植酸盐掺杂聚吡咯/纳米SiO_2/环氧树脂长效耐蚀涂层的制备及缓蚀性能

以FeCl_3为氧化剂,植酸钠(IP_6)为掺杂剂,纳米SiO_2为分散介质,通过化学氧化法合成了具有核-壳结构的IP_6掺杂聚吡咯(PPy)/纳米SiO_2粒子。利用电感耦合等离子体原子发射光谱法考察了氧化剂和分散剂用量以及反应温度对掺杂率的影响。利用TEM、XRD和热重分析法(TG)对IP_6掺杂PPy/纳米SiO_2粒子的形貌、结构和热稳定性进行了表征。利用电化学阻抗(EIS)技术对IP_6掺杂PPy/纳米SiO_2/环氧树脂长效耐蚀复合涂层的耐蚀性进行了评价。结果表明:PPy均匀包覆在纳米SiO_2粒子表面,形成形貌规则且具有核-壳结构的稳定IP_6掺杂聚吡咯(PPy)/纳米SiO_2粒子。当n(Py)∶n(FeCl_3)=2∶1,m(SiO_2)∶m(Py)=1∶5,反应温度为-5℃时,制备的PPy/纳米SiO_2材料中IP_6掺杂率为98.53%。以IP_6掺杂PPy/纳米SiO_2粒子为功能成分,环氧树脂为成膜物质,制备的IP_6掺杂PPy/纳米SiO_2/环氧树脂长效耐蚀复合涂层对1.0mol/L HCl介质中的Q235钢腐蚀具有良好的抑制效果。     

TiO2/PLCL可降解聚合物纳米复合材料的制备及形状记忆性能

制备TiO2/聚(L-丙交酯-ε-己内酯)(PLCL)纳米复合材料并研究其性能.采用ε-己内酯开环聚合法对TiO2纳米粒子进行表面改性,通过傅立叶变换红外光谱(FTIR)、热重分析(TGA)和透射电子显微分析(TEM)对聚己内酯(PCL)接枝改性后的TiO2纳米粒子(g-TiO2)进行表征.g-TiO2纳米粒子能均匀地分散在三氯甲烷溶液中.采用溶液浇铸的方法成功地制备了TiO2/PLCL复合材料.研究g-TiO2纳米粒子的含量对材料力学性能和形状记忆性能的影响.结果表明,5％ g-TiO2/PLCL复合材料的力学性能有显著的提高,与纯PLCL相比,抗拉强度提高了113％,伸长率提高了11％.含有g-TiO2纳米粒子的复合材料的形状记忆性能优于纯PLCL.g-TiO2纳米粒子具有物理交联作用,有助于形状记忆效应的提高.     

RuO2包覆的TiO2纳米复合粒子的表面与界面分析

将溶胶-凝胶法与水热合成技术相结合制备了RuO2包覆量为1.5%的TiO2纳米复合粒子,并采用X射线衍射(XRD)、原子力显微镜(AFM)、傅立叶变换红外光谱(FT-IR)及X射线光电子能谱(XPS)详细研究了纳米复合粒子的表面与界面性质.结果表明,RuO2以非晶态高度分散在TiO2纳米粒子表面形成包覆层,TiO2的晶型为锐钛矿型;纳米复合粒子呈球形,平均粒径约为47.5nm,RuO2包覆层的平均厚度约为0.75nm;RuO2包覆层与核材料TiO2纳米粒子表面存在化学键的作用,这种化学包覆有利于提高纳米复合粒子结构和性能的稳定性.     

Ag/TiO2纳米复合材料的结构及抗菌性能研究

采用化学氧化法在金属Ti表面制备出了多孔纳米TiO2,通过离子束溅射在TiO2表面沉积纳米Ag,最终在Ti表面制备出Ag/TiO2纳米复合材料.利用X射线衍射(XRD)、扫描电镜(SEM),电子探针(EPMA)等分析手段分析了500℃热处理条件下,不同Ag含量对TiO2晶型转变的影响及结构变化.同时,采用细菌生长的抑菌圈法进行测试,研究了Ag/TiO2纳米复合材料对不同菌种的抗菌性能的影响.结果表明:通过化学氧化法和离子束溅射相结合的方法可以得到具有优异抗菌性能的Ag/TiO2纳米复合材料.     

Ag-TiO2复合纳米颗粒的自组装法制备及其光催化性

采用空气-水界面自组装法制备TiO2纳米粒子,将其放入AgNO3溶液中浸泡,后在较低温度下进行热处理(400℃),获得Ag-TiO2复合纳米颗粒.利用X射线衍射(XRD)仪、扫描电镜(SEM)、透射电镜(TEM)、紫外可见光谱(UV-vis)等分析测试手段进行表征.结果表明:复合粒子可以显著提高TiO2颗粒光催化活性.以甲基橙为模拟污染物,经过光催化试验,证实复合纳米粒子具有较好的光催化活性,降解率达到96.25％.     

溶胶-凝胶法制备纳米CuO-TiO2复合粉体

以乙酸铜和钛酸丁酯为初始原料,利用溶胶-凝胶法制备纳米CuO-TiO2粉末,采用差热-失重(DTA-TG)、红外吸收光谱(FTIR)、X射线衍射(XRD)、透射电镜(TEM)等分析手段对粉料进行表征.结果表明CuO-TiO2干凝胶在进行热处理后得到纳米级CuO和TiO2粒子,平均粒子尺寸在40 nm左右;随CuO含量的增加,TiO2晶化温度和相变温度(TiO2由锐钛矿相向金红石相)降低,纳米粒子的团聚相应减少.     

高能球磨制备纳米TiO2/纳米晶Cu超细复合粉体

采用高能球磨法制备了TiO2/Cu复合粉体并采用X射线衍射(XRD)、显微图像分析仪等测试分析方法,对球磨过程中复合粉末相结构、组织形貌和粒度分布的变化进行了研究.结果表明:球磨24 h后可形成纳米TiO2粉体/纳米晶Cu复合粉体,Cu粉晶粒达59 nm;随着球磨时间的增加,纳米TiO2团聚体逐渐嵌入Cu颗粒中,被很好地分散开,呈弥散分布;同时复合粉体粒度细化到300 nm以下,比表面积大大增加,粉体也由球形逐渐地过渡到多角形.     

纳米复合材料CdS/TiO2NTs的制备及光催化产氢活性

通过离子交换和沉淀反应制备纳米复合材料CdS/TiO2NTs.采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、漫反射紫外-可见吸收光谱(DRUVAS)、荧光光谱(FES)、X射线荧光分析(XRF)等手段对该复合材料的结构进行表征.SEM结果表明:钛酸盐纳米管的形成经由TiO2颗粒-片状的钛酸盐-卷曲的钛酸盐纳米管的自组装过程.XRD、DRUVAS、FES和FES结果表明:平均粒度大约 8 nm 的六方相CdS均匀的负载于锐钛矿型TiO2纳米管表面,其吸收边扩展到可见区.与TiO2纳米管及TiO2粉末相比,CdS/TiO2NTs 纳米复合材料展示了较高的可见光催化分解水产氢活性.     

包裹和热压制备Al2O3/Cu复合材料及性能研究

采用非匀相沉淀法制备了纳米Cu包裹Al2O3复合粉体,并利用热压烧结制备出Al2O3/Cu复合材料.利用X-ray衍射(XRD)、热重/差式-量热扫描法(TG/DSC)、透射电镜(TEM)对复合粉体的成分、热学特性以及形貌特征进行了表征;利用扫描电镜(SEM)、显维硬度计及万能试验机测试分析了复合材料的微观结构及力学性能.结果表明,利用非匀相沉淀法可以得到Cu包裹Al2O3的纳米复合粉体,包裹层为非连续态的纳米Cu颗粒,颗粒呈球形,尺寸为10nm左右.同单相Al2O3陶瓷相比,Al2O3/Cu复合陶瓷的力学性能有显著提高,断裂韧性是单相Al2O3陶瓷的1.5倍,复合陶瓷的抗弯强度比单相Al2O3陶瓷提高,且数值离散性下降.     

Ag/TiO_2纳米复合材料的制备及结构研究

首先采用化学氧化在块体Ti表面制备出多孔纳米TiO2,随后通过高能离子束轰击实现Ag纳米粒子在TiO2表面的有效固定,最终在Ti表面制备出Ag/TiO2纳米复合材料。采用XRD、SEM及TEM手段对其进行了结构表征。结果表明,化学氧化法可制备出多孔纳米TiO2,其晶粒尺寸为10 nm左右;通过调节高能Ar离子束轰击的时间,可对TiO2晶粒尺寸进行小范围有效控制。     

Preparation and characterization of visible light-driven AgCl/PPy photocatalyst

Visible light photoactive AgCl/polypyrrole (PPy) composites were prepared via the reaction between excessive Ag⁺ and Cl⁻ ions in the presence of PPy_. The AgCl/PPy composites were systematically characterized using Fourier transform infrared (FTIR) spectroscopy, Raman spectra, X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission electron microscope (TEM) and Thermal gravity analysis (TGA). It was found that face-centered cubic AgCl nanocrystallite and 0.2 wt% PPy component existed in the composite and spherical AgCl/PPy nanoparticles were in the range of 200-600 nm. The AgCl/PPy composites showed higher visible light-driven photocatalytic activity and stability than that of AgCl. A photoreduction mechanism was postulated for AgCl/PPy photocatalyst on dye methyl orange (MO). The used AgCl/PPy photocatalyst was facilely regenerated by an oxidation process in aqueous FeCl₃ solution.     

Ag/AgCl-decorated polypyrrole nanotubes and their sensory properties

A facile method to prepare Ag/AgCl-decorated polypyrrole nanotubes (PPy/Ag–AgCl nanocomposites) has been demonstrated. PPy nanotubes were assembled on the reactive self-degraded template of a fibrillar complex of FeCl₃ and methyl orange (MO). By introducing PPy nanotubes into AgNO₃ solution, Ag and AgCl nanoparticles could be uniformly decorated onto the PPy nanotube surface in situ by the reaction of PPy and AgNO₃. The morphology and structure of the nanocomposites were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The possible application of PPy/Ag–AgCl nanocomposites as a vapor sensor has also been reported. The responses of these nanocomposites were observed to be reversible by monitoring the change in the resistance of the nanocomposites upon exposure to ammonia vapor. PPy/Ag–AgCl composite nanotubes sensors showed enhanced chemiresistor sensitivity compared with PPy nanotubes.     

Facile sonochemical synthesis and photocatalysis of Ag nanoparticle/ZnWO_4-nanorod nanocomposites

A facile sonochemical method was developed to synthesize metallic Ag spherical nanoparticles on the surface of ZnWO_4 nanorods by forming heterostructure Ag/ZnWO_4 nanocomposites.The Ag/ZnWO_4 nanocomposites were characterized by X-ray powder diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).The experimental results showed that fcc metallic Ag nanoparticles were supported on surface of monoclinic sanmartinite ZnWO_4 nanorods.The Ag3d_(3/2) and Ag 3 d_(5/2) peaks have well-separated binding energies of 6.00 eV,certifying the existence of metallic Ag.The Ag/ZnWO_4 nanocomposites were evaluated for photodegradation of methylene blue(MB)induced by ultraviolet-visible(UV-Vis)radiation.In this research,heterostructure 10 wt% Ag nanoparticle/ZnWO_4-nanorod composites have the highest photocatalytic activity of 99%degradation of MB within 60 min.The increase in photocatalytic activity was the result of photoinduced electrons in conduction band of ZnWO_4 that effectively diffused to metallic Ag spherical nanoparticles and the inhibition of electron-hole recombination process.     

Polypyrrole/conductive mica composites: Preparation,characterization, and application in supercapacitor

Polypyrrole/conductive mica (PPy/CM) composites were prepared by coating polypyrrole (PPy) onto the surfaces of the conductive mica (CM) via the in situ chemical oxidative polymerization method. The encapsulating morphologies were revealed with the scanning electron microscopy (SEM) technique. The PPy/CM composites were characterized with Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The composites possess high electrical conductivity at room temperature, the weak temperature dependence of the conductivity. Based on the cyclic voltammetry and the charge/discharge behavior of the PPy/CM composites, it was found that the composites performed typical electrochemical supercapacitor behavior.     

Rapid communication Preparation of TiO_2 nanometer thin films with high photocatalytic activity by reverse micellar method

Two kinds of TiO2 nanometer thin films were prepared on stainless steel by the reverse micellar and sol-gel methods, respectively. The calcined TiO2 thin films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), BET surface area and X-ray photoelectron spectroscopy (XPS). Photocatalytic activity was evaluated by photocatalytic decoloration of methyl orange aqueous solution. The results showed that the TiO2 thin films prepared by reverse micellar method (designated as RM-TiO2 films) showed higher photocatalytic activity than those by sol-gel method (designated as SG-TiO2 films). This is attributed to the fact that the former is composed of smaller monodispersed spherical particles with a size of about 15 nm and possesses higher surface areas.     

Polypyrrole/vermiculite nanocomposites via self-assembling and in situ chemical oxidative polymerization

Conductive polypyrrole (PPy) was chemically grafted from the self-assembled monolayer (SAM) coated on expanded vermiculite (VMT), resulting in PPy/VMT nanocomposites after VMT particles were surface modified. X-ray diffraction (XRD) analysis confirmed that the main peaks of PPy/VMT nanocomposites are similar to the SAM–VMT particles, which reveal that the crystal structure of SAM–VMT is well maintained after the coating process under polymerization conditions and exhibit semi-crystalline behavior. Thermogravimetric analysis shows that the thermal stability of PPy/VMT nanocomposites was enhanced and these can be attributed to the retardation effect of amine-functionalized VMT as barriers for the degradation of PPy. The morphology of PPy/VMT nanocomposites showed the sheet structure and encapsulated morphology. The composites possess high electrical conductivity at room temperature, weakly temperature dependence of the conductivity.     

碳对接触反应法制备TiC-Al2O3P/Al复合材料组织的影响

以Al、TiO2、C为原材料,用接触反应法制备了TiC-Al2O3P/Al复合材料,采用XRD和SEM手段测定了材料的相组成、组织形貌及相分布,分析了碳含量对组织的影响。试验结果表明,该复合材料主要由分布于Al基体中的球状或近球状的TiC颗粒、不规则的Al2O3颗粒和少量的TiAl3组成,且随含碳量的增加,TiAl3减少;当C和TiO2比超过1.5后,TiAl3基本消失,但出现TiC2相。     

Two step novel chemical synthesis of polypyrrole nanoplates for supercapacitor application

Simple and inexpensive two step novel chemical method for the synthesis of polypyrrole (PPy) nanoplates has been reported. These PPy nanoplates are characterized with X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Polypyrrole nanoplates exhibit amorphous nature as confirmed from XRD study. Based on SEM and TEM analysis, the formation of the spherical bunches of PPy nanoplates with average size of about 20 nm are inferred. The electrochemical performance of PPy electrode was evaluated by cyclic voltammetry (CV) and galvanostatic charge-discharge measurement. A high specific capacitance of 533 F g⁻¹ was obtained within the potential range of −0.4 to 0.6 V in 0.5 M H₂SO₄ solution. Moreover, PPy electrode exhibited high discharge/charge efficiency of 93% and the capacitance retention of 83% at a current density of 10 mA cm⁻² indicating good electrochemical reversibility and rate capability.     

Electrospinning PVDF/PPy/MWCNTs conducting composites

Conducting PVDF/PPy composites (PPy composites) were prepared by using the highly porous electrospun (e-spun) nonwoven web as a host polymer. E-spun nonwoven web was made by electrospinning a solution of PVDF and CuCl₂·2H₂O in solvent of N,N-dimethylacetamide (DMAc). The PPy composites were fabricated by exposing a nonwoven web containing oxidant to pyrrole vapors. Field-emission scanning electron microscopy (FE-SEM) analysis was conducted to show the microstructure of the nonwoven webs and the uniform coating of PPy on the e-spun fiber surfaces of the PPy composite. The information of PPy on the e-spun fibers surface was confirmed by attenuated Fourier-transform infrared spectrometer (ATR FT-IR) and X-ray photoelectron spectroscope (XPS). The thermal property of PPy composites was also investigated by differential scanning calorimeter (DSC) and thermogravimetric analyzer (TGA). The electrical conductivity of the PPy composites was affected by the fabrication method and oxidant content in the nonwoven web. The electrical conductivity and mechanical strength of the PPy composites were improved when surface-modified multi-walled carbon nanotubes (MWCNTs) were added to the e-spun fibers. Energy-filtered transmission electron microscopy (EF-TEM) results confirmed that the MWCNTs were well arranged and embedded in the e-spun fibers. The observed conductivity of the conducting PPy-MWCNTs composite was 10^?1 S/cm.