溶剂热条件下钴微纳米颗粒的构筑习性

以乙酸钴为钴源,水合肼为还原剂,在不同表面活性剂下,溶剂热法制备出不同形貌的二维、三维钴微纳米颗粒。通过扫描电子显微镜(SEM)、X射线能量色散谱(EDS)和X射线衍射(XRD)对产物进行了表征。采用自制的2-十一烷基-1-二硫脲乙基咪唑啉季铵盐(SUDEI)为表面活性剂时,制备出直径400~600nm,厚度约100nm的六角盘状二维产物,采用其他表面活性剂只能制备出三维的花状钴。初步探讨了溶剂热条件下钴微纳米颗粒的构筑习性。     

碱式氯化镁晶须的制备及其生长机理研究

以六水氯化镁和氨水为原料,醇水溶液为溶剂,通过沉淀法制备碱式氯化镁晶须。采用X射线衍射、扫描电子显微镜、透射电子显微镜、拉曼光谱等手段对晶须结构进行表征,并探究其生长机理。结果表明：不同溶剂所制备的碱式氯化镁晶须化学式均为2Mg(OH)₂·Mg(OH)Cl·4H₂O。碱式氯化镁晶须的形成机制符合负离子配位多面体生长基元理论,晶须是沿着(201)晶面生长,乙醇或乙二醇的加入都能使晶须沿着一维方向生长且表面更光滑。当采用质量分数为20%乙二醇时所制备晶须的长径比为95,且具有更好的分散性和尺度均一性。     

暴露{001}晶面TiO_2纳米片自组装微球的制备及光降解性能

为提高TiO_2的光催化性能,基于光催化反应的表面特性,通过一步溶剂热法制备了暴露{001}晶面TiO_2纳米片自组装微球,并研究了不同钛源、不同溶剂和不同反应时间对产物的影响;通过FESEM、TEM、HRTEM、XRD、XPS等手段对所得产物进行表征;通过甲基橙降解时评价样品的光降解性能。结果表明:选用异丙醇钛为钛源、异丙醇为溶剂、二乙烯三胺为盖帽剂、反应时间为12 h条件下合成的自组装微球具有大小均一、分散性好的多级结构并且暴露出高活性{001}晶面;且合成的TiO_2微球具有较高的光降解性能,仅在光照15 min后,甲基橙的降解率便达到了100%。     

表面活性剂对电沉积纳米WO3-Cu复合镀层组织及其性能的影响

为了解不同表面活性剂对纳米复合电沉积过程的作用,研究常用的阴离子、阳离子和非离子表面活性剂对WO_3-Cu复合镀层电沉积过程的影响。采用扫描电子显微镜和能谱分析仪分析添加表面活性剂前后镀层表面微观形貌和镀层成分的变化,通过润湿性试验、自清洁试验、耐磨性试验和光催化试验分别评价表面活性剂对WO_3-Cu复合镀层润湿性能、自清洁性能、耐磨性能和光催化性能的影响。结果表明:表面活性剂可有效改变WO_3纳米颗粒在镀层中的沉积和镀层的表面形貌,其中阳离子和非离子表面活性剂联合添加时制备的复合镀层中WO_3含量达到最高值25.9%;经氟化处理后,其镀层表面接触角可达155°;与纯铜相比,复合镀层有良好的自清洁性、耐磨性和光催化性。     

Mg-Al层状双氢氧化物和MgAl2O4微纳结构制备

以十六烷基三甲基溴化铵(cetyltrimethylammonium brom ide,CTAB)为表面活性剂,尿素为碱剂,采用溶剂热法合成Mg-A l层状双氢氧化物玫瑰花状结构和片球结构,通过高温煅烧制备花状结构的MgA l2O4.利用X射线衍射研究产物晶体结构,利用扫描电子显微镜分析产物形貌和粒径,考察表面活性剂添加量、反应物浓度和反应时间对产物形貌的影响.结果表明,表面活性剂CTAB的添加量为1 g时有利纳米片自组装,形成玫瑰花状结构或片球状结构;随反应物浓度增加,产物形貌从不规则的聚集体过渡到玫瑰花状结构,最终转变成片球状的微纳结构.     

超高速液相色谱用纳米ZrO_2晶体颗粒的制备及机理

以正丁醇/水二元油包水体系形成的微乳液滴为反应器,采用正丙醇锆为锆源反应物、水为沉淀剂和硬脂酸(表面活性剂)发生反应,制备了纳米ZrO_2颗粒。采用扫描电子显微镜、Malvern粒度分布仪、X射线衍射仪、热重-差热分析仪和N2吸附-脱附仪对所得到的ZrO_2颗粒表征。结果表明,经过500和700℃焙烧,ZrO_2颗粒分别由无定型向亚稳定四方形、亚稳定四方形向单斜型转变,且制备的纳米ZrO_2颗粒为表面光滑、无孔、均一、单分散的球体,可用于超高速液相色谱材料。     

乙二醇基铁/氧化钛纳米复合粒子的制备及其电流变性能

采用两步法制备出乙二醇基铁/氧化钛纳米复合粒子,并将制备的纳米复合粒子分散在硅油中得到一系列的电流变液。首先采用高温回流法制备出乙二醇基铁模板,然后分别用水解法和溶剂热制备出氧化钛纳米颗粒包覆在乙二醇基铁模板表面。使用X射线衍射仪(XRD),扫描电子显微镜(SEM),电流变仪等对纳米复合粒子进行结构的表征和性能的测试。研究了不同种类的表面活性剂复配体系对纳米复合粒子电流变性能的影响。通过对比,水解法得到纳米复合粒子相比于溶剂热在形貌和电流变性能方面都有所提高,水解法制备得到的纳米颗粒基的电流变液电流变效率可以达到200。     

纳米Ni-Al2O3体相催化剂的TEM和TPR表征及反应机理探讨

以尿素为沉淀剂、六水硝酸镍为前躯体、表面活性剂（聚异丁烯马来酸三乙醇胺酯）和石油烃-150SN混合物作为模板剂,采用超增溶自组装法制得纳米 Ni-Al2 O3体相催化剂。对 Ni-Al2 O3体相催化剂进行了 TEM表征和氢气还原曲线（TPR）分析,并对沉淀反应的机理进行了探讨。结果表明,超增溶自组装纳米Ni-Al2 O3体相催化剂是晶体结构,形状除了球形,还有纳米棒、纳米丝等其他形状;通过超增溶自组装法制备出的微粒分散性良好,颗粒均匀、粒径分布（10~50 nm）较窄。Ni-Al2 O3经过 H2还原后仍是规整有序的晶体,而且还原后比还原前的晶体结构要规整有序,还原后的颗粒的粒径仍在纳米粒子范围内,属于纳米颗粒。TPR 分析结果表明,曲线出现了两个还原峰,低温峰归属于 NiO 结构,高温峰归属于镍与氧化铝相互作用产生的表面尖晶石结构。     

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.     

纳米聚乙烯／二氧化硅复合微球的制备

通过使用熔融乳液法将聚乙烯（PE）用表面活性剂聚乙烯-b-聚乙二醇嵌段共聚物（PE～b—PEG）乳化成纳米级胶束,同时采用溶胶-凝胶法将硅源水解并自组装到纳米PE胶束表面上,制备了纳米聚乙烯／二氧化硅复合微球．产物分别用纳米激光粒度仪、扫描电子显微镜（SEM）进行表征．实验结果表明：在适量的表面活性剂PE-b—PEG存在的条件下,复合微球的可控尺寸在30～190nm范围内,平均粒径为94nm．     

苯乙烯 - 马来酸酐无规共聚物/银纳米微粒的合成及表征

金属纳米材料能够产生量子尺寸效应及表面效应，在许多领域具有很好的应用前景.以DMF(N,N-二甲基甲酰胺)为溶剂及还原剂，苯乙烯-马来酸酐无规共聚物为大分子稳定剂，在不同的反应条件下，合成制备了银纳米微粒.通过紫外-可见吸收光谱、透射电子显微镜等测试手段对所合成的纳米银样品进行了表征.结果表明：通过上述反应所得到的银纳米微粒的DMF溶液可以在420 nm处出现纳米银所具有的特征吸收峰，增加了反应前驱体浓度及反应时间，使银纳米微粒的特征吸收峰变得更加明显.透射电子显微镜的结果表明，所得到的银纳米微粒具有较窄的尺寸分布，从而证明苯乙烯-马来酸酐无规共聚物可以对纳米银表面进行较好的修饰.     

琼脂糖凝胶中树枝状银的生长研究

以琼脂糖凝胶作为模板、还原剂和稳定剂,通过溶胶-凝胶法制备琼脂糖/纳米银复合凝胶,对所得到的银纳米粒子进行了表征. 在复合凝胶外侧使用铝箔破坏凝胶中银纳米粒子的平衡状态,实现银纳米粒子在凝胶中的聚集并生成三维树枝状结构,并对树枝状银进行了表征. 结果表明,银纳米粒子为球形,粒径在20 nm左右,分散性好. 以琼脂糖凝胶为模板生长的树枝状银形状完整,尺寸与复合凝胶的样品大小有关,可达厘米级. 树枝状银的形貌可通过改变硝酸银浓度进行调控. 树枝状银结构的形成是扩散限制凝聚的结果. 关键词:琼脂糖;银纳米粒子;树枝状银;复合凝胶;可控制备     

对苯二酚在金、银纳米粒子修饰的玻碳电极上电化学响应的比较

制备了柠檬酸钠保护的金和银纳米粒子,并用自组装法制备了金和银纳米粒子修饰的玻碳电极,在近中性的磷酸缓冲溶液中,比较研究对苯二酚在金和银纳米粒子修饰玻碳电极上的电化学响应情况。结果表明金和银纳米粒子均对对苯二酚的电氧化过程具有优越的电催化效果;与银纳米粒子修饰电极相比,金纳米粒子修饰电极表现出了良好的稳定性;对苯二酚在金纳米粒子修饰玻碳电极上的电化学反应是受扩散控制的。     

Facile Preparation and Formation Mechanism of Uniform Silver Nanoparticles Using OP-10 as Emulsifier in Reverse Microemulsion

Using the polymerizable hydrophobic styrene monomer as the dispersion medium and the traditional nonionic surfactant OP-10 as emulsifier, stable silver nanoparticles of narrow size distribution were prepared by a reverse (w/o) microemulsion method. The powder X-ray diffraction (XRD) pattern indicated that the obtained silver nanoparticles were of face-centered cubic structure. The results of the transmission electron microscopy (TEM) show that the final silver nanoparticles are of spherical structure with a...     

Ag recovery from copper anode slime by acid leaching at atmospheric pressure to synthesize silver nanoparticles简

In this paper, recovery of silver from anode slime of Sarcheshmeh copper complex in Iran and subsequent synthesis of silver nanoparticles from leaching solution is investigated. Sarcheshmeh anode slime is mainly consisted of Cu, Ag, Pb and Se. Amount of Ag in the considered anode slime was 5.4% (by weight). The goal was to recover as much as possible Ag from anode slime at atmospheric pressure to synthesize Ag nanoparticles. Therefore, acid leaching was used for this purpose. The anode slime was leached with sulfuric and nitric acid from room to 90 °C at different acid concentrations and the run which yielded the most recovery of Ag was selected for Ag nanoparticles synthesis. At this condition, Cu, Pb and Se are leached as well as Ag. To separate Ag from leach solution HCl was added and silver was precipitated as AgCl which were then dissolved by ammonia solution. The Ag nanoparticles are synthesized from this solution by chemical reduction method by aid of sodium borohydride in the presence of PVP and PEG as stabilizers. The synthesized Ag nanoparticles showed a peak of 394 nm in UV–vis spectrum and TEM images showed a rather uniform Ag nanoparticles of 12 nm.     

纳米粒子对复合化学镀镍层性能的影响

在化学镀镍溶液中添加银纳米粒子,在钢铁基体上制备Ni-P／Ag纳米复合镀层。研究了添加银纳米粒子前后镀液的镀速、镀层的厚度、镀态和热处理态的硬度变化,分析了银纳米粒子对镀层性能的影响。研究结果表明,银纳米粒子使得镀层的沉积速率加快,厚度增加,硬度提高。镀层的表面形貌也由于银纳米粒子的存在而发生了改变。     

Facile preparation and formation mechanism of uniform silver nanoparticles ising OP-10 as emulsifier in reverse microemulsion

Using the polymerizable hydrophobic styrene monomer as the dispersion medium and the traditional nonionic surfactant OP-10 as emulsifier, stable silver nanoparticles of narrow size distribution were prepared by a reverse (w/o) microemulsion method. The powder X-ray diffraction (XRD) pattern indicated that the obtained silver nanoparticles were of face-centered cubic structure. The results of the transmission electron microscopy (TEM) show that the final silver nanoparticles are of spherical structure with an average diameter of 15.2 nm and of a Gaussian distribution. The internal high-ordered structure of silver nanoparticles was characterized by the field-emission high-resolution transmission electron microscopy (FEHRTEM), indicating that the silver is monocrystalline and it has only one nucleation site during the formation process of a nanoparticle. The time-resolved UV-visible absorption spectra was used to monitor the process of the reaction in situ. The results show that the concentration of silver nanoparticles increases but the size changes little and the morphology transforms from obvious ellipsoidal shape to nearly spherical shape during the process. The experimental results indicate that the droplets’ dynamic exchange which is closely related to the nature of surfactant film is the control factor of the kinetics. The dynamic exchange mechanism of silver nanoparticle formation is proposed to involve continual encounter of two separate droplets forming transient fused dimer in which the chemical reaction occurs followed by re-separation without combination. Attributed to the dual role of surfactant in the nanoparticle formation, tailored nanoparticles can be successfully synthesized in control in the premise of a certain stability of reverse microemulsion.     

纺织品中原位生成超微银粒及其性能测试

采用化学镀的方法在棉纤维中原位生成超微银晶粒，研究了不同反应备件如银离子浓度以及超声作用时间等对生成银晶粒大小的影响，并时样品做了一系列如XRD、SEM、紫外透过率等表征以及性能测试。结果表明：样品的平均晶粒大小达到了纳米级，而且它的抗紫外效果好、耐洗牢度也很强，因此有望在实际中得到应用。     

Self-assembled structures of colloidal silver nanoparticles on solid substrates

With a two-phase method,well-dispersed 5.2 nm Ag nanoparticles with narrow size distribution (±0.5 nm) are synthesized.The assembled structures of colloidal Ag nanoparticles on highly oriented pyrolytic graphite (HOPG),silicon chip and microscopic glass have been investigated by atomic force microscopy (AFM).With different spin-coating speeds and concentrations of colloidal silver nanoparticles,various assembly structures could form on those substrates.On HOPG,Ag nanoparticles were absorbed and aligned along single-atom-height step edges to form a linear one-layer structure.And on silicon chip and microscopic glass,one-layer closed packing fractal structure and two-layer closed packing ring were observed respectively.     

反相微乳液体系Ag@SO2核壳纳米粒子的制备工艺研究

以反相微乳液体系制备二氧化硅包覆银纳米粒子核壳微球,从中探讨了不同R值（R=n水／n表面活性剂）所形成的微乳液滴的粒径分布;以及柠檬酸三钠稳定的银离子浓度和正硅酸乙酯（TEOS）浓度对二氧化硅包覆银纳米粒子核壳微球粒径和形貌的影响。结果表明：R越大,微乳液滴粒径越小。当R=10时,0．15mL的0．0123mol/L柠檬酸三钠溶液、0．25mL的0．02467mol／L硝酸银溶液、0．15mL的0．0924mol／L硼氢化钠溶液、0．05mL的正硅酸乙酯和0．1mL氨水所得到的核壳微球形貌和单分散性较好。