Characterization of synthesizedA-zeolite

Confirmations of the successful synthesis of a particular zeolite demand investigation of the crystals by XRD, SEM, MAS-NMR and chemical analysis. In this work, we have used the DTA exothermic lattice breakdown of theA-zeolite, which gives typical peaks at around 900–1200°C for characterization. The effects ofpH, concentration, time of crystallization and temperature were studied and it was quickly and easily possible to distinguishA-zeolite formation from others originating from the synthesis matrix under different conditions by using DTA/TG analyses. The parameters were optimized for the synthesis of the zeolite and DTA measurements yielded enough information to identify theA-zeolite; this was confirmed by XRD and SEM.     

Hybrid inorganic/organic interpenetrating polymer networks based on zeolite 13x and polystyrene

A hybrid inorganic/organic interpenetrating polymer network (IPN) of a three-dimensional network structure zeolite crystal (13X, powder) and crosslinked or linear polystyrene (PS) was prepared and characterized by differential scanning calorimetry (DSC), solid-state¹³C-NMR, and scanning electron microscopy (SEM). The size and shape of the crystalline zeolite particles were revealed on SEM micrographs in both the pure zeolite and the IPNs. Solubility tests and the results of DSC with solid-state ¹³C-NMR confirm that some organic PS chains are incorporated within the internal three-dimensional channels of the zeolite particles. We speculate that the internal PS chains may adopt an extended “one-dimensional” conformation and exhibit no bulk polymer glass transition. These novel hybrid inorganic/organic IPNs are a new kind of IPN structure. © 1995 John Wiley & Sons, Inc.     

Characterization of the behaviour of flavour microcapsules in cotton fabrics

Nanotechnology processes have recently been introduced into the textile field. One of these processes involves encapsulated nanoparticles or nanoproducts, known as microcapsules. They are available with a wide range of products which confer different properties related to the nature of the encapsulated product. The composition of the wall material determines the release of the product into the fabric and is the object of study in the present work. The behaviour of microencapsulated peppermint was analyzed on cotton fabrics.Different application methods have been tested, impregnation versus bath exhaustion. As impregnation turned out to be the most efficient, some recipes were assayed and the effect of microcapsules on maintenance conditions was evaluated in order to determine the most suitable method with the longest lasting effect on fabrics.The effect of microcapsules is usually measured by the presence of a property such as odour measurements when flavours are encapsulated. The aim of this work is to explain the behaviour of the cotton fabrics with microcapsules bound to their fibers, to determine the relationship between their macroscopic properties and microscopic characteristics. A procedure based in FTIR spectroscopy is also proposed to quantify the presence of microcapsules in the fabrics.IR spectra of the textiles were obtained to determine the presence of microcapsules, which was corroborated by SEM techniques.     

Activity of TiO2 deposited by the CVD method on ammoxidized surface of a carbonaceous material in hydrogenation of styrene

Hydrogenation of styrene has been applied as a test reaction to study the catalytic activity of TiO₂ deposited by the CVD (chemical vapour deposition) method on the surface of a carbonaceous material enriched in nitrogen (C_N).     

Basic study of the gelation of dimethacrylate‐type crosslinking agents

An investigation was made of the gelation of dimethacrylate‐type crosslinking agents in view of an application for separation media. The study mainly centered on a crosslinking agent, glycerol dimethacrylate (GDMA), which is relatively hydrophilic because of a hydroxyl group in the middle of its structure. The gelation of GDMA was compared with that of other hydrophobic crosslinking agents such as ethylene glycol dimethacrylate and 1,6‐hexanediol dimethacrylate. The diluents used in the study were toluene, toluene with methanol, and cyclohexanol. The gelation was observed in real time with a charge coupled device camera and dynamic light scattering (DLS). Also, the separated dry gels were extensively characterized with scanning electron microscopy, BET (N₂ absorption and desorption isotherm), and Fourier transform infrared. DLS analysis showed a stronger molecular interaction of GDMA gelation in toluene, whereas this interaction was much weaker in an alcoholic solvent such as toluene with methanol or cyclohexanol. This indicated that GDMA gelation might proceed through hydrogen bonding as well as a crosslinking reaction of vinyl groups. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 949–958, 2006     

平朔气煤的煤岩显微组分结构研究

用显微光度计、扫描电子显微镜(SEM)、傅立叶变换红外光谱(FTIR)、X射线衍射光谱(XRD)和X光电子能谱(XPS)等测试手段研究了平朔气煤的等密度梯度离心分离(DGC)显微组分富集物的结构。结果表明,镜质组和稳定组结构相似,含氧基团基本相同,但丝质组结构则不同,它含有较多的羧基和羰基。根据实验结果讨论了三种显微组分的大分子结构,认为它们是由许多结构相似而又不相同的结构单元所构成。镜质组和稳定组的单元核心主要为脂环、缩聚芳环,环数为5—6个;丝质组单元核心主要为缩聚芳环,环数为7—8个,环缩合程度最高,芳香层片在空间排列规则,相互定向程度大。     

A comparative study on the thermal decomposition of some transition metal carboxylates

Thermal decomposition of transition metal malonates, MCH₂C₂O₄?xH₂O and transition metal succinates, M(CH₂)₂C₂O₄?xH₂O (M=Mn, Fe, Co, Ni, Cu, Zn) has been studied employing TG, DTG, DTA, XRD, SEM, IR and Mössbauer spectroscopic techniques. After dehydration, the anhydrous metal malonates and succinates decompose directly to their respective metal oxides in the temperature ranges 310–400 and 400–525°C, respectively. The oxides obtained have been found to be nanosized. The thermal stability of succinates have been found to be higher than that of the respective malonates.     

Emanation Thermal Analysis of SiC Based Materials

Results of emanation thermal analysis (ETA) characterizing microstructure changes of SiC based materials during heat treatment in argon are demonstrated. This method made it possible to reveal fine changes of the texture of SiC nano-sized powders, SiC micro-sized powders and SiC whiskers under in situconditions of the heating. ETA curves can serve as fingerprints of the respective samples.This revised version was published online in November 2005 with corrections to the Cover Date.     

Y2O3:Eu3+纳米线阵列的制备与表征

Y2O3:Eu3+红色荧光粉由于色纯度高、化学性质稳定和量子效率接近100%而广泛用于荧光灯和投影电视等方面.近年来,Y2O3:Eu3+的大量研究工作主要集中于纳米粉末的制备方法及其与体相材料不同的发光特性[1～3].最近,有关Y2O3:Eu3+及其稀土化合物的纳米管、纳米线和纳米带一维材料的制备成为研究热点.Wu Changfeng等[4,5]利用表面活性剂合成了Y2O3 : Eu3+纳米管.激光格位选择激发测试结果表明,Eu3+在纳米管中占据3个不同的格位,其611 nm处的红色发光峰出现了宽化.He Yu等[6]采用水热法及退火处理制备出了Y2O3:Eu3+纳米带,发现Eu3+的发射峰不仅宽化,而且出现了625 nm的新峰.Li Yadong等[7～9]采用水热法制备了稀土氧化物、硫氧化物和氢氧化物等的纳米线和纳米管,并探索了其形成机理,同时发现Y2O3S : yb3+,Er3+具有上转换的性质.