草酸反萃取法直接沉淀负载铈有机相的表征分析

研究了氢氧化钠介质皂化条件下,用草酸溶液从负载铈的P507有机相中直接反萃取沉淀铈的试验结果。利用红外光谱(IR)、X射线衍射(XRD)、扫描电子显微镜(SEM)及热重-差热分析仪(TG-DSC)等手段,对反萃所得铈沉淀物及最终焙烧产物的物相、形貌和热失重等进行了分析、测试与表征。实验结果表明:沉淀有机相为球形有机铈的配合物,焙烧产物为球形的立方晶系的CeO2晶体,说明前驱物与产物形貌有遗传继承性。IR证实了萃合物的结构与最终CeO2晶体结构完全不同,热重表明吸附水失重为3.5%,所得最终产物的化学组成为CeO2.1/3H2O。     

光聚合壳聚糖基絮凝剂的光谱表征研究

由于壳聚糖的大分子键上分布着大量的氨基、羟基和N-乙酰基等活性功能基团,将其改性作为天然绿色絮凝剂越来越受到关注,但对其的接枝共聚产物的光谱学表征研究鲜有报道。因此,对壳聚糖基絮凝剂进行光谱学表征与分析研究具有重要意义。论文以壳聚糖(CS)、丙烯酰胺(AM)、二甲基二烯丙基氯化铵(DMDAAC)为接枝共聚单体,采用光聚合技术制备壳聚糖基絮凝剂CS-P(AM-DMDAAC)。采用X射线衍射(XRD)、紫外光谱(UV)、红外光谱(IR)研究其结构特征;分析了壳聚糖、丙烯酰胺、二甲基二烯丙基氯化铵及三者接枝共聚产物的X射线衍射(XRD)、紫外光谱(UV)、红外光谱(IR)的图谱特征和振动吸收峰归属。研究了壳聚糖脱乙酰度、壳聚糖浓度、阳离子度对接枝共聚产物壳聚糖基絮凝剂CS-P(AM-DMDAAC)的X射线衍射(XRD)、紫外光谱(UV)、红外光谱(IR)的影响。UV光谱和IR光谱研究结果证明CS,AM和DMDMAAC成功发生接枝共聚反应制备出CS-P(AM-DMDAAC),壳聚糖浓度增加导致其光谱对称性减弱。XRD图谱研究表明接枝共聚反应使得壳聚糖的晶型结构趋向不定型结构转变,不定型结构相比于晶型结构更易于水化,故接枝共聚产物具有更加优异的溶解性。     

纳米掺N TiO2的制备及光谱分析

以钛酸四丁酯(TBT)及乙二胺(EDA)为前驱体,乙醇为溶剂,冰醋酸为抑制剂,通过溶胶-凝胶法制备了纳米掺NTiO2,并对其结构及光谱性质进行了表征,根据差热-热重分析(TG-DTA)确定了所制备样品的晶型转换温度及最佳的煅烧温度;根据紫外-可见漫反射光谱(UV-Vis/DRS)表征了其光谱吸收特性;根据X射线衍射光谱(XRD)确定了其粒径及晶相结构;根据X射线光电子能谱(XPS)分析了其表面组成。实验考察了光谱吸收带红移程度与乙二胺、钛酸四丁酯的配比及煅烧温度的关系。研究结果表明,制备的纳米掺NTiO2为锐钛矿相,其光谱吸收带发生了明显的红移,乙二胺与钛酸四丁酯的配比及煅烧温度对其光谱吸收有明显的影响。当乙二胺与钛酸四丁酯的摩尔比为1:10,煅烧温度为600℃时,所制备样品对可见光的吸收最强。     

壳聚糖亚胺环钯化合物的合成与表征

用水杨醛接枝改性后的壳聚糖亚胺与Li₂PdCl₄甲醇溶液反应得到壳聚糖环钯化合物。壳聚糖、壳聚糖席夫碱及其钯化合物用红外光谱(IR)、X射线衍射光谱(XRD)、热分析(DTA-TG)、荧光光谱以及X射线光电子能谱(XPS)等分析手段进行了表征分析。根据表征结果提出了席夫碱及壳聚糖亚胺环钯化合物的结构。     

硅量子点的控制合成、表征及对Cu2+的高灵敏传感

通过一步无溶剂法合成了具有较好发光稳定性和水溶性的硅量子点(Silicon quantum dots,Si-QDs),并利用透射电镜(TEM)、红外吸收光谱(IR)、X射线光电子能谱(XPS)、X射线衍射(XRD)和荧光光谱等手段对其进行了表征.试验发现,Si-QDs在378 nm的激发光照射下,可产生峰值位于468 ...     

多面体低聚倍半硅氧烷-ZrO2复合气凝胶的制备与表征

以官能团化的多面体低聚倍半硅氧烷（POSS-［C2H4Si(OEt)3］8）和正丁醇锆为原料,以乙醇作为溶剂,通过溶胶-凝胶及二氧化碳超临界干燥成功制备了三种不同锆含量POSS-ZrO2的复合气凝胶。并用傅里叶变换红外光谱分析仪（FTIR）、扫描电镜（SEM）、X射线衍射仪（XRD）和比表面吸附仪（BET）对其进行表征。结果表明:该气凝胶中有SiOZr键,并且所得气凝胶都是无定型的,其比表面积随着锆含量的增加而变小,最高可达491 m2/g,并且其孔径分布都比较广。     

磷酸二氢钾插层改性高岭土复合物的制备与表征

实验制备了磷酸二氢钾插层改性高岭土用于新型复合阻燃材料。首先以二甲基亚砜(DMSO)为前驱体,采用超声法制备了高岭土-二甲基亚砜(K-DMSO)插层物,再将醋酸钾(KAc)取代DMSO,制备预插层体高岭土-醋酸钾(K-KAc)。最后通过第三步插层取代法,将磷酸二氢钾(KDP)引入,制备了高岭土-磷酸二氢钾(K-KDP)插层复合物,产物的插层率达到81.3%。通过红外光谱(FTIR)、X射线衍射(XRD)和扫描电子显微镜(SEM)对各步反应产物进行了表征。FTIR谱图显示,K-KDP在1 201 cm-1出现PO的振动峰;XRD显示各步插层反应中高岭土(001)晶面特征衍射峰依次向低角度方向移动,层间距相应从0.716 nm增加到1.59 nm;SEM显示插层后的高岭土粒子分散更为均匀。     

纳米级发光材料A2SnO4(A=Ca,Sr,Ba):Eu发光性质的研究

采用络合溶胶-凝胶法制备出系列纳米级发光材料A2SnO4(A=Ca,Sr,Ba):Eu.并采用相关光谱、X射线衍射(XRD)、荧光光谱(PL)对所制备的纳米发光粉体进行表征.结果表明:制备的纳米发光粉体的粒径均匀,集中在100 nm左右;XRD结果证明碱土金属锡酸盐结构均为具有确定结构的单一物相;并且这些发光粉体的性质与碱土金属离子的半径密切相关.     

氧化物辅助生长法合成氮化硼纳米管

硼、氧化硅、硅的混合粉末与氨气在1423K反应生成了氮化硼纳米管.产物用X射线衍射(XRD),透 射电镜(TEM)和傅立叶红外光谱(FTIR)进行了表征.氮化硼纳米管的直径为20～50nm,长达几十微米.氮化硼 纳米管的头部是开口或封口的,没有观察到纳米颗粒被包覆在纳米管的端部.因此,氮化硼纳米管的生长被认为 是一种氧化物辅助生长的机理.同多晶六方氮化硼的红外光谱相比,在1520cm-1处的小吸收峰表现了氮化硼纳 米管的一维结构特征.     

钙钛矿型纳米复合氧化物SrCoO_3的制备与表征

采用硬脂酸燃烧合成法制备了钙钛矿型纳米复合氧化物钴酸锶(SrCoO3),通过X射线衍射测试(XRD),红外光谱测试(IR)手段对所制备的系列纳米催化剂进行了表征。结果表明:所制目标产物钴酸锶为钙钛矿型,颗粒分布均匀,粒径在27纳米级。     

Characterization of ceramic oxide refractories by XRF and XRD

The present study was undertaken to establish a methodology for characterizing ceramic oxide refractory materials, as no detailed information could be found in the literature on this point. The following refractories were analysed: two silica, one alumina, one silica–alumina, two zirconium, three chrome and three magnesia refractories. X‐ray fluorescence (XRF) spectrometry was used for chemical characterization and x‐ray diffraction (XRD) for phase analysis. Phases were determined because of their influence on the end properties of refractory materials. Five analytical programmes for XRF analysis and an XRD analysis method were established. We optimized sample preparation in the form of beads for the XRF measurement by determining the most appropriate sample/flux ratio for each type of refractory. Calibration and validation standards were prepared from mixtures of reference materials, owing to the scarcity of refractory reference materials. The chemical and phase composition of different ceramic oxide refractory bricks was determined and related to the deterioration of these refractories in industrial service, because refractories with a similar chemical composition and different crystalline phases can exhibit different properties. Copyright © 2004 John Wiley & Sons, Ltd.     

氧化锑/高岭土复合阻燃微粉的结构分析

用球磨法制备了氧化锑／高岭土复合阻燃微粉,采用Ｘ射线衍射（ＸＲＤ）、红外吸收光谱（ＩＲ）对复合微粉的结构进行了分析,ＸＲＤ分析表明：随着复合微粉组分的变化,高岭土和氧化锑的ＸＲＤ特征衍射吸收峰发生移动,衍射强度发生变化,相应晶面间距发生膨胀和收缩,晶格畸变明显。ＩＲ分析表明：随着复合组分的变化,高岭土和氧化锑的ＩＲ特征振动吸收峰发生红移、蓝移、振动消失等系列变化。     

Surface modification and characterization of Jordanian kaolinite: Application for lead removal from aqueous solutions

Kaolinite clay was tested for removal of lead ions from aqueous solution. This clay was washed with sulfuric acid solution followed by chemical surface modification using 3-chloropropyltriethoxysilane and sodium hydroxide. XRF results showed that silica to alumina ratio was 2.8:1 for the treated sample compared to 1.6:1 for the raw one.XRD analysis displayed different distinct kaolinite and quartz peaks before treatment while kaolinite peaks were diminished after the treatment. SEM morphology indicated that the raw kaolinite appears as plate structure with no local pores on the plates. However, after treatment the surface was found to have micropores.Different adsorption isotherm models were applied to the experimental data and found that Shawabkeh-Tutunji equation best fit these data adequately. It was also found that chemisorption took place at the surface of the modified kaolinite with maximum adsorption capacity of 54.35 mg/g.     

Preparation of arsenic‐containing white rice grains as calibration standards for X‐ray fluorescence analysis of total arsenic in cereals

A preparation method of arsenic‐containing white rice grains as calibration standards was developed for the X‐ray fluorescence (XRF) analysis of arsenic in rice grains. Calibration standards were prepared by adding 10 g of white rice grains (from Japan) to 100 ml methanol‐containing dimethylarsinic acid corresponding to 2–100 µg arsenic. The mixture was heated, dried at 150 °C, cooled to room temperature, and then stored in a silica gel desiccator. A total of 5.0 g of each calibration standard was packed into a polyethylene cup (32 mm internal diameter and 23 mm height) covered with a 6‐µm‐thick polypropylene film and then analyzed by wavelength‐dispersive XRF spectrometry. The calibration curve for arsenic obtained from the white rice grains containing arsenic showed good linearity over a concentration range of 0.21–5.00 mg kg^?1 arsenic. The limit of detection of arsenic was 0.080 mg kg^?1. To check the reliability of the XRF method, the concentrations of arsenic in six samples of grain cereals and two samples of flour were compared with those obtained by atomic absorption spectrometry after acid decomposition. The values obtained by both analytical methods showed good agreement. Copyright © 2016 John Wiley & Sons, Ltd.     

Hydrothermal treatment of gadolinium oxide in presence of silica

Abstract

Hydrothermal and solvothermal (isopropanol) treatments of gadolinium oxide and silica were investigated under different pressure and temperature conditions. Products were examined by infrared vibrational spectroscopy (IR), x-ray powder diffraction (XRD) and thermal analysis (DTA, TG). Hexagonal gadolinium hydroxide was obtained in hydrothermal conditions, even in presence of silica, while no change was observed from isopropanolic medium treatment. Hydrothermally treated samples are more reactive as precursors for solid state reactions in inorganic synthesis.     

Si-Al-Zr-O系非晶原位晶化过程中的拉曼光谱和红外光谱研究

借助Raman,IR和XRD等技术探讨了Si-Al-Zr-O系非晶在原位受控晶化过程中微结构变化.结果表明,Si-Al-Zr-O系非晶在920℃左右出现网络结构重整,形成了富Si区和富Zr和Al区.在920～950℃间,从富Zr区析出初晶相四方氧化锆,并从富Al区形成Al-Si尖晶石相.随着温度进一步升高,Al-Si尖...     

Synthesis of CoFe2O4 nanoparticles embedded in a silica matrix by the citrate precursor technique

A metals–citrate–silica gel was prepared from metallic salts, citric acid and tetraethylorthosilicate by sol–gel method (citrate precursor technique) and it was further used to prepare magnetic nanocomposites. The gel was dried at 100 °C and then calcined at temperatures between 600 and 1000 °C to obtain powder samples. The nanocomposites were characterized by XRD, IR, VSM and TEM techniques. The diffraction patterns show the formation of a single magnetic phase identified as CoFe₂O₄. Magnetic nanoparticles with average size less than 50 nm were obtained which are well dispersed in the silica matrix. The combination of different metals concentrations and calcining temperatures allowed obtaining samples with magnetization ranging from 3.6 to 25.3 emu/g.     

Nanostructured carbons for solid phase extraction

Nanostructured carbons have been obtained by the template method using zeolite NaY and silica gels (SG60, Fluka and ZK, POCh) as structure directing agents. Texture and porous structure of carbons were characterized by TEM, XRD and nitrogen adsorption. Surface chemistry was investigated by the potentiometric titration method. It has been shown that all carbons show developed and uniform porous structure with mean size in the micropore range (1.1 nm) for zeolite derived carbon and in the mesopore range (3.4 and 4.8 nm) for silica gel derived carbons. The BET surface area of silica gel derived carbons is in the range 1230-1280 m²/g whereas zeolite derived carbon possesses very high BET surface area, 3000 m²/g. Potentiometric titration showed that carbons obtained by the template method contain significant amount of acid surface groups (carboxylic, lactone/enol and phenolic) with the total amount 1.1-1.5 mmol/g. To study adsorption-desorption properties of nanostructured carbons towards phenol and chlorophenols the solid phase extraction method was used. High recoveries of chlorophenols were obtained (80-93%) at the breakthrough volumes 1700-3000 mL. The recoveries are much higher than that obtained with commercially available carbon ACC (Supelco).     

原位活体骨铅X射线荧光光谱分析

报道了应用X射线荧光光谱技术在中国本土获得的普通人群原位人体活体骨铅数据,发表了中国大陆普通居民的胫骨和根骨活体骨铅浓度及其研究结果。采用Pb的K系谱线进行了原位活体分析人胫骨和根骨骨铅含量。普通人群样本中所测骨铅含量加权平均值在0.4～22.7μg.(g骨矿物质)-1之间,不确定度在7.0～12.5μg.(g骨矿物质)-1之间,平均最小检出限20.3μg.(g骨矿物质)-1。在污染调查区居民中发现骨铅最高可达73.9μg.(g骨矿物质)-1。     

Focus on sulfur count rates along marine sediment cores acquired by XRF Core Scanner

The aim of this study is to investigate the information provided by sulfur count rates obtained by X‐ray fluorescence core scanner (XRF‐CS) along sedimentary records. The analysis of two marine sediment cores from the Niger Delta margin shows that XRF‐CS sulfur count rates obtained at the surface of split core sections with XRF‐CS correlate with both direct quantitative pyrite concentrations, as inferred from X‐ray powder diffraction (XRD) and sulfur determination by wavelength dispersive X‐ray fluorescence (WD‐XRF) spectrometry, and total dissolved sulfide (TDS) contents in the sediment pore water. These findings demonstrate the potential of XRF‐CS for providing continuous profiles of pyrite distribution along split sections of sediment cores. The potential of XRF‐CS to detect TDS pore water enrichments in marine sediment records, even a long time after sediment recovery, will be further discussed. Copyright © 2016 The Authors. X‐Ray Spectrometry Published by John Wiley & Sons Ltd.