对特定性能掺杂石英陶瓷开发

本文对国外已开发的具有特定性质的掺杂石英陶瓷作了一个比较系统介绍，文中不仅介绍了掺杂方法，掺杂石英陶瓷种类的性质，及掺杂石英陶瓷制备，而且还指出了掺杂石英陶瓷应用和它的开发前景。     

熔融石英陶瓷的开发及应用

概述了熔融石英陶瓷的制造工艺及性能特点，对比分析了其国内外发展概况，介绍了石英陶瓷辊，闸板砖，空心辊，旋转等几种高档熔融石英陶瓷制品的开发进展及应用情况。     

高纯石英应用及化学提纯技术研究进展

高纯石英作为—种稀有矿产资源，由于其稳定的物理化学性质，在半导体、光伏、光学及光纤通信等高新技术领域有着广泛的应用。总结了高纯石英在高精尖产业的应用现状，详细介绍了脉石矿物杂质、包裹体杂质、类质同象类杂质的存在形式及特征，在此基础上综述了酸浸出法、碱浸出法、热处理法等化学提纯技术研究现状，并展望了我国高纯石英提纯技术未来的发展方向。     

纯石英光纤在激光医学领域的应用

本文从诊断和治疗两个方面介绍了医用激光的现状及发展方向，结合纯石英光纤的光传输特性，论述了纯石英光纤在不同波长的医用激光系统中的应用情况和发展前景，并且着重讨论了纯石英光纤在高功率、高能量密度的医用激光中的独特地位以及高性能包层材料的最新进展     

石英晶体微天平分析技术进展

介绍了石英晶体微天平的工作原理，技术关键和应用情况，并从称量灵敏度分布曲线的理论出发，对如何正确使用石英晶体微天平分析技术进行了探讨，建议制造通用型的石英晶体微天平，以期为大气环境和水质纯度分析及实时实地监测提供一种全新的分析方法。     

石英陶瓷开发前景

本文对国外已开发和应用的石英陶瓷和特种石英陶瓷制品作了一个比较系统介绍。文中不仅介绍了它们的性质和制备方法，而且还介绍了它的应用和开发前景。     

中国节能公司填补国内石英提纯技术空白

近日，中国节能投资公司所属中节能新材料投资有限公司与江西省九江市签署脉石英深加工项目协议。该项目建成投产后，将填补国内脉石英提纯技术和高纯超细石英产品的空白，部分满足我围高纯超细石英产品的需求，同时将只卡加快我国高纯超细石英产品的研发和应用起到积极的示范作用。     

石英质宝玉石的种类及鉴定特征

石英质矿物在珠宝界应用数量和范围颇大,根据结晶程度、形态,石英可分为单晶石英、隐晶质石英、显晶质石英、非晶质石英和交代石英.研究表明,红外反射光谱可以区分晶质石英和非晶质石英,红外吸收光谱则可区分部分天然石英质宝玉石和合成石英质宝玉石,结合宝玉石的物理、化学、光学性质有助于鉴定石英质宝玉石的种类.     

石英陶瓷的研究应用现状及发展前景

本文综述了石英陶瓷的应用现状,对其研究、应用进行了较为详细的探讨,然后介绍了石英陶瓷增强技术的发展情况,并对石英陶瓷的发展前景和趋势作了介绍。     

石英陶瓷在浮法玻璃生产中的应用

对比分析了石英陶瓷的成型工艺及制品的性能特点,介绍了石英陶瓷制品在浮法玻璃生产中的应用情况,对石英陶瓷制品在浮法玻璃生产中的进一步应用进行了分析,认为充分挖掘石英陶瓷在浮法玻璃生产中的应用潜力具有重要的现实意义.     

Effect of fumed silica nanoparticles on glass fiber filled thermotropic liquid crystalline polymer composites

Glass fiber filled thermotropic liquid crystalline polymer (gLCP)/silica composites were prepared by melt compounding. The total torque of the gLCP/silica composites decreased and the melt flow index increased with increasing silica content, which indicates that the fumed silica nanoparticles act as good processing aids and enhance the processing behavior of gLCP/silica composites. The rheological properties of the gLCP/silica composites were significantly dependent on the silica content. The complex viscosity and storage modulus (G′) of the gLCP/silica composites decreased with increasing silica content. This was attributed to the ability of the silica nanoparticles to break the glass fiber–glass fiber interactions in the gLCPs. The storage modulus and loss modulus (G″) of the gLCP/silica composites increased with increasing frequency, and the increment was more significant at low frequency. Incorporation of a small quantity of silica nanoparticles improved the thermal stability and mechanical properties of gLCP/silica composites. However, at high silica nanoparticle content the mechanical properties of gLCP/silica composites decreased because of the aggregation of silica nanoparticles. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Synthesis and characterization of poly(butyl acrylate)/silica and poly(butyl acrylate)/silica/poly(methyl methacrylate) composite particles

Poly(butyl acrylate)/poly(methyl methacrylate) (PBA/PMMA) core–shell particles embedded with nanometer‐sized silica particles were prepared by emulsion polymerization of butyl acrylate (BA) in the presence of silica particles preabsorbed with 2,2′‐azobis(2‐amidinopropane)dihydrochloride (AIBA) initiator and subsequent MMA emulsion polymerization in the presence of PBA/silica composite particles. The morphologies of the resulting PBA/silica and PBA/silica/PMMA composite particles were characterized, which showed that AIBA could be absorbed effectively onto silica particles when the pH of the dispersion medium was greater than the isoelectric potential point of silica. The critical amount of AIBA added to have stable dispersion of silica particles increased as the pH of the dispersion medium increased. PBA/silica composite particles prepared by in situ emulsion polymerization using silica preabsorbed with AIBA showed higher silica absorption efficiency than did the PBA/silica composite particles prepared by direct mixing of PBA latex and silica dispersion or by emulsion polymerization in which AIBA was added after the mixing of BA and silica. The PBA/silica composite particles exhibited a raspberrylike morphology, with silica particles “adhered” to the surfaces of the PBA particles, whereas the PBA/silica/PMMA composite latex particles exhibited a sandwich morphology, with silica particles mainly at the interface between the PBA core and the PMMA shell. Subsequently, the PBA/silica/PMMA composite latex obtained had a narrow particle size distribution and good dispersion stability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3425–3432, 2006     

Preparation of nanosilica reinforced waterborne silylated polyether adhesive with high shear strength

Waterborne adhesives are extremely environment‐friendly but unfortunately deficient in mechanical properties. In this article, nanosilica, stemming from tetraethyl orthosilicate (TEOS), silica sol, and/or fumed silica powder, was employed to reinforce the waterborne silylated polyether adhesives. Effects of TEOS content, silica sol content, and the type and content of fumed silica on the shear strength of the adhesive were investigated using a scanning electronic microscope and an electronic instron tester and the strengthening mechanisms of different silica source were discussed. All the shear strengths of silylated polyether adhesives first increased and then decreased as TEOS content, silica sol content or fumed silica content increased. Colloidal silica particles was less efficient than fumed silica particles for reinforcing the polyether adhesive but can increase the shear strength of hydrophobic fumed silica embedded adhesive. Comparing the adhesives with the hydrophilic fumed silica (HS‐5) or the extremely hydrophobic fumed silica (TS‐720), the adhesive with moderate hydrophobic fumed silica (TS‐610) had the highest shear strength. The maximal shear strength of 2.5 MPa was achieved when TEOS, silica sol, and fumed silica were combined. It seemed that TEOS, silica sol, and fumed silica played crosslinking (with polyether chain), dispersing (for fumed silica), and reinforcing roles on waterborne adhesive, respectively. This reinforcing mechanism opened a new way to fabricate waterborne adhesives (or coatings) with high performances. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Influence of amorphous silica on the hydration in ultra-high performance concrete

Amorphous silica particles (silica) are used in ultra-high performance concretes to densify the microstructure and accelerate the clinker hydration. It is still unclear whether silica predominantly increases the surface for the nucleation of C–S–H phases or dissolves and reacts pozzolanically. Furthermore, varying types of silica may have different and time dependent effects on the clinker hydration. The effects of different silica types were compared in this study by calorimetric analysis, scanning and transmission electron microscopy, in situ X-ray diffraction and compressive strength measurements. The silica component was silica fume, pyrogenic silica or silica synthesized by a wet-chemical route (Stoeber particles). Water-to-cement ratios were 0.23. Differences are observed between the silica for short reaction times (up to 3 days). Results indicate that silica fume and pyrogenic silica accelerate alite hydration by increasing the surface for nucleation of C–S–H phases whereas Stoeber particles show no accelerating effect.     

Preparation of acrylate polymer/silica nanocomposite particles with high silica encapsulation efficiency via miniemulsion polymerization

Acrylate polymer/silica nanocomposite particles were prepared through miniemulsion polymerization by using methyl methacrylate/butyl acrylate mixture containing the well-dispersed nano-sized silica particles coupling treated with 3-(trimethoxysilyl)propyl methacrylate (MPS). The encapsulation efficiency of silica particles was determined through the elution and hydrofluoride acid etching experiments, and the size distribution and the morphology of the composite latex particles were characterized by dynamic light scattering and transmission electron microscopy. The coupling treatment of silica with MPS can improve the encapsulation efficiency of silica and the degree of grafting of polymer onto silica. When 0.10 g MPS/g silica was used to modify silica, the encapsulation efficiency of silica was greater than 95%, and the degree of grafting of acrylate polymer onto silica was about 60%. Although the average size and the size distribution index of the composite latex particles increased as the weight fraction of silica increased, the stable latex containing the ‘guava-like’ composite particles was obtained. The grafting of polymer onto silica particles improved the dispersion of silica particles in the solvents for acrylate polymer and in the polymer matrix.     

Property modulation of poly(N‐isopropylacrylamide) hydrogels by incorporation of modified silica

Poly(N‐isopropylacrylamide) (PNIPA)/silica composite hydrogels were prepared and the effects of the silica incorporation on the swelling and breaking characteristics of the hydrogels were investigated. To improve the dispersive property of silica in the PNIPA matrix via the formation of covalent bonds between the polymer and silica, vinyl groups were introduced in the silica by reacting it with a coupling agent, 3‐methacryloxypropyltrimethoxysilane. When unmodified silica was used as filler in the PNIPA‐composite hydrogel, the swelling ratio of the composite hydrogel below the critical gel transition temperature (CGTT) increased with increasing silica content. However, when the modified silica was used as the filler, the swelling ratio below CGTT decreased with increasing silica content because of the enhanced distribution and additional crosslinking. Above CGTT, the swelling ratios of the PNIPA/silica hydrogels were similar regardless of the silica modification. The gel breaking stress of the hydrogels increased with increasing silica content, and this enhancement was larger for the modified silica hydrogel. Scanning electron microscopy images showed that the modified silica particles were distributed more evenly in the PNIPA matrix than the unmodified ones were and that the size of cell‐like structure of the hydrogel decreased with increasing modified silica content. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

橡胶用沉淀法白炭黑的现状与发展趋势

介绍橡胶用沉淀法白炭黑的现状和发展趋势。沉淀法白炭黑聚集结构的控制方式有添加表面活性剂、用合适的酸作沉淀剂、二次法沉淀和减少白炭黑表面羟基等。沉淀法白炭黑分散性的测试方法有光学显微镜法和粒径分布测定法。轮胎用白炭黑主要为易分散性白炭黑和高分散性白炭黑。白炭黑产业未来的发展方向是淘汰落后产能,开发补强性和分散性更好的新品种,尤其是能显著降低轮胎滚动阻力的高分散性沉淀法白炭黑。     

Preparation and properties of melt‐blended polylactic acid/polyethylene glycol‐modified silica nanocomposites

One commercial type of fumed silica modified with methoxy polyethylene glycol (mPEG) plasticizer was incorporated into polylactic acid (PLA) biobased polymer to improve its performance. The modification on silica was confirmed through Fourier transform infrared spectra, nuclear magnetic resonance, and TGA assessments. The grafting percentage of mPEG onto silica was about 19.8 wt %. Transmission electron microscope revealed a similar degree of dispersion for control silica and modified silica‐filled PLA nanocomposites. Not much difference in the glass transition temperatures at various silica contents was found for PLA/control silica systems from the differential scanning calorimetry measurement, but the glass transition temperature of PLA/modified silica nanocomposite at 10 phr of modified silica showed up to 11°C decrement. It was suggested that the mPEG plasticizer efficiently plasticized the PLA matrix through the enhanced segmental mobility of PLA chains. Young's modulus of PLA was about 2133 ± 53 MPa, and the value for the nanocomposite increased to 2547 ± 54 MPa at 10 of phr control silica mainly due to the reinforcing effect from nanoparticles. For modified silica, Young's modulus decreased at various silica contents. The elongation at break for modified silica‐filled cases was higher than that of control silica‐filled cases. These results were attributed to the plasticizing effect of surface modifier. Optical transmittance for pristine PLA was generally in a similar order as PLA/control silica and modified silica cases at various silica contents. The results agreed with the morphology observation as well. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

白炭黑应用的新领域

阐述了由于白炭黑的特殊结构而具有的特殊性能，以及工业上两种主要生产白炭黑的方法，即气相法和沉淀法，综述了国外除橡胶工业外，白炭黑产品一些新的应用领域如医药、农药、日用化工等方面的应用及国内白炭黑应用开发的情况，指出白炭黑是一种有发展前景的产品。     

硅溶胶硅酸钾混合物微量热法研究

在25.0℃及搅拌条件下,采用等温热导微量热法研究了硅溶胶与硅酸钾的混合过程。结果表明,硅溶胶与硅酸钾混合,立刻发生了SiO2溶解和复杂的化学反应,并产生了完全不同于硅溶胶和硅酸钾的SiO2胶体粒子和化学成分以及热效应,热效应受硅溶胶所占的相对重量百分比的影响。其反应的特征是硅溶胶和硅酸钾的反应级数从低到高时刻都在快速不断交替变化;随着硅溶胶所占比例的提高,热谱曲线峰高、硅溶胶与硅酸钾的混合化学反应完全的曲线总面积(总焓变QT)和热力学焓变(ΔH)数值都表现出不断增大的趋势。