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By means of the wet chemical surface modification, the surface of Fe2O3 was modified by vinyltrimethoxysilane (VTMS). Infrared spectroscopy (IR) was used to investigate the structure of the modified Fe2O3, and the result showed that VTMS has been attached onto the surface of Fe2O3. Effect of VTMS concentration on the active index of the modified Fe2O3 was also studied, and the result indicated that the active index of the modified Fe2O3 increases with the increase of VTMS concentration and the optimal concentration of VTMS is 12 wt %. The effect of the modified Fe2O3 on the tear strength of silicone rubber before and after aging was studied and it was found that in comparison with the unmodified Fe2O3 the addition of the modified Fe2O3 results in the significant increase of the tear strength before ageing because of the increase of the crosslinking density of silicone rubber. The tear strength of silicone rubber filled with the modified Fe2O3 after ageing is higher than that with the unmodified Fe2O3, indicating that the modification of Fe2O3 can improve the heat‐resistance of silicone rubber owing to the fine dispersion of the modified Fe2O3 in silicone rubber. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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Hongqiang Li Yanping Li Xuejun Lai Hongwei Cao Renxu Yuan Xingrong Zeng 《应用聚合物科学杂志》2019,136(15):47360
With the growing incidence of extreme climate and serious pollution, the capability to resist high-voltage arc discharge has been considered as one of crucial performances for silicone rubber in the field of electrical power. Herein, to enhance the tracking and erosion resistance of addition-cure liquid silicone rubber (ALSR), a kind of ureido-attached vinyl MQ silicone resin [hydrolytic condensation products of monofunctional silane (M) and tetrafunctional silane (Q)] (U-VMQ) was synthesized. The chemical structure of U-VMQ was characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance, and the effects of U-VMQ on the mechanical properties, thermal stability, and tracking and erosion resistance of ALSR were investigated. The results showed that U-VMQ was beneficial for the improvement of mechanical properties and thermal stability of ALSR. With 2 phr of U-VMQ containing 2.5 wt % of vinyl content, the ALSR successfully passed the inclined plane tracking at 4.5 kV, and the electrical erosion rate was only 0.13%. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47360. 相似文献
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以Al2O3, Fe2O3和Na2CO3为原料,对Na2O-Al2O3-Fe2O3系烧结过程中的反应行为进行了详细研究. 基于溶出率与时间、温度的关系,证明Na2O×Al2O3和Na2O×Fe2O3的生成反应动力学都服从Zhuralev-Lesokin-Tempelman模型,表观活化能分别为186.59和80.92 kJ/mol,表明Na2O×Fe2O3比Na2O×Al2O3在动力学上更易形成;Al2O3易与Na2O×Fe2O3反应形成Na2O×Al2O3和Fe2O3,在1273 K烧结30 min,所得熟料Al2O3溶出率达98.51%;Fe2O3对Na2O×Al2O3的形成有双重作用,在1273 K下可加速Na2O×Al2O3的形成,超过1323 K,促使Na2O×Al2O3分解成Na2O和b-Al2O3,且随着温度升高或时间延长,分解程度增高,从而导致熟料中Al2O3溶出率显著降低. 相似文献
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为提升三氧化二铁(Fe2O3)催化剂的脱硝性能,扩展催化剂的活性温度窗口,采用共沉淀法引入助剂钇(Y)元素对Fe2O3催化剂进行改性。通过X射线衍射(XRD)、氮气等温吸-脱附(N2-BET)、X射线光电子能谱(XPS)、氨气程序升温脱附(NH3-TPD)、氢气程序升温还原(H2-TPR)等表征方法对样品进行了表征分析。XRD和N2-BET结果表明,Y的掺杂使催化剂结构发生变化,比表面积增加、孔径减小。XPS和NH3-TPD结果证明,Y掺杂Fe2O3具有更多的表面吸附氧(OⅠ)、Fe2+以及更多的酸量。H2-TPR结果表明,Y的掺杂使催化剂的氧化还原能力略有下降。测试了不同含量Y掺杂的Fe2O3催化剂在150~400℃的脱硝性能,其中Fe<... 相似文献
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PVA/Fe2O3磁敏感性水凝胶的制备及性能 总被引:2,自引:0,他引:2
采用循环冷冻-解冻方法制备了聚乙烯醇(PVA)/Fe2O3磁敏感性水凝胶. 考察了水凝胶的力学性能、溶胀性能和磁敏感性,并用扫描电镜观察了其表面形貌. 结果表明,当Fe2O3含量为1%(w)时,水凝胶的力学性能最好;水凝胶的溶胀度和脱水率随时间增加有相似的变化趋势,都随磁性粒子含量升高而降低;溶胀性能降低其交联程度增加;PVA和Fe2O3相容性较好;水凝胶在3000 Oe的磁场强度下达到饱和,呈现出很强的顺磁性,磁滞损耗较多,表明具有较好的磁敏感性. 相似文献
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Fe2O3对CaO-SiO2玻璃和微晶玻璃性能的影响 总被引:2,自引:0,他引:2
利用溶胶-凝胶法制得Fe2O3-CaO-SiO2系基础玻璃,研究不同含量的Fe2O3对CaO-SiO2玻璃和微晶玻璃性能的影响.经分析,不同组分的玻璃凝结时间不同,处于低共熔点的样品凝结时间最短,而离低共熔点最远的样品凝结时间最长.样品的密度并不随成分而变化.溶胶凝胶转变过程中,不同组分所得的凝胶玻璃有一定的耐酸碱性.而微晶玻璃的耐酸碱性比玻璃都略有增强.微晶玻璃的饱和磁化强度和磁铁矿在玻璃中所占的体积分数有关.随着玻璃中Fe2O3含量的增加,饱和磁化强度增大. 相似文献
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Zhenying Liu Wei Lian Yin Liu Jinbo Zhu Changguo Xue Zhongde Yang Xin Lin 《International Journal of Applied Ceramic Technology》2021,18(3):1074-1081
The effects of Fe2O3 on phase evolution, density, microstructural development, and mechanical properties of mullite ceramics from kaolin and alumina were systematically studied. X-ray diffraction results suggested that the ceramics consisted of mullite, sillimanite, and corundum, in the sintering range of 1450°C–1580°C. However, as the sintering was raised to 1580°C, mullite is the main phase with a content of 94%, and the corundum phase content is 5.9%. Simultaneously, high-temperature sintering had a positive effect on the densification of the mullite ceramics, where both the bulk density and flexural strength could be optimized by adjusting the content of Fe2O3. It was found that 6 wt% Fe2O3 was optimal for the formation of rod-shaped mullite after sintering at 1550°C for 3 h. The sample's maximum bulk density was 2.84 g/cm3, with a flexural strength of 112 MPa. Meanwhile, rod-shaped mullite grains with an aspect ratio of ~9 were formed. As a result, a dense network structure was developed, thus leading to mullite ceramics with excellent mechanical properties. The effect of Fe2O3 on the properties might be attributed to the fact that Al3+ ions in the [AlO6] octahedron were replaced by Fe3+ ions, resulting in lattice distortion. 相似文献
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在铁氧化物中引入硅的氧化物 ,并用S2 O82 -浸渍铁硅复合氧化物 ,制得固体酸催化剂S2 O82 -/Fe2 O3 SiO2 (Ⅰ )。用马来酸酐与正己醇的酯化反应考察了催化剂的活性。通过XRD和TEM分析 ,对催化剂的结构进行了表征。结果表明 ,Ⅰ的最佳制备条件为 :n(Fe)∶n(Si)为 5∶1、70℃陈化 3h ,2 0 0℃焙烧 2h、用 0 2 5mol/L的 (NH4) 2 S2 O8浸渍 3h、在 5 5 0℃下煅烧 6h ;Ⅰ的催化活性比S2 O2 -8/Fe2 O3 和SO2 -4/Fe2 O3 SiO2 更强 ,S2 O2 -8对Fe2 O3 SiO2 的促进作用明显高于SO2 -4;SiO2 的引入提高了催化剂的分散效果 ;有较好的使用重复性 ;它代替硫酸、对甲苯磺酸用于催化马来酸酐和正己醇的酯化反应可得无色透明的酯化产物 相似文献
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利用工业废弃物电石渣,经适当预处理,并掺入适量的Fe2O3对电石渣进行改性,配制成新型复合固硫剂。在高温条件下进行了固硫实验,达到了较为理想的固硫效果。研究了影响改性电石渣高温固硫效果的因素,分析了该改性电石渣的固硫机理。结果表明,改性电石渣高温固硫的适宜条件为:煤燃烧温度1200℃、Ca/S=2.2、改性电石渣的粒径为100目。在该条件下,对实验用烟煤(含硫量2.92%)燃烧20min,其高温固硫率高达88.5%,较相同条件下的普通钙基固硫剂的固硫率提高30%以上。 相似文献
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采用Fe2O3掺杂TiO2为催化剂,超声辐照为主要手段对实际糠醛废水进行了降解试验研究,考察了各种反应参数对糠醛废水降解效果的影响.结果表明,Fe2O3掺杂TiO2对糠醛废水的超声降解效果具有明显的辅助和提高.当超声波频率为40 kHz,功率为160 W,初始COD为1 128 mg·L-1,超声反应时间为1.5 h的务件下,糠醛废水的COD去除率为67%,而同样条件下,按质量浓度750mg·L-1加入1.0%Fe2O3掺杂量的催化剂TiO2,其超声降解废水COD去除率可达95%. 相似文献
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Qingling Liu Elif Demirel Yong Chen Ting Gong Xuezhi Zhang Yongsheng Chen 《应用聚合物科学杂志》2019,136(25):47685
Membrane filtration provided a potential solution to get high quality microalgae biomass and recyclable medium. However, the fouling of membrane by microalgae cells and organic matter greatly affects membrane harvesting efficiency. In this study, membrane performance was tested in terms of flux declining and backwashing recovery for microalgal harvesting. Compared with the unmodified poly(vinyl chloride) (PVC) membrane, the membrane with 1.0% Fe2O3 incorporation had a 66% increase in average flux, reaching 138 L m− h−1. Foulants on the membrane surface were characterized using attenuated total reflection-Fourier transform infrared (ATR-FTIR) and confocal laser scanning microscope (CLSM), as well as sodium hydroxide extraction followed by total organic carbon (TOC) quantification and fluorescence excitation–emission matrix (FEEM) identification of organic components. FEEM and TOC analysis of the extracted foulants revealed that the surface of 1.0% Fe2O3 incorporated membrane had less fouling than the unmodified PVC membrane, which may be attributed to its hydrophilicity after Fe2O3 incorporation. CLSM analysis and ATR-FTIR analysis of the fouled membrane surface further revealed that the protein substance on the 1.0% Fe2O3 incorporated PVC membrane was lower than those in the unmodified membrane, which further confirmed the enhanced antifouling performance of the 1.0% Fe2O3 incorporated PVC membrane. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47685. 相似文献
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采用固定床反应器考察了干混法添加油酸包覆型Fe2O3对煤加氢热解特性的影响,并与添加常规Fe2O3进行比较。对其催化作用下得到的半焦进行了TG、BET和XRD表征,焦油进行GC模拟蒸馏分析。结果表明:(1)采用常规Fe2O3考察铁的添加量时,在添加量为5%时焦油产率最高,由不加催化剂时的14.3%提高到16.3%。添加油酸包覆型Fe2O3时,煤的热解转化率更高,焦油产率由不加催化剂时的14.3%提高到18.0%。(2)添加油酸包覆型Fe2O3和常规Fe2O3得到的半焦反应性基本相同,半焦的孔结构则是添加油酸包覆型Fe2O3时最发达;添加油酸包覆型Fe2O3的半焦表面Fe晶粒的直径28 nm,小于添加常规Fe2O3的半焦表面Fe晶粒的直径39.5 nm。(3)加入常规Fe2O3和油酸包覆型Fe2O3都使得焦油品质得到提高,但两者相比,常规Fe2O3作用下得到的焦油品质更高。 相似文献
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Fe2O3/TiO2纳米材料的制备及其紫外-可见光催化性能 总被引:5,自引:0,他引:5
采用溶胶-凝胶法制备了不同Fe含量的纳米Fe2O3/TiO2复合光催化材料,并用X射线衍射和透射电镜研究了样品的晶体结构和形貌,分别在紫外和可见光下研究了不同Fe含量复合催化剂的光催化降解甲基橙的活性.结果表明在Fe复合比例较低时,样品为锐钛矿结构;在紫外光情况下,最佳Fe2O3/TiO2复合比例为0.5%,在比例为10%情况下催化效果也比较好;而在可见光情况下,最佳fe2O3/TiO2复合比例为0.1%. 相似文献
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三氧化二铁超细粉末的制备 总被引:1,自引:0,他引:1
以含三价铁离子的酸性溶液为源物质,采用溶胶-凝胶法制备三氧化二铁超细粉末,在650℃下焙烧后得到Fe2O3超细粉末,用X射线衍射(XRD)对粒子进行表征,结果表明该超细粉末达到纳米级,其平均粒径达23nm。 相似文献