共查询到19条相似文献,搜索用时 140 毫秒
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纳米SiC改性酚醛树脂的热稳定性 总被引:4,自引:0,他引:4
用超声波对纳米SiC进行物理分散,用偶联剂对其进行表面化学改性,以获得纳米粒子分散良好、界面结合良好的纳米SiC改性酚醛树脂;根据改性酚醛树脂的DTA-TG试验结果分析其热稳定性。结果表明:纳米SiC改性酚醛树脂较纯酚醛树脂的热稳定性要好,其中SiC纳米粒子含量为树脂的5%的改性酚醛树脂S05的热稳定性提高最大;经表面改性的SiC纳米粒子改性酚醛树脂S05较未进行表面改性的SiC纳米粒子改性酚醛树脂S05G的热稳定性提高要大。 相似文献
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KH-570对纳米氧化锌表面接枝改性研究 总被引:1,自引:0,他引:1
利用硅烷偶联剂(KH-570)对纳米氧化锌粉体进行超声表面改性,采用红外光谱(FT-IR)、热分析(TG-DSC)、透射电镜(TEM)、粘度、索式提取和活化指数实验等分析手段对表面改性前后的纳米ZnO进行了表征。实验结果表明,KH-570与粉体之间既有物理包覆,又有化学包覆。经KH-570改性的纳米ZnO由亲水性变为亲油性,且粒子分布更加均匀。 相似文献
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概述了无机纳米粒子表面改性的必要性,讨论了纳米粒子的表面改性方法。在此基础上阐述了改性后的纳米粒子在摩擦学领域的研究进展,最后简述了可以适用的纳米粒子种类,指出了纳米粒子改性存在的几点问题。 相似文献
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一种抗紫外自清洁纳米涂料的制备及应用 总被引:1,自引:0,他引:1
采用硅烷偶联剂对纳米粒子(粒径30nm的TiO2、SiO2、ZnO)进行表面改性,并将改性后的纳米粒子用于氟碳涂料中,得到抗紫外自清洁纳米改性涂料。利用透射电镜TEM及沉降实验对纳米粒子的改性效果进行了表征,得到结果:改性后纳米粒子能均匀地分散到甲苯等有机溶剂中。通过紫外分光光度计和接触角测量仪分别对改性后的涂膜对紫外光的吸收及表面疏水的自清洁性能进行了表征,结果表明,改性后的涂膜能有效地吸收大气中的紫外光,并且测得纳米改性的涂膜比未改性的涂膜接触角明显增大,有较好的表面疏水自清洁功效。 相似文献
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甲基丙烯酸甲酯对纳米SiO2的表面接枝聚合改性研究 总被引:1,自引:0,他引:1
将经过硅烷化处理的偶联剂γ-MPS接枝到纳米SiO2表面,然后在引发剂AIBN的作用下引发单体MMA发生自由基聚合包覆.利用FTIR、TG、CA(接触角)以及TEM等手段分别表征了改性工艺条件对粒子改性前后化学组成结构、接枝率、表面亲水性以及形貌等的影响.系统研究了单体用量、引发剂用量以及反应时间对SiO2/γ-MPS/PM-MA纳米复合粒子接枝改性效果的影响.结果表明,经过PMMA接枝包覆制得了高接枝率的复合粒子,并大大改善了纳米粒子的分散性. 相似文献
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Kailun YAO Jin TAO Zuli LIU Qianghua LU DongXI Xiaoping LUO Qin NINGDepartment of Physics State Key Lab. of Laser Technology Huazhong University of Science Technology 《材料科学技术学报》2004,20(4):417-420
Physical and chemical properties of the magnetic nanoparticles coated with oleate have been investigated by means of transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Mossbauer spectroscopy, superconducting quantum interference device (SQUID) magnetometry, infrared spectra (IR) and the contact angle device. The results show that doped Al ions in Fe3O4 nanoparticles are located on the octahedral sites of the spinel structure. Oleate is coated on the magnetic nanoparticles with two layers by chemical absorbing, the outer layer can be washed away. The wetting of the surface of magnetic nanoparticles coated with monolayer has been changed from hydrophilicity to hydrophobicity, and the nanoparticles can be dispersed very well in some organic solutions. 相似文献
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壳聚糖修饰银纳米颗粒的制备及抗菌性能研究 总被引:2,自引:0,他引:2
采用液相化学还原法,以壳聚糖为修饰剂,硼氢化钠为还原剂,制备了壳聚糖修饰银纳米颗粒(chitosan-Ag NPs)。通过X射线粉末衍射仪、透射电子显微镜、傅立叶变换红外光谱仪等对所制备样品的结构和形貌进行了表征。结果表明,所制备纳米颗粒具有面心立方Ag的晶型结构,壳聚糖通过氨基和羟基中的N、O原子与Ag+的化学键合作用修饰在纳米颗粒表面,起到了限制颗粒粒径长大和防止其团聚的作用。采用肉汤连续稀释法检测了样品对大肠杆菌和金黄色葡萄球菌的抑菌杀菌性能,结果表明chitosan-Ag NPs具有优异的抗菌性,抗菌性能受到粒径大小的影响。 相似文献
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The traditional epoxy resin used for electrical and electronic industry has a poor thermal conductivity and no longer meets the increasingly cooling requirements of electric equipments and electronic devices. Ceramic nanoparticles with high thermal conductivity and low dielectric constant represent good candidates to improve the thermophysical properties of epoxy resin. This paper reports the effects of surface modification of AlN nanoparticles on morphology, glass transition, electrical property and thermal conductivity of the epoxy composites. Gamma-aminopropyl triethoxysilane was used as a silane coupling agent for the surface modification of the AlN nanoparticles. It was found that the surface modification of the nanoparticles not only improved the dispersion of the nanoparticles, but also showed an enhancement in electrical and thermophysical properties of the epoxy composites. The surface modification technology presented a strategy to prepare nanocomposites having high thermal conductivity simultaneously with low dielectric loss. 相似文献
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Shashi B. Rana Vimal K. Bhardwaj Satbir Singh Amarpal Singh Navneet Kaur 《Journal of Experimental Nanoscience》2014,9(9):877-891
In this study, a precipitation method was used to synthesise ZnO nanoparticles using suitable precursors. An efficient surface modification method was proposed in order to reduce the agglomeration among synthesised small sized ZnO nanoparticles using 2-aminothiophenol as a capping agent. This article briefly investigated the effects of capping agent like 2-aminothiophenol on the optoelectronic properties of ZnO nanoparticles. The modified effectivity of 2-aminothiophenol has been examined on the nanosized ZnO nanoparticle for fluorescence and UV–visible (UV–vis) studies. The mechanism was studied for ZnO nanoparticles light emitting capability under different conditions. By facilitating the capping of ZnO with 2-aminothiophenol, fluorescence emission of the surface defects vanishes and ultraviolet (UV) emission increases. Surface capping by 2-aminothiophenol effectively covers most of the surface defects of ZnO and results in quenching of the visible region. The UV–vis absorption spectra of modified ZnO nanoparticles has been influenced by modified ZnO nanoparticles as a result of surface modification; where marked blue shift in absorption edge results. By surface modification of ZnO nanoparticles, change in optoelectronics properties has opened the new scope and possibilities to explore and fine tune the optical character of the modified ZnO for various optoelectronics applications such as UV laser. 相似文献
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AbstractInorganic nanoparticles are indispensable for science and technology as materials, pigments and cosmetics products. Improving the dispersion stability of nanoparticles in various liquids is essential for those applications. In this review, we discuss why it is difficult to control the stability of nanoparticles in liquids. We also overview the role of surface interaction between nanoparticles in their dispersion and characterization, e.g. by colloid probe atomic force microscopy (CP-AFM). Two types of surface modification concepts, post-synthesis and in situ modification, were investigated in many previous studies. Here, we focus on post-synthesis modification using adsorption of various kinds of polymer dispersants and surfactants on the particle surface, as well as surface chemical reactions of silane coupling agents. We discuss CP-AFM as a technique to analyze the surface interaction between nanoparticles and the effect of surface modification on the nanoparticle dispersion in liquids. 相似文献
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利用油酸对纳米二氧化钛进行有机表面修饰, 将修饰后的纳米粉体超声分散到变压器油中制备纳米二氧化钛改性变压器油, 研究了表面修饰对纳米二氧化钛在变压器油中分散性的影响. 采用X射线粉末衍射(XRD)、透射电镜(TEM)、红外光谱(FT-IR)和热分析(TG)对纳米二氧化钛的形貌、结构和表面修饰状态进行表征。结果表明, 油酸与纳米二氧化钛表面以双齿桥连配位方式键合, 在纳米二氧化钛表面形成了良好的修饰层。随着修饰剂的增加, 尽管油酸在纳米二氧化钛表面的配位方式没有发生改变, 但化学包覆量明显增加, 表面油酸分子的排列也更为紧密, 从而使纳米二氧化钛粒子在变压器油中的分散性和稳定性显著提高。当钛盐与油酸摩尔比为1:24时, 二氧化钛纳米粒子可以稳定分散在变压器油中, 室温静置30 d后仍保持澄清透明。 相似文献
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