前的氧化钒薄膜主要成分为V2O3,经过热氧化处理后,低价的氧化钒被氧化,薄膜中VO2含量增加,薄膜发生金属-半导体相变,其中450℃、2h为最佳处理参数,其电阻相变幅度超过2个数量级,薄膜的相变温度仅为30℃。 相似文献