Synthesis,characterization, and colloidal properties of polythiophene/borax conducting composite

In this study, synthesis of polythiophene (PT) and polythiophene/borax pentahydrate (PT/borax) conducting composite were carried out by in‐situ oxidative polymerization. The composite was subjected to various characterization techniques namely: FTIR, particle size, magnetic susceptibility, density, conductivity, dielectric, TGA, XRD, SEM, and zeta (ζ)‐potential measurements. The effects of time, pH, various surfactants, electrolytes and temperature on the ζ‐potential of PT and PT/borax composite were investigated. In a basic medium the ζ‐potential of the composite was observed to decrease up to ζ = −66.5 mV. The most effective surfactant on the ζ‐potential of the composite was sodium dodecyl sulfate, which reduced the value of ζ‐potential to ζ = −39.2 mV. It was concluded that the presence of mono‐valent (NaCl) salt has no impact on ζ‐potential whereas, di‐valent (BaCl₂) salt shifted the ζ‐potential value to more positive regions. Elevated temperatures caused almost no change on the ζ‐potential of the composite. Also an electrorheological effect (a tremendous viscosity increase) was determined from the PT/borax colloidal systems under an externally applied electric field, and the results obtained will be discussed in the forthcoming article. POLYM. COMPOS., 2011. © 2010 Society of Plastics Engineers     

2-二茂铁基青霉烯的合成与表征

以4-乙酰氧基氮杂环丁酮(4-AA)为原料,依次与二茂铁硫代甲酸和烯丙氧基草酰氯作用引入两条不同的侧链后,经Wittig反应关环、脱羟基和羧基保护基得到标题化合物。该路线条件温和、立体选择性好,总收率33.3%。中间体及产品的结构均通过IR、MS和1HNMR确认。     

Synthesis and characterization of TiO2 nanoparticles

TiO₂ nanoparticles were synthesized by thermal decomposition of a precipitate obtained from a precursor solution of titanium isopropoxide (IV) and isopropyl alcohol. The as-prepared precipitate was heated at various temperatures and the obtained samples were morphologically, texturally and structurally characterized using TGA–DTA, gas adsorption, SEM, XRD and FTIR. The UV–vis radiation absorption and the photocatalytic activity also were verified. The TiO₂ sample heated at 300 °C shows the best results to be applied as blocker in solar skin protector.     

Synthesis,characterization and antimicrobial activity of colloidal copper nanoparticles stabilized by cationic thiol polyurethane surfactants

Metal nanoparticles have attracted considerable interest particularly because of the size dependence of physical and chemical properties and its enormous technological potential. Among different metal nanoparticles, copper nanoparticles have attracted great attention because copper is one of the most key metals in new technology. Chemical methods are used to synthesize copper nanoparticles. Chemical reduction is the most frequently applied method for the preparation of stable, colloidal dispersions in organic solvents. In this paper, the new cationic thiol polyurethane surfactants with different alkyl chain length were synthesized (PQ10, PQ14 and PQ18). The chemical structure of the synthesized surfactants was confirmed using infra-red spectroscopy (IR) and proton nuclear magnetic resonance spectroscopy (¹HNMR). Copper nanoparticles colloidal solution of 40–80 nm diameters was prepared using sodium borohydride in aqueous solution at room temperature as reducing agent. The synthesized surfactants decrease the aggreegation of copper nanoparticles. The nanostructure of the synthesized surfactant with copper nanoparticles with diameters ranging from 31.5 to 10.3 nm was prepared and characterized using ultra violet spectrophotometer (UV), infra-red spectroscopy (IR) and transmission electron microscope (TEM). The results declare formation and stabilization of copper nanoparticle using synthesized cationic surfactants. Antimicrobial activity of the synthesized cationic surfactants and their nanostructure with copper nanoparticles were evaluated against pathogenic bacteria and fungi.     

Synthesis and characterization of organic-inorganic hybrid thin films from poly(acrylic) and monodispersed colloidal silica

Hybrid thin films containing nano-sized inorganic domain were synthesized from poly(acrylic) and monodispersed colloidal silica with coupling agent. The 3-(trimethoxysilyl)propyl methacrylate (MSMA) was bonded with colloidal silica first, and then polymerized with acrylic monomer to form a precursor solution. Then, the precursor was spin coated and cured to form the hybrid films. The silica content in the hybrid thin films was varied from 0 to 50 wt%. The experimental results showed that the coverage area of silica particle by the MSMA decreased with increasing silica content and resulted in the aggregation of silica particle in the hybrid films. Thus, the silica domain in the hybrid films was varied from 20 to 35 nm by the different mole ratios of MSMA to silica. The results of scanning electron microscope, transmission electron microscope, and elemental analysis support the above results. The prepared hybrid films from the crosslinked acrylic polymer moiety showed much better film uniformity, thermal stability and mechanical properties than the poly(methyl methacrylate) (PMMA) based hybrid materials. Large pin-holes were found in the PMMA-silica hybrid films probably due to the significant difference on thermal properties between the two moieties or the evaporation of solvent. The refractive index decreased linearly with increasing the silica fraction in the hybrid films. Excellent optical transparence was obtained in the prepared hybrid films. These results show that the hybrid thin films have potential applications as passive films for optical devices.     

6-氯-2-吡啶酮的合成和结构表征

以吡啶为起始原料，经光氯化法合成2,6-二氯吡啶。再以水为介质在加压条件下使2,6-二氯吡啶酸性水解而合成6-氯-2-吡啶酮，产率可达85％，并通过红外光谱、核磁、质谱对其的结构进行了测定，证明了合成方法的可靠性。     

复合掺杂的纳米二氧化锡粒子的制备与表征

分别采用微乳液法（辛基酚聚氧乙烯醚＋正己醇／环己烷／水组成的微乳液体系）和柠檬酸溶胶-凝胶法制备了镁与铈、锌、锆复合掺杂的纳米二氧化锡颗粒，通过热分析（TG-DTA）、X射线衍射（XRD）、比表面积测定（BET）、红外吸收光谱（FT-IR）和紫外-可见光谱（Uv-Vis）对其结构进行表征。结果表明，两种方法制备的产物均为金红石结构，微乳液法制备的颗粒较后者具有较小的晶粒粒径、较大的比表面积和紫外吸收边；复合掺杂后，样品的粒径减小，比表面积增大，样品的紫外-可见吸收发生红移；其中，镁-铈复合掺杂的样品具有最小的晶粒粒径和最大的比表面积，分别为4．53nm和78．50m^2／g；复合掺杂能够抑制二氧化锡颗粒生长，增大其比表面积。     

二氧化钛介孔材料的制备

基于溶胶-凝胶过程,以十六烷基溴化铵为模板剂,合成了TiO2以及V/Ce/F-TiO2 介孔材料。利用XRD、Ｎ２吸附、TEM、TG-DTA和UV-Vis DRS等手段表征了材料的晶相组成、晶粒尺寸、介孔结构、热稳定性及吸光性能。通过系统研究表明,延长凝胶时间和优化陈化工艺可以得到TiO2介孔材料。TiO2和V/Ce/F/TiO2的平均孔径为3.1～5.1 nm,最大比表面积可达189 m2/g。焙烧温度大于450 ℃脱除模板剂时可引起孔道的塌陷,而掺杂V/Ce/F后可稳定材料的介孔结构。相对于纯TiO2光催化剂,掺杂V/F的TiO2吸光带边红移至可见光区。     

苯并咪唑-2-丙酸甲酯的合成及表征

以邻苯二胺和丁二酸酐为原料,首次合成了苯并咪唑-2-丙酸甲酯.用IR、1HNMR、元素分析对其进行表征,X-射线分析数据表明其晶体结构为单斜晶系,Cc空间群,对影响反应的温度因素进行了讨论分析.     

fnSiO2@mSiO2核壳粒子的制备及表征

本文将掺杂有三元荧光共振能量转移染料对的SiO2纳米核引入介孔SiO2球形粒子中,形成在单一波长激发下能产生多色荧光发射的核壳结构。产物通过TEM、XRD、BET等方法进行了表征。结果表明:成功制备得到以荧光纳米粒子为核,介孔SiO2为壳层的核壳粒子(fnSiO2@mSiO2),介孔孔径为2.5nm。     

2-异丙基-5-甲基-2-己烯醛的合成与表征

以异戊醛为原料,在回流加热条件下进行羟醛缩合反应合成了2-异丙基-5-甲基-2-己烯醛。考察了催化剂种类和用量、相转移催化剂用量和反应时间等关键因素对反应的影响。实验结果表明,氢氧化钠作催化剂,其用量为异戊醛质量的3.0%,四丁基溴化铵作相转移催化剂,其用量为异戊醛质量的1.0%,反应3 h时,产物收率为83.3%。产品用红外光谱以及1H和13C核磁共振谱进行表征。     

胶体晶体模板法制备三维有序排列的大孔SiO2材料

将粒径为480 nm的聚苯乙烯微球离心组装为胶体晶体模板,以正硅酸乙酯为硅源配制SiO₂溶胶并填充到模板间隙,原位形成凝胶,最后通过焙烧去除模板,得到三维有序大孔（3DOM）SiO₂。通过SEM检测,大孔以六方有序的方式排列,其孔径及孔径收缩率分别为360 nm和25％。大孔之间由小窗口连通,构成内部三维交联的大孔网络。低温N₂吸附测试表明,大孔孔壁上存在中孔孔隙,其中在3～4 nm有一集中的孔分布。XRD显示,制备的3DOM材料由无定形SiO₂组成。     

Synthesis and characterization of polymers containing naphthyl-2H-benzotriazoles, 2. Polymer synthesis and characterization

2-(2-Hydroxy-7-(meth)acryloyloxynaphthyl)-2H-benzotriazoles were polymerized and copolymerized with styrene and methyl methacrylate in dichloromethane using azoisobutyronitrile as the initiator. The polymer composition was determined by UV spectroscopy and compared with elemental analytical data; the molecular weights were determined by GPC. In homopolymerization, low molecular weight products were obtained due to the bulky naphthyl-2H-benzotriazole units. In the case of copolymerization with methyl methacrylate it was found, that the composition of the polymers was very close to the initial ratio of the monomers, whereas in copolymers with styrene the amount of incorporated benzotriazole was higher.     

纳米ZrO2/SnO2催化剂的制备与表征

以ZrOCl₂·8H₂O和SnCl₄·5H₂O为原料，通过溶胶-凝胶法和正丁醇共沸蒸馏处理方法，合成具有纳米尺寸的ZrO₂/SnO₂复合催化剂。通过差示扫描量热仪、X射线衍射及场发射扫描电镜的测定，结果表明，合成得到的复合催化剂晶粒为10～20 nm，具有四面体相和三斜相两相。     

Synthesis and characterization of the atomic laminate Mn2AlB2

Herein, we synthesize dense, predominantly single-phase polycrystalline samples of the Mn₂AlB₂ ternary compound, using reactive hot-pressing of manganese, aluminum, and boron powder mixtures under vacuum. With a Vickers hardness of 8.7?GPa, Mn₂AlB₂ is relatively soft for a transition metal boride and lacked dominant cracks at the corners of the indentations. With Young’s and shear moduli of 243?GPa and 102?GPa at 300?K, respectively, it is reasonably stiff. The Poisson’s ratio is calculated to be 0.19. With compressive strengths of 1.24?±?0.1?GPa, the samples were quite strong considering the grain size (1–15?μm). The electrical resistivity at 300?K was ～5 μΩm and decreased linearly upon cooling. At 0.0036?K^?1, the temperature coefficient of resistivity was relatively high compared to MoAlB. The average linear thermal expansion coefficient was also found to be relatively high at 18.6?×?10^-6?K^?1 from 298 to 1173?K. Mn₂AlB₂ was not thermally stable above ～1379?K. While Mn₂AlB₂ was not machinable with conventional tooling, intriguingly, high-speed carbide tools bits readily penetrate the surface – with no cracking or chipping for a few millimeters – before stopping.     

中空结构Cu_2S微球的制备与表征

以四水合醋酸铜为原料,采用乙二醇回流法首先制备出氧化亚铜微球,然后以氧化亚铜为模板,在室温下制备出具有中空结构的硫化亚铜微球。利用现代分析手段对产物的尺寸、形貌、晶体结构以及成分进行了表征,并探讨了中空结构Cu2S微球的形成机理。     

2-甲基咪唑封闭型水性多异氰酸酯的合成及表征

将基于TDI的多异氰酸酯与二羟甲基丙酸(DMPA)反应,再用三乙胺(TEA)中和成盐及2-甲基咪唑(2-MI)封端后,制得一种水分散性封闭多异氰酸酯(WBI)。研究了封闭时间对封闭率的影响,采用FT-IR对封闭反应过程进行跟踪,通过TGA、DSC研究了其解封温度。结果表明,封闭反应的适宜条件为:2-MI与—NCO物质的量比为1.1～1.2∶1;反应温度60℃;反应时间2.5 h,解封温度为125.6～137.8℃。将WBI作为涂料固化剂可明显改善漆膜性能。     

苯并-P-胺基-2-磷杂-1,3-二氧杂环己烷的合成及表征

以廉价、易得的三氯化磷、仲胺、邻羟甲基苯酚为原料,通过简单的两步反应,合成了6种新型多功能亚磷酰胺配体,收率达85%以上。通过1HNMR谱和1 3CNMR谱对其结构进行了表征,所得结果与标题化合物相符。     

Synthesis and characterization of poly(2-methylaziridine)

Summary The cationic polymerization of 2-methylaziridine using boron trifluoride etherate as initiator at different monomer/initiator ratios, temperatures, solvents, and times of polymerization was carried out. The effect of these variables on the polymerization yield and viscosity of the polymers was studied. All the polymers were characterized by elemental analysis, FT-IR, ¹H-NMR, ¹³C-NMR spectroscopy, thermogravimetric analyses and differential scanning calorimetry.     

Synthesis and characterization of polycrystalline Mo2BC ceramic

Single-phase polycrystalline Mo₂BC ceramic bulks were synthesized successfully from molybdenum, boron, and graphite powders using the spark plasma sintering method. Herein, it was established that the synthesis temperature of the Mo₂BC ceramic could be as low as 1300 °C. Transmission electron microscopy (TEM) characterization confirmed that the crystal structure of the Mo₂BC ceramic was comparable to that of the MoAlB ceramic. The Vickers hardness of the Mo₂BC ceramic was measured to be 18.1 GPa. Additionally, the compressive strength, flexural strength, and fracture toughness were determined to be 1.74 GPa, 457.72 MPa, and 3.26 MPa· m^1/2, respectively. The Mo₂BC bulk exhibited typical brittle features, in which intergranular and transgranular fractures were the main failure modes.