无机矿化剂辅助水热合成高长径比的α-Fe2O3多孔纳米线

本文以K2SO4为矿化剂,在100℃低温水热条件下.制备出大量形貌均一、高分散的直径约40 nm、长度为2～3μm的αFeOOH纳米线.该纳米线在300℃煅烧2 h后,得到一维形貌保持良好且表面具有多孔结构、长径比可达20的α-Fe2O3纳米线.通过XRD、FTIR、TG-DSC、HRTEM、SAED以及N2物理吸附技术对产物的形貌和结构进行了表征.研究发现.无机盐对一维纳米线形貌的控制至关重要,还详细讨论了K2SO4在α-FeOOH纳米线的成核和生长过程中所起的作用.     

蔗渣木聚糖磷酸酯的合成与表征

以蔗渣木聚糖为主要原料,正磷酸盐(NaH2PO4与Na2 HPO4)为酯化剂,尿素为催化剂,在湿法工艺下合成了蔗渣木聚糖磷酸酯.考察了酯化温度、酯化时间、蔗渣木聚糖与酯化剂和催化剂配比、pH等因素对取代度的影响,采用正交试验设计对合成条件进行优化,运用统计分析方法探讨了各因素影响的主次顺序和显著性,得到较佳的合成条件为...     

氟化物体系中老化方式对合成MCM-22分子筛的影响

 以氟化钠为矿化剂、六亚甲基亚胺为模板剂,在静态水热条件下考察了静态老化、动态老化及超声老化对合成MCM-22分子筛的影响. 实验结果表明,三种老化方式对合成MCM-22分子筛均有促进作用,其中超声老化的促进作用最明显. 采用超声老化的方法,在氟化物体系中使MCM-22分子筛可合成SiO2/Al2O3摩尔比范围扩大到 20～100, 合成时间缩短到 48～62 h, 同时分子筛的形貌发生了改变.     

Trition X-100/C_(10)H_(21)OH/H_2O体系层状液晶中纳米羟基磷灰石粉体的合成

本文以Triton X-100/C10H21OH/H2O体系层状溶致液晶为模板,Ca(NO3)2和(NH4)2HPO4为反应物,在一定的pH条件下,通过三元相图确定了层状液晶单相区域,并合成了羟基磷灰石(HA)纳米颗粒。用傅立叶红外光谱(FTIR),X射线衍射(XRD)和透射电子显微镜(TEM)对产物进行了表征。并考察了不同助表面活性剂浓度和不同表面活性剂浓度对产物的形貌和尺寸的影响。结果表明所制备的HA纳米颗粒平均直径为8~10nm、长度在100nm左右,呈针状。助表面活性剂浓度对HA形貌及尺寸影响不大,但是在一定范围内改变表面活性剂浓度可以起到调控HA纳米颗粒形貌和尺寸的作用。     

二维层状磷酸亚磷酸钒(Ⅳ)化合物[V_2O_2(OH)(HPO_3)(HPO_3)_(0·7)(PO_3OH)_(0·3)]·(C_6N_2H_(16))_(0·5)的水热合成与结构表征

迄今,在中温水热条件下已合成了大量具有空旷骨架结构的过渡金属磷酸盐微孔材料[1],这类材料在非线性光学材料、磁性材料、超导材料及催化等诸多方面具有潜在的应用前景[2~5].自从第一个以有机胺为模板的磷钒氧化合物[(CH3)2NH2]K4[V10O10(H2O)2(OH)4(PO4)7]·4H2O[6]的合成以来,又有几十种结构的磷钒氧化合物被报道.但以亚磷酸为结构基元构筑的磷钒氧化合物的报道较少.1995年,Zubieta等[7]报道了以哌嗪为模板剂的两个亚磷酸钒化合物[HN(Me)(CH2CH2)2N·(Me)H][(VO)4(OH)2(HPO3)4]和[H2N(CH2CH2)2NH2][(VO)3(HPO3)4(H2O…     

水热法合成ReMn2O5(Re=Gd，Sm，Yb)纳米粉体

本文采用水热法,以KMnO4和Mn(C2H3O2):为锰源,在250℃反应24 h合成了高各向异性的GdMn2O5、SmMn2O5和YbMn2O5纳米粉体.利用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、选区电子衍射(SAED)、和高分辨透射电镜(HRTEM)对产物的结构和形貌进行了表征.结果表明,所制备的ReMn2O5(Re=Gd,Sm,Yb)均为正交相结构.反应溶液中碱性矿化剂浓度对产物的形貌和尺寸有重要的影响.通过实验结果分析了纳米结构的形成机理.     

乙醇-无机盐双水体系中研究XO的萃取行为

研究了二甲酚橙(XO)在乙醇-无机盐双水相萃取体系中的萃取行为,对无机盐种类、缓冲溶液和其用量等条件进行了优化,在最优条件下研究了上下层体积与萃取率、分配比等因素的变化规律.结果表明:在使用K2HPO4 - KH2PO4缓冲溶液5.0 mL,95％乙醇6.0 mL,K2HPO46.0g,乙醇和蒸馏水体积比为1∶2的条件...     

[In2(HPO3)4]·(NH3CH2CH2NH3)的水热合成与晶体结构

用乙二胺作模板剂在水热条件下合成出一个新的三维开放骨架结构的亚磷酸铟[In2(HPO3)4]·(NH3CH2CH2NH3)(1), 并对其晶体结构进行了测定和表征.     

六方相WO3纳米带的制备与表征

以Na2WO4、K2SO4和H2C2O4为原料,采用两步水热合成法制备了六方相WO3纳米带.首先,在探索pH值、K2SO4加入量、反应温度和时间以及表面活性剂等因素对WO3纳米带的前驱物钨酸盐形貌的影响后,给出了前驱物钨酸盐纳米带的合成条件,并讨论了纳米带的形成机理;然后,在180℃的水热条件下对前驱物再处理48 h获得六方相WO3纳米带.测试结果表明,WO3纳米带的形貌保持较好,宽度在100～300 nm间,长度可达数微米,沿纳米带长轴方向为[001]方向.     

SAPO-11的绿色制备及在棕榈油催化加氢制备生物航煤方面的应用

通过加入晶种的方法降低在合成SAPO-11分子筛过程中有机胺类模板剂的含量从而减少对环境的污染。通过调节晶种及模板剂的含量,得到加入4%晶种、模板剂与Al2O3物质的量比值(ntemplate/nAl2O3)为0.6的条件下得到的晶体的形貌、结晶度等最好。分子筛负载Ni-Mo金属合成催化剂,以棕榈油加氢脱氧产物(HDO)为原料,在623 K下测得对生物航煤的选择性为66.1%,转化率为79.8%。     

YPO4/Eu3+微米束的尿素辅助水热合成及其发光性能

以Y( NO3)3、Eu( NO3)3和(NH4)2HPO4为原料,尿素作辅助剂,采用水热法成功制备出束状YPO4/Eu3+荧光粉.利用X射线粉末衍射仪、透射电镜、荧光光谱仪等研究了产物的晶体结构、形貌及发光特性;基于透射电镜分析探讨了YPO4/Eu3+微米束结构的形成机理.结果表明:YPO4/Eu3+属于四方晶系,空...     

油包水型微乳中层柱状磷酸锆的制备与表征

以氧氯化锆(ZrOCl2·8H2O)和磷酸三丁酯(C4H9O)3PO为原料, 在正庚烷(C7H10)-十六烷基三甲基溴化铵(CTAB)/正丁醇(C4H9OH)-水的反向微乳体系中制备了Zr(HPO4)2·H2O, (H3O)+Zr2(PO4)3和Zr(HPO4)8·H2O三种不同结构的层柱状磷酸锆. 运用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线衍射仪(XRD)等仪器对产物进行了表征, 考察了不同微乳组成对磷酸锆结构及尺寸的影响. 结果表明, 微乳体系对层柱状磷酸锆的可控制合成具有广泛意义.     

石墨炉原子吸收光谱法测定痕量镉的基体改进效应研究及其应用

研究了磷酸氢二钾对石墨炉原子吸收光谱法测定痕量镉的基体改进效应,试验表明,在磷酸盐存在下,镉的灰化温度能显著提高,钾对镉有一定的增感效应。以此建立了用磷酸氢二钾作基体改进剂,直接测定岩石、土壤和水系沉积物中痕量镉的方法。     

Urea-based hydrothermal growth, optical and photocatalytic properties of single-crystalline In(OH)3 nanocubes

Nearly monodisperse single-crystalline In(OH)(3) nanocubes were successfully synthesized using In(NO(3))(3) x 4.5 H(2)O as indium source in the presence of urea and cetyltrimethyl ammonium bromide (CTAB) by a two-step hydrothermal process: the stock solution was heated at 70 degrees C for 24 h and then at 120 degrees C for 12 h. The structure and morphology of the resultant In(OH)(3) samples were determined by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results revealed that most of as-synthesized In(OH)(3) nanocubes were uniform in size, with the average edge length of approximately 700 nm. The influences of the reaction temperature, the reaction time, the mineralizer, and the surfactant on the morphology of the obtained products were discussed in detail. Room-temperature photoluminescence (PL) spectrum of the In(OH)(3) nanocubes showed a peculiar strong emission peak centered at 480 nm. Furthermore, the photocatalytic properties of the In(OH)(3) nanocubes were tested. It was found that In(OH)(3) exhibited not only higher activity for benzene removal, but also better H(2) evolution from water than the commercial Degussa P25 TiO(2).     

影响α-磷酸锆结晶度和生长形态的因素

采用HF络合法, 通过改进实验条件制得了α-磷酸锆(α-ZrP)微晶。讨论了HF/Zr比, P/Zr比, Zr浓度, 玻璃瓶质和反应温度等因素对α-ZrP结晶度和生长形态的影响。发现α-ZrP趋向于生成片状, 其片状最大外表面是α-ZrP的层板平面(001), 析晶速度的快慢影响该面的面积和厚度。d002, d110, d112衍射峰的相对衍射强度(XRD结果)与析晶速度有关并与晶体形状(SEM结果)存在着对应关系。     

Voltammetric Characterization of 2‐Methoxy‐4‐Nitrophenyl Derivatized Carbon Powder

Carbon powder has been functionalized with 2‐methoxy‐4‐nitrophenyl groups by the reduction of 2‐methoxy‐4‐nitrobenzenediazonium‐1,5‐naphthalenedisulfonate salt in presence of hypophosporous acid as a reducing agent. This provides an easy and inexpensive methodology to modify the carbon particle surface. This derivatization is carried out in the presence of 2‐methoxy‐4‐nitrobenzenediazonium 1,5‐naphthalenedisulfonate salt along with the carbon powder and hypophosporous acid. The electrochemical behavior of the resulting 2‐methoxy‐4‐nitrophenyl functionalized carbon powder was characterized by immobilizing it onto basal plane pyrolytic graphite (bppg) electrode and studying its voltammetric behavior. The surface morphology of derivatized carbon powder has been examined by SEM studies which revealed that the size of the functionalized carbon particles are larger than bare carbon particles The effect of pH on peak potentials, scan rate and stability of the functionalized carbon particles has revealed that they are surface bound species.     

Micro-Raman observation on the HPO4(2-) association structures in an individual dipotassium hydrogen phosphate (K2HPO4) droplet

A single K(2)HPO(4) droplet with size of ～50 μm on a Teflon substrate was forced to enter into the supersaturated state by decreasing the relative humidity (RH), allowing accurate control over the concentration of the solute within a droplet of a nanogram. The K(2)HPO(4) solutions from dilute (0.1-1.0 mol·L(-1) bulk) to concentrated state (a droplet from RH 98.2% to 25.1%) were studied through micro-Raman spectroscopy in the spectral region of about 200-4000 cm(-1). The area ratio between the water stretching band to the sum of the ν(1)-PO(3), ν(2)-POH, and ν(4)-PO(3) bands of the HPO(4)(2-) at various RHs was used to describe the dehydration behavior of a microsized single K(2)HPO(4) droplet in dehumidifying process. The peak position of the v(1)-PO(3) band for the 1 mol·L(-1) bulk solution appeared at 991 cm(-1) and moved to 986 cm(-1) at 98.2% RH, to 978 cm(-1) at 70.2% RH, and then to 964 cm(-1) at 30.0% RH for a droplet, accompanying an increase of the full width at half-height (fwhh) of this peak from 16.3 to 17.2, 22.2, and then to 24.2 cm(-1), indicating transition of the HPO(4)(2-) anions from monomers to dimers/trimers/oligomers and then to polyanions with chain structures in the K(2)HPO(4) solutions. After 25.1% RH, the solid was proved to be K(2)HPO(4)·3H(2)O according to the Raman spectral features. Furthermore, the O-H stretching envelope of a K(2)HPO(4) droplet showed that the intensity ratios of the strong hydrogen bonding component (3255 cm(-1)) to the weak one (3417 cm(-1)) and the cage-like water (2925 cm(-1)) to the weak one (3417 cm(-1)) were sensitive to the HPO(4)(2-) association structures, which can be used to understand the effects of dimers/trimers/oligomers and chain structures of the HPO(4)(2-) associations on the hydrogen bonding of water molecules.     

Facile synthesis of LiMnPO4 olivines with a plate-like morphology from a dittmarite-type KMnPO4·H2O precursor

Dittmarite-type compound KMnPO(4)·H(2)O was used as a new precursor for the synthesis of nanostructured LiMnPO(4) phospho-olivines with a plate-like morphology at low temperature (about 200 °C) and a short reaction time (90-180 min). The dehydration of KMnPO(4)·H(2)O was studied by DTA and TG analysis. Structural and morphological characterization of both KMnPO(4)·H(2)O and LiMnPO(4) was performed by powder XRD, SEM and TEM analyses. The formation of nanostructured LiMnPO(4) was examined by electron paramagnetic resonance spectroscopy and TEM. It was found that the reaction between KMnPO(4)·H(2)O with the LiCl-LiNO(3) mixture includes a fast ionic exchange of K(+) with Li(+) in the framework of the dittmarite structure, followed by H(2)O release and the formation of the olivine-type structure. The morphology and texture of the dittmarite-type precursor results in a plate-like morphology of LiMnPO(4) with a preferred orientation along the [100] direction. The plate-like morphology of LiMnPO(4) is stable after annealing at 500 °C. The plates are composed of nanocrystallites, with various sizes in the range 10-20 nm. The EPR signal of LiMnPO(4) is due to the exchange-coupled Mn(2+) ions. It was demonstrated that the EPR line-width correlates with the Scherrer crystallite size.     

K_2O矿化剂对硅微粉结合SiC窑具析晶结构,性能与氧化动力学影响的研究

在硅微粉结合SiC窑具中添加适量的K2O矿化剂，能使体积效应大的a-方石英转化成体积效应小的α-鳞石英，其矿化能力与MnO2相当[1]，但比MnO2矿化剂更有适用价值。采用XRD法确定析晶结构及其含量，探讨析晶结构对窑具性能的影响，从中确定最佳的K2O添加量为1．5％。     

Solvent systems for countercurrent chromatography: an aqueous two phase liquid system based on a room temperature ionic liquid

A new aqueous two phase liquid system (ATPS) based on the ionic liquid 1-butyl-3-methyl imidazolium chloride (BMIM Cl), potassium dibasic phosphate (K(2)HPO(4)) and water was recently proposed in the literature. The full phase diagram of this ATPS was prepared and some tie lines were fully determined. It was compared to classical ATPSs based on polyethylene glycol with an average molecular mass of 1000 (PEG 1000) and 10,000 (PEG 10000) and K(2)HPO(4). Two countercurrent chromatography (CCC) columns, a hydrostatic Sanki and a J type hydrodynamic CCC columns were used to test the liquid phase retention of these ATPSs in all possible configurations. It was found that the BMIM Cl ATPS liquid phases were much easier to retain in the two CCC columns than the PEG 1000 ATPS phases. Using protein and alcohol solutes, it was established that the BMIM Cl ATPS has a polarity completely different from that of the PEG 1000 ATPS. For example, ovalbumin partitions equally between the two phases of the PEG 1000 ATPS (K(D)=1.4) when it is completely located in the BMIM Cl upper phase of the ionic liquid ATPS (K(D)=180). The discrimination factor of the ionic liquid system and its intrinsic hydrophobicity were respectively found three times higher and ten times lower than the respective values of the PEG 1000 ATPS.