磁性纳米ZnxCo1-xFe2O4空心微球的制备

用超声溶剂热法制备了磁性纳米ZnxCo1-xFe2O4空心微球,采用X射线衍射仪(XRD)和透射电子显微镜(TEM)对其结构和形貌进行了表征。结果表明,所制备的ZnxCo1-xFe2O4空心微球均为标准的立方结构,说明锌的掺杂并不影响产物的晶型,但对产物的粒径影响较大。所制备的CoFe2O4空心微球的平均粒径为50 nm左右,但Zn0.5Co0.5Fe2O4空心微球的平均粒径为200 nm左右;用振动样品磁强计(VSM)以及网络矢量分析仪测试了微球的磁性能和吸波性能,结果显示,微球的饱和磁化强度随锌含量的增加先略微增大后减小,而矫顽力随锌含量的增加单调递减。当x=0.3时微球的磁性和吸波性能都为最佳。     

钴铁氧体空心微球的模板法制备及其性能研究

用聚苯乙烯球作模板,硝酸铁和硝酸钴为起始反应试剂,通过沉积与表面反应法合成了CoFe2O4空心微球。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)对样品的结构和形貌进行了表征。结果表明,所制备的CoFe2O4空心微球为立方结晶石结构,其直径约为2.5μm,是由纳米颗粒组装而成。用振动样品磁强剂计(VSM)和网络矢量分析仪分别对该样品以及本实验室制得的CoFe2O4粉体的室温磁性和吸波性能进行了研究。结果表明,CoFe2O4空心微球比粉体的磁性和吸波性更好。其中,CoFe2O4空心微球的矫顽力达到182.70Oe;频率为6000MHz波段附近有1个明显的吸收峰,回损值大于-18db,并有继续增大的趋势。     

氧化铈空心微球的制备及表征

通过聚合物模板法和高温煅烧法制备了氧化铈空心微球,并考察了其光催化性能。采用透射电镜(TEM)和扫描电镜(SEM)研究氧化铈空心微球的尺寸和微观形貌,通过傅立叶转换红外线光谱(FTIR),X射线衍射(XRD)和比表面积(BET)表征空心微球、晶型结构、比表面积。结果表明,以粒径为220nm的聚苯乙烯微球可以制得球径约为220nm的CeO_2空心微球。壳层厚度约为20nm。在模拟可见光的条件下,氧化铈空心微球对罗丹名B的降解率在3h内可达到95%以上,表现出优异的光催化降解性能。     

单分散中空聚苯乙烯微球制备

采用搅拌乳化方法制备水包油(W1/O)型乳状液,经膜乳化法制得单分散的复乳(W1/O/W2)型乳状液,再通过液中干燥法制得单分散中空聚苯乙烯(PS)微球.考察了shirasu porous glass(SPG)膜孔径对乳状液液滴粒径及粒径分布、表面活性剂浓度对PS微球中空率和单分散性的影响.由激光粒度分析仪结果及PS微球的SEM照片证实,制得的PS微球,粒径呈单分散,是SPG膜孔径的2.0～2.4倍且具有中空结构.     

Fe_3O_4/聚苯乙烯-丙烯酸磁性微球的制备与表征

在Fe3O4磁流体存在下进行双层表面活性剂改性,采用改进的乳液聚合法制备了以苯乙烯和丙烯酸的共聚物为壳的磁性高分子微球。在扫描电镜下观察磁性微球的粒径为250nm左右;通过红外光谱(FT-IR)、XRD、热重分析等手段表征了磁性微球的组成成分、结构的变化以及Fe3O4磁性含量。实验表明,在优化的实验条件下,可以制得磁含量高达32%的磁性复合微球。     

P(St-co-AA)与 Fe3O4纳米粒自组装制备高分子磁微球

用微乳液聚合法制备了粒径均匀的聚苯乙烯-丙烯酸高分子微球P(St-co-AA),与共沉淀法所制纳米Fe3O4通过静电作用,使两种微球自组装成高磁含量的磁性微球[Fe3O4/P(St-co-AA)].采用XRD、TEM、SEM、IR等对样品进行表征,采用VSM对样品进行磁性能测试.结果表明P(St-co-AA)平均粒径约为70nm,表面含有羧基;所得磁粉为Fe3O4单相,平均粒径约为10nm.磁性能测试表明,当外加磁场为1.5×106/π(A/m)时,磁化强度达到饱和,饱和磁化强度为69A·m2·kg-1;自组装所制高分子磁性微球为球形,平均粒径约800nm,磁粉含量为15.8%.研究表明,pH值、搅拌等对复合磁性微球的形成有重要影响.     

CuFe2O4/海泡石磁性吸附剂的制备及性能

以硫酸铜、氯化铁为主要原料,采用化学共沉淀法制备CuFe2O4纳米磁性微粒,然后将其与海泡石复合制得CuFe2O4载量不同(质量分数,下同)的磁性海泡石.分别用X射线衍射(XRD)、透射电子显微镜(TEM)、振动样品磁强计(VSM)对样品的物相、形貌、磁学性能进行了表征.结果表明,合成的CuFe2O4结晶度高,晶粒度约...     

M~ⅡFe_2O_4(M=Fe,Ni)纳米空心微球的合成和磁性能(英文)

以气泡为模板,通过简单的一步水热法合成了尖晶石型MⅡFe2O4(M=Fe,Ni)纳米空心微球,并采用柠檬酸对其表面进行了修饰。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、红外光谱(IR)和振动样品磁强计(VSM)对修饰前后纳米空心微球的形貌、结构和磁性能进行了表征。结果表明,MⅡFe2O4(M=Fe,Ni)纳米空心微球的尺寸在300～600nm,前躯体溶液的pH值大于9或反应时间小于12h都不能生成空心结构。此外,MⅡFe2O4(M=Fe,Ni)纳米空心微球呈现较好的超顺磁性,但与纳米Fe3O4实心微粒相比较,Fe3O4纳米空心微球的饱和磁化强度却有所降低。     

MⅡFe2O4（M=Fe,Ni）纳米空心微球的合成和磁性能（英文）

以气泡为模板,通过简单的一步水热法合成了尖晶石型MⅡFe2O4(M=Fe,Ni)纳米空心微球,并采用柠檬酸对其表面进行了修饰。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、红外光谱(IR)和振动样品磁强计(VSM)对修饰前后纳米空心微球的形貌、结构和磁性能进行了表征。结果表明,MⅡFe2O4(M=Fe,Ni)纳米空心微球的尺寸在300～600nm,前躯体溶液的pH值大于9或反应时间小于12h都不能生成空心结构。此外,MⅡFe2O4(M=Fe,Ni)纳米空心微球呈现较好的超顺磁性,但与纳米Fe3O4实心微粒相比较,Fe3O4纳米空心微球的饱和磁化强度却有所降低。     

相反转工艺制备Fe_3O_4/P(St-BA)复合微球的研究

采用共沉淀法制备了油酸修饰的Fe3O4纳米粒子,并采用相反转工艺制备了Fe3O4/P(St-BA)复合微球。用透射电镜(TEM)和热失重(TGA)方法表征了Fe3O4纳米粒子、Fe3O4/P(St-BA)复合微球的形貌和Fe3O4含量。TEM显示大部分Fe3O4粒子被包覆在复合微球内部,同时有部分Fe3O4粒子嵌在微球表面。研究表明:Fe3O4/P(St-BA)复合微球具有良好的磁响应性,油酸量为0.4g修饰的Fe3O4粒子在混合单体中分散效果好。粒度测试结果显示转相水体系中聚乙烯醇和十二烷基硫酸钠复配制备的微球粒径较小且分布较窄;转相过程提高转速微球平均粒径变小,粒度分布变窄。     

Large-scale fabrication of H2(H2O)Nb2O6 and Nb2O5 hollow microspheres

Hollow micro-sized H₂(H₂O)Nb₂O₆ spheres constructed by nanocrystallites have been successfully synthesized via a bubble-template assisted hydrothermal process. In the reaction process, H₂O₂ acts as a bubble generator and plays a key role in the formation of the hollow structure. An in situ bubble-template mechanism has been proposed for the possible formation of the hollow structure. The spherelike assemblies of these H₂(H₂O)Nb₂O₆ nanoparticles have been transformed into their corresponding pseudohexagonal phase Nb₂O₅ through a moderate annealing dehydration process without destroying the hierarchical structure. Optical properties of the as-prepared hollow spheres were investigated. It is exciting that the absorption edge of the hollow Nb₂O₅ microspheres shifts about 18 nm to the violet compared with bulk powders in the UV/vis spectra, indicating its superior optical properties.     

水热法合成α-氧化铝空心微球

以葡萄糖和硝酸铝为原料,采用水热法合成大小及壁厚可控的α-氧化铝空心微球。通过扫描电子显微镜(SEM)、傅立叶红外光谱分析仪(FT-IR)、X射线衍射(XRD)、热分析(TG-DSC)等手段对合成产品进行表征。结果表明:得到的氧化铝空心微球分散性较好,可通过调节加入的葡萄糖浓度及硝酸铝量,得到大小及壁厚不同的氧化铝空心球,烧结温度对微球粒径大小影响不大,当烧结温度上升900℃时,壳层结构由不定形态变为γ-Al2O3,当烧结温度上升到1 100℃时,可得到α-Al2O3氧化铝空心微球。     

以PSA-A乳胶粒为模板批量制备TiO2空心球

以表面富载马来酸羧基的聚(苯乙烯-丙烯酸酯)阴离子(PSA-A)乳胶粒为模板,硫酸钛为原料,水为分散介质,制备了PSA-A/钛水解产物核壳微球,然后在空气中适当温度下煅烧得到粒径约为450nm的TiO2空心球壳,用TG、SEM、TEM、IR和XRD对样品进行了分析表征,并研究了核壳结构形成的过程和各实验条件对陈化过程中体系pH值变化速率的影响.得出影响核壳结构的关键因素为体系的pH值变化速率,以此依据设计出钛盐浓度为1mol/L,乳胶粒浓度为230g/L的高浓度条件下批量制备TiO2空心球壳的新实验方案,最终产物保持良好的空心球结构.     

In2O3 hollow spheres: One-step solvothermal synthesis and gas sensing properties

Hollow In₂O₃ spheres were prepared via a P123-assisted one-step solvothermal process for the first time. Ethanol medium played a key role in the direct cubic In₂O₃ phase formation whereas the triblock copolymer acted as a structure directing agent in the formation of the hollow spheres. The gas sensing properties of the as-prepared In₂O₃ hollow spheres were investigated. Compared to the products synthesized without P123, the In₂O₃ hollow spheres exhibited much faster response and higher sensitivity toward HCHO vapor.     

Synthesis and characterization of Co3O4 hollow spheres

Co₃O₄ hollow spheres were hydrothermally prepared at 130 °C for 16 h in the presence of Poly-vinylpyrrolidone (PVP). The as-prepared products were characterized by powder X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), infrared spectrum (IR), X-ray photoelectron spectrum (XPS), and optical absorption spectrum. PVP surfactant plays important roles in the formation of Co₃O₄ hollow spheres. These Co₃O₄ hollow spheres have average diameters of ca. 350 nm, and the wall thickness around the shell is about 42 nm. The possible formation mechanism of hollow Co₃O₄ spherical structures has simply been proposed.     

四方排列有序Ag/TiO2空心微球的制备及光催化性能

采用低温垂直沉积法制备了聚苯乙烯(PS)胶体模板,由于低温下粒子热运动受到抑制,排列时发生位错,因此模板中存在大面积四方排列结构。然后采用化学镀法、溶胶-凝胶法在PS微球表面依次沉积银纳米粒子、纳米TiO2,最后高温煅烧除去模板制备了四方排列有序Ag/TiO2空心微球。通过扫描电镜(SEM)、X射线衍射(XRD)对样品进行表征。结果表明这种材料很好地保持了模板的四方排列,具有高度有序的纳米结构。选择降解甲基橙溶液来检验样品的光催化性能,并与纳米TiO2薄膜、四方排列TiO2空心微球的光催化性能进行比较,结果表明四方排列Ag/TiO2空心微球具有最佳的光催化性能。这是有序空心纳米结构和银纳米粒子的沉积共同作用的结果。     

Template-free fabrication of TiO2 hollow spheres and their photocatalytic properties

Submicrometer-sized anatase TiO(2) hollow spheres were fabricated through a template-free solvothermal route using TiCl(4) as a raw material and a mixture of alcohols-acetone as solvent. Control of the hollow spheres' size was achieved by adjusting the ratio of alcohols to acetone. Products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution TEM, X-ray photoelectron spectra (XPS), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), and thermogravimetric (TG) analysis. It was found that the formation process of the TiO(2) hollow spheres might include the hydrolysis of Ti(IV) with the water formed from the solvothermal etherification reaction, the aggregation of the anatase TiO(2) nanoparticles, and the Ostwald ripening. Furthermore, the as-prepared TiO(2) hollow nanostructures exhibited good photocatalytic activity for the degradation of phenol.     

High-yield room temperature route to copper sulfide hollow nanospheres and their electrochemical properties

CuS hollow nanospheres have been successfully synthesized in high yield by reacting anhydrous cupric sulfate (CuSO(4)·5H(2)O) with thioacetamide (TAA) in ethylene glycol (EG) with the assistance of cetyltrimethylammonium bromide (CTAB). The products were characterized systematically by XRD, EDX, FESEM, TEM and BET measurement and size analysis, CV, LSV and CP. FESEM and TEM images revealed that the as-prepared CuS hollow nanospheres had a mean diameter of about 500 nm with a hollow cavity of about 340 nm and shell thickness of about 80 nm. The spheres were constructed by numerous nanoflakes. The Brunauer-Emmett-Teller (BET) surface area of the as-synthesized products was measured to be 99.77 m(2)g(-1). The Barrett-Joyner-Halenda (BJH) model analysis showed that the as-prepared CuS materials had a main pore size distribution of around 25 nm. CV curves, LSV of CuS for oxygen electroreduction and CP curves showed that the as-prepared CuS nanospheres were potential candidates which can be used as cathode catalysts for the oxygen reduction reaction (ORR) in alkaline media.     

以PSA-A乳胶粒为模板批量制备TiO2空心球

以表面富载马来酸羧基的聚（苯乙烯-丙烯酸酯）阴离子（PSA-A）乳胶粒为模板,硫酸钛为原料,水为分散介质,制备了PSA-A/钛水解产物核壳微球,然后在空气中适当温度下煅烧得到粒径约为450nm的TiO2空心球壳,用TG、SEM、TEM、IR和XRD对样品进行了分析表征,并研究了核壳结构形成的过程和各实验条件对陈化过程中体系pH值变化速率的影响.得出影响核壳结构的关键因素为体系的pH值变化速率,以此依据设计出钛盐浓度为1mol/L,乳胶粒浓度为230g/L的高浓度条件下批量制备TiO2空心球壳的新实验方案,最终产物保持良好的空心球结构.     

CuFe2O4活化过一硫酸盐降解四环素

采用水热合成法制备出了一种具有较高催化活性的催化剂CuFe2O4,并利用CuFe2O4活化过一硫酸盐(PMS)处理模拟抗生素废水盐酸四环素(TC),考察了操作条件初始pH、CuFe2O4投加量和PMS投加量对TC降解效果的影响。结果表明,初始pH在2~10的范围内,随初始pH的升高TC的降解率先稳定而后逐渐降低;TC的降解速率随着PMS投加量和CuFe2O4投加量的增加而逐渐增加。在CuFe2O4/PMS体系中存在活性物种·OH、SO4·-和1O2。在催化剂循环使用实验中,CuFe2O4展现出了较好的重复利用性能。在CuFe2O4/PMS体系中,TC降解出水对发光菌的抑制率先升高而后逐渐降低,也说明CuFe2O4/PMS体系对降解TC是一种有效的方法。