Sol–Gel Kinetics Followed by Cylindrical Attenuated Total Reflectance Infrared Spectroscopy

This paper describes a unique solution infrared technique, a cylindrical attenuated total reflectance cell, to monitor in situ kinetics of the sol-gel process, especially at short times after mixing. The sol-gel kinetics of acidic ethanol : TEOS : Al(III) solutions have been followed as a function of temperature and aluminum concentration. The hydrolysis rate and the condensation rate increase with temperature and Al/Si ratio. The Al(III) hydrolysis and concomitant increase in acidity increase the reaction rate. By controlling the initial pH, it is seen that a higher Al(III) concentration itself increases the reaction rate. The properties of a sol-gel glass depend upon the kinetics, which are controlled by the processing conditions, including cation content.     

Determination of the Hydroxyl Value of Soybean Polyol by Attenuated Total Reflectance/Fourier Transform Infrared Spectroscopy

A rapid method for the quantitative determination of the hydroxyl value (OHV) of hydroxylated soybean oils by HATR/FTIR spectroscopy is described. Calibration standards were prepared by the formic acid/hydrogen peroxide method and OH values were determined by the official method of AOCS Tx 1a-66, covering an analytical range of 3.5–125 mg of KOH/g of sample. A partial least squares (PLS) calibration model for the prediction of the hydroxyl value (OHV) was developed based on eight different spectral subregions between 3,150 and 990 cm⁻¹ and combinations of them. On average, 36 samples were used for the modeling and 17 were used for external validation. The resulting calibration was linear over the analytical range and had a standard deviation of 2.334. Validation of the method was carried out by comparing the OHV of a series of hydroxylated soybean oils predicted by the PLS model to the values obtained by the AOCS standard method. A correlation coefficient of R ² = 0.9843 and RMSEC and RMSEP values of, respectively, 3.393 and 3.643 were obtained. After the calibration of the spectrometer, the OHV could be obtained in 2–3 min per sample, a major improvement over conventional wet chemical methods. The advantages of these methodologies are that they do not destroy the sample, have a lower cost, expedite the analysis and do not produce residues. Therefore, they may yield excellent results when used to quantify OHV of soybean polyols obtained by hydroxylation reaction.     

Investigation of Planar Ziegler-Natta Model Catalysts Using Attenuated Total Reflection Infrared Spectroscopy

A sensitive method is presented for the investigation of planar Ziegler-Natta model catalysts by means of attenuated total internal reflection Fourier transform infrared spectroscopy. A solution of MgCl₂ in ethanol, optionally containing an internal donor, was spin-coated directly onto a planar ZnSe ATR crystal. Ethylene and propylene polymerization was monitored in situ and ex-situ, respectively, and interaction of a diester internal donor with MgCl₂ and TiCl₄ was investigated. The isotacticity of the polypropylene produced in the presence and absence of donor was estimated based on characteristic peaks in the infrared spectra.     

显微红外成像和衰减全反射技术在不同种属黄精中的鉴别研究

探讨了显微成像和衰减全反射两种红外模式对不同种属黄精的鉴别.以6种不同种属的黄精样品为研究对象,一份样品经冰冻切片机进行取样,采用显微红外仪器进行扫描;另一份样品经烘干打粉,采用衰减全反射模式扫描.结果表明,以多糖含量高低作为鉴别依据,衰减全反射模式可以快速判别出是否含有多糖以及简单比较不同种属黄精间含量差异,而显微红...     

衰减全反射红外光谱法测定含氢硅油的氢含量

依据Si—H键在2 160 cm-1处的特征吸收峰,利用衰减全反射-傅立叶变换红外光谱法(ATR-FTIR)和OMNI采样器附件对含氢硅油的氢含量进行定量分析,并用软件对ATR谱进行校正。结果表明:含氢硅油的活性氢质量分数与其红外吸收峰面积在实验浓度范围内有良好的线性关系,相关系数为0.9998。     

ATR红外光谱法快速鉴定水样采集袋材质

以无菌水样采集袋为研究对象,采用衰减全反射傅里叶红外光谱(ATR-IR)对无菌水样采集袋内、外层材质分别进行了鉴定,并对该水样采集袋材质的适用性与可行性进行了分析。结果表明,该水样采集袋内层材质为聚乙烯,外层材质为聚对苯二甲酸乙二醇酯,且该两种高分子材料适用作水样采集袋内、外层。ATR红外光谱法能快速鉴定无菌水样采集袋材质,且不需进行样品前处理,有助于水质监测工作者科学选择市场上的无菌水样采集袋用于水样保存。     

ITO薄膜的研究进展

ITO是锡掺杂氧化铟薄膜的简称,属于透明导电氧化物材料。常规沉积方法制备的ITO薄膜通常为非晶态或体心立方晶系晶体,为n型半导体材料,其载流子为自由电子,主要来源于沉积过程中薄膜化学计量比偏离或阳离子掺杂形成的施主杂质。ITO薄膜是当前研究和使用最为广泛的透明导电氧化物薄膜材料,由于具有低电阻率、高可见光透过率、高红外反射率等独特物理特性而被大量应用于平板显示器、太阳能电池、发光二极管、气体传感器、飞机风挡玻璃除霜器等领域。此外,ITO薄膜对微波还具有高达85%的衰减作用,因而在电磁屏蔽等军用领域显示出巨大的潜在应用价值。过去几十年里,针对ITO薄膜的研究工作主要聚焦于薄膜的光电性能上。当前,伴随着ITO薄膜的应用范围在航空航天和军用武器装备等领域的拓展,ITO薄膜在恶劣力学环境中的使用日渐增多。因此,除光电性能外,ITO薄膜的力学性能也开始受到研究者越来越多的关注,人们对薄膜器件在各类恶劣使用环境中的稳定性及耐久性提出了更高的要求,这一要求使得对ITO薄膜力学性能的深入研究分析有了重要的理论及实际意义。本文综述了近年来ITO薄膜在微结构特性、能带结构、光电性能及力学性能等方面的研究进展,简略探讨了ITO薄膜的研究发展方向。     

Quantitative Monitoring of the Amidation Reaction Between Coconut Oil and Diethanolamine by Attenuated Total Reflectance Fourier Transform Infrared Spectrometry

An analytical procedure was developed to monitor the batch reaction of coconut oil and diethanolamine which also would determine the cocodiethanolamide (CDEA) content of the final product. The method was based on attenuated total reflectance Fourier transform infrared spectrometry utilizing partial least squares regression. The calibration was modeled in the 1,781–1,714 and 1,658–1,639 cm⁻¹ spectral regions for coconut oil and CDEA respectively. The models were then applied to predict the amidation process yield and to monitor the in situ kinetics of reactions between coconut oil and DEA. The root mean square error of prediction was 0.590 and 0.336 for coconut oil and CDEA respectively. The proposed method can also be successfully applied to the determination of purity in commercial grade CDEA samples and would give reliable results in comparison with the potentiometric titration reference method.

Electrochromic property of nano-composite Prussian Blue based thin film

In this paper, we present fabrication of a nano-composite Prussian Blue (NPB) film to synchronously improve the contrast and switching time of regular Prussian Blue (PB) film by applying the concept of nano-technology. The NPB consists of indium tin oxide (ITO) nano-particles (3.0 ± 1.0 Ω, 40 ± 5 nm) as a medium layer for PB to gain larger operative reaction surface area in Li⁺ based electrolyte (1 M LiClO₄/PC) system. The procedures for preparation of NPB are: first, a well-dispersed ITO nano-particle solution is sprayed onto ITO glass (30 Ω/sq) at 200 °C; the PB film is then electroplated onto the pre-sprayed ITO nano-particles. Since ITO nano-particles can be well covered with PB, the NPB film forms a nano-porous electrochromic layer. The switching speed and contrast of NPB exhibit much better performances than traditional PB thin films. The structure, morphology, and electrochromic properties were characterized by scanning electron microscopy (SEM), cyclic voltammograms (CV), and UV-vis spectroscopy.     

普鲁士蓝基材料在水处理中的研究进展

普鲁士蓝(PB)、普鲁士蓝类似物(PBA)及它们的复合物具有较大的比表面积、多孔的结构、高的化学稳定性和丰富的过渡金属活性位点,在水处理领域具有广阔的应用前景.综述了PB基材料(PB、PBA和它们的复合物及衍生材料)的研究进展,讨论了材料的组成、制备及性能,归纳了其在水处理中的应用机制,分析了PB基材料研究的发展趋势.     

Screen Printed Biosensor for Hydrogen Peroxide Based on Prussian Blue Modified Hydroxyapatite

A disposable and sensitive screen-printed carbon electrode for the determination of hydrogen peroxide (H₂O₂) was fabricated with Prussian blue-modified hydroxyapatite (PB@HAP). PB@HAP was incubated with horseradish peroxidase (HRP). The synergistic effect between HAP and PB facilitated the electron-transfer process and retained the bioactivity of HRP. The proposed biosensor effectively overcame the shortcomings of electron mediator leakage because hydroquinone was added to the base solution. The biosensor showed a low detection limit of 7 μmol/L. A linear calibration plot was obtained over the concentration range, 1–15 mmol/L; the Michaelis constant was 1.31 mmol/L, which indicated that the enzyme retained high bioactivity and excellent appetency toward H₂O₂. Additionally, the screen-printed biosensor exhibited the characteristics of strong anti-interference, high long-term stability and good reproducibility. Based on the above, PB@HAP has potential for applications in immunosensors and glucose sensors.     

Growth of Pt Subnano Clusters on Limited Surface Areas of Prussian Blue Nanoparticles

We synthesized insoluble Prussian blue nanoparticles (PB NPs) and water-soluble PB NPs ([Fe(CN)₆]^4?-modified PB NPs) as synthetic fields and carriers of Pt subnano clusters. Pt²⁺ can attach on their surface Fe–CN sites. The amount of the attached Pt²⁺ on the insoluble and water-soluble PB NP surfaces was saturated to reach Pt/Fe = 15 and 40 mol%, respectively, based on the total metal ions of PB. The results showed that the attachment amount of Pt²⁺ on the surface CN sites was controlled by the surface modification. From results of TEM and STEM-HADDF-EDS, Pt subnano clusters (1.4 nm) were observed on water-soluble PB NPs after the reduction using hydrazine.     

Attenuated Toatal Reflectance Fourier-Transform Infrared Spectra of a Hydrated Sodium Soilicate Glass

Attenuated total reflectance Fouriertransform infrared (ATR-FTIR) spectra were measured in the region from 4300 to 400 cm⁻¹ for a hydrated Na₂O–SiO₂ glass containing 35 wt% water. The Si–OH bending vibration mode was observed. It was found that the incorporated water, molecular water as well as hydroxyls, affected the Si–O vibrations. The effect of incorporated water upon the glass structure is discussed.     

Amperometric glucose biosensor with high sensitivity based on self-assembled Prussian Blue modified electrode

A glucose biosensor, which was based on self-assembled Prussian Blue (PB) modified electrode with glucose oxidase (GOD) immobilized in cross-linked glutaraldehyde matrix, was developed. Fourier-transform infrared spectroscopy shows that the immobilized GOD retains its native conformation. Cyclic voltammetry was used to examine the electrocatalytic property of the enzyme electrode. The prepared glucose biosensor exhibits fast response (<4 s) and low detection limit of 5 × 10⁻⁶ M. The calculated apparent Michaelis constant K_M was 6.3 ± 1.2 mM, indicating a high affinity between the GOD and glucose. The effects of glutaraldehyde concentration and GOD loading on the sensitivity of the glucose biosensor have also been investigated. Under the optimal conditions, the biosensor shows a high sensitivity of about 80 mA M⁻¹ cm⁻² in a concentration range up to 1 × 10⁻³ M. The relative standard deviation (RSD) for intra-electrode and inter-electrode were 4% and 5%, respectively. In addition, the anti-interferent ability and stability of the biosensor were also discussed.     

New Hybrid Nanomaterial Based on Self-Assembly of Cyclodextrins and Cobalt Prussian Blue Analogue Nanocubes

Supramolecular self-assembly has been demonstrated to be a useful approach to developing new functional nanomaterials. In this work, we used a cobalt Prussian blue analogue (PBA, Co₃[Co(CN)₆]₂) compound and a β-cyclodextrin (CD) macrocycle to develop a novel host-guest PBA-CD nanomaterial. The preparation of the functional magnetic material involved the self-assembly of CD molecules onto a PBA surface by a co-precipitation method. According to transmission electronic microscopy results, PBA-CD exhibited a polydisperse structure composed of 3D nanocubes with a mean edge length of 85 nm, which became shorter after CD incorporation. The supramolecular arrangement and structural, crystalline and thermal properties of the hybrid material were studied in detail by vibrational and electronic spectroscopies and X-ray diffraction. The cyclic voltammogram of the hybrid material in a 0.1 mol·L⁻¹ NaCl supporting electrolyte exhibited a quasi-reversible redox process, attributed to Co²⁺/Co³⁺ conversion, with an E_1/2 value of 0.46 V (vs. SCE), with higher reversibility observed for the system in the presence of CD. The standard rate constants for PBA and PBA-CD were determined to be 0.07 and 0.13 s⁻¹, respectively, which suggests that the interaction between the nanocubes and CD at the supramolecular level improves electron transfer. We expect that the properties observed for the hybrid material make it a potential candidate for (bio)sensing designs with a desirable capability for drug delivery.     

近红外光谱分析技术的发展和应用

介绍了近红外光谱分析技术的发展历史、常用化学计量学方法及其实际应用情况。     

Blue Thread of the Tzitzit: Was the Ancient Dye a Prussian Blue or Tyrian Purple?

The Radzin process for renewing the use of the Biblical blue thread on the Jewish ritual fringed garment (tz\Xz\xj is examined. The colouring matter formed proved to be Prussian blue. Since a natural dye obtained from a shellfish is required, the Radzin product is disqualified as an authentic revival. An alternative identification of the ancient blue with Tyrian purple is inconsistent with the accepted designation of the latter as the Biblical purple “argaman”. The Biblical blue is to be identified with the ancient hyacinthine purple, which was evidently derived from Murex trunculus. The Janthina hypothesis is also discussed.     

Simultaneous Determination of Sodium Tripolyphosphate,Sodium Sulfate and Linear Alkylbenzensulfonate in Washing Powder by Attenuated Total Reflectance: Fourier Transform Infrared Spectrometry

An analytical procedure has been developed for the simultaneous quantitative determination of sodium tripolyphosphate (STPP), sodium sulfate (SS) and Linear Alkyl Benzene Sulfonate (LABS) in a single washing powder sample. The method is based on the partial least squares treatment of data obtained by the Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectrometric method in the wavenumber range of 800–1,290 cm⁻¹. Absorbance spectra were employed for measurement using 29 aqueous standard solutions of STPP, SS and LABS. The method is simple, rapid and accurate and has been applied to commercial washing powders analysis performing the STPP, SS and LABS determination with a simplified sample preparation step consisting only of powder dissolution in distilled water. The other advantage of this method is its minimal time consumption (about 15 min), in comparison with previously introduced methods based on the determination of separated analytes (more than 4 h). The relative standard deviations of the proposed method for analyzing these real samples were 0.99, 0.56 and 0.91% for STPP, SS and LABS, respectively.

Synthesis of Prussian Blue Metal Coordination Polymer Nanocubes via Cyanoferrate Monomer Design

The effect of cyanoferrate monomers on the metal coordination polymerization of Fe³⁺ and [Fe(CN)₅L]^3?, where L = CN, NH₃, pyrazine (Pz), pyridine (Py) and 4-(dimethylamino)-pyridine (DMAP), for the synthesis of Prussian blue (PB) polymers was investigated. The polymerizations were performed in water at ambient temperature in the absence of templates and/or surfactants. The morphology and crystallinity of the resulting polymers are influenced by the nature of the ligands L associated with the monomers. When L = CN or NH₃, crystalline polymers with irregular structures were produced. The polymerization employing [Fe(CN)₅L]^3? with L = Pz, Py and DMAP led to amorphous polymers with a tendency to form individual nanoparticles depending on the choice of L. Notably, in the case of [Fe(CN)₅DMAP]^3?, amorphous PB nanocubes with a regular size distribution were produced. Based on this study, the binding forces of L to Fe(II)(CN)₅ is highlighted as an important parameter for PB metal coordination polymer nanostructure control and design.     

Bidimensional spectroelectrochemical study on electrogeneration of soluble Prussian Blue from hexacyanoferrate(II) solutions

Electrogeneration of soluble Prussian Blue (PB) during the oxidation-reduction of the Fe(CN)₆³⁻/Fe(CN)₆⁴⁻ system has been detected using bidimensional spectroelectrochemistry (BSEC). This new technique allows us to obtain simultaneously two different spectroscopic signals together with an electrochemical signal, each one containing different information. Starting from pure Fe(CN)₆⁴⁻ solutions, some experimental conditions under which soluble PB appears, have been analysed. Fe(CN)₆⁴⁻/supporting electrolyte concentration ratio and potential scan rate have been found as the most influential factors. All experiments show clearly the generation of soluble PB but in no case the insoluble form has been detected. From the results, PB generation can be explained as a surface chemical process coupled with the electron transfer reaction.