联氨还原法制备磁性钴纳米粒子

在表面活性剂聚乙烯吡咯烷酮(PVP)的保护下,采用水合肼于乙醇体系中还原CoCl2·6H2O而得到磁性钴纳米粒子,通过X射线衍射检验确认该种方法合成的钴纳米粒子同时具有hcp相和fcc相.X射线光电子能谱的表征结果显示钴粒子表面价态为零价,说明制备过程中没有被氧化.用透射电镜和激光光散射仪对粒子的表面形貌和粒径进行了表征分析,结果显示粒径在30nm左右,近似圆球形,在正己烷中分散效果较好.     

Ag@SiO2复合纳米粒子的光化学还原法制备及表征

采用光化学还原法在大颗粒负载型SiO2表面上成功制备了负载型Ag@SiO2复合纳米粒子,利用透射电子显微镜、X射线衍射和紫外-可见分光光度计等分析方法对样品进行了表征.结果表明,球形银纳米粒子均匀分散于球形SiO2复合粒子表面,复合粒子粒径在150～180 nm,且颗粒均一、分散性好.银粒子的粒径在10～15 nm,样品中银粒子具有良好的面心立方结构,晶型很好,银粒子的等离子共振吸收的最大峰位于474 nm.     

液相共沉淀法制备铁酸锰纳米粉

以六水合氯化铁和四水合氯化锰为原料，氢氧化钠为沉淀剂，采用液相共沉淀法制备出了纳米级铁酸锰颗粒，通过X射线衍射（XRD）分析，证实了该产物的主要成分为具有尖晶石结构的铁酸锰颗粒；通过HRTEM研究表明，由该法所制备得到的纳米铁酸锰粒子主要呈椭球形，粒径分布较窄，平均粒径在5－10nm。     

基于纳米零价铁的类芬顿体系降解土霉素的研究

通过FeSO_4与NaBH_4在碱性条件下反应,制备纳米零价铁颗粒。X射线衍射表明产物是α-Fe~0,扫描电子显微镜得到纳米零价铁的粒径大约为20nm,氮吸附比表面积为19.607m~2·g~(-1),等电点为7.2。研究该纳米零价铁对水溶液中的土霉素的去除作用,发现纳米零价铁的投加量、土霉素初始浓度和溶液的pH值均对其去除效果产生影响。在纳米零价铁投加量为1.0g·L~(-1),pH值为6.5的条件下,在4h内将质量浓度为100mg·L~(-1)的土霉素基本完全降解,去除率为98.8%。该研究结果表明,纳米零价铁对水溶液中的土霉素有很好的去除效果。     

Au-SiO2复合纳米微球的制备与表征

采用溶胶-凝胶法制备SiO2纳米微球,以KH-550为粘结剂,利用简单的化学还原法,成功制备出Au-SiO2复合纳米微球,并通过扫描电子显微镜,透射电子显微镜,X射线衍射仪,紫外-可见分光光度计和多功能成像光电子能谱仪对其进行表征.结果表明,Au-SiO2复合纳米微球粒径约130 ～ 160 nm,且颗粒较均匀、分散性较好.样品中金纳米粒子均匀分散于SiO2纳米微球表面,粒径约4～9 nm,具有良好的面心立方结构,晶型良好,且Au物种主要以零价金属态存在.     

中国建平地区膨润土中的方石英赋存状态

对膨润土进行分散、离心分级,并对产物进行透射电镜和X射线衍射分析,研究了辽宁省建平地区典型火山岩型膨润土中方石英的赋存状态。结果表明:膨润土中的方石英包括α方石英、C型和CT型蛋白石。随膨润土颗粒粒径减小,独立α方石英含量先增加后减少,蛋白石中α方石英晶畴含量则先减少后增加。粗颗粒和细颗粒膨润土中的蛋白石为C型蛋白石,中颗粒膨润土中的蛋白石为CT型蛋白石。α方石英平均晶粒粒径约为17nm,蛋白石平均晶粒粒径约为20nm。膨润土原样中,部分方石英独立分布,但大部分吸附于蒙脱石颗粒表面及边缘或被蒙脱石包裹,团聚严重;经分散处理后,方石英与蒙脱石之间的团聚有所改善。粗颗粒的膨润土中,方石英相互吸附,团聚成较大颗粒,与蒙脱石团聚较少;随着膨润土颗粒粒径减小,方石英与蒙脱石间吸附加重;当颗粒粒径进一步减小时,方石英与蒙脱石间吸附有所减轻。     

铁钴纳米合金/天然橡胶复合材料的制备及性能研究

采用液相还原法制备铁钴合金纳米粒子（nano-FeCo）,通过不同的制备工艺与天然胶乳共混,制备铁钴纳米合金/天然橡胶复合材料（NR/nano-FeCo）。利用X射线衍射仪（XRD）和透射电子显微镜（TEM）对样品结构进行表征。并考察了复合材料的力学性能及不同制备工艺对复合材料性能的影响。结果表明,液相还原法制备的nano-FeCo粒子为无定形结构,粒径约为70 nm。在天然橡胶（NR）基体中分散均匀,分散相粒径在100 nm左右;随着纳米粒子的加入,有效地提高了复合材料的力学性能,同时,可提高NR的热老化性能。NR/nano-FeCo的最佳制备工艺是乳液共混法。     

不同pH环境下CMS改性纳米铁在异质多孔介质中的迁移

纳米铁在污染土壤和地下水的修复中受到广泛关注。为进一步探究其在多孔介质的迁移行为,本研究采用羧甲基淀粉钠（CMS）对纳米零价铁（nZVI）进行包覆,进行了改性纳米零价铁的沉降试验,测量zeta电位与粒径分布探究其分散性;进行了不同pH条件下改性纳米零价铁在酸洗砂与水洗砂的柱实验,分析了化学异质性与pH对纳米铁在多孔介质迁移的影响。结果表明,CMS包覆纳米铁不仅使纳米颗粒本身稳定,而且还减少其在多孔介质表面沉积,大大提高了迁移性。pH=6～8时,nZVI的zeta电位由18.3mV减小到2.9mV,有效粒径由685nm增大到880nm,稳定性变差;而CMS-nZVI的zeta电位值由-19.7mV增大到-53.5mV,颗粒间静电排斥力增强稳定性变好。经能量色散X射线光谱（EDS）分析,水洗砂表面存在碳、铝、铁等氧化物杂质,这些杂质带有正电荷,会增强与带负电的CMS-nZVI的吸附作用,不利于其迁移;而经过酸洗后的石英砂,其表面杂质大大减少,在pH=8时,CMS-nZVI在酸洗砂最大迁移率为77.0%要好于水洗砂的63.0%。此外较高pH环境有助于增加石英砂介质的表面负电荷,减少颗粒与介质的吸附,促进纳米颗粒的迁移。     

纳米钯催化剂的制备及其催化性能

通过以抗坏血酸作为还原剂,聚乙烯吡咯烷酮(PVP)为稳定剂的氯钯酸(Na_2Pd_2Cl_4)水溶液制备出具有一定形貌的高度分散的钯纳米粒子。采用X射线衍射(XRD)、紫外可见吸收光谱(UV-VIS),透射电子显微镜(TEM)等手段对钯纳米粒子结构进行了表征,结果表明,钯纳米粒子被还原成零价金属粒子,并具有一定的立方结构,通过Suzuki反应进行了催化性能的考察,含量仅为0.05%~0.10%(mmol)的钯纳米粒子具有较高的收率。     

沉淀法制备纳米氧化铬粉体的研究

以Cr(NO_3)_3·9H_2O和NH3·H_2O为原料,采用直接沉淀法制备了纳米Cr_2O_3粉体。通过差热分析、X射线衍射、透射电镜、比表面积分析研究了粉体的制备过程和合成粉体的性能。所得纳米Cr_2O_3分散性良好,粒度分布均匀,平均粒径20~30nm,粒子形状为球形。     

Photoinduced synthesis of CdTe nanoparticles using Te-modified gold electrode in poly(vinyl pyrrolidone)-containing electrolyte

Photocathodic stripping of a pre-deposited tellurium film on a gold electrode in 0.1 M Na₂SO₄ electrolyte containing Cd²⁺ ions and poly(vinyl pyrrolidone) (PVP) was used as a route to the photoelectrosynthesis of CdTe nanoparticles. Thus illumination of a Te-modified gold surface generated Te²⁻ species, which were removed from the surface into the bulk electrolyte containing Cd²⁺and PVP by vigorous stirring. The reaction of Te²⁻and Cd²⁺ produced PVP-protected nanosized CdTe particles dispersed in solution in the size range 20–40 nm. In this approach, PVP played a critical role as a stabilizer to form discrete CdTe particles instead of larger (agglomerated) ones. Electrochemical quartz crystal microgravimetry was used to monitor stripping of Te films during the light illumination and the synthesized CdTe nanoparticles were characterized by scanning electron microscopy, energy dispersive X-ray analyses and laser Raman spectroscopy.     

Radiation synthesis and characterization of poly(vinyl alcohol)/poly(N-vinyl-2-pyrrolidone) based hydrogels containing silver nanoparticles

A series of PVA/PVP based hydrogels at different compositions were prepared by gamma irradiation. The gel fraction degree of swelling were investigated. Highly stable and uniformly distributed silver nanoparticles have been obtained onto hydrogel networks. The morphology and structure of (PVA/PVP) hydrogel and dispersion of the silver nanoparticles in the polymeric matrix were examined by scanning electron microscopy (SEM) and infrared spectroscopy (FT-IR), respectively. The formation of silver nanoparticles has been confirmed by ultraviolet visible (UV–vis) spectroscopy. A strong characteristic absorption peak was found to be around 420 nm for the silver nanoparticles in the hydrogel nanocomposite. The X-ray diffraction pattern confirmed the formation of silver nanoparticles with average particle size of 12 nm. The diameter distribution of silver nanoparticles was determined by dynamic light scattering DLS. Transmission electron microscope (TEM) showed almost spherical and uniform distribution of silver nanoparticles through the hydrogel network and the mean size of silver nanoparticles ranging is 23 nm. The good swelling properties and antibacterial of PVA/PVP-Ag hydrogel suggest that it can be a good candidate as wound dressing.     

铂纳米花的控制合成

以氯铂酸钾（K2PtCl6）为前驱体、聚乙烯吡咯烷酮（PVP）为稳定剂及还原剂,在一定量溴化钾（KBr）的存在下,采用水热法制备了铂纳米花。考察了n（K2PtCl6）∶n（PVP）∶n（KBr）、反应温度、反应时间对产物形貌的影响。结果表明,在n（K2PtCl6）∶n（PVP）∶n（KBr）为1∶10∶15、反应温度为130℃、反应时间为3h的条件下,制备出形貌规则、大小均匀的花形自组装铂纳米颗粒。利用透射电子显微镜、X-射线光电子能谱和X-射线粉末衍射对产物进行了表征。所制备的铂纳米花由零价态的铂原子组成,具有面心立方（fcc）结构。     

一步聚合法合成多孔磁性高分子微球及其机理研究

在羰基铁粉存在下,将苯乙烯与甲基丙烯酸甲酯通过悬浮聚合方法制备了表面多孔的磁性高分子微球。采用SEM、FTIR及XRD等对样品进行了表征。研究表明,聚合形成的磁性高分子微球表面粘附着40 nm左右的聚合物粒子,这些粒子之间形成孔隙。具有两亲性和可接枝聚合的明胶分子促成了单体在羰基铁粉表面引发并聚合。     

疏水改性核壳结构颗粒对Pickering乳液的稳定作用

为了探究固体颗粒对乳液的稳定作用,采用双亲染料分子罗丹明B对核壳结构的Fe_3O_4@SiO_2纳米颗粒进行疏水改性,并将改性后的纳米颗粒作为稳定剂制备Pickering乳液。通过Zeta电位、FTIR、XRD、SEM、接触角测量、光学显微镜、电导率仪对Fe_3O_4@SiO_2纳米颗粒以及Pickering乳液的结构、形貌和性能进行表征与分析,结果表明:制备的纳米颗粒粒径小,约为150 nm,为单分散球形核壳结构;罗丹明B成功修饰到Fe_3O_4@SiO_2纳米颗粒表面,改性后颗粒接触角由30°增加至120°;随乳化剂颗粒质量浓度的增加,制备的乳液液滴的粒径减小。另外,所得Pickering乳液具有良好的磁场响应性,可通过外加磁场实现对乳液稳定性的可逆调控,且此过程可重复3次以上。     

铜铁尾矿制酸烧渣制备纳米Fe/SiO2核壳复合粒子的微波吸收性能

以铜铁尾矿制酸烧渣为原料,经熟化、酸浸、还原和净化等步骤制备亚铁离子;在乙醇-水液相体系中,以NaBH₄作为还原剂,反应生成纳米Fe粒子;最后通过正硅酸四已酯（TEOS）水解包覆制得纳米Fe/SiO₂核壳复合粒子。产物分别采用XRD、TEM、IR等手段进行表征。进一步地,使用矢量网络分析仪在2.0 ~ 18.0 GHz波段内来研究样品的吸波性能。结果表明,IR光谱上在1389 cm^-1和878 cm^-1分别出现对应于四配位Si—O键和Si—O—Fe键的特征吸收峰,说明在Fe粒子表面包覆有SiO₂。通过测试计算得知,当吸波样品厚度为4.5 mm时,其微波吸收性能在17.2 GHz处达到最小值-39.0 dB。由此可见,以铜铁尾矿制酸烧渣为原料,可制得吸波性能优良的纳米Fe/SiO₂核壳复合粒子微波吸收材料。     

纳米银粒子的制备及其催化性能的研究

采用化学还原的方法,以聚乙烯吡咯烷酮为稳定剂,硼氢化钠为还原剂合成了纳米级银粒子。TEM和XRD分析表明所制备的银纳米粒子粒径分布窄,其平均粒径为15nm左右,且具有较高的结晶度。进一步催化硼氢化钠还原甲苯胺蓝的实验表明该银溶胶具有较高的催化活性。     

Synthesis of highly stable dispersions of copper nanoparticles using sodium hypophosphite

Highly stable dispersions of copper nanoparticles with an average diameter of 80 nm were synthesized using a straightforward and cost‐effective method in the presence of polyvinylpyrrolidone (PVP) as a stabilizer and without any inert gas protection. Sodium hypophosphite was used as the reducing agent in low pH value aqueous medium. The copper nanoparticles were characterized by ultraviolet‐visible spectroscopy and scanning electron microscopy. The mechanism of the PVP on the stabilization of copper nanoparticles is also discussed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Magnetic poly(glycerol dimethacrylate) latex particles: synthesis, characterization and cellular interactions

Magnetic poly(glycerol dimethacrylate) (m-poly(GDMA)) latex particles were synthesized by precipitation polymerization in the presence of iron oxide nanoparticles obtained by co-precipitation of Fe²⁺ and Fe³⁺ salts. The mean size of iron oxide nanoparticles and m-poly(GDMA) latex particles was determined by dynamic light scattering as 57 and ~800?nm, respectively. Vibrating sample magnetometer results showed that iron oxide nanoparticles and m-poly(GDMA) latex particles are superparamagnetic, and their saturation magnetizations are 74.37 and 3.85 emu/g, respectively. MC3T3-E1 preosteoblasts were seeded in the presence of m-poly(GDMA) latex particles. Through the magnetic particles, magnetic field was applied onto the cells by an appropriate magnet (4500 G). Cell?Cparticle interactions were observed by optical microscope and scanning electron microscope. Mitochondrial activities of cells was measured by 3-[4,5-dimethylthiazol-2-y1]-2,5-diphenyl tetrazolium bromide test. The results show that the presence of m-poly(GDMA) particles in the culture medium did not affect the proliferation behaviour of MC3T3 cells and no toxicity against to L929 fibroblastic cell proliferation was observed when the particle concentration is 100?pg per cell.     

Gas-Phase Flame Synthesis and Characterization of Iron Oxide Nanoparticles for Use in a Health Effects Study

Iron oxide nanoparticles, to be used in a health effects study, were synthesized in a H₂/air diffusion flame and characterized by transmission electron microscopy, X-ray diffraction, surface area measurement, inductively coupled plasma mass spectrometry, and a spectrophotometric speciation method. The nanoparticles exhibited the maghemite (γ -Fe₂O₃) crystal structure and contained only trivalent iron. There were two size modes in the particles. The large size mode contained crystalline, non-agglomerated particles with a median diameter of approximately 45 nm; the small size mode contained particles that were in the size range of 3–8 nm and were mostly amorphous. Depending on the value taken for the small particle size, the small mode accounted for 73–82% of the particle surface area. The particles in the small size mode were likely formed from the vapor of FeO and Fe.