利用反相微乳液法制备纳米铜粒子

通过反相微乳液法制备了纳米铜粒子,并用透射电子显微镜(TEM)、电子衍射(SAED)和能谱对铜纳米粒子的形貌和物相进行了表征.在H2O/表面活性剂油酸钠摩尔比(W/O)为11、8时分别制得了粒径为50nm、10nm的铜粒子.结果表明:W/O值对纳米铜粒子的粒径有非常明显的影响,当其值由11降到8时,粒径则从50nm降到了10nm,且更加均匀.探讨了水与表面活性剂的摩尔比对制备的纳米铜颗粒的粒径的影响.     

碳纳米管表面修饰铜纳米粒子的制备及表征

以糠醇为碳源,模板(AAO)碳化法制备了高纯度的碳纳米管,硝酸铜作为金属源,以溶液浸渍法合成了碳纳米管表面修饰的铜纳米粒子。利用XRD、TEM、SEM、能谱仪和拉曼分析等手段对样品进行了结构和形貌的表征。结果表明:粒径为10~20nm的铜纳米颗粒均匀负载到孔径在90~100nm的碳纳米管表面。电子衍射证明,这些颗粒为单质铜和Cu2O的纳米单晶,且铜纳米粒子具有很好的结晶度。     

亲油性金纳米粒子的合成

利用相转移法成功地合成了粒径在2～7nm的硫醇表面修饰Au纳米粒子.采用透射电子显微镜、纳米粒度分布仪、红外光谱分析仪等现代测试技术对所合成的Au纳米粒子进行了表征.结果表明,表面为硫醇所修饰的Au纳米粒子,在有机溶剂中具有很好的分散性,表面修饰层的存在不仅有效地阻止Au纳米粒子的团聚,而且使得纳米粒子粒径分布窄,粒径可控.     

铜催化剂纳米粒子的尺寸对碳纤维形貌的影响

通过化学气相沉积法高重复性制备了纳米螺旋碳纤维和直线性碳纤维,并研究了金属铜纳米粒子催化剂的尺寸大小对碳纤维形貌的影响,认为粒径较大的铜纳米粒子容易催化聚合生成直线形碳纤维;反之,粒径较小的铜纳米粒子倾向于合成纳米螺旋碳纤维.利用场发射扫描电镜(FESEM)、透射电镜(TEM)和X射线粉末衍射(XRD)等测试方法对产物进行了表征.     

亲油性LaF3纳米粒子的制备及表征

在醇-水混合溶剂中合成了表面为油酸修饰的LaF3纳米粒子,并用透射电子显微镜、红外光谱和X射线粉末衍射仪对修饰LaF3纳米粒子进行了表征.结果表明:所制备的修饰LaF3纳米粒子大小均匀,粒径约为8nm;其纳米核为六方结构的LaF3;由于表面修饰剂油酸与LaF3纳米粒子表面之间发生化学键合作用,使得油酸修饰LaF3纳米粒子在苯及润滑油中的分散性明显提高.     

微波辐射在联氨还原法制备金属Co纳米微粒中的应用

采用次亚磷酸钠为辅助还原剂,联氨为主还原剂,在微波辐射下还原钴盐制备六方结构o纳米粒子.采用透射电子显微镜和激光散射仪观察并测定纳米Co粒子的形貌、粒径大小及分布,确认Co纳米粒子为类球形,粒径为10～15nm.在正己烷中存在软团聚,团聚体平均尺寸约30nm.采用XPS考察产物的表面价态,证明金属Co纳米晶是以零价态存在的.     

铜纳米粒子的可控制备及其抗菌性能研究

以氯化铜为铜源,水合肼为还原剂,十六烷基三甲基溴化铵(CTAB)为稳定剂,氨水为络合剂,通过液相还原法合成了纳米铜粉。通过改变还原剂浓度制备了4组不同粒径纳米铜粉末,FESEM等表征发现,随着水合肼浓度的降低,纳米铜粉粒径增加。通过肉汤稀释振荡培养法测试纳米铜的最小抑菌浓度,结果表明,随着纳米铜粒径的增加,抗菌性能降低,所合成纳米铜的最小抑菌浓度在750～3000mg/L;初步分析认为铜纳米粒子主要是通过水解或电离出铜离子而发挥抗菌作用。     

含纳米CaCO3,Cu混合物添加剂润滑油的研究

采用纳米碳酸钙、纳米铜粒子混合物作为润滑油添加剂.选择合适的表面活性剂制备含纳米碳酸钙和纳米铜粒子混合物添加剂的润滑油.利用四球摩擦磨损试验机考察含纳米碳酸钙、纳米铜粒子添加剂的润滑油的摩擦学性能;用扫描电子显微镜(SEM)观察表面磨痕的形貌.用原子力显微镜和扫描电子显微镜(SEM)观察分析在磨损表面纳米粒子的形态与分布.研究结果表明,纳米碳酸钙、纳米铜的粒子混合物的最佳添加量为:纳米碳酸钙与纳米铜的总添加量的质量分数为0.6%,纳米碳酸钙与纳米铜的质量分数之比为1∶1;该润滑油具有最佳的摩擦学性能.研究还表明,润滑油中纳米碳酸钙、纳米铜粒子混合物添加剂的优良摩擦学性能与纳米粒子在表面存在形态相关.     

联氨还原法制备镍纳米粒子

在表面活性剂聚乙烯吡咯烷酮（PVP）的保护下，采用水合肼于水体系中还原镍盐而得到镍纳米粒子。该粒子具有fcc相；表面价态为零价，说明制备过程中没有被氧化；粒子粒径在40nm左右，近似圆球形，在正己烷中分散效果较好。     

玻璃基底上二维有序Au纳米结构阵列消光特性的理论研究

采用离散偶极子近似方法(discrete dipoleapproximation,简称DDA)从理论上对玻璃基底上不同粒径的Au纳米粒子结构阵列的消光光谱以及消光峰与纳米粒子粒径的关系进行了研究。计算结果显示玻璃基底上的Au纳米粒子结构阵列的消光谱中出现明显区别于Au单体纳米粒子的共振峰,玻璃基底上的Au纳米粒子结构阵列的消光性质与单体纳米粒子的粒径密切相关,随着纳米粒径的增大表面等离子体共振吸收峰出现明显红移,并且在粒径>40nm时出现多峰吸收现象。计算结果与实验结果基本一致。给出玻璃基底上的Au纳米粒子结构阵列的共振吸收峰随单体纳米粒子粒径变化的关系图。对Au纳米结构阵列的吸收机制进行系统的理论分析。     

Fabrication of PDPhSM matrix nanocomposite thin films by pulsed laser ablation

We have developed a new method to fabricate poly(diphenylsilylenemethylene) (PDPhSM) matrix nanocomposite thin films containing copper nanoparticles produced by pulsed laser ablation in this paper. First of all, 1,1,3,3-tetraphenyl-1,3-disilacyclobutane (TPDC) films were deposited on 4 cm² silicon substrates cut from c-Si wafers by conventional vacuum evaporation under a pressure of 3.0 × 10⁻⁵ Torr; then copper nanoparticles were deposited onto the TPDC films by pulsed laser ablation; finally the TPDC films with copper nanoparticles were heated in an electric furnace in an air atmosphere at 553 K for 10 min to induce ring-opening polymerization of TPDC. The results indicated that it is possible to fabricate PDPhSM matrix nanocomposite thin films using copper nanoparticles produced by laser ablation. The morphology and size distribution of copper nanoparticles can be controlled by pulsed laser ablation conditions. Also, the polymerization efficiency depends on the size and chemical state of copper nanoparticles.     

Simple new synthesis of copper nanoparticles in water/acetonitrile mixed solvent and their characterization

Copper nanoparticles were successfully synthesized by the borohydride reduction of copper nitrate salt in water/CH₃CN mixed solvent under inert argon-purged conditions. Cu nanoparticles were synthesized in large-scale production for the first time by introducing CH₃CN into water and preventing oxidation during the preparation of nanoparticles. Nanoparticles were characterized by using UV-visible absorption spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) techniques. High resolution TEM pictures showed the formation of homogeneous cubic-structured copper nanoparticles with sizes less than 100 nm. This new kind of synthesis method shows the excellent stability compared with that of citrate-protected copper nanoparticles, which may provide an efficient way to improve the fine tuning of the structure and size of copper nanoparticles.     

In vitro germination and biochemical profiling of citrus reticulata in response to green synthesised zinc and copper nanoparticles

Green synthesis of nanoparticles by using plants is an emerging class of nanobiotechnology. It revolutionizes all the fields of nanobiotechnology by synthesizing chemical‐free nanoparticles for various purposes. In the present study, zinc and copper nanoparticles were synthesized by using the white leaves of Allium cepa and further characterized through Zeta analyzer and Scanning electron microscopy. Zeta analyzer elucidated that zinc nanoparticles ranged from 8‐32 nm while copper nanoparticles ranged from 15‐30 nm. Scanning electron microscopy clarified that zinc nanoparticles were irregular while copper nanoparticles were spherical in shape. The effects of green synthesized nanoparticles were evaluated on the germination frequency and biochemical parameters of plant tissues. The nucellus tissues were inoculated on Murashige and Skoog (MS) medium augmented with 30 µg/ml suspension of zinc and copper nanoparticles. Green synthesized nanoparticles enhanced the in vitro germination parameters because of their low toxicity and high efficacy. Significant results were obtained for germination parameters in response to the applications of zinc nanoparticles as compared to copper nanoparticles. These nanoparticles could also induce stress in plantlets by manipulating the endogenous mechanism as a result various defence compounds are produced which have potential in treating various human ailments. Copper nanoparticles showed higher toxicity as compared to zinc nanoparticles and triggered the production of antioxidative enzymes and non‐ enzymatic compounds.Inspec keywords: botany, zinc, copper, nanoparticles, nanofabrication, biochemistry, scanning electron microscopy, electrokinetic effects, biological tissues, toxicology, nanobiotechnology, biological techniquesOther keywords: in vitro germination, biochemical profiling, citrus reticulata, green synthesised zinc nanoparticles, green synthesised copper nanoparticles, green chemistry, secondary metabolites, nanoparticles synthesis, white leaves, Allium cepa, zeta analyser, scanning electron microscopy, onion extract, nucellus tissues, Murashige‐Skoog medium, biologically synthesised nanoparticles, toxicity, root length, shoot length, seedling vigour index, plantlets, endogenous mechanism, human ailments, antioxidative enzymes, nonenzymatic compounds, size 8 nm to 32 nm, Zn, Cu     

Scalable microwave-assisted continuous flow synthesis of CuO nanoparticles and their thermal conductivity applications as nanofluids

We have demonstrated the novel and scalable synthesis of CuO nanoparticles by an integration of microwave and flow synthesis. The shape and size of CuO nanoparticles were tuned by changing the concentration of copper precursor. The production rate of CuO nanoparticles was found to be 5?g/h with 70% conversion of copper acetate into the CuO nanoparticles. The thermal conductivity of CuO nanofluid prepared in ethylene glycol showed linear enhancement with increase in the volume content of CuO nanoparticles produced in batch and flow reactors.     

Synthesis of copper nanoparticles by electrolysis of DNA utilizing copper as sacrificial anode

Copper nanoparticles have been synthesized by anodic oxidation through a simple electrolysis process employing de-oxy ribonucleic acid (DNA) as electrolyte. Platinum was taken as cathode and copper as anode. The applied voltage was 4 V and the electrolysis was performed for duration of 1 h. The copper nanoparticles were prepared in situ from the electron beam irradiation on residues of electrolyte consisting of DNA and copper particles: DNA (Cu) complexes. The size of the nanoparticles ranges between 5-50 nm. A tentative explanation has been given for the formation of copper nanoparticles.     

Infrared nanosecond laser effects on the formation of copper nanoparticles

For the first time copper nanoparticles were formed inside Cu ion-doped glass after infrared irradiation by a nanosecond laser and sucessive annealing at 700 °C for 1 h. The surface plasmon resonance was observed in the absorption spectra of copper nanoparticles. Their spectral position is in good agreement with the values predicted by Mie theory for the copper nanoparticles. The possible mechanisms responsible by the observed results are discussed.     

Copper-containing nanocomposites: Synthesis and phase composition

Composites comprising copper nanoparticles dispersed in a low-density polyethylene matrix were obtained by thermal decomposition of copper diacetate. The powdered nanocomposite was studied by X-ray diffraction. The phase composition of nanoparticles depends on the metal content in the matrix. The average size of nanoparticles determined from the characteristic broadening of diffraction peaks falls within 10–25 nm.     

Silica SBA-15 template assisted synthesis of ultrasmall and homogeneously sized copper nanoparticles

The synthesis of spherical copper nanoparticles with extremely narrow size distribution by electroless copper deposition on mesoporous silica support is described. The materials were characterized by nitrogen sorption, transmission electron microscopy, x-ray diffractometry and Fourier transform infrared spectroscopy. The copper nanoparticles have a cubic crystalline structure and an average particle size of 5.5 +/- 0.8 nm. The copper nanoparticles are stable, without detectable oxidation or further agglomeration under ambient conditions even after months. These results demonstrate that electroless copper reduction can be conducted and constrained within the mesoporous silica framework, which pave the way for engineered mesoreactors.     

Structure and optical properties of CuxO- and CuxSe-doped sol–gel silica glasses

Copper oxide and copper selenide nanoparticles were produced within the silica glasses through the sol–gel technique. Chemistry of these copper compounds (variability in stoichiometry and copper oxidation state) provides a variety of optical properties of nanoparticles composed from them. A series of glasses with the nanoparticles different in stoichiometry was fabricated. The linear absorption spectra reveal the changes of the fundamental absorption edge position and appearance of the intense absorption band in the near IR. Photoluminescence is observed both for copper oxide and copper selenide nanoparticles evidencing Cu(I) states.     

Parametric study of cost-effective synthesis of crystalline copper nanoparticles and their crystallographic characterization

Pure and high-crystalline copper nanoparticles were synthesized at room temperature by reduction of copper nitrate with hydrazine hydrate in cetyltrimethyl ammonium bromide (CTAB) solution without using any extra gases. A parametric study has been carried out in terms of hydrazine concentration, solution pH, and stirring. Pure copper nanoparticles without oxidation were obtained at 0.1–0.2 M N₂H₄ and pH = 10. The growth mechanism of various shaped copper nanoparticles is discussed based on structural analysis by transmission electron microscopy and selected area electron diffraction.