硼硅酸盐泡沫玻璃研究

以C和Sb2O3组合作为发泡剂,通过粉末烧结发泡工艺制备了硼硅酸盐泡沫玻璃,采用SEM观察了试样的微观结构形貌,并研究了试样的耐酸腐蚀性能.结果表明:当发泡剂C的质量分数为0.9%、Sb2O3的质量分数为8.1%时,在1200 ℃、保温30 min条件下,可以制备出平均孔径为0.2～1.0 mm、气孔分布较均匀的硼硅酸盐泡沫玻璃.试样中气孔结构主要与气泡内的气体压力、玻璃的表面张力和粘度有关.将试样浸泡在0.1 mol/L的稀硫酸中做耐酸腐蚀性实验,60 d内试样的质量先有微量增加后保持不变,这主要是由于稀硫酸进入试样的气孔结构中后形成了一层保护膜,从而阻碍了进一步的侵蚀.     

Cr2O3对废建筑玻璃研制的微晶玻璃结构及性能影响

本研究以正交实验确定的最佳制备微晶玻璃的工艺条件为基础,探讨cr2O3晶核剂不同添加量对利用废建筑玻璃研制的微晶玻璃的微观结构及性能的影响.利用XRD法和SEM 法确定不同试样的晶相与形貌;用半定量法确定各试样的晶相与玻璃相的含量,按微晶玻璃的测试标准测试各试样的体积密度、吸水率、抗折强度.实验结果:添加cr2O3;晶核剂析出的主晶相为Na2Ca3Si6O16和SiO2,Na2Ca3Si6O16晶体呈针状,SiO2晶体呈粒状;且试样中的晶相含量随着晶核剂添加量增加而增加.经分析:确定Cr2O3最佳添加量为8wt%,对应的晶相(Na2Ca3Si6O16SiO2、Na2CrO4)含量为47.21%,抗折强度为95.05Mpa.体积密度为2.336g/cm3,吸水率为O.12%.     

Na2SiF6晶核剂对废碎建筑玻璃制微晶玻璃的影响

利用废碎建筑玻璃制微晶玻璃,探讨不同含量的Na2SiF6晶核剂对微晶玻璃结构及性能的影响.用×RD和SEM及相关分析软件表征不同样品的晶相及微观形貌并测试试样的相关性能指标.实验结果表明:添加Na2SiF6晶核剂试样中形成三种晶相:Na2Ca3Si6O16、SiO2、Ca4F2Si2O7,其中Na2Ca3Si6O16和SiO2为主晶相,Na2SiF6晶核剂能够促进玻璃析晶.确定Na2SiF6最佳添加量为8%.对应的晶相(Na2Ca3Si6O16、SiO2、Ca4F2Si2O7)含量为54.56%,抗折强度为141.1 5MPa,体积密度为2.423g/cm3,吸水率为0.025%.     

温度制度对硼硅酸盐泡沫玻璃结构的影响

实验以SiO2和H3BO3为主要原料制备了硼硅酸盐泡沫玻璃.通过改变烧成温度和保温时间,探讨了温度制度对泡沫玻璃的结构的影响.利用SEM分析了泡沫玻璃的气泡结构,并对试样进行了抗酸性测试.随着温度的提高和保温时间的延长,气泡的尺寸逐渐增大,直至连通、破裂.在1250 ℃保温60 min制得的泡沫玻璃的气泡结构最佳.在0.1 mol/L的稀硫酸中浸泡2个月,质量变化率为0.46%～2.28%.     

微晶泡沫玻璃与固体废弃物的循环利用

概述了微晶泡沫玻璃的制备工艺原理及流程,从结构方面讨论了微晶泡沫玻璃的性能及应用,介绍了废玻璃、粉煤灰、尾矿、冶炼渣、硼泥、煤矸石、陶瓷废料等固体废弃物在微晶泡沫玻璃中的应用。     

整体法制备CaO—Al2O3-SiO2系统微晶玻璃晶核剂的选择

措助X射线衍射仪、扫描电镜等现代分析测试手段．分析研究在基础玻璃中加入不同的晶核剂,对整体析晶法制备CaO-Al2O3-SiO2。系统微晶玻璃晶化行为的影响。研究表明．CaF2能有效促进CaO-Al2O3-SiO2系统玻璃的整体析晶．形成以β-硅灰石为主晶相的微晶玻璃．晶核剂质量浓度不同对玻璃析晶的影响不同。     

烧成工艺制度对泡沫微晶玻璃性能的影响

本文利用废玻璃粉和废陶瓷粉制备泡沫微晶玻璃,在确定配方范围的基础上,通过正交优化设计的方法,对制备泡沫微晶玻璃的烧成工艺制度进行优化,使之具有轻质、高强、低导热系数的优良性能.结果表明:烧结温度和发泡温度对泡沫微晶玻璃比强度的影响显著.确定了泡沫微晶玻璃的最优烧成工艺制度为:烧结温度1050℃,发泡温度870℃,发泡时间35 min.优化烧成工艺制度下制备泡沫微晶玻璃试样的表观密度为450 kg/m3,抗压强度为6.84 MPa,导热系数为0.045 W/(m·K),吸水率为0.1％.     

以高炉渣废玻璃为原料一次烧结法制备微晶玻璃

研究了以高炉渣、废玻璃粉为主要原料,以TiO2为成核剂,采用一次烧结法制备微晶玻璃。该材料以透辉石为主晶相,配料中高炉渣质量分数可达55%。这为高炉渣的综合利用开辟了一个新的途径,具有明显的环境效益、经济效益和社会效益。     

CaF2对废碎建筑玻璃制微晶玻璃析晶的影响

探讨CaF2晶核剂不同添加量对废碎建筑玻璃制微晶玻璃结构及性能的影响.用XRD和SEM及相关分析软件表征不同样品的晶相及微观形貌并测试试样的相关性能指标.实验结果表明:添加CaF2试样中析出的主晶相是Na2Ca3Si6O16、SiO2、NaCa2FSiO4,确定4%为最佳的CaF2添加量,此时微晶玻璃析出晶相的总量为53.96%,对应的性能指标为:体积密度2.145 g·cm-3,吸水率0.371%,抗折强度93.12MPa.     

Cr2 O3、TiO2对高炉渣制备微晶玻璃晶化方式的影响

以包钢高炉渣为主要原料,采用熔融法制备CaO-SiO2-MgO-Al2O3系微晶玻璃,主要通过差热分析方法,并借助于Augis-Bennett方程和Ozawa方程研究了分别添加2%Cr2O3和8%TiO2作晶核剂时基础玻璃的晶化方式.研究结果表明:添加2%Cr2O3作晶核剂时,晶体生长指数均可实现大于3,晶化方式为整体晶化;而添加8%TiO2作晶核剂时,晶体生长指数均不可能大于3,晶化方式为表面晶化.因此,Cr2O3是高炉渣制备透辉石类微晶玻璃适宜的晶核剂成分,可单独用作晶核剂,而TiO2无法使基础玻璃整体晶化,不能单独用作晶核剂.研究结果为利用高炉渣成功研制开发透辉石类微晶玻璃在晶核剂种类选择确定方面提供了理论指导.     

Fe2O3作晶核剂的CaO-SiO2系玻璃析晶动力学研究

用溶胶凝胶法制备了CaO-SiO2（含Fe2O3）系玻璃,采用差热分析方法研究了玻璃析晶动力学.结果表明：该方法制备工艺简单,Fe2O3作玻璃组分,使玻璃产生不同性质;作晶核剂使析晶过程明显,经分析样品为整体析晶,析晶活化能为438.023kJ/mol.     

CaO-Al_2O_3-SiO_2系统玻璃晶化时首析晶相及TiO_2的作用机理预测和研究

通过ＣａＯＡｌ２Ｏ３ＳｉＯ２系统玻璃的结构分析预测玻璃晶化时首析晶相是钙长石。选取ＣａＯＡｌ２Ｏ３ＳｉＯ２三元相图成玻璃区内的某点作为基础玻璃的组成，在基础玻璃中加入ＴｉＯ２。用ＤＴＡ，ＸＲＤ和ＳＥＭ方法的研究结果表明，不管玻璃中加ＴｉＯ２与否，晶化时首先析出的晶相都是钙长石，且均为从表面向内部生长，与预测相符。ＴｉＯ２作为晶核剂，效果不太明显，在高温时ＴｉＯ２只能使玻璃网络结构松弛，粘度降低，促进玻璃中晶相的成核和生长。     

晶核剂Cr2O3、Fe2O3对玻璃熔化性能的影响

高炉渣的主要成分与玻璃相似,采用熔融法以高炉渣为主要原料制备微晶玻璃(高炉渣配比为70%),以少量纯化学试剂调整基础玻璃成分,通过实验研究了晶核剂Cr2O3、Fe2O3对玻璃熔化性能的影响规律.结果表明:基础玻璃中加入0.5%~2.5%的Cr2O3作晶核剂时,随着Cr2O3加入量的增多,熔化温度呈现逐渐升高趋势,当向基础玻璃中加入1.0%~3.0%Fe2O3作晶核剂时,随着Fe2O3加入量的增多,熔化温度逐渐降低.将0.5%~2.5%Cr2O3、1.0%~3.0%Fe2O3按一定比例配合作为复合晶核剂,总量控制在3.5%,Cr2O3与Fe2O3对玻璃熔化性能的影响可以互相抵消.晶核剂Cr2O3、Fe2O3的引入,可明显降低玻璃的熔化性温度,为了保证玻璃液的顺利浇注成型,至少应将温度控制在1360 ℃以上.     

Li取代对LAS系微晶玻璃核化行为的影响

以Li2O-Al2O3-SiO2三元系(LAS)微晶玻璃为研究对象,采用DTA、XRD等测试技术研究了不同Li2O含量LAS玻璃的核化行为,分析了Li取代对LAS玻璃核化行为的影响。研究结果表明,随着Li含量的降低,LAS系玻璃的相转变温度、析晶峰温度逐步增大,最佳核化温度逐渐升高,最佳核化时间没有明显的变化。     

Nucleating agent for poly(L‐lactic acid)—An optimization of chemical structure of hydrazide compound for advanced nucleation ability

A series of compounds having hydrazide groups was prepared and evaluated as nucleating agent for poly(L ‐lactic acid) by differential scanning calorimetry. Hydrazide compounds derived from benzoic acid, 2‐hydroxybenzoic acid, 3‐tert‐butylbenzoic acid, and 2‐aminobenzoic acid, where two of hydrazide compounds connected by four methylene chain were evaluated in series. Benzoylhydrazide type was found to be more effective on the enhancement of crystallization of poly(L ‐lactic acid). Effects of connecting length of methylene chain numbers between two of benzoylhydrazide on the nucleation ability were also evaluated. Benzoylhydrazide‐type compound having 10 methylenes, that is, decamethylenedicarboxylic dibenzoylhydrazide demonstrated excellent nucleation ability, and the resulted crystallization temperature and enthalpy of PLA with the compound of 1 wt % loading were 131°C and 46 J g^?1. The achieved crystallization temperature and enthalpy were over 10°C and over 10 J g^?1 higher than PLA with conventional nucleating agents, such as talc and ethylenebis (12‐hydroxystearylamide). Thus, the improvement in processability, productivity, and heat resistance of PLA is suggested to be achieved by using decamethylenedicarboxylic dibenzoylhydrazide as a nucleating agent. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 198–203, 2007     

Biodegradable foams of poly(lactic acid)/starch. I. Extrusion condition and cellular size distribution

Biodegradable foams derived from poly(lactic acid) (PLA) and starch were prepared by extrution using water as a blowing agent and talc as nucleation agent. Foam cellular size and size distribution was significantly affected by extrusion conditions (i.e., extruder temperature profiles, die diameters, and screw speed), and material compositions, (i.e., water concentration, PLA/starch ratio, and nucleation agent concentration). Foam with a relatively fine cellular size and uniform cellular size distribution was obtained under optimized conditions of PLA/starch ratio at 40/60, 15% water, 195°C temperature before the die, 3‐mm die nozzle diameter, 200‐rpm screw speed, and 2% talc. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Effect of structural relaxation on crystal nucleation in a soda-lime-silica glass

The influence of structural relaxation on crystal nucleation has been underexplored and remains elusive. This article discusses its possible effect on the nucleation process using a stoichiometric soda-lime-silica (2Na₂O·CaO·3SiO₂) glass as a model system. We show that the relaxation effect is powerful at low temperatures, close and below the glass transition, , and leads to a continuous increase in the nucleation rate. At any given temperature, the nucleation rate eventually reaches its ultimate steady-state corresponding to the fully relaxed supercooled liquid (SCL). However, the time to reach the steady-state is two to three orders of magnitude longer than the average relaxation time estimated by the Maxwell relation (shear viscosity / shear modulus). The proposed nucleation mechanism and model, which take relaxation into account, and related experimental results also explain the alleged “breakdown” of CNT at low temperatures reported for various glasses. It confirms a few recent papers that this apparent flaw is merely because most researchers did not prolong nucleation treatments enough to complete the relaxation process to achieve a steady state. Another remarkable result is that the actual maximum nucleation temperature, , is significantly lower than the previously reported values. Finally, a comparative analysis of the kinetic coefficient using viscosity versus growth velocity favors the last. These results for this soda-lime-silica glass extend and validate recent findings for lithium disilicate on the significant (but often neglected) effect of relaxation on crystal nucleation.     

一种新型纳米稀土氧化物玻璃防雾剂的研究

利用硝酸-H2O2法制取纳米CeO2和La2O3颗粒。然后以乙醇和异丙醇为溶剂,乙二醇和甘油为添加剂,加入一定量的表面活性剂,以及纳米CeO2和La2O3颗粒,余量为水来制备防雾剂。该文所制备的防雾剂润湿效果很好,其接触角为3.75°,亲水性强,防雾效果好。     

Dual effect of ZrO2 on phase separation and crystallization in Li2O–Al2O3–SiO2–P2O5 glasses

ZrO₂ is an effective nucleation agent for low-expansion lithium–aluminum silicate (LAS) glass–ceramic (GC) with high Al₂O₃ content. However, the effect of ZrO₂ is still not fully understood in LAS glasses with low contents of Al₂O₃ and P₂O₅. In this work, the effect of ZrO₂ on the phase separation and crystallization of Li₂O–Al₂O₃–SiO₂–P₂O₅ glasses were investigated. The results revealed that ZrO₂ significantly increased T_g and the crystallization temperature of Li₂SiO₃ and Li₂Si₂O₅ crystals. Li₃PO₄ crystals precipitated preferentially in the glass containing 3.6-mol% ZrO₂, wherein Zr was stable in the network and no precipitation of ZrO₂ nanocrystals was observed. Moreover, the separation of phosphate-rich phases in the as-quenched glasses increased with the addition of ZrO₂. The findings of the study revealed a dual role of ZrO₂. First, ZrO₂ acted as a glass network former rather than a nucleation agent, increasing glass viscosity and the nucleation barrier of Li₂SiO₃ through its strong network connectivity. Second, as Zr preferentially combined with non-bridging oxygen to form Si–O–Zr linkages, a sufficient amount of charge-balancing Li⁺ ions existed in the network, which promoted the separation of phosphate-rich phases. It indicated that the incorporation of ZrO₂ contributes to the activation of the nucleation role of P₂O₅, thus contributing to the formation of nanocrystals and fine microstructure of GCs.