共查询到20条相似文献,搜索用时 45 毫秒
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采用白炭黑对天然胶乳胶膜补强,并通过正交试验研究硫黄、促进剂PX、碳酸锌、白炭黑用量对硫化胶膜物理性能的影响。结果表明:以硫化胶膜的拉伸强度为考察指标,4个因子的影响从大到小依次为促进剂PX、白炭黑、碳酸锌、硫黄,优化用量为促进剂PX0.9份、白炭黑1.11份、碳酸锌0.6份、硫黄1份,相应配方硫化胶膜的拉伸强度可达到31.37 MPa;以硫化胶膜的撕裂强度为考察指标,4个因子的影响从大到小依次为白炭黑、促进剂PX、硫黄、碳酸锌,优化用量为白炭黑1.31份、促进剂PX0.7份、硫黄1.25份、碳酸锌0.5份,相应配方硫化胶膜的撕裂强度可达到65 kN·m-1。 相似文献
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通过一种简便的PVP调控法,制备了不同粒径的单分散性的二氧化硅纳米粒子(Si O2NPs)。利用PVP加入量的不同,所制备的Si O2NPs粒径分别约为150 nm、400 nm和600 nm,并且所得产物都有很好的单分散性和良好的水分散性,其中粒径150 nm的Si O2NPs是非常合适的药物载体,具有在癌症化疗领域的应用潜力。通过傅立叶变换红外光谱和热重分析可知,这种Si O2NPs是由PVP和Si O2共同构成的纳米复合材料,PVP含量约为总质量的12.9 wt%。 相似文献
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Spherical silica nanoparticles were mixed with a PP matrix and the thermal behavior of the nanocomposites was studied. The nanocomposites presented drastic improvements in the degradation behavior under thermo‐oxidative conditions, showing complex multistep processes. Under inert conditions the improvements were lower. Our results indicate that mechanisms based on the labyrinth effect, nanoconfinement or trapping model, are not able to explain the whole enhanced thermal stability in these nanocomposites. Moreover, the high specific area of the nanoparticles (≈70 m2 · g?1) indicates that processes based on the adsorption of volatile polar products coming from the oxidative degradation mechanism are plausible.
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Cuiling Ren Jinhua Li Qian Liu Juan Ren Xingguo Chen Zhide Hu Desheng Xue 《Nanoscale research letters》2008,3(12):496-501
A new method for preparing magnetic iron oxide nanoparticles coated by organic dye-doped silica shell was developed in this
article. Iron oxide nanoparticles were first coated with dye-impregnated silica shell by the hydrolysis of hexadecyltrimethoxysilane
(HTMOS) which produced a hydrophobic core for the entrapment of organic dye molecules. Then, the particles were coated with
a hydrophilic shell by the hydrolysis of tetraethylorthosilicate (TEOS), which enabled water dispersal of the resulting nanoparticles.
The final product was characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy,
photoluminescence spectroscopy, and vibration sample magnetometer. All the characterization results proved the final samples
possessed magnetic and fluorescent properties simultaneously. And this new multifunctional nanomaterial possessed high photostability
and minimal dye leakage. 相似文献
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《化学反应工程与工艺》2015,(5)
三元复合体系中碱成分的引入导致油田注采系统内出现严重结垢现象,为解决注采设备内难以处理的硅垢问题,本实验以乌头酸(AA)、二乙醇胺(DEA)、柠檬酸(CA)、丙烯酰胺(AM)为单体,异丙醇为链转移剂,过硫酸铵为引发剂,合成一种新型针对硅垢的共聚物防垢剂(ADCA)。确定在下列条件下合成得到的防垢剂防垢效果较佳:聚合温度75℃,聚合时间2 h,引发剂用量5%,单体摩尔配比AA:DEA:CA:AM为2.0:1.0:1.0:1.2。在p H为8,温度为60℃,防垢剂加量70 mg/L的条件下,对硅垢的防垢率为77.84%。防垢率的测定和X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)及扫描电镜(SEM)的对比实验结果表明防垢剂ADCA防硅垢效果较显著。初步认为防垢机理主要为吸附和螯合作用。 相似文献
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研磨介质对搅拌磨效率的影响 总被引:1,自引:0,他引:1
介绍了搅拌磨的主要特点,探讨了介质制度-研磨介质的性能(材质、密度、硬度等)及其使用情况(填充率、配比、形状、补给、浆液浓度等)对搅拌磨工作效率的影响。 相似文献
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Majid Soleimani Azam Khani Naser Dalali Gholamreza Rezaei Behbehani 《Journal of surfactants and detergents》2013,16(3):421-426
This work aimed to understand the effect of protease immobilization on silica nanoparticles and how such immobilization affects protease performance as catalysis for enhancing the removal of protein soils. Detergent products contain many components that may affect the free enzyme activity and stability. Various factors such as temperature, pH and humidity are know to affect enzyme activity and cleaning efficiency. Therefore, the effect of enzyme immobilization on the removal of protein based soil was investigated on cotton fabrics as the model soil. The effect of temperature and humidity on the stability of free and immobilized enzyme was compared. It was found that the immobilized enzyme increased cleaning efficiency toward protein soil removal on cotton fabrics, whereas the free enzyme imposed a small effect on the enzymatic activity towards the same soil substrates. In addition, the stability of the immobilized enzyme against temperature and humidity was much higher than its corresponding value by free enzyme. 相似文献
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氧化硅有序介孔材料MCM-41的微波水热合成及用于组装ZnO纳米粒子 总被引:1,自引:0,他引:1
与传统水热合成工艺相比,采用微波水热合成新工艺可以快速合成比表面积大、孔体积和孔径大、孔径分布范围更窄、孔洞呈六方排布的有序介孔材料MCM-41.微波水热合成工艺合成的MCM-41具有合成效率高、成功率高等特点,为此类介孔材料商业化提供了高效的技术手段.采用传统水热工艺合成MCM-41通常需要48~72 h,而采用微波水热合成技术仅需要30 min.采用X射线粉晶衍射(XRD),氮气吸附等技术手段对合成MCM-41材料的物相、比表面积、孔体积、孔径等进行了表征.采用微波水热合成MCM-41的工艺参数为:微波处理的温度120 ℃,时间30 min,微波辐射功率500 W,经过滤、洗涤、干燥、焙烧等处理后,得到的MCM-41具有六方排布的孔系,晶格常数a0=4.4nm,比表面积可达1113 m2/g,平均孔径为2.7 nm,与选用同样配方采用传统水热合成工艺合成的MCM-41的性能相当,却极大提高了合成效率.采用微波水热合成工艺,同样可以合成立方晶系的MCM-48和六方晶系的SBA-15等介孔氧化硅分子筛材料.此外,在微波合成的MCM-41中采用液相工艺成功组装了ZnO纳米粒子,并对组装在MCM-41中的纳米ZnO粒子进行了光催化降解苯酚的实验研究. 相似文献
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Silicon - Pure and Ag-decorated ZnO nanoparticles (NPs) were synthesized using a two stage of modified sol-gel technique on microsized substrates, namely sand particles in an effort to prevent... 相似文献
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以正硅酸甲酯为硅源,采用溶剂甲醇和N,N-二甲基甲酰胺,通过酸碱两步催化溶胶-凝胶法,结合CO2超临界干燥技术制备出高透光率SiO2气凝胶.利用扫描电镜、比表面积和空隙分析仪、紫外-可见分光光度计对该气凝胶的结构和光学性能进行了研究.结果表明,用N,N-二甲基甲酰胺为溶剂获得的气凝胶具有好的三维纳米多孔结构,平均孔径15.16 nm,比表面积922.1 m2/g;0.4 cm厚的样品在波长800 nm处的透光率高达92.4%.由于该气凝胶具有较高的透过率,因此在太阳能集热器方面具有极高的应用价值. 相似文献
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Iron-Based Nanoparticles for Toxic Organic Degradation: Silica Platform and Green Synthesis 总被引:1,自引:0,他引:1
Meeks ND Smuleac V Stevens C Bhattacharyya D 《Industrial & engineering chemistry research》2012,51(28):9581-9590
Iron and iron oxide nanoparticles (NPs) are finding wide applications for the remediation of various toxic chloro-organic compounds (such as trichloroethylene, TCE), via reductive and oxidative processes. In this study, Fe NPs (30-50 nm) are synthesized by reduction from ferric ions immobilized (by ion exchange) on a platform (two types of sulfonated silica particles), in order to prevent the NP agglomeration. Next, the Fe NPs are oxidized and their effectiveness for the oxidative dechlorination of TCE via the heterogeneous decomposition of hydrogen peroxide to OH? on the surface of the iron oxide NPs was demonstrated. For the reductive approach, the use of ascorbic acid as a "green" reducing agent in conjunction with a secondary metal (Pd) inhibits NP oxidation and agglomeration through surface adsorbed species. The Fe/Pd NPs have been successfully applied for the dechlorination of TCE (k(SA), surface-area normalized reaction rate, = 8.1 ×10(-4) L/m(2)h). 相似文献
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