包覆Fe2O3超微粒复合共聚物的动态力学性能研究

采用种子乳液聚合法将Ｆｅ２Ｏ３超微粒包覆在苯乙烯／丙烯酸／丙烯酸丁酯核－壳型复合共聚物中，形成包覆有无机粒子的有机高分子核－壳型复合微球，从微观的分子尺寸上改变了复合共聚物的性能，并咩 重研究Ｆｅ２Ｏ３的含量对这种复合共聚物的动态力学性能的影响。     

包覆Fe2O3的St／AA／BA复合共聚物热分解动力学

采用种子乳液聚合法将Ｆｅ２Ｏ３超微粒包覆在苯乙烯／丙烯酸／丙烯酸丁酯（Ｓｔ／ＡＡ／ＢＡ）核－壳型复合共聚物中，形成具有功能性高分子材料，并利用热失重实验法研究其热分解行为。结果表明，加入Ｆｅ２Ｏ３后，复合共聚物的热稳定性降低。对各种配比的复合共聚物热重（ＴＧ）曲线采用Ｆｒｅｅｍａｎ－Ｃａｒｒｏｌ微商法处理，研究其热分解反应动力学，求得热分解反应级数ｎ＝０．５～１，分解反应活化能Ｅ＝１８１～２５２ｋＪ／ｍｏｌ，为研究这种核－壳型复合共聚物稳定性提供了基础。     

含铁磷酸盐玻璃的制备及其结构研究

本工作用分析纯ＬｉＣＯ３，Ｆｅ２Ｏ３和ＮＨ４Ｈ２ＰＯ４制得了２０Ｌｉ２Ｏ－ｘＦｅ２Ｏ３－（８０－ｘ）Ｐ２Ｏ５系统玻璃，并应用红外和穆斯堡尔谱对其结构和铁的化学结合状态进行了研究。结果表明，玻璃中存在Ｆｅ（２＋）和Ｆｅ（３＋）离子，Ｆｅ（２＋）的配位数为６，而Ｆｅ（３＋）有４和６两种配位数。随Ｆｅ２Ｏ３含量的增加，Ｆｅ（２＋）／Ｆｅ比值减少，而Ｆｅ（３＋）（４配位）／Ｆｅ增加，发生［ＦｅＯ６］到［ＦｅＯ４］的配位变化，并且出现了焦磷酸盐基团的振动光谱．显然，玻璃的性质与Ｆｅ（２＋）／Ｆｅ和Ｆｅ（３＋）／Ｆｅ比值有关。     

（Si—Fe2O3）—（Al—Fe2O3—SiO2）复合体系自蔓延热力学分析

研究了（Ｓｉ－Ｆｅ２Ｏ３）－（Ａｌ－Ｆｅ２Ｏ３－ＳｉＯ２）复合体系的单位质量热效应ΔＨ＾０和绝热燃烧温度Ｔａｄ。指出ΔＨ＾０与Ａｌ－Ｆｅ２Ｏ３－ＳｉＯ２在复合体系中所占质量分数Ｒ呈线性关系。其斜率由ＳｉＯ２在Ａｌ－Ｆｅ２Ｏ３－ＳｉＯ２中的质量分数γ控制,其截距恒定且数值等于Ｓｉ－Ｆｅ２Ｏ３系单位质量热效应。当γ＝γ２＝１７ｗｔ％时,Ａｌ－Ｆｅ２Ｏ３－ＳｉＯ２加入对复合体系Ｔａｄ无影响,当γ〈γ２时     

钇金属茂与羰基铁茂复合催化甲基丙烯酸甲酯的聚合

报道一种新的复合Ｚｉｅｇｌｅｒ－Ｎａｔｔａ催化剂－「（ＣＯ）２ＦｅＣｐ）」２／「（ＣＨ３）２Ｓｉ（ＣｐＭｅ）２ＹＣｌ」２／Ａｌ（ｉ－Ｂｕ）３催化甲基丙烯酸甲酯聚合的结果。研究了ＭＭＡ／（Ｙ＋Ｆｅ）摩尔比、Ａｌ／（Ｙ＋Ｆｅ）摩尔比及反应温度对聚合的影响。     

α—Fe2O3—Al2O3—Na2O纳米陶瓷制备及其湿敏特性

采用溶胶－凝胶法制备了α－Ｆｅ２Ｏ３－Ａｌ２Ｏ３－Ｎａ２Ｏ复合超微粉,对微粉及其烧结后的物相及粒度进行了分析。湿敏特性测试结果表明：纳米级α－Ｆｅ２Ｏ３－Ａｌ２Ｏ３－Ｎａ２Ｏ陶瓷元件的感湿灵敏度高于简单氧化物机械混合后制成的α－Ｆｅ２Ｏ３－Ａｌ２Ｏ３－Ｎａ２Ｏ陶瓷元件,并具有较快的响应特性及较好的稳定性。     

复合型光催化剂TiO_2/a-Fe_2O_3/Fe降解四环素溶液的研究(Ⅰ)

比较了ＴｉＯ２ 与复合型光催化剂ＴｉＯ２／ａ － Ｆｅ２Ｏ３／Ｆｅ 分别对四环素的光催化降解效果。证明了ＴｉＯ２／ａ － Ｆｅ２Ｏ３／Ｆｅ 是优于ＴｉＯ２ 的降解四环素的光催化剂,并寻找了ＴｉＯ２ 与ａ － Ｆｅ２Ｏ３ 的最佳配比。初步考察了利用太阳光降解的可能性。     

复合型光催化剂TiO2／a—Fe2O3／Fe降解四环素溶液的研究（I）

比较了ＴｉＯ２与复合型光催化剂ＴｉＯ２／ａ－Ｆｅ２Ｏ３／Ｆｅ分别对四环素的光催化降解效果。证明了ＴｉＯ２／ａ－Ｆｅ２Ｏ３／Ｆｅ是优于ＴｉＯ２３的降解四环素的光催化剂,并寻找了ＴｉＯ２与ａ－Ｆｅ２Ｏ３的最佳配比,初步考察了利用太阳光降解的可能性。     

Fe—Al2O3p复合材料的热处理

采用硬度、拉伸和磨损等试验手段，检测了Ｆｅ－Ａｌ２Ｏ３Ｐ复合材料的强化效果；通过光学显微镜、ＳＥＭ等微观分析技术，分析了淬火处理后Ｆｅ基与Ａｌ２Ｏ３颗粒间的复合状况。结果表明，淬火处理可强化基体，降低Ａｌ２Ｏ３颗粒与基体间的硬度梯度，使两者复合更紧密，提高材料的整体性能。     

氧化—硫化焙烧法法处理高砷矿物原料的研究

对氧化物体系Ｃｕ－Ａｓ－Ｏ,Ｆｅ－Ａｓ－Ｏ和硫化物体系Ｃｕ－Ａｓ－Ｓ的热力学分析表明,热力学稳定的砷化物的Ｃｕ３Ａｓ,Ｃｕ３（ＡｓＯ４）２,ＦｅＡｓ２,ＦｅＡｓＯ４。     

Si02／醋丙核壳复合物的合成及其对木材的改性

以醋丙共聚物（VAc-MMA-AA）包覆硅溶胶纳米Si02粒子，形成Si02／VAc-MMA-AA核壳乳液，将该核壳复合乳液与杨木木材复合，制成无机／聚合物核壳复合物复合木材．利用EM、SEM及FT-IR红外光谱表征该核壳粒子及改性后复合木材的结构和形态，研究了经Si02／VAc-MMA-AA核壳复合物改性后复合木材的性能，结果表明。用该核壳复合物改性的木材WPG为45％时，氧指数为40．1％，并且该复合木材在顺纹和径向方向的抗压强度分别提高了86．9％、83．3％，抗弯曲强度提高了42．2％，弹性模量提高了58．9％．     

SiO_2／醋丙核壳复合物的合成及其对木材的改性

以醋丙共聚物(VAc-MMA-AA)包覆硅溶胶纳米SiO_2粒子,形成SiO_2/VAc-MMA-AA核壳乳液,将该核壳复合乳液与杨木木材复合,制成无机/聚合物核壳复合物复合木材.利用EM、SEM及FT-IR红外光谱表征该核壳粒子及改性后复合木材的结构和形态,研究了经SiO_2/VAc-MMA-AA核壳复合物改性后复合木材的性能,结果表明,用该核壳复合物改性的木材WPG为45%时,氧指数为40.1%,并且该复合木材在顺纹和径向方向的抗压强度分别提高了86.9%、83.3%,抗弯曲强度提高了42.2%,弹性模量提高了58.9%.     

氧化石墨烯包覆磁性纳米粒子复合材料的制备及其对亚甲基蓝的模拟吸附

制备了一种氧化石墨烯包覆磁性纳米粒子复合材料,并运用X射线衍射、扫描/透射电镜、傅里叶红外光谱、振动样品磁强计对该复合材料进行了表征。研究结果表明,该复合材料具有Fe3O4核、氧化石墨烯壳的核壳结构,复合材料中皱纹丝状的氧化石墨烯紧密和磁性纳米粒子相连,Fe3O4成单晶状。该复合材料的制备首先在球形的Fe3O4纳米粒子表面包覆SiO2涂层,再在涂层表面赋予-NH2基,最后和氧化石墨烯反应,最终得到具有核壳结构的复合材料。对复合材料的吸附性能进行了初步模拟测试,以亚甲基蓝为吸附质,对溶液pH值、吸附剂量对吸附量的影响以及吸附等温线进行了研究,结果表明该复合材料能够在吸附后在外加磁场下快速分离,是一种优异的吸附剂。     

Synthesis of nano-CaCo3 composite particles and their application

Nano-calcium carbonate composite particles were synthesized by the soapless emulsion polymerization technique of double monomers. The composite particles formation mechanism was investigated. The effects of composite particles on the mechanical properties of nano-CaCO3-ABS （acrylonitrile-butadiene-styrene copolymer） composite material were studied. It was validated that the composite particles are made up of the nano-calcium carbonate cores and the shells of alternating copolymers of butyl acrylate （BA） and styrene （St）. The shells are chemically grafted and physically wrapped on the surface of nano-calcium carbonate particles. When the composite particles were filled in ABS matrix, the CaCO3 particles are homogeneously dispersed in the composite material as nanoscales. The impact strength of the composite material is obviously enhanced after filling appropriate amounts of composite particles. It can be concluded that the soapless emulsion polymerization of double monomers is an effective method for nano-CaCO3 surface treatment. 2008 University of Science and Technology Beijing. All rights reserved.     

Synthesis of Polyaniline-Fe_3O_4 Nanocomposites and Their Conductivity and Magnetic Properties

By using inorganic Fe3O4 nanoparticles of different content as nucleation sites, PAn-Fe3O4 nanorods were successfully synthesized through a simple, conventional, and inexpensive one-step in-situ polymerization method. The TEM images revealed the size and morphology of the resultant nanocomposite. The EDS pattern confirmed the existence of Fe3O4 in the composite. The FT-IR spectral analysis confirmed the formation of PAn encapsulated Fe3O4 nanocomposite. With the content of Fe3O4 increasing, the conductivity of the nanocomposites gradually decreases, meanwhile, the saturation magnetization increases and reveals a super paramagnetic behavior. With controllable electrical, magnetic, and electromagnetic properties, the well-prepared nanocomposites may have the potential applications in chemical sensors, catalysis, microwave absorbing, and electro-magneto-rheological fluids, etc.     

Formation of Copolymer-Ag Nanoparticles Composite Micelles in Three-dimensional Co-flow Focusing Microfluidic Device

A novel method was presented to create composite micelles of amphiphilic copolymers and Ag nanoparticles(NPs) in a three-dimensional co-flow focusing microfluidic device(3D CFMD). Self-assembly of the copolymers was initiated by the fast mixing of water and a blend dispersion of hydrophobic Ag NPs and amphiphilic copolymers. At the same time, the hydrophobic Ag NPs enter the core of copolymer micelles, based on the hydrophobic interaction. The copolymer-Ag NPs composite micelles have a core-shell structure with copolymer shell and Ag NPs core. COMSOL Multiphysics is used to simulate the concentration distribution of copolymers and Ag NPs under different flow rates. Co-assembly microfluidic conditions are determined based on simulation results. Under suitable microfluidic conditions, both block copolymers and gradient copolymers can co-assemble with hydrophobic Ag NPs to form composite micelles, respectively. This microfluidic coassembly method will have a good prospect in the preparation of composite micelles of amphiphilic copolymers and metal nanoparticles.     

掺杂对Al_2O_3/TiAl复合材料性能的影响

本研究采用Ti-Al-TiO2-La2O3体系,通过热压烧结工艺原位合成了Al2O3/TiAl复合材料.借助X射线衍射(XRD)、扫描电镜(SEM)等分析研究了材料的物相组成和微观组织结构,同时分别将掺杂La2O3和掺杂Fe2O3对合成Al2O3/TiAl复合材料微观结构和力学性能的影响进行了对比.结果表明:掺杂La2O3合成的Al2O3/TiAl复合材料基体尺寸相对掺杂Fe2O3合成产物较小,分散更加均匀,致密度更高.当La2O3掺杂量为3.93wt%时,Al2O3/TiAl复合材料的抗弯强度和断裂韧性达到最大值,分别为701.95MPa和7.79MPa·m1/2.由于稀土氧化物具有对基体和增强颗粒的净化,细化晶粒等作用,因此提高了TiAl基体与Al2O3增强颗粒结合强度,所以掺杂La2O3合成材料的力学性能相比掺杂Fe2O3合成的产物较高.     

SiO2/Fe2O3复合颜料的制备工艺

在Fe2O3颗粒的悬浮液中以硅酸钠为硅源,稀盐酸调节反应体系的pH值,合成SiO2-Fe2O3核-壳粒子.研究Fe2O3表面包覆SiO2的影响因素,确定最优改性剂和改性条件.采用XRD、SEM对表面改性前后的Fe2O3进行表征,用酸溶率评价包膜效果.以硅酸钠作为硅源,在反应温度85℃、pH值为9~10、改性时间为2 h时,制备出SiO2-Fe2O3复合颜料.包覆后的Fe2O3的耐温性和耐酸性显著提高,干粉耐温性达到1000℃.     

高岭土/聚甲基丙烯酸甲酯核壳结构复合粒子对聚丙烯动态机械性能的影响

采用乳液聚合方法,以高岭土为核,甲基丙烯酸甲酯(MMA)为壳制备了具有核壳结构的共聚物。将制得共聚物与聚丙烯共混,用动态机械分析仪测试其共混物的动态机械性能,得出共混体系中温度与内耗因子的关系,温度与储能模量的关系以及温度与损耗模量的关系,并对所得的参数进行对比分析。研究表明,该种核壳结构的共聚物粒子与聚丙烯有很好的相容性,可以提高聚丙烯材料的阻尼性能,且可降低聚丙烯材料的玻璃化温度从而改善聚丙烯的柔韧性。     

Synthesis of nano-CaCO_3 composite particles and their application

Nano-calcium carbonate composite particles were synthesized by the soapless emulsion polymerization technique of dou-ble monomers. The composite particles formation mechanism was investigated. The effects of composite particles on the mechanical properties of nano-CaCO3-ABS (acrylonitrile-butadiene-styrene copolymer) composite material were studied. It was validated that the composite particles are made up of the nano-calcium carbonate cores and the shells of alternating copolymers of butyl acrylate (BA) and styrene (St). The shells are chemically grafted and physically wrapped on the surface of nano-calcium carbonate particles.When the composite particles were filled in ABS matrix, the CaCO3 particles are homogeneously dispersed in the composite material as nanoscales. The impact strength of the composite material is obviously enhanced after idling appropriate amounts of composite particles. It can be concluded that the soapless emulsion polymerization of double monomers is an effective method for nano-CaCO3 surface treatment.