Preparation of calibration materials for microanalysis of Ti minerals by direct fusion of synthetic and natural materials: experience with LA-ICP-MS analysis of some important minor and trace elements in ilmenite and rutile

Calibration materials for microanalysis of Ti minerals have been prepared by direct fusion of synthetic and natural materials by resistance heating in high-purity graphite electrodes. Synthetic materials were FeTiO3 and TiO2 reagents doped with minor and trace elements; CRMs for ilmenite, rutile, and a Ti-rich magnetite were used as natural materials. Problems occurred during fusion of Fe2O3-rich materials, because at atmospheric pressure Fe2O3 decomposes into Fe3O4 and O2 at 1462 degrees C. An alternative fusion technique under pressure was tested, but the resulting materials were characterized by extensive segregation and development of separate phases. Fe2O3-rich materials were therefore fused below this temperature, resulting in a form of sintering, without conversion of the materials into amorphous glasses. The fused materials were studied by optical microscopy and EPMA, and tested as calibration materials by inductively coupled plasma mass spectrometry, equipped with laser ablation for sample introduction (LA-ICP-MS). It was demonstrated that calibration curves based on materials of rutile composition, within normal analytical uncertainty, generally coincide with calibration curves based on materials of ilmenite composition. It is, therefore, concluded that LA-ICP-MS analysis of Ti minerals can with advantage be based exclusively on calibration materials prepared for rutile, thereby avoiding the special fusion problems related to oxide mixtures of ilmenite composition. It is documented that sintered materials were in good overall agreement with homogeneous glass materials, an observation that indicates that in other situations also sintered mineral concentrates might be a useful alternative for instrument calibration, e.g. as alternative to pressed powders.     

Influence of Amylose-Amylopectin Ratio on Properties of Extruded Starch Plastic Sheets

Abstract

Starch plastic sheets were prepared by extrusion processing of mixtures of granular high-amylopectin and high-amylose starches in the presence of glycerol and water as plasticizers. Amylose content varied between 0 and 70% (w/w). Structural characterization and determination of the mechanical properties of the sheets were performed after aging the materials between 40–65% relative humidity for 2 and 35 weeks and at 90% relative humidity for two weeks. The materials were semicrystalline and viscoelastic. The materials were described as complex heterogeneous multiphase materials. They consisted of amorphous and crystalline phases of amylose and amylopectin as well as granular structures and domains of amylose, amylopectin and amylose-amylopectin helices. Single-helical type crystallinity was formed solely by amylose directly after processing while B-type crystallinity was rapidly formed in amylose-rich materials and slowly during aging of amylopectin-rich materials.

The stress-strain and stress-relaxation properties were related to differences in amylose content, degree of crystallization and water content. The amorphous amylopectin rich materials were flexible and soft but showed an increase in stiffness and a decrease in elongation due to crystallization. Amylopectin-rich materials showed unfavorable relaxation, shrinkage and cracking during aging. The materials rich in amylopectin were sensitive to water content while the amylose-rich materials were not sensitive to water in the range of 9–13% (w/w). Stress-strain relaxation behaviors of the materials were dependent on starch structure and on experimental conditions such as strain rate and extension by which the ratio of elastic and viscous response were varied. An increase in relaxation times was found with increasing amylose content and water content for the materials with solely amylose crystallinity.     

Principal component analysis and cluster analysis for the characterization of dental composites

Various experimental dental materials were characterized using chemometric methods. The main aim of the study was to ascertain which composite materials present the best properties for use in restorative dentistry. Bisphenol-alpha-glycidyl methacrylate-based composites containing hydroxyapatite as a filler and a coupling agent were prepared using a photocuring polymerization procedure. Several chemical and mechanical properties of experimental composites were measured and the corresponding data were further studied using principal component analysis and cluster analysis. Results from the characterization allowed the most appropriate materials to be selected. Various composites presented acceptable general properties suggesting their suitability as substitutes for commercial materials in dentistry.     

超支化共轭聚合物的合成、性质及在光电器件中的应用研究进展

简述超支化共轭聚合物光电活性材料研究进展,设计、合成了多种具有3-D立体结构的超支化共轭聚合物,研究了它们的结构与性能的关系及其在器件上的应用.实验结果表明,这种聚合物具有良好的溶解性,可成膜性和高的发光效率.可应用于发光二极管(LED),发光电化学池(LEC),光伏打电池等器件.这类化合物不仅可以作为发光材料,还可以通过修饰得到具有分子或离子识别、信息存储性能的特殊功能材料.     

Production of reference materials for the detection and size determination of silica nanoparticles in tomato soup

A set of four reference materials for the detection and quantification of silica nanoparticles (NPs) in food was produced as a proof of principle exercise. Neat silica suspensions were ampouled, tested for homogeneity and stability, and characterized for total silica content as well as particle diameter by dynamic light scattering (DLS), electron microscopy (EM), gas-phase electrophoretic molecular mobility analysis (GEMMA), and field-flow fractionation coupled with an inductively coupled mass spectrometer (FFF-ICPMS). Tomato soup was prepared from ingredients free of engineered nanoparticles and was spiked at two concentration levels with the silica NP suspension. Homogeneity of these materials was found sufficient to act as reference materials and the materials are sufficiently stable to allow long-term storage and distribution at ambient temperature, providing proof of principle of the feasibility of producing liquid food reference materials for the detection of nanoparticles. The spiked soups were characterized for particle diameter by EM and FFF-ICPMS (one material only), as well as for the total silica content. Although questions regarding the trueness of the results from EM and FFF-ICPMS procedures remain, the data obtained indicate that even assigning values should eventually be feasible. The materials can therefore be regarded as the first step towards certified reference materials for silica nanoparticles in a food matrix.     

Enhancing the flame-retardant performance of wood-based materials using carbon-based materials

We sought to improve the flame-retardant performance of wood-based materials through the development of a coating material using carbon-based materials. The coating materials were applied to the surfaces of wood-based materials used for interior materials and furniture. We measured fire characteristics of the coated wood-based materials using a cone calorimeter. The coating materials were prepared by the mixing of carbon materials, such as natural graphite, expandable graphite, and exfoliated graphite nanoplatelets, in water-based coating materials. TG analysis revealed that water-based coating materials/carbon material-blended composites had good thermal durability in the working temperature ranges. The flame-retardant performance was confirmed through cone calorimeter experiments, and the result of the experiment satisfied the standard for flame-retardant performance in ISO 5600-1.     

Evaluation of multi-modal high salt binding ion exchange materials

The performance and selectivity of novel cation and anion exchange multi-modal chromatographic materials were evaluated. Desorption profiles of 13 proteins possessing a range of properties (e.g. size, charge and hydrophobicity) were determined on the cation exchange materials. Batch experiments were carried out by loading individual proteins on each resin at low salt, and examining the desorption of the proteins during sequential washes with increasing salt concentrations. While all of the resins exhibited some binding of proteins at elevated salt concentrations, this effect was more pronounced on the resins with aromatic ligands as compared to the materials with aliphatic ligands. As expected, materials with higher ionic capacities exhibited higher binding at elevated salts. In addition, some proteins exhibited high binding at elevated salt concentrations to all of the resins. The combined effect of charge and other secondary interactions with these multi-modal chromatographic materials enables high salt binding of a range of proteins as well as unique selectivities for the recovery of certain classes of proteins. Since the anion exchange materials all exhibited high binding at elevated salt concentrations the work with these materials focused on a study of elution strategies to remove proteins from these aromatic based materials. After evaluating various elution protocols, a combined strategy of pH change and chaotropic salt were shown to minimize electrostatic and hydrophobic interactions and was found to be an effective elution strategy for this class of anion exchange materials using peanut lectin as a model protein.     

Photopolymers for Rapid Prototyping of Soluble Mold Materials and Molding of Cellular Biomaterials

To substitute cross-linked photopolymers in rapid prototyping of mold materials and therefore extend the range of materials which can be casted, organo-soluble photopolymers were developed. Branched bisalkylacrylamides were suitable as base component for such formulations, due to their high reactivity, good mechanical properties, and excellent solubility of the formed polymers. These molding materials were used to prepare cellular biocompatible materials which could be used as bone replacement materials. Biocompatible crosslinkers based on methacrylates from hydrolyzed gelatine or lactic acid ethyleneglycol blockcopolymers and commercially available reactive diluents are the base components of such a formulation. Biocompatibility was investigated by osteoblast-like cells. Cellular biocompatible parts were obtained by thermal polymerization in soluble mould materials prepared by 3D-photoshaping.     

Photopolymers for Rapid Prototyping of Soluble Mold Materials and Molding of Cellular Biomaterials

Summary. To substitute cross-linked photopolymers in rapid prototyping of mold materials and therefore extend the range of materials which can be casted, organo-soluble photopolymers were developed. Branched bisalkylacrylamides were suitable as base component for such formulations, due to their high reactivity, good mechanical properties, and excellent solubility of the formed polymers. These molding materials were used to prepare cellular biocompatible materials which could be used as bone replacement materials. Biocompatible crosslinkers based on methacrylates from hydrolyzed gelatine or lactic acid ethyleneglycol blockcopolymers and commercially available reactive diluents are the base components of such a formulation. Biocompatibility was investigated by osteoblast-like cells. Cellular biocompatible parts were obtained by thermal polymerization in soluble mould materials prepared by 3D-photoshaping.     

含氟硼二吡咯单元金属有机骨架材料的研究进展

MOFs是一种具有高度有序孔道结构和较大比表面积的材料,而含氟硼二吡咯(BODIPY)发色团的MOFs材料是将BODIPY发色团设计成可与金属中心配位的配体并直接与金属离子配位或将该发色团作为光吸收天线引入到MOFs材料中所制备的材料,此类材料因对可见光有较强的吸收而受到广泛关注。本文总结了含BODIPY发色团MOFs材料的制备方法,探讨了此类材料的结构特点、光物理性质及应用前景,最后展望了未来此类材料的前景和发展趋势。本文可为BODIPY发色团的MOFs材料在光化学领域的发展提供参考。     

利用珍珠岩尾粉制备发泡材料

以信阳珍珠岩尾粉、凝灰岩为主要原料,石墨为发泡剂,添加适量废玻璃粉、添加剂,在不同的温度下烧制成发泡材料.利用热分析仪分析了混合料的发泡温度,用x射线衍射仪、压力试验机等对样品进行结构表征和性能测试.结果表明:珍珠岩尾粉凝灰岩发泡材料合适的发泡温度为930?.保温时间为30min,样品密度为0.43g/cm3,抗压强度...     

Value assignment of nutrient concentrations in five standard reference materials and six reference materials

A number of food-matrix reference materials (RMs) are available from the National Institute of Standards and Technology (NIST) and from Agriculture Canada through NIST. Most of these materials were originally value-assigned for their elemental composition (major, minor, and trace elements), but no additional nutritional information was provided. Two of the materials were certified for selected organic constituents. Ten of these materials (Standard Reference Material [SRM] 1,563 Cholesterol and Fat-Soluble Vitamins in Coconut Oil [Natural and Fortified], SRM 1,566b Oyster Tissue, SRM 1,570a Spinach Leaves, SRM 1,974a Organics in Mussel Tissue (Mytilus edulis), RM 8,415 Whole Egg Powder, RM 8,418 Wheat Gluten, RM 8,432 Corn Starch, RM 8,433 Corn Bran, RM 8,435 Whole Milk Powder, and RM 8,436 Durum Wheat Flour) were recently distributed by NIST to 4 laboratories with expertise in food analysis for the measurement of proximates (solids, fat, protein, etc.), calories, and total dietary fiber, as appropriate. SRM 1846 Infant Formula was distributed as a quality control sample for the proximates and for analysis for individual fatty acids. Two of the materials (Whole Egg Powder and Whole Milk Powder) were distributed in an earlier interlaboratory comparison exercise in which they were analyzed for several vitamins. Value assignment of analyte concentrations in these 11 SRMs and RMs, based on analyses by the collaborating laboratories, is described in this paper. These materials are intended primarily for validation of analytical methods for the measurement of nutrients in foods of similar composition (based on AOAC INTERNATIONAL's fat-protein-carbohydrate triangle). They may also be used as "primary control materials" in the value assignment of in-house control materials of similar composition. The addition of proximate information for 10 existing reference materials means that RMs are now available from NIST with assigned values for proximates in 6 of the 9 sectors of the AOAC triangle. Five of these materials have values assigned for total dietary fiber-the first such information provided for materials available from NIST.     

Preparation of nickel-mesoporous materials and their application to the hydrodechlorination of chlorinated organic compounds

Mesoporous materials have attracted considerable attention for use as a catalyst or a catalyst support due to their remarkable textural properties such as high surface area and large pore volume with a narrow pore size distribution. Many efforts have been made to design mesoporous materials for use in heterogeneous catalyst systems. Recent progress and results regarding the preparation of nickel-mesoporous materials and their application to the hydrodechlorination of chlorinated organic compounds were discussed in this review. Mesoporous materials were used as a support for nickel catalyst or a nickel-incorporated mesoporous catalytic material in this work. Two research areas were described and discussed in this review. One is the preparation of mesoporous alumina-supported nickel catalysts and their application to the hydrodechlorination of 1,2-dichloropropane and o-dichlorobenzene. The other is the preparation of mesoporous silica-supported nickel catalysts and their application to the hydrodechlorination of 1,1,2-trichloroethane and chlorobenzene.     

Double pulse laser induced breakdown spectroscopy applied to natural and artificial materials from cultural heritages: A comparison with micro-X-ray fluorescence analysis

The laser-induced breakdown spectroscopy (LIBS) is an applied physical technique that has shown in recent years its great potential for rapid qualitative analysis of materials. Thanks to the possibility to implement a portable instrument that perform LIBS analysis, this technique is revealed to be particularly useful for in situ analysis in the field of cultural heritages. The purpose of this work is to evaluate the potentiality of LIBS technique in the field of cultural heritages, with respect to the chemical characterization of complex matrix as calcareous and refractory materials for further quantitative analyses on cultural heritages. X-Ray Fluorescence (XRF) analyses were used as reference. Calibration curves of certified materials used as standards were obtained by XRF analyses. The LIBS measurements were performed with a new mobile instrument called Modì (Mobile Double pulse Instrument for LIBS Analysis). The XRF analyses were performed with a portable instrument ArtTAX. LIBS and XRF measurement were performed on both reference materials and samples (bricks and mortars) sampled in the ancient Greek–Roman Theatre of Taormina. Although LIBS measurements performed on reference materials have shown non linear response to concentrations, and so we were not able to obtain quantitative results, an integrated study of XRF and LIBS signals permitted us to distinguish among chemical features and degradation state of measured building materials.     

Preparation of calibration materials for microanalysis of Ti minerals by direct fusion of synthetic and natural materials: Experience with LA–ICP–MS analysis of some important minor and trace elements in ilmenite and rutile

Calibration materials for microanalysis of Ti minerals have been prepared by direct fusion of synthetic and natural materials by resistance heating in high-purity graphite electrodes. Synthetic materials were FeTiO₃ and TiO₂ reagents doped with minor and trace elements; CRMs for ilmenite, rutile, and a Ti-rich magnetite were used as natural materials. Problems occurred during fusion of Fe₂O₃-rich materials, because at atmospheric pressure Fe₂O₃ decomposes into Fe₃O₄ and O₂ at 1462?°C. An alternative fusion technique under pressure was tested, but the resulting materials were characterized by extensive segregation and development of separate phases. Fe₂O₃-rich materials were therefore fused below this temperature, resulting in a form of sintering, without conversion of the materials into amorphous glasses. The fused materials were studied by optical microscopy and EPMA, and tested as calibration materials by inductively coupled plasma mass spectrometry, equipped with laser ablation for sample introduction (LA–ICP–MS). It was demonstrated that calibration curves based on materials of rutile composition, within normal analytical uncertainty, generally coincide with calibration curves based on materials of ilmenite composition. It is, therefore, concluded that LA–ICP–MS analysis of Ti minerals can with advantage be based exclusively on calibration materials prepared for rutile, thereby avoiding the special fusion problems related to oxide mixtures of ilmenite composition. It is documented that sintered materials were in good overall agreement with homogeneous glass materials, an observation that indicates that in other situations also sintered mineral concentrates might be a useful alternative for instrument calibration, e.g. as alternative to pressed powders.     

Double pulse laser induced breakdown spectroscopy applied to natural and artificial materials from cultural heritages : A comparison with micro-X-ray fluorescence analysis

The laser-induced breakdown spectroscopy (LIBS) is an applied physical technique that has shown in recent years its great potential for rapid qualitative analysis of materials. Thanks to the possibility to implement a portable instrument that perform LIBS analysis, this technique is revealed to be particularly useful for in situ analysis in the field of cultural heritages. The purpose of this work is to evaluate the potentiality of LIBS technique in the field of cultural heritages, with respect to the chemical characterization of complex matrix as calcareous and refractory materials for further quantitative analyses on cultural heritages. X-Ray Fluorescence (XRF) analyses were used as reference. Calibration curves of certified materials used as standards were obtained by XRF analyses. The LIBS measurements were performed with a new mobile instrument called Modì (Mobile Double pulse Instrument for LIBS Analysis). The XRF analyses were performed with a portable instrument ArtTAX. LIBS and XRF measurement were performed on both reference materials and samples (bricks and mortars) sampled in the ancient Greek–Roman Theatre of Taormina. Although LIBS measurements performed on reference materials have shown non linear response to concentrations, and so we were not able to obtain quantitative results, an integrated study of XRF and LIBS signals permitted us to distinguish among chemical features and degradation state of measured building materials.     

Hierarchical Co‐Assembly Enhanced Direct Ink Writing

Integrating intelligent molecular systems into 3D printing materials and transforming their molecular functions to the macroscale with controlled superstructures will unleash great potential for the development of smart materials. Compared to macromolecular 3D printing materials, self‐assembled small‐molecule‐based 3D printing materials are very rare owing to the difficulties of facilitating 3D printability as well as preserving their molecular functions macroscopically. Herein, we report a general approach for the integration of functional small molecules into 3D printing materials for direct ink writing through the introduction of a supramolecular template. A variety of inorganic and organic small‐molecule‐based inks were 3D‐printed, and their superstructures were refined by post‐printing hierarchical co‐assembly. Through spatial and temporal control of individual molecular events from the nano‐ to the macroscale, fine‐tuned macroscale features were successfully installed in the monoliths.     

锂离子电池纳米正极材料

综述了锂离子电池纳米正极材料的研究进展,阐述了这种材料用于锂离子电池的优势和存在的问题,把纳米正极材料分为过渡金属嵌锂化合物、金属氧化物和金属硫化物和其它纳米正极材料。归纳了不同纳米正极材料的主要制备方法,探讨了材料的制备方法与其结构、形貌和电化学性能之间的关系,展望了纳米正极材料用于锂离子电池的未来前景。     

Retention and enantioselective properties of ovomucoid-bonded silica columns Influence of physical properties of base materials and spacer length

The influence of the physical properties of base silica materials and spacer length on chiral separation of enantiomers on ovomucoid (OVM)-bonded materials was investigated. With regard to the pore size of the base silica materials, the 300-Å materials gave higher enantioselectivity, than the 120-Å materials, despite the smaller amounts of bonded OVM proteins. However, higher resolution was obtained with the latter materials. With regard to the spacer length, aminopropyl (AP)-, aminobutyl-, N-(4-aminobutyl)-3-aminopropyl- and N-(6-aminohexyl)-3-aminopropyl-silica gels were activated by N,N′-di-succinimidyl carbonate (DSC) and the proteins were bound. The first two materials showed excellent chiral resolution properties for the solutes tested, and the AP materials gave higher enantioselectivity and resolution. On the other hand, only oxprenolol enantiomers were slightly resolved on the last two materials. Also, AP-silica gels activated by DSC were compared with glycerylpropyl (GP)-silica gels activated by 1,1′-carbonyldiimidazole. The former materials gave higher resolution for acidic and basic solutes despite the lower enantioselectivity, whereas for the unchanged hexobarbital the latter materials gave higher enantioselectivity and almost equal resolution. The above results reveal that the 120-Å base silica gels are more suitable than the 300- Å base silica gels for obtaining larger amounts of bonded OVM proteins and that a less hydrophobic spacer such as an AP group and a hydrophilic spacer such as a GP group are suitable.     

表面包覆保护的离子电池新型正极材料LiFeBO3电化学性能

以偏硼酸锂和草酸亚铁为原料,采用固相反应,合成了用于动力锂离子电池新型正极材料LiFeBO<,3>,并用乙丙共聚物(EPM)对该材料进行包覆保护处理;采用XRD、SEM和元素分析等测试技术对样品进行表征.实验表明.LiFeBO<,3>具有较高的放电重量比容量,而且包覆EPM后的硼酸铁锂具有更好的电化学性能,5%EPM包覆的硼酸锂首次放电容量达190 mA·h/g,0.5 C下充放电循环50次后容量衰减只有4.2%.