共查询到20条相似文献,搜索用时 948 毫秒
1.
采用共沉淀-相转化法制备出纳米级掺Dy3+铁氧体磁颗粒。选择阴离子表面活性剂月桂酸、月桂酸钠、十二烷基硫酸钠对磁颗粒进行了在线表面改性,得到磁性能和表面性能不同的复合纳米磁性材料,研究了活性剂及其用量对产物构建成分、相结构、磁性能的影响。TEM图片显示磁颗粒的形貌多数为类球形,平均粒径约18 nm;XRD图谱分析发现,活性剂及其用量不同,得到的产物其构建成分、相结构也不同;VSM测试结果表明,用月桂酸改性的产物磁性能最优、十二烷基硫酸钠改性者磁性能最差,产物室温下的饱和磁化强度(MS)随活性剂用量的增大呈现出降低的变化规律。 相似文献
2.
3.
复合电沉积CoNiP-BaFe12O19磁性薄膜 总被引:1,自引:0,他引:1
采用复合电沉积技术制备了磁性CoNiP-BaFe12O19复合薄膜, 分别用SEM、EDS、XRD、VSM 对复合薄膜进行了表征. SEM、EDS、XRD 测试表明BaFe12O19粒子被成功地掺入CoNiP硬磁薄膜中. 考察了基础电解液和复合电解液的电化学行为, 并探讨了BaFe12O19粒子和表面活性剂CTAB 的加入对薄膜中各成分相对含量的影响. 结果表明, 当表面活性剂CTAB 加入量为0.6 g·L-1时, 复合膜中BaFe12O19相对含量最高达20%. VSM 测试表明BaFe12O19粒子的掺入显著地增加了薄膜的矫顽力和剩磁比. 相似文献
4.
Fe3O4/P(NaUA-St-BA)核-壳纳米磁性复合粒子的合成与表征 总被引:6,自引:0,他引:6
以表面包敷有反应型的表面活性剂NaUA(十一烯酸钠)的Fe3O4磁性胶体粒子为种子,运用无皂乳液聚合方法原位制备出Fe3O4/P(NaUA-St-BA)核-壳纳米磁性复合粒子,Fe3O4磁性胶体粒子的粒径为10nm左右,IR和TG结果分析表明,苯乙烯、丙烯酸酯和NaUA在Fe3O4粒子的表面发生了聚合反应,形成P(NaUA-St-BA);TEM和激光粒度分析仪测试结果显示,Fe3O4/P(NaUA-St-BA)复合粒子具有核-壳结构而且粒子分布均匀、平均粒径60nm;TG测试的结果表明,NaUA在Fe3O4粒子的包覆率为13.83%,P(NaUA-St-BA)共聚物的包覆率71.85%;振动样品磁强仪(VSM)测试的磁滞回线则表明由无皂乳液聚合得到的Fe3O4/P(NaUA-St-BA)复合粒子具有超顺磁性,可避免磁性微球在磁场中的团聚。另外,合成的磁性胶乳可稳定存放数月。 相似文献
5.
采用表面活性剂3-氨丙基三乙氧基硅烷(APTES)修饰Fe3O4磁性纳米粒子, 经质子化后, Fe3O4磁性纳米粒子表面披覆大量的正电荷, 与表面带负电荷的巯基丙酸(MPA)修饰的核壳CdSe/CdS/ZnS量子点(QDs)通过强烈的静电作用而发生组装, 得到兼具磁性和荧光性能的磁性荧光纳米材料. 利用透射电子显微镜(TEM)、傅里叶变换红外光谱仪(FTIR)、X射线衍射仪(XRD)、荧光分光光度计和振动样品磁强计(VSM)等测试手段对磁性荧光纳米材料进行表征. 研究表明, 由两种粒子组装的核壳结构复合粒子拥有良好的磁性能和荧光性能. 相似文献
6.
报道了一种制备磁性复合微球的方法——DPE法.在自由基控制剂1,1-二苯基乙烯(DPE)存在条件下,甲基丙烯酸甲酯(MMA)与丙烯酸(AA)发生无皂乳液聚合,制备能与Fe3O4粒子相螯合的活性短链共聚物,加入Fe3O4粒子把短链共聚物引到其表面,引发其它单体继续在Fe3O4粒子表面聚合,制备磁性复合微球.研究了AA、DPE、引发剂及Fe3O4粒子加入量等对制备磁性复合微球的影响.并在此基础上,对优化后工艺制备的磁性复合微球进行了TEM、TGA及磁响应性表征.结果表明,利用该新的方法制备出了磁含量为20%、比饱和磁化强度为32.2emu/g、平均粒径为265nm且表面不含任何杂质的磁性复合微球. 相似文献
7.
超声合成Fe3O4@SiO2复合纳米磁性粒子用于质粒DNA的提纯 总被引:1,自引:0,他引:1
用超声合成了Fe3O4@SiO2复合纳米磁性粒子, 并用于质粒DNA的提取. 用透射电镜(TEM)、红外光谱(FT-IR)、震动样品磁场计(VSM)、X光电子能谱仪(XPS)等方法对合成的复合磁性粒子的表面形貌、结构、磁性质等进行了表征, 合成的复合磁微粒粒径分布均匀, 在15~20 nm, 磁响应性好. 用该复合磁微粒提取DNA的纯度能达到A260/A280= 1.8±0.1, 琼脂糖电泳证明质粒DNA结构基本没有被破坏, 主要为超螺旋结构, 能满足PCR等后续分子生物学操作的要求. 相似文献
8.
9.
Polyol合成法制备生物医药用超小粒径Fe3O4磁性纳米晶体 总被引:2,自引:2,他引:0
采用一罐polyol合成法还原Fe(Ⅲ)乙酰丙酮化合物制备了粒径可调、单分散、直径5nm以下的磁性Fe3O4纳米晶体.其晶粒表面为所用聚合物表面活性剂PVP所包覆.运用透射电镜/高分辨透射电镜、X射线衍射、振动样品磁强计和超导量子干涉仪对其结构和性能进行了表征.结果表明所制得的Fe3O4磁性纳米晶体在室温下显示出优良的超顺磁性,且结晶度高、分散性好、化学性质稳定同时表面易修饰.磁滞回线的模型分析说明该Fe3O4纳米晶粒是磁性单畴.该法制得的超顺磁Fe3O4纳米晶粒在生物和医学领域具有重要的应用价值. 相似文献
10.
采用静电纺丝结合氢气热还原法制备了一系列平均直径约为60~70 nm的Fe-Ni合金/Ni铁氧体复合纳米纤维. 使用热重-差热分析、X射线衍射、扫描电镜、透射电镜、选区电子衍射和振动样品磁强计等技术对前驱体纤维的热分解行为以及目标产物的晶体结构、相组成、形貌和磁性能进行了表征. 结果显示, Ni铁氧体纳米纤维的制备温度及其还原温度对相应还原产物的相组成和磁性能有着显著的影响; 所得Fe-Ni合金/Ni铁氧体复合纳米纤维由于Fe-Ni合金的引入表现出更为优良的磁性能, 且各磁性相间存在良好的交换耦合, 其整体磁行为如同一个单相磁性材料. 在复合纳米纤维磁性能上所观察的变化可根据Fe-Ni合金和Ni铁氧体内禀磁特性的不同以及晶粒尺寸、相组成和磁相互作用的变化来进行解释. 相似文献
11.
导电聚苯胺与Fe3O4磁性纳米颗粒复合物的合成与表征 总被引:28,自引:0,他引:28
对十二烷基苯磺酸(DBSA)掺杂的导电聚苯胺(PAn-DBSA)的氯仿溶液,在pH为中性的条件下,采用“修饰-再掺杂(Modification-re-doped)法”合成了含有Fe3O4磁性纳米颗粒的导电聚苯胺复合物的有机溶液.用FTIR,XRD,TEM,UV-Vis和SQUID等对所得复合物进行了表征,结果表明,该复合物呈现超顺磁性和半导体的导电性,并具有较好的透明性. 相似文献
12.
PAN Ying WANG Qing HUANG Wen-jun QIAO Feng-li LIU Yu-ping ZHANG Yu-cheng HAI De-yang DU Ying-ting WANG Wen-yue ZHANG Ai-chen 《高等学校化学研究》2012,28(3):443-448
A novel kind of multi-core magnetic composite particles, the surfaces of which were respectively modified with goat-anti-mouse IgG and antitransferrin receptor(anti-CD71), was prepared. The fetal nucleated red blood cells(FNRBCs) in the peripheral blood of a gravida were rapidly and effectively enriched and separated by the modified multi-core magnetic composite particles in an external magnetic field. The obtained FNRBCs were used for the identification of the fetal sex by means of fluorescence in situ hybridization(FISH) technique. The results demonstrate that the multi-core magnetic composite particles meet the requirements for the enrichment and speration of FNRBCs with a low concentration and the accuracy of detetion for the diagnosis of fetal sex reached to 95%. Moreover, the obtained FNRBCs were applied to the non-invasive diagnosis of Down syndrome and chromosome 3p21 was detected. The above facts indicate that the novel multi-core magnetic composite particles-based method is simple, reliable and cost-effective and has opened up vast vistas for the potential application in clinic non-invasive prenatal diagnosis. 相似文献
13.
Wei Wang 《Journal of Dispersion Science and Technology》2013,34(4):557-561
Carbohydrate microspheres coated with magnetic nanoparticles were prepared by hydrothermal synthesis where a species of carbohydrate, such as vitamin C, glucose, and soluble starch, were used to obtain microsphere templates as the core of the composite microspheres. The dimension of the carbohydrate microspheres could be well controlled by adjusting the concentration of the starting material, the temperature, and the reaction time. The morphology of the magnetic composite microspheres was characterized by field‐emission scanning electron microscopy (FE‐SEM). The composition, as well as the structure of the composite microspheres, was confirmed by Fourier transform infrared spectroscopy (FTIR) and x‐ray diffraction (XRD). 相似文献
14.
A simple method for preparation of magnetic cellulose fibers by coating (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)-oxidized viscose with oleic-acid-coated or uncoated, freshly prepared magnetic nanoparticles (MNp) is presented. MNp attachment was facilitated by chemical activation of the cellulose fibers through introduction of negatively charged carboxylic groups using the well-established TEMPO-mediated oxidation protocol. The resulting composite materials preserved the intrinsic properties of the cellulose fibers, but gained notable specific features due to the presence of magnetic nanoparticles. The obtained composite materials were characterized using spectral (Fourier-transform infrared spectroscopy) and microscopic (scanning electron microscopy) methods. Thermogravimetric analyses were carried out to evaluate the thermal stability of the magnetic fibers. The magnetic properties were evaluated using vibrating-sample magnetometry. 相似文献
15.
Tindaro Ioppolo Edoardo Rubino 《Journal of polymer science. Part A, Polymer chemistry》2014,52(3):272-275
In this article, the effect of an external magnetic field on the morphology-dependent resonances (MDRs) of a polymeric dielectric microsphere is investigated. The microsphere is mechanically coupled to a composite polymeric Metglas slab. When an external magnetic field is applied to the slab, it elongates leading to a change in the morphology of the microsphere. This in turn leads to a shift in the excited optical resonances. Experiments are carried out to investigate the effect of an external static and harmonic magnetic field on the MDRs shift. The results show that this configuration can be used as an optical magnetic field sensor or as an optical tuning element. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 272–275 相似文献
16.
17.
18.
两种磁性复合微球的制备及其性能对比 总被引:1,自引:1,他引:1
为了得到蛋白吸附性能良好的免疫磁性载体,文章用反相微乳的方法合成了壳聚糖磁性复合微球(Chitosanmagneticcompositemicrospheres简称CMCM),与常用的单体聚合法制备的聚苯乙烯磁性复合微球(Polystyrenemagneticcompositemicrospheres,简称PMCM)从粒径和表观形貌、微球铁含量、磁响应性、表面官能基团等性质做了对比表征,结果表明,CMCM是一种比PMCM更理想的免疫磁性微球载体材料。 相似文献
19.