共查询到19条相似文献,搜索用时 78 毫秒
1.
采用乙二醇为溶剂,无水FeCl3为铁源,聚丙烯酸为稳定剂,通过改变3-氨基丙醇的用量,合成了一系列不同微球直径和晶粒大小的超顺磁Fe3O4微球。高分辨率透射电镜和X-射线衍射分析证实所得产物为Fe3O4,红外光谱和热重分析表明,微球表面成功包覆聚丙烯酸。微球的大小和组成微球的颗粒粒径分别用透射电镜和X-射线衍射分析,结果表明,所得微球的直径随着3-氨基丙醇的用量增加而减小,组成微球的颗粒粒径随着3-氨基丙醇的用量增加而增大。磁性测试表明所制备微球室温下具有良好的超顺磁性。该制备方法步骤简单,可望用于其他无机氧化物纳米微球或颗粒的制备。 相似文献
2.
Monodisperse Fe3O4 microspheres with tunable diameters and high magnetic saturation were synthesized by a solvothermal reduction method. It was found that the morphology and structure of the Fe3O4 microspheres could be tuned by simply altering the amount of the reactants such as ferric chloride, sodium acetate, water, and the reaction time. The Fe3O4 microspheres obtained via this method possessed high purity, crystallinity, and a nearly spherical shape. Furthermore, they were monodispersed and no aggregation was found. Such monodisperse Fe3O4 microspheres had tunable diameters of 400-700 nm and the fabrication time was only 2-4 h. The products showed high magnetic saturation values, and their yields were typically more than 94%. 相似文献
3.
4.
以单分散的苯乙烯-甲基丙烯酸甲酯共聚物(P(St-co-MMA))微球为载体,FeSO_4·7H_2O和FeCl_3·6H_2O为铁源,NaOH为沉淀剂,在氧化石墨烯(GO)存在下,利用反相共沉淀法通过原位复合技术在P(St-co-MMA)微球表面包覆磁性氧化石墨烯(P(St-co-MMA)/Fe_3O_4/GO)。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅里叶变换红外光谱仪(FT-IR)、X射线衍射仪(XRD)、振动样品磁强计(VSM)和氮吸附-脱附等温线对P(St-co-MMA)/Fe_3O_4/GO样品的结构和性能进行表征分析。研究结果表明:纳米级的磁性氧化石墨烯成功地负载在了微米级的共聚物P(St-co-MMA)表面,所制备的P(St-co-MMA)/Fe_3O_4/GO微纳米复合物平均孔径为14.55nm,孔体积为0.204 2cm~3/g,比表面积为56.14m~2/g。该复合物具有超顺磁性和良好的磁响应性,能够满足磁分离的要求。 相似文献
5.
6.
通过霍夫曼降解光化学原位聚合制备的聚丙烯酰胺包覆的Fe3O4纳米粒子得到了氨基化磁性纳米凝胶,用缩合剂1-乙基-3-(3-二甲胺)碳二亚胺成功地将α-胰凝乳蛋白酶固定到氨基化磁性纳米凝胶上,并采用光子相关光谱、傅里叶变换红外光谱、透射电子显微镜、X射线粉末衍射和热重-示差扫描量热联用等多种手段对其进行了表征.固定化了的α-胰凝乳蛋白酶平均粒径约为31 nm;热重法测得每克凝胶上的载酶量为69 mg,BCA 法测得每克凝胶上的载酶量为61 mg;酶的固定化和氙灯辐照并未改变Fe3O4的晶形结构;固定化酶比活力为0.93 U/(mg·5min),为自由酶活力的59.3%;磁含量高达88%,具有优异的磁响应性能,可应用于诸多生物医药领域的快速检测、分离及酶的再生利用. 相似文献
7.
以“水质电解器检测饮用水的实验现象”为线索,通过探究电解产物组成,设计阳极氧化-共沉淀法制备Fe3O4磁性材料的实验。实验内容包括制备Fe3O4磁性材料,研究自来水硬度、电导率以及pH等影响因素,利用X射线粉末衍射、场发射扫描电镜和震动样品磁强计获取材料的组成、形貌和磁性信息。该实验从生活取材,融合无机及分析化学、纳米材料制备和现代测试分析技术及知识,实操性强;以“学生为中心”开展实验教学,重视教学目标的达成,有助于培养学生知识转化和科研创新能力,提高专业文化自信。 相似文献
8.
9.
以3-卤氧化吲哚和吗啉(或硫代吗啉)为起始原料,碳酸钠为催化剂,于60 ℃发生3-叔胺基化反应,合成了10个新型的3-吗啉四取代氧化吲哚 (3aa~3bh),收率86%~94%,其结构经1H NMR, 13C NMR和HR-MS(ESI-TOF)表征。 相似文献
10.
目的旨在研究四氧化三铁纳米颗粒在大鼠脑积水模型中的磁共振及CT成像中的应用,为临床应用提供理论依据,为合理开发该纳米颗粒奠定实验基础。方法采用单纯随机分组法将60只分为空白对照组(20只,给予无菌生理盐水注入枕大池)和实验组(40只,利用高岭土制作大鼠脑积水模型,利用MR筛选大鼠脑积水模型,向模型蛛网膜下腔内注入四氧化三铁纳米颗粒,1h后行CT检查,并于1个月后在显微镜下观察空白对照组与实验组四氧化三铁纳米颗粒在脑、心、肝、脾肺、肾等器官蓄积情况。结果 (1)实验组手术和麻醉导致6只大鼠死亡,实验组死亡率15%。对照组死亡率10%。总死亡率为13.3%。(2)实验组32只大鼠形成脑积水,在存活大鼠中模型成功率为88.9%,模型总制作成功率80.0%。(3)四氧化三铁在大鼠椎管磁共振成像中显示欠佳,CT具有较好的对比效果;(4)蛛网膜下腔内注入四氧化三铁纳米颗粒1个月后在脑、肝、脾、肺、肾等器官无明显蓄积。结论椎管内注入超磁性四氧化三铁纳米颗粒是安全可靠的,可以作为脑积水颅脑CT检查的造影剂。 相似文献
11.
12.
水热法可控制备铋铁系化合物材料 总被引:1,自引:3,他引:1
本文以Fe(NO3)3·9H2O和Bi(NO3)3·5H2O为反应原料,以NaOH为矿化剂, 利用水热方法制备出几种纯相的铋铁系化合物材料,通过调节NaOH的浓度范围可以很容易的控制铋铁系化合物的物相。在NaOH浓度为0.1~0.4 mol·L-1区间,可以得到立方相的软铋矿Bi25FeO40,当NaOH浓度提高到0.8~2.0 mol·L-1区间,可以得到六方钙钛矿结构的BiFeO3,再提高NaOH浓度至8.0 mol·L-1以上可以得到正交相的Bi2Fe4O9,在NaOH浓度为12.0 mol·L-1时可以获得纳米片状Bi2Fe4O9。同时探讨了铋铁系化合物的生长机理。 相似文献
13.
As one of efficient analytes, fluorescent microspheres have shown much usability on many biochemical and biomedical processes. Recent applications with fluorescent microspheres have included cytokine quantitation, single nucleotide polymorphism genotyping, phosphorylated protein detection, and characterization of the molecular interaction of nuclear receptors. These,coupled with the rapid advances in molecular biology and synthesis techniques of drugs, have presented a basis for drug screening in a high-throughput format. Based on fluorescent microspheres,earlier assay formats of HTS relied mainly on proximity-dependent energy transfer including scintillation proximity assay (SPA) (Amersham Pharmacia Biotech) and FlashPlatesTM (NEN Life Science Products, Boston, MA). Indeed, drug screening-based such fluorescent emission is still accounting for about 20~50% of current content of high-throughput screening (HTS). Now, SPA is almost a standard technique in common HTS-lab. In literature, SPA microspheres is generally prepared from inorganic scintillators such as yttrium silicate and hydrophobic polymers such as polyvinyl toluene. However, in HTS research, such microspheres often show the disadvantages of strong hydrophobicity and low quantum efficiency. The strong hydrophobicity is mainly attributed to the hydrophobic monomer, vinyl toluene. The low quantum efficiency can be as a result of low transparence of the polymer, polyvinyl toluene. Thus, the subsequent treatments for such microspheres, so as coat a polyhydroxy film to decrease the hydrophobicity, are actually considerably complicated.It has been well known that poly(methyl methacrylate) (PMMA), a good biocompatible polymer with not only adequate mechanical strength but also excellent transparence, can be regarded as an ideal candidate material for fluorescent matrix. In present study, methyl methacrylate as monomer and 2,5-diphenyloxazole (DPO) as fluorescent dye were used to the fluorescent microspheres. In guaranteeing the hydrophilicity of microsphere surfaces, dispersion polymerization was in common use (stabilizer, Polyvinyl pyrrolidone). As is apparent, with such a method in hand, one would normally find that almost no subsequent treatment for microspheres can be involved. Also such a novel fluorescent microspheres is a more suitable and the method used in present research is more practical method in comparison to common method. As the original work, the purposes of this article are to synthesize such fluorescent microspheres and probe the probable roles of synthesis conditions on microsphere synthesis. The effects of stabilizers, initiators, dispersion mediums, monomer content, and reaction temperature on the synthesis process and the particle size, as well as its panicle distribution have been shown. Also the probable role of fluorescent dye in the polymerization has been thermodynamicaily discussed. 相似文献
14.
以非离子型嵌段共聚物为模板剂、正硅酸乙酯为硅源,制备了一种比表面积为712m2·g-1、孔径6.93nm、孔容1.06cm3·g-1、粒径10μm的介孔SBA-15微球,采用扫描电镜考察了各种合成条件对介孔氧化硅微球形貌的影响,对SBA-15介孔微球的合成条件优化和形成机理进行了研究和探讨。结果表明:介孔氧化硅微球的生长可以看作一个由微小溶胶粒子发生渐进聚沉、成长为较大溶胶粒子的过程;共表面活性剂和无机盐的引入对介孔微球的形成具有辅助作用;合成体系的酸度和晶化阶段之前的陈化条件是介孔微球形成的关键所在。在共聚物的盐酸溶液(1mol·L-1)中,不添加共表面活性剂和无机盐,仅控制陈化条件于35℃静置24h,100℃水热处理24h,可得到大粒径的介孔SBA-15微球。 相似文献
15.
16.
超顺磁性高分子微球的制备与表征 总被引:18,自引:2,他引:18
用化学共沉淀方法制备了Fe3O4纳米微粒,并用油酸(十八烯酸)和十二烷基苯磺酸钠为双层表面活性剂进行表面修饰,制备了稳定的水分散性纳米Fe3O4可聚合磁流体.在Fe3O4磁流体存在下,将苯乙烯与甲基丙烯酸通过乳液聚合方法制备了磁性高分子微球.透射电镜研究表明,Fe3O4微粒的平均粒径在10nm左右,乳液聚合形成的磁性高分子微球的粒径平均约为130nm;用超导量子干涉仪对微粒及高分子微球进行了磁性表征,结果表明,合成的Fe3O4纳米微粒以及磁性高分子微球均具有超顺磁性.同时,还用红外光谱及X射线衍射表征了磁性高分子微球的化学成分和晶体结构.用热失重方法测得磁性高分子微球中磁性物质的含量为23.6%. 相似文献
17.
Dr. Ion Bunia Dr. Vlad Socoliuc Dr. Ladislau Vekas Dr. Florica Doroftei Dr. Cristian Varganici Dr. Adina Coroaba Prof. Bogdan C. Simionescu Dr. Marcela Mihai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(50):18036-18044
The preparation of superparamagnetic composites obtained by CaCO3 mineralization from supersaturate aqueous solutions is presented. The preparation was conducted in the presence of oleic acid stabilized magnetite nanoparticles as a water‐based magnetic fluid and insoluble templates as gel‐like cross‐linked polymeric beads. The presence of the magnetic particles in the composites provides a facile way for external manipulation using a permanent magnet, thus allowing the separation and extraction of magnetically modified materials. Two ion exchangers based on divinylbenzene/ethyl acrylate/acrylonitrile cross‐linked copolymer—a cation ion exchanger (CIE) and an amphoteric ion exchanger (AIE)—were used, as well as different addition orders of magnetite and CaCO3 crystals growth precursors. The morphology of the composites was investigated by SEM, the polymorphs content by X‐ray diffraction, and the thermal stability by thermogravimetric analysis. Polymer, CaCO3, and magnetite in the composite particles were shown to be present by energy dispersive X‐ray (EDX), XPS, and TEM. The sorption capacity for CuII ions was tested, as compared to samples prepared without magnetite. 相似文献
18.
Oxide microspheres in the system Al2O3-ZrO2 (AZ), with the Al2O3:ZrO2 molar ratios as 87:13, 78:22, 74:26 and 64:36 were obtained from emulsified bi-component sols by the sol-emulsion-gel method. The surfactant concentration and viscosity of the sols were found to affect the characteristics of the derived microspheres. The gel and calcined microspheres were investigated by using thermogravimetry analysis (TGA), differential thermal analysis (DTA), X-ray diffraction (XRD), optical and scanning electron microscopy (SEM) and particle size analysis. TGA indicated the removal of most of the volatiles, i.e. 40 ± 2 wt% up to about 500°C. Crystallization of gel microspheres at about 900°C was confirmed by DTA and XRD. XRD results also indicated the retainment of tetragonal (t-)ZrO2, in the absence of stabilizers, at 1600°C. The optical and scanning electron microscopy confirmed the spherical morphology of the gel and calcined particles. The particle size distribution of the AZ microspheres calcined at 1200°C for 1 h exhibited a size range of 5–60 m with the average particle size (d
50) varied from 23 to 26 m. 相似文献
19.
以稀土硝酸盐-葡萄糖的混合溶液作为前驱体,采用一步水热法和随后的热处理得到了多层核壳结构Gd_2O_3:Eu~(3+)空心微球,并用X-射线衍射(XRD)、场发射扫描电镜(FESEM)、透射电镜(TEM)、X-射线能量色散光谱(EDS)和荧光光谱等测试手段对所得样品进行了表征.结果表明:所得空心球样品为纯的立方相的Gd_2O_3.具有规则的多层核壳空心结构,空心球的直径在2~3μm左右,壁厚约为100 nml,并且Gd_2O_3:Eu~(3+)空心球是由尺寸约为30 nm的球形纳米颗粒白组装而成.样品中含有Gd、Eu、O元素.该空心球样品具有强的Eu~(3+)的特征红光发射以及长的荧光寿命,可以用来作为时间分辨荧光标记物. 相似文献