超细粒子催化剂的研究进展及其应用

介绍了超细粒子催化剂的性质及现有的一些制备方法，并对制备方法的优缺点进行了评价。着重探讨了溶胶-凝胶技术所具备的特点及一些内在缺点，并展望了超细粒子催化剂的应用前景。     

超细粒子催化剂用于CO加氢反应的研究

超细粒子催化剂以其良好的性能应用在CO加氢反应中,与沉淀法制得的催化剂相比,超细粒子催化剂活性高、产品选择性好、反应寿命长。本文还研究了加入不同助剂、由不同方法制备的和无定型合金超细粒子催化剂的F—T反应特性。     

超临界溶液快速膨胀技术在微细粒子制备上的应用

超临界流体快速膨胀法 (RESS)是近 1 0年发展起来的一项制备超细粒子的新技术 ,可生产粒径达到纳米至微米级且粒径和形态分布均匀的超细粒子。虽然理论研究目前还处于探索阶段 ,但该方法已经在很多领域展示了诱人的应用前景。就近年来超临界溶液快速膨胀技术的原理、典型的实验装置、工艺特点和应用研究成果进行了扼要的论述     

超细高氯酸铵的制备及改性技术研究进展

介绍了固体推进剂的发展方向、要求,阐述了超细粒子制备和改性的意义、高氯酸铵在高能推进剂中的作用以及超细化和改性的重要性,研究了超细高氯酸铵（UFAP）的制备和改性技术现状,提出了UFAP制备和改性中存在的问题以及超临界流体沉积技术在超细高氯酸铵的制备和改性方面的优越性。     

HMX炸药喷射结晶超细化实验研究

为改善HMX炸药的重结晶细化效果，提出了一种基于重结晶和流体喷射原理的喷射结晶超细化技术。通过实验，对影响细化效果的4个工艺条件进行了优化设计，制备出亚微米级的HMX炸药超细粒子。     

铜酞菁同质多晶现象的研究及其超细粒子的制备

采用路易斯酸配位法溶解了铜酞菁，并对路易斯酸溶解铜酞菁的机理进行了简单讨论，同时研究了溶解过程中不同溶剂对铜酞菁晶型的影响．最后，用路易斯酸溶解配位法和微射流纳米分散技术相结合的方法成功制备了铜酞菁超细粒子，并用激光粒度仪、原子力显微镜、紫外可见分光光度计对超细粒子的粒径和吸收光谱进行了表征．     

溶胶—凝胶法制备超细高纯氧化铝

采用溶胶—凝胶（ｓｏｌ－ｇｅｌ）法制备了超细高纯Ａｌ２Ｏ３。通过考察溶液的初始ｐＨ值、柠檬酸用量、Ａｌ３＋浓度以及反应温度等因素对合成粒子的平均粒径的影响规律，确定了制备氧化铝超细粒子的工艺条件：ｐＨ＝０．４０，ＣＯＡｌ３＋＝０．１ｍｏｌ／Ｌ～０．２ｍｏｌ／Ｌ，ＣＯＡｌ３＋：Ｃｏｃｉｔ＝１∶３，Ｔ＝７０℃。本法制备的氧化铝超细粒子为球形，平均粒径为１４ｎｍ，纯度达９９．９８％。     

超细粒子与流态化

本文通过介绍超细粒子的基本持性,进一步分析了其团聚性,并简要综述了由于团聚性而使其在流态化中显示的特性,指出了超细粒子在流动床催化反应器的应用具有远大的前途。     

TiO_2超细粒子的微乳法制备、表征及性能研究

采用表面活性剂OP-7、正庚烷、水和异戊醇形成的微乳体系制备TiO2超细粒子,并考察水和异戊醇含量对TiO2超细粒子平均粒径的影响。所得产物易于分离,溶剂可回收,产率达80%。结果表明,500℃灼烧2h所制备的TiO2超细粒子为锐钛型。采用FTIR、XRD、BET、DSC、TEM对TiO2超细粒子进行表征,由FTIR分析可知,表面无残留有机物;由DSC分析可得晶型转变温度为437 3℃;根据XRD分析计算的平均粒径为9 7nm,颗粒分散度较高;采用BET法测定比表面积为85 8m2/g。以苯酚的光催化氧化作为目标反应来评价TiO2超细粒子的光催化活性。苯酚光催化降解反应2 5h,降解率可达85%。     

玻纤增强聚苯硫醚复合材料的增韧研究

针对玻纤增强聚苯硫醚材料韧性差的问题，对聚苯硫醚傲璃纤维复合体系的增韧进行了研究，考察了玻纤、改性聚合物、有机超细粒子对复合材料力学性能的影响。采用基体增韧（预增韧）与有机超细粒子增韧技术，在保持复合材料拉伸强度和模量的同时，较大地提高了冲击强度，获得了综合力学性能优异的纤维增强聚苯硫醚材料。     

超临界流体技术在超微粒子制备中的应用

介绍了超临界流体技术在超微粒子制备中的原理和方法,给出了此技术在高分子材料,无机和有机材料方面的实例,同时分析了在材料领域中的应用前景。     

煤系中隐晶石墨开发的初步研究

在煤系地层隐晶石墨的加工工艺中 ,采用酸碱法 ,可使隐晶石墨品位提纯到 99.5 %～ 99.9% ;利用超声波粉碎隐晶石墨 ,可获得粒经 <0 5 μm的含量占 99.9% ;用微波法合成了金属及其卤化物隐晶石墨夹层复合物和氟化隐晶石墨 ;研制出了隐晶石墨节能抗磨剂等生产工艺 ,在进一步研究后 ,将可实现工业化应用     

Nanomaterials for Heterogeneous Combustion

Nanophase materials and nanocomposites, characterized by an ultra fine grain size (less than 100 nm) have attracted wide spread interest in recent years by virtue of their unusual mechanical, electrical, optical, magnetic, and energetic properties. Studies have shown that the thermal behavior of nano‐scaled materials is quite different from micron‐sized powders. Nanosized metallic and explosive powders have been used as solid propellant and explosive mixtures to increase efficiency. At the same time recent studies reveal that the presence of nanosized metals in propellants does not necessary translate into an increased burning rate and burning temperature. The reasons of this effect are far from being clear. This paper presents a new approach to the production of nanocomposites of some energetic materials – ammonium nitrite, cyclotrimethylene trinitramine (RDX), and aluminum – by the vacuum co‐deposition technique. The thermal behavior of the synthesized nanopowder and nanocomposites is investigated. A substantial difference in burning rate of RDX nanopowder has been found in comparison to micron‐sized material. Experimental results allow investigating the effects of nanosized materials on the combustion characteristics.     

超重力旋转床脱除微米级粉尘的实验研究

用超细滑石粉模拟工业微米级粉尘,通过实验研究了超重力旋转床的除尘特性.考察了旋转床在不同的气量q<,G>、液量q<,L>、转速n和轴向放置平面丝网层数n<,m>下的除尘效果,确定了实验室规模下适宜的除尘工艺条件:q<,G>=600 m<'3>/h,q<,L>>0.6 m<'3>/h,N=1 400 r/min,n<,m...     

碳酸钙填充聚丙烯熔体弹性研究

利用高压毛细管流变仪测量的第一法向应力差（N1）和挤出胀大比（B）研究了纳米CaCO3和微米CaCO3分别填充和同时填充聚丙烯（PP）体系的熔体弹性。对纳米CaCO3或微米CaCO3单独填充PP体系，N1和B随着剪切速率的增加呈非线性上升趋势；随着CaCO3含量的增加，体系的N1和B先减小后增加；在一固定的剪切速率下，纳米CaCO3填充PP的N1高于微米CaCO3填充体系的，但不同粒径的微米CaCO3填充PP体系的N1差别不大。对纳米CaCO3和微米CaCO3同时填充PP体系。当CaCO3总质量分数不高而微米CaCO3与纳米CaCO3的质量比不超过1：1时，体系的N1与纳米CaCO3单独填充PP体系相比有显著下降，但与微米CaCO3单独填充PP体系相比。下降不明显。     

Structure,nanomechanics, and dynamics of dispersed surfactant‐free clay nanocomposite films

The current work presents a new approach to achieve high quality dispersion of surfactant‐free nanoclay tactoid particles in sub‐micron thin films despite the absence of organic modifier. Natural Montmorillonite particles, Cloisite, were dispersed in thin films of polycaprolactone (PCL) through a flow coating technique assisted by ultra‐sonication. Wide‐angle X‐ray scattering (WAXS), grazing‐incidence wide‐angle X‐ray scattering (GI‐WAXS), and transmission electron microscopy (TEM) were used to confirm the level of natural clay dispersion down to the level of tactoids (sub‐micron scale stacks of clay sheets). These characterization techniques were carried out in conjunction with an analysis of nanomechanical properties via strain‐induced buckling instability for modulus measurements (SIEBIMM), a high‐throughput technique to characterize thin film mechanical properties. The buckling patterns indicate that the natural clay tactoids separate buckling‐enhancing (high‐modulus) crystalline regions and interconnect buckling‐suppressing amorphous (low‐modulus) regions. Due to the tactoid length scale, the glass transition behavior of the composites as characterized by broadband dielectric relaxation spectroscopy was unmodified by the clay. Likewise, the glass transition temperature, T_g, and fragility (slope of relaxation time behavior approaching T_g), remain unaffected, indicating that these dispersed tactoids do not induce pronounced confinement effects on dynamics. POLYM. ENG. SCI., 58:1285–1295, 2018. © 2018 Society of Plastics Engineers     

微米级硝化纤维素的制备及性能研究

为了使硝化反应在近似均相的条件下进行,采用对精制棉进行水解处理,用稀酸水解法制得结晶度较为一致的微晶纤维素,再用硝硫混酸进行硝化得到微米级硝化纤维素。用扫描电镜和红外光谱对其微观形貌和结构进行了表征。用DSC分析了其热性能,并测试了其撞击感度和黏度。结果表明,制备微米级硝化纤维素的最佳条件为:硝硫混酸体积比为1∶3,硝化时间30min,硝化温度为35℃。制得的微米级硝化纤维素样品粒度均匀,其特性落高为57.466cm,黏度为478mPa·s,分解峰温达到211.20℃,硝化均匀,含氮量可达12.8%。     

微电子化学试剂

大规模集成电路单晶硅片制作过程中需要大量的相关材料和化学品；其中需要大量的高纯和超净化学试剂，即微电子化学试剂，又称MOS试剂。本文对微电子化学试剂的市场及其开发应用的进展作了简单介绍。     

Gradient and weather resistant hybrid super‐hydrophobic coating based on fluorinated epoxy resin

A weather resistant super‐hydrophobic coating that can offer good substrate adhesion and yet to be easily processed at large scale can be of practical use in emerging fields of self‐cleaning and anti‐icing paint, combing all these properties together remains challenging task. Here we describe a composite coating composed of a fluorinated epoxy resin emulsion with embedded in situ surface‐modified dual‐scale nano‐silica, which displayed durable super‐hydrophobicity and excellent adhesive strength. The as‐prepared coating possesses water contact angle of 158.6 ± 1°, sliding angle around 3.8 ± 0.2° which remain stable even under acidic/alkaline, heat/cool, and accelerated aging treatment. The results demonstrate that surface roughness had a micron‐ and nanometer scale distribution with increased particle loading beyond 40 wt %. Through quantitative comparison of surface Attenuated Total Reflection (ATR) with bulk FT‐IR transmission spectra, a gradient coating with surface enrichment of hydrophobic groups was determined. The air‐side fluorinated polysiloxane‐rich layer endows coating with weather‐resistance and ultra‐hydrophobicity while bottom epoxy resin layer enhances substrate adhesion. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40955.     

HDPE／CaCO3复合材料片材制品的力学性能

通过制备不同含量的微米级和纳米级碳酸钙(CaCO3)填充的高密度聚乙烯(HDPE)片材制品,对其力学性能进行分析。研究了微米级和纳米级CaCO3对HDPECaCO3复合材料片材制品的力学性能的影响规律,并对此影响规律进行了合理的解释。