界面聚合法制备纳米聚苯胺的研究进展

由于聚苯胺的制备方法简单、环境稳定性高、原料易得和独特的酸碱掺杂-脱掺杂机制,使其成为目前研究最为广泛的导电高分子材料之一.介绍了利用界面聚合法制备各种不同形貌的纳米聚苯胺及其复合材料的研究进展,重点介绍了界面聚合法制备聚苯胺纳米纤维的研究进展和作用机理.     

退火温度对纳米ZnO结构和形貌的影响

通过溶胶-凝胶法制备出不同形貌的ZnO纳米结构.详细研究了退火温度对ZnO纳米结构形貌的影响.结果表明退火温度对ZnO纳米结构的形貌有很大的影响.从扫描电镜结果看,900℃可以形成ZnO纳米棒,长度在2～3 gm,直径在200 nm左右.而且还讨论了ZnO纳米结构的生长机制.     

纳米氧化锌的制备技术及其应用前景

综述了纳米氧化锌的主要制备方法,结构表征和材料特性.介绍了液相和气相合成法等不同制备方法的反应特征、产物形貌及其性能.分析了水热法、模板法、溶胶凝胶法和化学气相氧化法的生长机理.讨论了纳米氧化锌的应用前景,并对纳米氧化锌的后续研究重点提出了一些建议.     

Ti/TiO_2界面的整流特性研究

采用电化学阳极氧化法在钛片表面构筑了一层结构有序、纳米级的TiO2纳米管阵列膜层,考察了制备电压对TiO2纳米管阵列形貌和尺寸的影响,应用扫描电子显微镜(SEM)对膜层的形貌进行了表征,测量了Ti/TiO2界面的整流特性,研究了TiO2纳米管阵列膜层结构与Ti/TiO2界面的整流特性的关系。结果表明:制备电压对TiO2纳米管阵列的结构起到关键的作用,二氧化钛纳米管之所以具有整流特性是由于Ti/TiO2界面具有类似p-n结的性质。利用二氧化钛纳米管的整流特性,人们可以制备出各种性能优良的材料和器件。     

水热法制备ZnO纳米棒阵列及其表征

采用两步低温水热法在Si片衬底上制备形貌规整的ZnO纳米棒阵列,纳米棒长度约为5μm.利用扫描电镜(SEM)、PL光谱测试对ZnO纳米棒的微观表面形貌和光学特性进行表征分析.探究制备过程中两次水热的生长液浓度对ZnO纳米棒形貌的影响,通过表征对比获得最优的生长液浓度范围.实验首先利用提拉退火等工序在衬底上获得ZnO的晶种层,再经过两次水热反应制备出分布均匀、有序生长、取向一致的较为理想的纳米棒阵列.     

有机硅-无机硅纳米复合物的制备及结构表征

利用溶胶-凝胶法原位制备有机硅-无机硅纳米复合物,采用XRD和傅立叶变换红外光谱仪对其进行结构分析,利用透射电子显微镜表征了有机硅-无机硅纳米复合物的形貌,全量程界面张力测量仪测定了α-烯烃烷基磺酸盐与有机硅-无机硅纳米复合物的复配体系与大庆油水体系的油水动态界面张力.结果表明:该方法制备的有机硅-无机硅纳米复合物颗粒大小在40nm以下;有机硅-无机硅纳米复合物与α-烯烃烷基磺酸盐复配体系,能使大庆油田油水体系的油水界面张力降低至10-4mN/m数量级.     

ZnSe-Au杂化纳米晶的制备与表征

为研制新型ZnSe基杂化纳米晶,确定ZnSe-贵金属杂化纳米晶组元间的作用机制,制备出了ZnSe-Au杂化纳米晶.利用X射线衍射仪(XRD)和高分辨透射电子显微镜(TEM)研究了杂化纳米晶的物相组成、形貌和生长机制.利用紫外可见分光光度计及荧光分光光度计对杂化纳米晶的光学性能进行了表征.结果表明:ZnSe-Au杂化纳米晶生长机制为异相形核、外延生长的机制;相对于单独的Au纳米颗粒,杂化纳米晶中Au的局域表面等离子共振吸收被显著红移.由于界面电子转移过程的存在,ZnSe的光致发光猝熄.     

氧化锌纳米带的合成及应用研究

分别采用PVA模板法、尿素热溶剂法和乙二胺热溶剂法合成了氧化锌纳米带,并通过扫描电镜观察了纳米带的形貌,同时重点研究了反应温度对纳米带生长的影响.并以所制得的氧化锌纳米带应用于可卡因适体传感器的制备,实验结果表明,该传感器稳定性好,灵敏度高,选择性好,制作简单,成本低,应用于可卡因的测定,结果令人满意.     

催化热分解法纳米碳管的制备与提纯

通过催化热分解法制备了多壁纳米碳管,研究了制备纳米碳管的最佳实验条件·对制备的纳米碳管进行了提纯实验·应用X射线衍射、透射电镜对自制的原料纳米碳粉进行了粒度测定、形貌观察·纳米碳粉为球形颗粒,粒度为50～80nm·应用透射电镜对纳米碳管进行了形貌观察,纳米碳管为定向生长,直径在20～30nm之间·在1000℃,1.5h时,得到了较高收率,纯净的碳纳米管·     

低温固相合成形貌和晶相可控的CdS纳米晶

用表面活性剂为形貌控制剂,通过低温固相反应成功制备出具有不同晶相和形貌的CdS纳米晶.研究结果表明,在反应过程中,表面活性剂所形成的结构对最终纳米晶的形貌起着决定性的作用.若以表面活性剂聚氧乙烯9醚为形貌控制剂,则所制备的产物为立方晶系的β-CdS球形纳米粒子,纳米粒子的直径为5-15 nm;而用聚乙二醇400为形貌控制剂时,则所制备的产物为六方晶系的CdS纳米棒,纳米棒的直径为20-80 nm、长度为100-400 nm.用X射线粉末衍射和透射显微镜技术对所制备纳米晶的成分、晶相、形状和尺寸进行了表征分析.对不同形貌CdS纳米晶的形成机理作了深入的讨论,提出了CdS纳米棒的表面活性剂软模板诱导自组装生长机理.     

Valance electron structure of carbide-diamond interface and catalytic mechanism for diamond synthesis under high-pressure and high-temperature

The metallic films surrounding a synthetic diamond formed under high-pressure and high-temperature (HPHT) in the presence of Fe-based and Ni-based catalysts were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was showed that the carbide was the primary carbon source for the nucleation and growth of diamond. Based on the EET (empirical electron theory in solid and molecules) theory, the valence electron structure of interface between carbide (Fe₃C, Ni₃C, (Fe, Ni)₃C) and diamond was calculated using the bonding length difference (BLD) method. The boundary criterion of Thomas-Fermi-Dirac-Cheng (TFDC): “the electron density being equal on the contacting surfaces of atoms” was applied to analyze the valence structure of carbide-diamond interface. The result based on the calculation valance electron structure is in good accordance with the experimental result. This study is very helpful to reveal the catalytic mechanism of diamond nucleation and growth and design the new catalyst for diamond synthesis.     

Investigation of electron transfer across the ice/liquid interface by scanning electro- chemical microscopy

Charge transfer across a liquid/liquid (L/L) interface is not only related to chemical sensors, drug delivery and phase transfer catalysis, but also significant for mimicking biological membranes[1—3]. The thermodynamics, kinetics and mechanism regarding of this type of heterogeneous transfer process have been intensively investigated in the past three decades. An external potential is usually applied to polarizing the interface in the case of conventional electrochemistry at L/L interfaces.…     

界面生长法制备纳米硒-铜复合物

在均相溶液中,利用肼还原法得到了单质硒和铜,然后通过在正丁醇-水形成的油水界面上生长,制备出不同纳米结构的硒-铜复合物。对复合物的光电性质进行了研究,研究发现硒—铜复合物的紫外吸收较单一的纳米硒和纳米铜都有一定的红移。通过透射电镜、X-衍射测试,测定了产物的形貌和组成,对其形成机理进行了初步解释。     

Investigation of electron transfer across the ice/liquid interface by scanning electrochemical microscopy

The study of interfacial electron transfer (ET) reaction between feericinium (Fc^ ) produced in situ in 1,2-dichloroethane (DCE) and ferrocyanide in ice matrix under low temperatures by the scanning electrochemical microscopy (SECM) is reported .Tetrabutylammonium (TBA^ ) is used as the common ion (potential -determining ion )in both phases to control the interfacial potential difference,The potential drop across the liquid/liquid interface can be quantitatively adjusted by changing the ratio of concentrations of TBA^ between beh two phases ,The apparent hetero-gencous rate constants for Fc^ reduction by Fe(CN)6^4- at the interface under different temperatures have been obtained by a best-fit analysis,where the experimental approach curves are fitted to the theoretical simulated curves.A sharp change has been observe for heterogeneous rate constants around the freezing point of the aqueous phase,which reflects the phase transition process.     

Effect of interface morphology on the mechanical properties of titanium clad steel plates

Interface morphology has important influence on the bond quality of titanium clad steel plates. The mechanical properties of titanium clad steel plates with wavy and straight interfaces were investigated by tensile-shear tests and bending tests. The interface morphology of the plates was examined by optical microscopy (OM) and scanning electron microscopy (SEM). The experimental results show that the shear strength of a wavy interface is higher than that of a straight interface. A wavy interface is the guarantee for obtaining high shear strength to provide a greater shear resistance. During the macrobending process, cracks appear in the swirl of the wave tip and ferrotitanium intermetallics. For in-situ observing the bending process by SEM, the wave tip of a wavy interface and the massive ferrotitanium intermetallics of a straight interface are places where cracks initiate and propagate. The results are the same as those observed in the macrobending process. Because of high hardness, the wave tip and the massive ferrotitanium intermetallics are hard in terms of compatible deformation.     

纤锌矿ZnS在油--水界面处的室温制备及光催化性能

通过控制硫化锌室温成核反应在油-水液-液界面处进行,并采用羟基端基自组装分子层修饰的聚合物膜作为柔性衬底,最终在衬底表面制得硫化锌纳米晶膜. X射线衍射表征显示产物为高温稳定的纤锌矿结构. 扫描电镜和透射电镜观察发现硫化锌膜由粒径30~50 nm的颗粒构成. 产物对甲基橙的光催化降解研究证实在紫外光辅助下硫化锌纳米晶膜对有机物的降解能力. 鉴于上述结果,提出了一种结合油-水液-液界面及自组装分子层功能化的衬底,在室温且无添加剂条件下一步制备高温稳定相ZnS功能膜的方法,并分析了产物形貌与光催化性能间的关系.     

Catalytic self-assembly preparation and characterization of carbon nitride nano-tubes by a solvothermal method

A solvothermal reaction of anhydrous CaNaCl3 and sodium using cyclohexane as solvent and NiCI2 as catalyst precursor has been carried out to prepare carbon nitride nanotubes successfully at 230℃ and 1.8 MPa. The carbon nitride nanotubes were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron diffraction (ED), electron energy loss spectrum (EELS) and Raman spectrum.SEM and TEM results indicated that the tubes have a length of 20-30 μm, a uniform outer diameter of about 50-60 nm,an inner diameter of 30-40 nm and are highly ordered assembled as bundles. The EELS measurement indicated that the ratio of N/C was about 1.00. The ED and XRD analyses revealed that the tube may have a new CN crystalline structure. The growth mechanism of nanotubes was discussed.     

原位合成TiB/Ti复合材料的微观结构及力学性能

利用钛与硼之间的自蔓延高温合成反应经普通的熔铸工艺原位合成制备了TiB增强的钛基复合材料.通过XRD、SEM、TEM和HREM等分析方法测试了合成材料的物相及微观结构.结果表明原位合成的增强体为TiB,合金化元素铝的加入并不导致新相形成,增强体均匀地分布在基体合金上.由于TiB的B27结构导致TiB易于沿[010]方向生长而长成短纤维状.增强体与基体合金界面非常洁净,没有任何界面反应.由于原位合成增强体的加入,复合材料的力学性能与基体合金比较有了明显的提高.     

防水透气型加气混凝土砌块界面剂的研究

通过正交试验、优化试验和电镜扫描试验,以粘结性、防水性、保水性和透气性为基本指标,研究防水透气型加气混凝土砌块界面剂及其工作机理.     

Regulating the steric effect at the zero-dimensional interface

The regulation mechanism of a zero-dimensional interface towards a catalytic reaction in the setting of a single-atom catalyst has been elusive to researchers. In a recent article published in Journal of the American Chemical Society, Zeng and Zhou et al. differentiated the electronic and steric effects on the oxygen evolution reaction at two distinct zero-dimensional interfaces. The steric interaction resulted in the desired adsorption behavior of intermediates at the interface, which lowered the energy barrier to the rate-determining step (RDS) and thus facilitated the oxygen evolution reaction. For the first time, this work validated the impacts of electronic and steric effects on the atomic interface of catalysts by delicately designing the anchoring site of single atoms on the support. The elegant design concept presented in this work pushes the research field of interface engineering to the atomic level and blazes a trail for the rational development of high-performing catalysts.