NaOH和Ca（OH）2对C3A—CaSO4.2H2O—H2O系统早期水化影响的研究

用ＸＲＤ等测试手段，研究了Ｃａ（ＯＨ）２和ＮａＯＨ对Ｃ３Ａ－ＣａＳＯ４．２Ｈ２Ｏ－Ｈ２Ｏ的早期（５～１０ｍｉｎ）水化的影响，实验表明，Ｃ３Ａ和石膏在水中，在饱和及不饱和的Ｃａ（ＯＨ）２溶液，或在〈０．４ｍｏｌ／ＬＮａＯＨ溶液中水化，能迅速形成结晶良好的钙矾石，在这种条件下石膏对Ｃ３Ａ水化并有延缓作用。在有足够固体Ｃａ（ＯＨ）２或Ｃ３Ｓ存在的条件下，或在ＮａＯＨ≥０．４ｍｏｌ／Ｌ的溶液中，石膏和Ｃ３     

朝阳产“机选3^#”高岭土合成洗用4A沸石的研究

研究了利用辽宁省明阳产含铝较低的低质“机选３＾＃”高岭土，通过液相补铝合成Ｃａ＾２＋交换能力较高的洗涤剂助剂４Ａ沸石的方法，经实验考察确定，在原始物料组成为硅铝比（ＳｉＯ２／Ａｌ２Ｏ３）２．０，钠硅比（Ｎａ２Ｏ／ＳｉＯ２）２．８，水钠比（Ｈ１Ｏ／Ｎａ２Ｏ）５０，经３５℃，２ｈ胶化和８５０１７０，４ｈ晶化的合成制备条件下，所得产品的Ｃａ＾２＋交换能力为２９８．８ｍｇＣａＣｏ３／ｇ沸石，产率为８３％。     

理化因子对嗜盐隐杆藻细胞生长及胞外多糖产量的影响

比较不同ＮａＣｌ、Ｃａ２＋、ＰＯ３－４等离子浓度对嗜盐隐杆藻（Ａｐｈａｎｏｔｈｅｃｅｈａｌｏｐｈｙｔｉｃａ）细胞生长及胞外多糖（Ｅｘｏｐｏｌｙｓａｃ－ｃｈａｒｉｄｅＥＰＳ）产量的影响。在各影响因子不同浓度的培养条件下,０．５ｍｏｌ／Ｌ的ＮａＣｌ、１．０ｇ／Ｌ的Ｃａ（ＮＯ３）２·４Ｈ２Ｏ、０．１ｇ／Ｌ的ＫＨ２ＰＯ４分别是其最佳生长浓度。ＥＰＳ的产量在０．５ｍｏｌ／ＬＮａＣｌ、,０．５ｇ／ＬＣａ（ＮＯ３）２·４Ｈ２Ｏ、０．５ｇ／Ｌ的ＫＨ２ＰＯ４培养条件下最高。在较低的Ｃａ２＋、Ｍｇ２＋、ＰＯ３－４浓度下可提高ＥＰＳ产率。     

铝硅酸溶胶—MgSiF6—H3PO4系统的^27Al,^29Si,^31PNMR和XRD研究

用＾２７Ａｌ、＾２９Ｓｉ和＾３１Ｐ核磁共振和ＸＲＤ了铝硅酸胶－ＭｇＳｉＦ６－Ｈ３ＰＯ４系统的物相组成及Ａｌ、Ｓｉ、Ｐ在其中所处的结构状态。结果表明，在铝硅酸溶胶中加入ＭｇＳｉＦｔ会导致Ａｌ＾＋５离子从溶胶胶粒中溶出，溶胶胶粒结构的破坏，从而引起胶胶粒中Ａｌ／Ｓｉ比和Ａｌ、Ｓｉ所处结构状态的变化。ＭｇＳｉＦ６与从溶胶胶粒溶出的Ａｌ＾３＋、Ｎａ＾＋离子作用形成水溶性很低的ＮａＭｇＡｌＦ６从而使得铝硅酸     

竹红菌素在DMF—H2O混合体系中的电化学研究

本文研究了竹红菌素ＨＡ，ＨＢ以及１３－ＳＯ３Ｎａ－ＤＤＨＡ在ＤＭＦ－Ｈ２Ｏ（体积分数ψ＝１）混合体系中的电化学氧化还原性质，结果表明，它们都为两步单电子还原过程，反应机理为：油 ＨＡ，ＨＢ：ＨＡ（ＨＢ）＋ｅ＋Ｈ＾＋－ＨＡ（ＨＢＨ）＋ｅ－ＨＡＨ，水溶性１３－ＳＯ３Ｎａ－ＤＤＨＡ：（第一步）１３－ＳＯ３Ｎａ－ＤＤＨＡ＋ｅ－１３－ＳＯ３ＮａＤＤＨＡ，（质子化）１３－ＳＯ３Ｎａ－ＤＤＨＡ＋Ｈ＾＋－１３－Ｓ     

AlN／SiCw（Y2O3＋SiO2）复合材料热处理增强研究

研究了热处理对ＡｌＮ／ＳｉＣｗ（Ｙ２Ｏ３＋ＳｉＯ２）复合材料机械性能的影响。结果表明，该材料经热处理后的强度提高，当添加剂Ｙ２Ｏ３／ＳｉＯ２＝１／２．５摩尔比时，提高幅度最大。经ＸＲＤ，ＳＥＭ，ＴＥＭ／ＥＤＡＸ和ＨＲＥＭ分析，热处理增强的机理主要是粒界玻璃相在高温氧化气氛中和ＡｌＮ颗粒表层作用，生成的纤维２Ｈ＾δＳｉａｌｏｎ相和ＳｉＣｗ形成空间交错结构。     

铝硅酸溶胶－MgSiF_6－H_3PO_4系统的~（27）Al、~（29）Si、~（31）PNMR和XRD研究

用２７Ａｌ、２９Ｓｉ和３１Ｐ核磁共振和ＸＲＤ研究了铝硅酸溶胶－ＭｇＳｉＦ６－Ｈ３ＰＯ４系统的物相组成及Ａｌ、Ｓｉ、Ｐ在其中所处的结构状态。结果表明：在铝硅酸溶胶中加入ＭｇＳｉＦ６会导致Ａｌ＋３离子从溶胶胶粒中溶出，溶胶胶粒结构的破坏，从而引起溶胶胶粒中Ａｌ／Ｓｉ比和Ａｌ、Ｓｉ所处结构状态的变化。ＭｇＳｉＦ６与从溶胶胶粒溶出的Ａｌ３＋、Ｎａ＋离子作用形成水溶性很低的ＮａＭｇＡｌＦ６，从而使得铝硅酸溶胶－ＭｇＳｉＦ６－Ｈ３ＰＯ４系统Ｎａ、Ｆ溶出率较低。Ｈ３ＰＯ４的加入也会促进Ａｌ３＋的溶出，但系统中不发生ＰＯ４四面体聚合状态的变化     

Ca8M（SiO4）4Cl2（M=Mg,Zn）中Ce^3＋的发光性质

报道了氯硅酸镁钙Ｃａ８Ｍｇ（ＳｉＯ４）４Ｃｌ２及氯硅酸锌钙Ｃａ８Ｚｎ（ＳｉＯ４）４Ｃｌ２中Ｃｅ＾３＋的发光特性，研究并分析了Ｃｅ＾３＋在这两种材料中的激发光谱，发射光谱及荧光衰减特性，在ＵＶ辐射激发下，Ｃｅ＾３＋发射出强的蓝紫光。室温下Ｃｅ＾３＋在两种材料中的荧光寿命分别为６１ｎｓ和４４ｎｓ。     

Na^＋和Ti^4＋对CaO—Al2O3—SiO2系玻璃结构和晶化的影响

使用ＲＡＭＡＮ光谱和ＤＴＡ方法研究了含少量Ｎａ＋和Ｔｉ４＋的ＣａＯ－Ａｌ２Ｏ３－ＳｉＯ２系玻璃，发现在纯ＣＡＳ系玻璃（Ｃａ／Ａｌ≥１／２，Ａｌ／Ｓｉ≤１）中，Ａｌ３＋仅有一部分进入玻璃网络，少量Ｎａ＋的引入，有助于Ａｌ３＋进一步进入玻璃网络中，Ｎａ＋起了间接补强玻璃网络的作用，Ｎａ＋和Ｃａ２＋离子对Ａｌ３＋进入玻璃网络结构程度的影响可认为是Ｎａ＋和Ｃａ２＋离子分别以［ＡｌＯ４］Ｎａ和［ＡｌＯ４］Ｃａ［ＡｌＯ４］基团的形式进入玻璃网络中，由于结合几率和体积效应，使［ＡｌＯ４］Ｎａ较［ＡｌＯ４］Ｃａ［ＡｌＯ４］更易进入玻璃网络中。Ｔｉ４＋以［ＴｉＯ４］的形式进入玻璃网络，它对Ａｌ３＋是否能进入玻璃网络无明显影响。Ｎａ＋和Ｔｉ４＋的单独引入，均能使玻璃网络的聚合程度增强，析晶活化能提高；而当Ｎａ＋和Ｔｉ４＋同时引入时，玻璃网络聚合程度和纯ＣＡＳ系玻璃相差不大，析晶活化能有所降低。少量Ｎａ＋的引入，不会影响析出主晶相的种类和数量，而Ｔｉ４＋的引入，则会影响到所析出主晶相的种类和数量。     

CaO-SiO_2-P_2O_5-H_2O系统中CBC材料的溶胶凝胶过程研究 Ⅱ凝胶的烧成过程

利用ＸＲＤ，ＩＲ，ＳＥＭ及２９Ｓｉ，３１ＰＮＭＲ等测试技术研究了ＣａＯＳｉＯ２Ｐ２Ｏ５Ｈ２Ｏ系统中干凝胶在烧成过程中的物相变化及物相间发生的化学反应。认为凝胶在烧成过程的不同阶段发生的主要化学反应如下：（１）６７３～７７３Ｋ：由Ｃａ２Ｐ２Ｏ７和Ｃａ（ＮＯ３）２·４Ｈ２Ｏ反应生成了ＯＨＡｐ；（２）７７３～８７３Ｋ：由Ｃａ２Ｐ２Ｏ７和ＣａＯ反应生成了βＣ３Ｐ；（３）８７３～９７３Ｋ：由ＣａＯ和ＳｉＯ２反应生成βＣ２Ｓ。因此粉末材料的主要晶相有：ＯＨＡｐ，βＣ３Ｐ和βＣ２Ｓ，其中Ｓｉ和Ｐ之间有相互固溶现象。     

C_3S-S-H系统水化产物的热力学稳定性

依据高C3S水泥和混合材复合体系的组成特征,用热力学方法分析了C3S-S-H系统在不同n(Ca)/n(Si)组成时的水化反应.结果表明,C3S-S-H系统水化产物的稳定性由系统n(Ca)/n(Si)组成决定,当n(Ca)/n(Si)>1.88时,最稳定的水化产物是C2SH1.17;当1.25相似文献   

Blast-furnace slag hydration. Surface analysis

X-ray photoelectron spectrometry (XPS) was used to determine the variation of the characteristic ratios Ca/Si, Al/Si and Mg/Si of two different slags (one in granulated, the other in pelletized form) during hydration. The results show that the slag surface is modified as soon as it becomes in contact with water or alkaline solution. The hydrated superficial layer is depleted of calcium but contains alkali ions if instead of water, NaOH or KOH solutions are used in mixing.     

C–(N)–S–H and N–A–S–H gels: Compositions and solubility data at 25°C and 50°C

Calcium silicate hydrates containing sodium [C–(N)–S–H], and sodium aluminosilicate hydrates [N–A–S–H] are the dominant reaction products that are formed following reaction between a solid aluminosilicate precursor (eg, slags, fly ash, metakaolin) and an alkaline activation agent (eg NaOH) in the presence of water. To gain insights into the thermochemical properties of such compounds, C–(N)–S–H and N–A–S–H gels were synthesized with compositions: 0.8≤Ca/Si≤1.2 for the former, and 0.25≤Al/Si≤0.50 (atomic units) for the latter. The gels were characterized using thermogravimetric analysis (TGA), scanning electron microscopy with energy‐dispersive X‐ray microanalysis (SEM‐EDS), and X‐ray diffraction (XRD). The solubility products (K_S0) of the gels were established at 25°C and 50°C. Self‐consistent solubility data of this nature are key inputs required for calculation of mass and volume balances in alkali‐activated binders (AABs), and to determine the impacts of the precursor chemistry on the hydrated phase distributions; in which, C–(N)–S–H and N–A–S–H compounds dominate the hydrated phase assemblages.     

The dissolution behavior in alkaline solutions of a borosilicate glass with and without P2O5

There are a variety of applications for glasses in alkaline environments, including glass fibers and glass‐coated steel to reinforce concrete structures. To understand how a simple glass reacts in such environments, the dissolution behavior of a 25Na₂O–25B₂O₃–50SiO₂ (mol%) glass, doped with and without 3 mol% P₂O₅, in pH 12 KOH and pH 12 KOH saturated with Ca²⁺ ions was studied. Ca²⁺ ions in the solution significantly reduce the glass dissolution rate by forming a passivating calcium silicate hydrate (C–S–H) gel layer on the glass surface. When these corroded glasses were then exposed to Ca‐free KOH, the C–S–H layer redissolves into the undersaturated solution and the glass dissolution rate increases. For phosphate‐doped borosilicate glass, PO₄^3? units released from the dissolving glass react with Ca²⁺ ions in saturated solutions to form crystalline hydroxylapatite on the glass surface, but this layer does not protect the glass from corrosion as well as the C–S–H does. The nature of the C–S–H layer was characterized by Raman spectroscopy, which reveals a gel layer constituted mainly of silicate anions.     

Alkali activation of a novel calcium‐silicate hydraulic binder with CaO/SiO2 = 1.1

A quasi‐amorphous low‐calcium‐silicate hydraulic binder, with an overall CaO/SiO₂ (C/S) molar ratio of 1.1, was produced. This cementitious material was then hydrated with aqueous solutions containing 3 wt% alkalis (either NaOH, Na₂CO₃ or Na₂SiO₃). The evolution of the hydration processes of the samples were monitored by compressive strength testing, XRD, FTIR, ²⁹Si and ²⁷Al MAS NMR, isothermal calorimetry and TGA. It was found that the nearly exclusive hydration product formed was a C‐S‐H phase with a semi‐crystalline structure. More importantly, the paste prepared with the Na₂SiO₃ solution developed compressive strength values similar to those of ordinary portland cements (OPC) with faster early age kinetics. In addition, the isothermal calorimetry results indicated that these new hydraulic binders present much lower heat of hydration values compared with a traditional OPC. The results presented here open the possibility of producing cement with a compressive strength comparable to that of OPC but with lower CO₂ emissions during the production process and with lower hydration heat related problems during the production of concrete structures.     

利用电解锰渣制备As(Ⅲ)吸附材料及其性能研究

通过对工业废弃物电解锰渣(electrolytic manganese residues, EMRs)进行改性制备As(Ⅲ)吸附材料（改性EMRs），探究了NaOH用量、超声及微波对其表面结构及吸附性能的影响。结果表明：该工业废渣在固液比M(EMRs)∶V(NaOH, aq) = 1∶10(C _NaOH，aq = 2.0 mol·L^-1)条件下，经超声反应（200 W）2 h脱除大部分Si、S、Ca后，再微波（700 W）反应5 min以使Fe、Mn等活性吸附基团在其表面沉积，最后经105℃烘干制得改性EMRs。SEM结果表明，EMRs改性后表面形成片层纳米结构，对砷具有良好的吸附性能，可将初始As(Ⅲ)浓度为50 mg·L^-1废水出水中砷降至0.042 mg·L^-1，符合国家地表水环境质量标准Ⅰ类水质量要求(GB 3838—2002)；同时，经3% NaOH溶液再生处理后可继续使用。XPS结果表明，改性EMRs吸附砷性能与其表面Fe₃O₄、FeOOH、MnO₂等对As(Ⅲ)具有吸附作用或氧化作用的活性物种的增多密切相关。     

Initial hydration of tricalcium silicate as studied by secondary neutrals mass spectrometry: II. Results and discussion

The hydration of tricalcium silicate (C₃S) was studied by secondary neutrals mass spectrometry (SNMS), a method that enables determination of the Ca/Si ratio of the formed calcium silicate hydrate (C-S-H) phase with an extremely low information depth. It was found that the magnitude of this parameter within the hydrate layer formed at the surface of the nonhydrated C₃S is not constant and increases with increasing distance from the liquid-solid interface. It was also found that, at a constant distance from the surface, the Ca/Si ratio declines with hydration time. The kinetics of the hydration process is characterized by a very fast initial reaction, followed by a dormant period and a subsequent period of renewed hydration. The rate of hydration becomes distinctly accelerated by elevated temperature and retarded by the presence of sucrose, while NaCl affects the initial hydration kinetics only to a small degree.     

Hydration of low porosity slag-lime pastes

Slag-lime pastes of low porosity (water/solid ratio of 0.20) were hydrated from 6 hours to 180 days at 20°C. The kinetics and mechanisms of the hydration process were studied from the results obtained in this investigation. The depth of the hydrated layer on the slag particles is found to be thin indicating that the hydration reaction is very slow. The molar compositions of the formed hydrates could also be calculated from the free lime, nonevaporable water and uncombined slag contents. A high lime product (molar C/S+A ratio of 2.5–2.6) is formed during the early stage of the hydration process, then the molar C/S+A ratio drops to a value of 1.5 and finally rises to a value of 1.7 at 180 days. The surface areas and pore volumes of hydrates were determined from water and nitrogen adsorption measurements. For water vapor adsorption, the water molecules in the adsorbed phase seem to be highly oriented in an ordered array. This effect might be associated with the polar character of water molecule, when adsorbed on an ionic surface like high lime hydrate. The results of x-ray diffraction and SEM observations indicate only the formation of ill-cyrstallised hydration products.     

Pore solution in alkali-activated slag cement pastes. Relation to the composition and structure of calcium silicate hydrate

In this work, the relationship between the composition of pore solution in alkali-activated slag cement (AAS) pastes activated with different alkaline activator, and the composition and structure of the main reaction products, has been studied. Pore solution was extracted from hardened AAS pastes. The analysis of the liquids was performed through different techniques: Na, Mg and Al by atomic absorption (AA), Ca ions by ionic chromatography (IC) and Si by colorimetry; pH was also determined. The solid phases were analysed by XRD, FTIR, solid-state ²⁹Si and ²⁷Al NMR and BSE/EDX.The most significant changes in the ionic composition of the pore solution of the AAS pastes activated with waterglass take place between 3 and 24 h of reaction. These changes are due to the decrease of the Na content and mainly to the Si content. Results of ²⁹Si MAS NMR and FTIR confirm that the activation process takes place with more intensity after 3 h (although at this age, Q² units already exist). The pore solution of the AAS pastes activated with NaOH shows a different evolution to this of pastes activated with waterglass. The decrease of Na and Si contents progresses with time.The nature of the alkaline activator influences the structure and composition of the calcium silicate hydrate formed as a consequence of the alkaline activation of the slag. The characteristic of calcium silicate hydrate in AAS pastes activated with waterglass is characterised by a low structural order with a low Ca/Si ratio. Besides, in this paste, Q³ units are detected. The calcium silicate hydrate formed in the pastes activated with NaOH has a higher structural order (higher crystallinity) and contains more Al in its structure and a higher Ca/Si ratio than those obtained with waterglass.     

Structure Control of Calcium Silicate Hydrate Gels for Dye Removal Applications

The structure of calcium silicate hydrate (C‐S‐H) gels was modified by hydrothermal reaction with aqueous acetic acid solvent, and then the C‐S‐H gels were used for dye removal from aqueous solution. With increasing acetic acid concentration, the Ca:Si molar ratio decreased and the length of the silicate anion chain structure of the C‐S‐H gels increased. The silicate anion chain length affects the number of available silanol groups on the surface of the C‐S‐H gel: the longer the silicate anion chain length, the greater the number of negative charges and the higher the surface potential. C‐S‐H gels with a long silicate anion structure exhibited higher adsorption capacity for methylene blue than gels with a short silicate anion structure. The enhanced adsorption capacity of the C‐S‐H gels is related to the higher number of silanol groups in the bridging silica tetrahedra of the intermediate anion chain structure compared with those in the end units of silica tetrahedra.