磁性纳米TiO_2粉体的制备

使用自制的高强度机械搅拌反应器,通过两种不同的方案制备了磁性纳米TiO_2粉体。通过X射线衍射图谱对其晶体结构进行分析,透射电镜观测纳米粒子的粒径和分散性,VSM图比较它们的磁性能。结果表明：在本实验条件下,将Fe_3O_4混合于氨水溶液中,与Ticl,溶液反应后通过冷冻干燥的方法得到的磁性纳米TiO_2粉体纯度高,粉体分散性好,粒径分布范围窄,并且具有较好的超顺磁性。     

利用稀土镝对Fe3O4纳米磁粒子改性的研究

采用湿化学法制备了稀土镝铁氧体纳米磁粒子,并用月桂酸进行了表面修饰。利用透射电子显微镜（TEM）、X射线衍射仪（XRD）、振动样品磁强计（VSM）等仪器对产物进行表征,研究Dy3＋的掺杂对Fe3O4纳米磁粒子磁性能的影响;同时对镝铁氧体磁粒子形貌、粒径分布、晶型结构进行了分析。结果表明,用适量的稀土Dy3＋对Fe3O4纳米磁粒子进行掺杂,可以显著地提高其磁性能,且晶型结构不变;制备的镝铁氧体磁粒子的平均粒径约13.2nm,表面修饰后的磁粒子室温下的饱和磁化强度为189.4mT,具有超顺磁性。     

纳米铜粒子的表面聚合物修饰

为解决纳米铜粒子团聚问题，扩大其应用范围，采用微胶囊技术制备尿素－甲醛纳米铜微胶囊，形成核壳结构来提高铜纳米粒子的分散性，是比较有效的方法.样品的红外、x-射线衍射、SEM、TEM测试、分散性研究结果表明：微胶囊试样的壁材为脲醛树脂，囊芯为纳米铜，试样尺寸在500 nm左右；微胶囊修饰的纳米铜在水中的分散性较在其他溶剂中要好；纳米铜微胶囊在各种溶剂中的分散性要好于纯纳米铜；表面聚合物修饰的纳米铜能分散在极性溶剂中.     

负载纳米TiO2、Ag复合微胶囊光催化性能的研究

以纳米Ag粒子掺杂光催化剂TiO2,采用原位聚合法成功制备负载纳米TiO2/Ag的复合微胶囊;利用扫描电子显微镜、紫外-可见吸收光谱等测试手段对其形貌和光谱性质进行了表征,探讨不同纳米TiO2、Ag加入量的微胶囊在不同光催化时间下对亚甲基蓝光催化效果的影响.结果表明:纳米Ag(1.94%)掺杂TiO(22.78%)的复合微胶囊对亚甲基蓝具有最大脱色率为10.82%,单独添加纳米TiO2和单独添加纳米Ag粒子的微胶囊样品与常规微胶囊比较没有显著差异.     

磁性二氧化硅纳米粒子的制备及性能

为了克服磁性四氧化三铁纳米粒子易团聚、易氧化、耐酸性差等缺点,提高其在催化剂、靶向药物载体、生物分离、核磁共振成像、磁热疗等领域的利用效率,采用共沉淀法合成了四氧化三铁纳米粒子,然后以其为核用Stber法制备出二氧化硅包覆四氧化三铁的复合纳米粒子. 对包覆前及包覆后的磁性纳米粒子分别进行了X射线衍射、透射电子显微镜、振动样品磁强计的表征,并研究了二氧化硅的包覆对四氧化三铁纳米粒子磁性和耐酸性的影响. 实验结果表明:磁性四氧化三铁及磁性二氧化硅纳米粒子的粒径分别为约20 nm和40 nm;磁性四氧化三铁的磁饱和强度为5.7 emu/g,磁性二氧化硅纳米粒子的磁饱和强度也达到5.1 emu/g;此外,在稍微降低磁性的条件下,表面二氧化硅的包覆显著改善了四氧化三铁纳米粒子的分散性和耐酸性.     

ZnFe_2O_4纳米粒子的制备及其磁性能

以乙酰丙酮铁和乙酰丙酮锌为原料、三甘醇为溶剂,采用一步法制备ZnFe2O4纳米粒子。通过透射电子显微镜(TEM)、X-射线粉末衍射仪(XRD)和磁性能测量系统(MPMS)等表征手段对ZnFe2O4纳米粒子进行了表征。结果表明,所制备的ZnFe2O4纳米粒子平均粒径约为6 nm,尺寸均匀,水溶性良好,在室温条件下呈现超顺磁性。     

Fe_3O_4/AuNPs磁性复合粒子的制备与表征

通过溶剂热法合成了较大粒径的磁性Fe3O4纳米粒子,使用3-氨丙基三乙氧基硅烷(APTES)在乙醇/异丙醇体系中将其表面功能化一层氨基,随后将金纳米粒子(Au NPs)自组装于Fe3O4粒子表面,得到了Fe3O4/Au NPs纳米粒子;采用透射电子显微镜(TEM)、X-射线衍射(XRD)、振动样品磁强计(VSM)和紫外-可见光吸收光谱仪(UV-Vis)对复合粒子的形态、结构及性质进行表征.结果表明:所制备的Fe3O4磁纳米粒子粒径均一,平均粒径约为250 nm,形状几乎都呈球形,磁性Fe3O4/Au NPs复合粒子包覆均匀、具有良好的的分散性和磁化率,同时兼有磁性和金纳米粒子的特性.     

介晶结构四氧化三铁纳米粒子的一种简易合成方法

采用氯化铁、氢氧化钠和少量水在乙二醇中进行常压加热反应得到了尺寸可控、形貌均匀的介晶结构四氧化三铁纳米粒子。所得纳米粒子饱和磁化强度为72.6 emu·g~(-1),既具有超顺磁性,又表现快速的磁响应特性。体系中少量水分的存在十分重要,没有水的参与反应不能进行。随着水加入量的增加,所得纳米粒子的尺寸逐渐变小。     

复合磁性纳米粒子的合成和特性研究

通过在磁性纳米粒子表面修饰柠檬酸得到了分散性良好的水基磁流体,为了研究磁性纳米粒子在生物医药上的应用,通过Stober法合成了Fe3O4/SiO2复合粒子。透射电镜(TEM)和红外光谱仪(IR)研究表明,SiO2成功地包裹在Fe3O4粒子表面,且复合粒子的分散性好,粒径均匀。振动样品磁强计测试表明磁性复合粒子仍然具有较强磁性。     

免疫磁性微球的制备及对IgG的分离

采用反相悬浮包埋法制备SPA-Sepharose免疫磁性微球,并对产物的结构、粒径、磁性能进行了表征,所得产物粒径大约为5μm,表面包裹葡萄球菌蛋白A(Staphylococcal Protein A,简称SPA),分散性较好,具有超顺磁性。利用SPA对免疫球蛋白G(IgG)的特异性吸附反应及磁性微球的超顺磁性,从猪血清中分离IgG,试验结果表明:SPA免疫磁性微球对猪血清的最大吸附效率是70.12%,可反复使用29次。     

四氧化三铁磁流体的制备及性能分析

采用化学共沉淀法制备了Fe3O4磁流体。以阴离子表面活性剂油酸钠对磁性颗粒进行包覆,分析了pH值、温度和Fe2＋/Fe3＋比例等制备条件对Fe3O4磁流体的影响。运用磁天平、粒度测试仪对磁流体的粒径和磁化率进行了测定,并用傅里叶变换红外光谱仪（FT-IR）、透射电子显微镜（TEM）和振动样品磁强计（VSM）等对磁流体进行了表征。实验和分析结果表明,所制备的磁流体具有超顺磁性,粒径约为16 nm,饱和磁化强度在73.8 emu/g以上。     

Interaction mechanism between carboxylmethyl cellulose and iron ore concentrates in iron ore agglomeration

Carboxylmethyl cellulose(CMC) has become a commercial organic binder in agglomeration of iron ore concentrates. The relative molecular mass and degree of substitution(DS) of CMC have a large impact on its binding performance. The interaction mechanism between CMC and iron ore particles was analyzed through Zeta potential measurements, adsorption measurements and infrared spectra. The results show that the interaction is chemical adsorption-oriented and the CMC's adsorption performance is related to the properties of CMC as well as the type of iron oxides. CMC has a greater affinity to Fe2O3 than Fe3O4, and CMC with higher relative molecular mass shows a higher adsorption isotherm. Pelletization of practical iron ore concentrates added with CMC further illustrates that CMC with higher relative molecular mass or DS exhibits a better binding performance, which is consistent with the results of adsorption tests.     

Structure and Properties of BaFe12O19 Coated Fly Ash Cenospheres by Sol-Gel Process

1 IntroductionFly ash cenospheres are generated in large amountsas a by-product in thermal power plants and pose majordisposal problems . Fly ash cenosphere particles areunique, property stable , non-toxic , non-metallic hollowmicro-particles . Due to the unique hollowstructure andphysical mechanics properties ,fly ash cenosphere parti-cles have been dispersed in different matrices ,such aspolyester resins ,cement ,and nickel for producing com-posite materialsinthe bulkand coatingformsfor a va…     

热疗用磁流体的热磁稳定性研究

采用两步法制备了环糊精(β-Cyclodextrin)改性纳米四氧化三铁(Fe3O4)磁流体.通过在交变磁场下感应加热对其磁热稳定性进行了研究,在交变磁场下加热后悬浮裸磁颗粒或改性颗粒的磁性液体最高升温分别达到63℃和53℃,感应加热实验结果表明所制磁流体可用于肿瘤的热疗研究.     

纳米磁性膨润土复合材料表征及降解甲基橙研究

以纯化膨润土为原料,通过铁盐与膨润土浆液反应制备非均相纳米磁改性Fe3O4/膨润土复合材料,研究其对甲基橙的降解性能。结果表明,纳米磁性颗粒以Fe3O4附载于膨润土上形成磁性集合体,其对甲基橙废水等温吸附符合Langmuir等温吸附模型。在pH为7、温度为25℃、纳米磁性膨润土投加量为1g/L、H2O2投加量为2.5mmol/L、降解时间为120min条件下,对模拟甲基橙废水降解率达96%,CODCr去除率为94.7%,色度去除率为88.8%。     

氨基功能化纳米Fe_3O_4的制备及在痕量Pb(II)分析中的应用研究

采用一步法合成出氨基功能化Fe3O4纳米粒子,并借助XRD、FT-IR、等对产品进行表征。所制备的氨基化纳米Fe3O4材料粒径在100nm左右,大小分布均匀,分散性较好。提出一种新的方法,氨基化纳米Fe3O4分离富集与火焰原子吸收光谱法联用测定水样中痕量Pb(II),考察该纳米材料对水溶液中痕量Pb(II)的分离富集性能。结果表明:在pH为7、T=303.15K的条件下,氨基化Fe3O4纳米材料对Pb(II)离子的吸附率可达98%。该方法的检出限(3σ)为0.17μg·mL-1(n=11),相对标准偏差(RSD)为2.02%(n=6)。     

Characteristics of magnetic Fe3O4 nanoparticles encapsulated with human serum albumin

Magnetic nanoparticles （Fe304） were prepared by chemical precipitation method using Fe^2＋ and Fe^3＋ salts with sodium hydroxide in the nitrogen atmosphere. Fe3O4 nanoparticles were coated with human serum albumin（HSA） for magnetic resonance imaging as contrast agent. Characteristics of magnetic particles coated or uncoated were carried out using scanning electron microscopy and X-ray diffraction. Zeta potentials, package effects and distributions of colloid particles were measured to confirm the attachment of HSA on magnetic particles. Effects of Fe3O4 nanoparticles coated with HSA on magnetic resonance imaging were investigated with rats. The experimental results show that the adsorption of HSA on magnetic particles is very favorable to dispersing of magnetic Fe3O4 particles, while the sizes of Fe3O4 particles coated are related to the molar ratio of Fe3O4 to HSA. The diameters of the majority of particles coated are less than 100 nm. Fe3O4 nanoparticle coated with HSA has a good biocompatibility and low toxicity. This new contrast agent has some effects on the nuclear magnetic resonance imaging of liver and the lowest dosage is 20μmol/kg for the demands of diagnosis.     

Separation of hematite from banded hematite jasper(BHJ) by magnetic coating

The separation of iron oxide from banded hematite jasper(BHJ) assaying 47.8% Fe, 25.6% Si O2 and 2.30%Al2O3 using selective magnetic coating was studied. Characterization studies of the low grade ore indicate that besides hematite and goethite,jasper, a microcrystalline form of quartzite, is the major impurity associated with this ore. Beneficiation by conventional magnetic separation technique could yield a magnetic concentrate containing 60.8% Fe with 51% Fe recovery. In order to enhance the recovery of the iron oxide minerals, fine magnetite, colloidal magnetite and oleate colloidal magnetite were used as the coating material. When subjected to magnetic separation, the coated ore produces an iron concentrate containing 60.2% Fe with an enhanced recovery of56%. The AFM studies indicate that the coagulation of hematite particles with the oleate colloidal magnetite facilitates the higher recovery of iron particles from the low grade BHJ iron ore under appropriate conditions.     

Application of polymerizable surfactant in the preparation of polystyrene/nano-Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> composite

Monooctadecyl maleate, as a polymerizable surfactant, was synthesized by the mono-esterification of maleic anhydride and octadecanol, and was utilized to surface-modify nano-Fe₃O₄ particles. A polymerizable magnetic fluid was obtained by directly dispersing modified nano-Fe₃O₄ particles into styrene monomer, and the polystyrene/nano-Fe₃O₄ composite was prepared through free radical polymerization of polymerizable magnetic fluid. The structure and dispersion status in different dispersion phases of modified nano-Fe₃O₄ particles were studied by Fourier transform infrared (FTIR) spectrometry, X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The experimental results show that the nano-Fe₃O₄ particles modified by monooctadecyl maleate with the size of about 7–10 nm can be uniformly dispersed into styrene and fixed in the composite during the procedure of polymerization. Thermogravimetric analysis (TGA) and vibrating sample magnetometry (VSM) indicate that the thermal stability of polystyrene/nano-Fe₃O₄ composite is improved compared to that of pure polystyrene, and the composite is a sort of superparamagnetic materials.     

羧甲基纤维素钠作用下CaCO3微球的制备及表征

为获得粒径均匀、表面光滑的CaCO3微粒,研究羧甲基纤维素钠(CMC)作用下CaCO3微球的制备及性能表征.考察CMC质量浓度、搅拌速度、沉积反应温度对CaCO3粒子形貌的影响,确定合成CaCO3微球的较优实验条件,并用粒度分析仪、X射线衍射仪(XRD)、热重分析仪(TGA)、Zeta电位仪对性能进行表征,提出CMC作用下CaCO3微球生长机理.结果表明CMC质量浓度ρ(CMC)为0.5g/L时可得到表面光滑的球文石型CaCO3,粒径分布在6～8μm,CMC的质量分数w(CMC)为5.12%,表面电位为-37.3mV.这种形态的颗粒可适用于生物、医药等领域.