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21.
Synthesis of Carbon–Nitrogen–Phosphorous Materials with an Unprecedented High Amount of Phosphorous toward an Efficient Fire‐Retardant Material 下载免费PDF全文
Dr. Wenyao Zhang Jesús Barrio Prof. Christel Gervais Dr. Andraž Kocjan Prof. Aiping Yu Prof. Xin Wang Prof. Menny Shalom 《Angewandte Chemie (International ed. in English)》2018,57(31):9764-9769
Phosphorus incorporation into carbon can greatly modify its chemical, electronic, and thermal stability properties. To date this has been limited to low levels of phosphorus. Now a simple, large‐scale synthesis of carbon–nitrogen–phosphorus (CNP) materials is reported with tunable elemental composition, leading to excellent thermal stability to oxidation and fire‐retardant properties. The synthesis consists of using monomers that are liquid at high temperatures as the reaction precursors. The molten‐state stage leads to good monomer miscibility and enhanced reactivity at high temperatures and formation of CNP materials with up to 32 wt % phosphorus incorporation. The CNP composition and fire‐retardant properties can be tuned by modifying the starting monomers ratio and the final calcination temperature. The CNP materials demonstrate great resistance to oxidation and excellent fire‐retardant properties, with up to 90 % of the materials preserved upon heating to 800 °C in air. 相似文献
22.
Wenyao Liang Ying Luo Shuangshuang Song Xianming Dong Xiaoyuan Yu 《Polymer Degradation and Stability》2013
A novel photocatalytic polyacrylamide grafted TiO2 (PAM-g-TiO2) nanocomposite was prepared and embedded into a low density polyethylene (LDPE) plastic. Photocatalytic degradation of the LDPE/PAM-g-TiO2 composite film was carried out under ambient conditions under ultraviolet light irradiation. The properties of composite film were compared with those of the pure LDPE film by measuring the changes in weight loss, carbonyl index, molecular weight, tensile strength and elongation at break. PAM-g-TiO2 embedded LDPE showed highly enhanced photocatalytic degradation. Irradiating the LDPE/PAM-g-TiO2 composite film for 520 h under UV light reduced its weight by 39.85% and average molecular weight (Mw) by 94.60%, while that of pure LDPE film was only 1.03% and 69.59%, respectively. The addition of PAM-g-TiO2 brought about the good dispersion of TiO2 in LDPE matrix and improved the hydrophilicity of composite film, which were able to facilitate the degradation of LDPE. The photocatalytic degradation mechanism of the films is briefly discussed. 相似文献
23.
Haiyang Zhu Lianying Miao Sheng Chen Xinzhong Lü Wenyao Song 《Discrete Mathematics》2018,341(8):2211-2219
Let be the set of all positive integers. A list assignment of a graph is a function that assigns each vertex a list for all . We say that is --choosable if there exists a function such that for all , if and are adjacent, and if and are at distance 2. The list--labeling number of is the minimum such that for every list assignment , is --choosable. We prove that if is a planar graph with girth
and its maximum degree is large enough, then . There are graphs with large enough and having . 相似文献
24.
Xiaoyan Liang Yuxin Leng Lihuang Lin Haihe Lu Wenyao Wang Yunhua Jiang Bin Shuai Hanlin Peng Baozhen Zhao Cheng Wang Wenqi Zhang Zhengquan Zhang Ruxin Li Zhizhan Xu 《Optics and Lasers in Engineering》2006,44(2):130-137
A 120 TW/36 fs laser system based on Ti:sapphire chirped-pulse amplification (CPA) has been successfully established in our lab. The final four pass Ti:sapphire amplifier pumped by an energetic single-shot Nd:YAG—Nd:glass laser was designed and optimized. With 24 J/8 ns pump energy at 532 nm, 300 mJ/220 ps chirped pulse was amplified to 5.98 J in this amplifier, and a total saturated gain of 20 was achieved. The focused intensity of compressed beam could reach to 1020 W/cm2 with the M2 of 2.0. 相似文献
25.
使用手性阴离子表面活性剂作为超分子模板, 采用共结构导向法制备手性介孔二氧化硅(CMS), 并运用圆二色谱(CD)对CMS对映选择性吸附结果进行检测, 比较了有无共结构导向剂(CSDA)在介孔表面的排列对吸附选择性的影响. 结果表明, 当使用构型相反的手性超分子模板剂对原合成CMS材料的介孔内表面进行修饰时, 可诱导结构共导向剂N?三甲氧基硅基丙基?N, N, N?三甲基氯化铵(TMAPS)发生手性相反的排列进而导致完全相反的对映选择性吸附. 实验证明此方法合成的CMS的对映选择性吸附及分离能力主要是由修饰在介孔表面的TMAPS螺旋排列形成的手性印迹所导致. 此手性超分子模板诱导TMAPS手性印迹的策略具有一定的普适性, 可对原合成介孔材料对映选择性吸附进行原位调控, 对于拓展其在立体选择性识别、 不对称催化及药物输送等方面的应用具有一定的指导意义. 相似文献
26.
Optically active polymers are promising multifunctional materials with great application potentials. Herein, environmentally friendly optically active polyurethanes (OPUs) were obtained by introducing rotatory binaphthol monomer to polyurethane. The influence of binaphthol monomer content on the structure, mechanical properties, infrared emissivity, and thermal insulation of OPUs was studied intensively. Structure characterization indicated that the optically active polyurethanes have been successfully synthesized. The OPU synthesized with BIMOL and BDO at the mole ratio of 1:1 presented better thermal resistance. In addition, OPUs showed enhanced tensile strength and stretchability with the increase of BINOL content to a certain extent due to its rigid structural features and high molecular weight. The optically active polyurethanes showed lower infrared emissivity values (8–14 μm) than waterborne polyurethane (WPU), and the infrared emissivity decreased from 0.850 to 0.572 as the content of the BINOL monomer increased. Moreover, OPU4 exhibited the best heat insulation and cooling ability with about a 7 °C temperature difference. The thus-synthesized optically active polyurethanes provide an effective solution for developing highly effective thermal insulation materials. 相似文献
27.
28.
采用原位溶剂热反应制备多级 Ag/Bi/Nv-g-C3N4(氮空位-g-C3N4)/Ti3C2Tx肖特基结, 并对其物相组成和晶体结构、微观形貌和孔结构、表面元素组成和化学态、光学和光电化学性质进行了表征。由于 Ag、Bi和 Ti3C2Tx协同的表面等离激元共振效应,Ag/Bi/Nv-g-C3N4/Ti3C2Tx表现出全光谱吸收特性。由载流子浓度差驱动的界面极化电荷转移诱导形成的肖特基结, 显著提高了光生载流子(包括热电子和热空穴)的分离效率和利用率。因此, 与 Nv-g-C3N4、Ti3C2Tx、Ag/Nv-g-C3N4、Bi/Nv-g-C3N4和 Ag/Bi/Nv-g-C3N4相比, Ag/Bi/Nv-g-C3N4/Ti3C2Tx表现出显著增强的全光谱催化活性, 其在可见光和近红外光照射下光催化降解四环素的反应速率常数分别为 0.033和 0.008 6 min-1, 为对比样品的 10~2.1倍和 8.6~1.8倍。 相似文献
29.
采用原位溶剂热反应制备多级Ag/Bi/Nv-g-C3N4(氮空位-g-C3N4)/Ti3C2Tx肖特基结,并对其物相组成和晶体结构、微观形貌和孔结构、表面元素组成和化学态、光学和光电化学性质进行了表征。由于Ag、Bi和Ti3C2Tx协同的表面等离激元共振效应,Ag/Bi/Nv-g-C3N4/Ti3C2Tx表现出全光谱吸收特性。由载流子浓度差驱动的界面极化电荷转移诱导形成的肖特基结,显著提高了光生载流子(包括热电子和热空穴)的分离效率和利用率。因此,与Nv-g-C3N4、Ti3C2Tx、Ag/Nv-g-C3N4、Bi/Nv-g-C3N4和Ag/Bi/Nv-g-C3N4相比,Ag/Bi/Nv-g-C3N4/Ti3C2Tx表现出显著增强的全光谱催化活性,其在可见光和近红外光照射下光催化降解四环素的反应速率常数分别为0.033和0.008 6 min-1,为对比样品的10~2.1倍和8.6~1.8倍。 相似文献
30.
Chen Angkang Li Chonggui Zhang Chaomin Li Wenyao Yang Qi 《Journal of Solid State Electrochemistry》2022,26(3):729-738
Journal of Solid State Electrochemistry - Currently, lithium-ion batteries are widely used in many areas, but they are still limited by the lower cycle stability and energy density. The development... 相似文献