Electrorheological Particles Composed of Polyaniline Core and BaTiO_3 Layer Shell

Composite particles consisting of polyaniline( PAn) core and barium tilanate ( BaTiO3) Layer shell were synthesized. The PAn-BaTiO3 composites particles were characterized with TEM and XRD. The dielectric behavior of particles was tested and the electrorhcologicak(ER) behavior of the suspensions of PAn/ BaTiO3 panicles in chlorinated paraffin oil with a 20vol % was investigated under DC electric field. The results show that the ER effect of composite particle is far stronger than that of pure polyaniline and barium titanate which mere synthesized by the stone method. pH and thickness of BuTiO3 have an important. influence on the ER effects.     

Synthesis and electrochemical properties of SnO2-polyaniline composite

The SnO2-polyaniline(SnO2-PAn) composite was prepared by microemulsion polymerization method using aniline, ammonium peroxodisulfate and SnO2 as starting materials. The SnO2-PAn composite was characterized by X-ray diffractometer, scanning electron microscope and electrochemical techniques. The results show that PAn in the composites is amorphous. PAn formed in the reaction is deposited preferentially on the SnO2 particles, giving a SnO2-PAn composite, in which SnO2 is coated with PAn. SnO2-PAn composite shows a reversible capacity of 657.6 mA.h/g and the capacity loss per cycle is only 0.092% after 80 cycles, suggesting that SnO2-PAn composite is a promising anode material for lithium ion batteries.     

Synthesis and electrochemical properties of SnO2-polyaniline composite

The SnO2-polyaniline（SnO2-PAn） composite was prepared by microemulsion polymerization method using aniline, ammonium peroxodisulfate and SnO2 as starting materials. The SnO2-PAn composite was characterized by X-ray diffractometer, scanning electron microscope and electrochemical techniques. The results show that PAn in the composites is amorphous. PAn formed in the reaction is deposited preferentially on the SnO2 particles, giving a SnO2-PAn composite, in which SnO2 is coated with PAn. SnO2-PAn composite shows a reversible capacity of 657.6 mA.h/g and the capacity loss per cycle is only 0.092% after 80 cycles, suggesting that SnO2-PAn composite is a promising anode material for lithium ion batteries.     

导电聚苯胺/聚甲基丙烯酸甲酯复合膜的合成及特征

采用原位氧化聚合法合成了聚苯胺(PAn)／聚甲基丙烯酸甲酯(PMMA)复合材料．通过溶液浇铸的方法制成了性能优良的可溶性导电自支撑膜，电导率达10^-2S／cm；考察了各种反应条件对复合膜电导率的影响，获得了最佳的聚合反应条件，并进行了环境稳定性测试，其循环伏安曲线表明聚苯胺具有稳定的电化学活性，元素分析结果表明复合的聚苯胺存在一饱和值，超过饱和值，提高聚苯胺的含量对电导率影响不大，并对复合膜进行了红外光谱测试．     

Electrorheological Particles Composed of Polyaniline Core and BaTiO3 Layer Shell

Composite particles consisting of polyaniline(Pan )core and barium titanate(BaTiO3) layer shell were synthesized. The PAn-BaTiO3 composites particles were characterized with TEM and XRD. The dielectric behavior of particles was tested and the electrorheological (ER) behavior of the suspensions of PAn/BaTiO3 parti-cles in chlorinated paraffin oil with a 20vol% was investigated under DC electric field.The results show that the ER effect of composite particle is far stronger than that of pure polyaniline and barium titanate which were synthe-sized by the same methed. PH and thickness of BaTiO3 have an important influence on the ER effects.     

包覆Fe_2O_3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（Ｓｔ／ＡＡ／ＢＡ）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，并着重研究Ｆｅ２Ｏ３的含量对这种复合共聚物的动态力学性能的影响。结果表明，随着Ｆｅ２Ｏ３含量的增加，复合共聚物的内耗明显增加，刚性显著下降。因而Ｆｅ２Ｏ３加入对复合共聚物有增韧作用，改善了复合共聚物的力学性能。     

Dielectric Behavior of BaTiO_3/ PVDF Nanocomposites In-situ Synthesized by the Sol-Gel Method

1　IntroductionFerroelectricceramic polymercompositesconsistingofferroelectricceramicpowderembeddedinapolymermatrixhaveattractedmuchattentionsincetheycombinetheexcellentferroelectricpropertiesoftheceramicsandtheflexiblemechanicalpropertiesofthepolymer[1] …     

草酸络合物沉淀法制备钛酸钡超细粉的研究

根据传统的草酸盐沉淀法合成超细BaTiO3粉末的条件不易控制的问题,提出了一种新的改进草酸盐沉淀法：先使Ti^4 与C2O4^2-形成TiO(C2O4)2^2 络离子,再使其与Ba^2 反应生成草酸氧钛钡前驱体,然后干燥、煅烧得超细BaTiO3粉末。草酸氧钛络合物的形成应控制在pH=2.5-3,前驱体的煅烧温度,以及反应时物料的混合对最终产物的粒度及分布有较大的影响。在反应物Ba/Ti比为1－1．01,煅烧温度800℃,时间为1h,反应物料充分混合的条件下,采用所提出的新工艺可制备出质量较理想的BaTiO3粉末。     

Preparation and electrochemical characterization of C/PANI composite electrode materials

1 INTRODUCTIONRecently , surpercapacitor has attracted greatattention for its unique power performance[1 ,2],while electrode materials ,as one key factor to de-termine the performance of supercapacitor , nowbecome the focus of many researches . The super-capacitor materials can be categorized into threetypes :carbon electrode materials[3], metal oxide e-lectrode materials[4]and conductive polymer elec-trode materials[5].Conductive polymer electrode materials havehigher capacitance than tha…     

正丁醇钛－乙酸钡水解法合成BaTiO_3粉体的工艺研究

本文着重研究了Ｔｉ（ＯｎＢｕ）４－Ｂａ（ＯＡｃ）２水解法合成高纯超细ＢａＴｉＯ３粉体的制备工艺和工艺参数。对不同工艺条件下制得的ＢａＴｉＯ３粉体进行了ＴＧ－ＤＴＡ、ＸＲＤ、ＴＥＭ、ＳＡＸＳ和ＩＣＤ－ＡＥＳ的测试和分析，找出了其中的规律。采用本工艺方法合成的ＢａＴｉＯ３粉体，纯度达到９９．８０ｗｔ％，比表面积为６８ｍ２／ｇ，一次粒子平均粒径为４６．７ｕｍ，二次粒子粗径分布在２０～３００ｕｍ之间。     

包覆MgO对BaTiO3基陶瓷性能的影响

采用均匀沉淀法将MgO均匀地包覆在BaTiO3基陶瓷粉体表面,制备包覆MgO的BaTiO3基陶瓷复合粒子,研究了不同包覆量对BaTiO3基陶瓷的微观结构、微观形貌、介电性能、绝缘性能和击穿电压的影响。实验表明：包覆剂MgO能有效抑制晶粒长大,从而获得晶粒均匀的陶瓷,此细晶效应是由于晶界区MgO的抑制作用;MgO有助于形成“壳-芯”结构晶粒,降低并展宽BaTiO3基陶瓷的ε峰,增加电阻率和击穿电压强度。     

Synthesis of Composite Nanoparticles Bearing Epoxy Functional Groups：Encapsulation of Silica by Emulsion Polymerization of GMA

Poly （ glycidyl methacrylate ） / silica （PGMA/silica） composite nanoparticles , containing epoxy functional groups on the surface, were synthesized via emulsion polymerization. With batch process, high yield and binding efficiency （ both around 90% ） were achieved. The amount of crosslinked GMA was approximately 8wt%- 14wt% to the polymerized monomer. It was found that both the encapsulating ratio and the number of the original silica beads per composite particles altered with the amount of silica added. The obtained particles, with their average particle size of about 60- 70 nm, had a spherical shape and a clear core- shell structure.     

氧化钌/聚苯胺复合材料的制备与电化学性能研究

以RuCl3.nH2O为原料通过溶胶-水热法制得纳米RuO2粒子,然后在RuO2溶胶体系中通过常规的化学氧化法由苯胺氧化聚合制备纳米RuO2/聚苯胺复合材料,采用扫描电镜（SEM）和X-射线衍射（XRD）对其形貌和微观结构进行表征,并用循环伏安法研究了不同RuO2质量分数的复合材料电极的电化学性能。结果表明,RuO2质量分数为5%时,RuO2/聚苯胺复合材料形成致密的表面包覆型结构,聚苯胺电化学电容消失,复合材料电极电容很小。RuO2质量分数大于或小于5%时,RuO2粒子呈弥散状分布在聚苯胺中;RuO2质量分数为3%时,复合材料比电容达到极值374.6 F/g,这种复合材料具有很好的电化学特性,适于用作超级电容器电极。     

Rheological properties of magnetorheological fluid prepared by gelatin-carbonyl iron composite particles

Gelatin — carbonyl iron composite particle was prepared by micro emulsion method. The analysis of scanning electron microscope(SEM) shows that the ultrafine particles are spheroids coated by gelatin, and the average sizes of particles are 3 – 10 μm. The specific saturation magnetization σ_s is 130.9 A · m²/kg, coercivity H _c is 0.823 A/m, and residual magnetism r is 4.98 Am²/kg for the composite particles. It is shown that the particles possess properties of soft magnetic. The yield stress of magnetorheological fluid (MRF) with composite particle reaches 70 kPa at 0.5 T magnetic induction. Magnetorheological effects are superior in lower magnetic field intensity and the subsidence stability of the MRF is excellent compared with pure carbonyl iron powder.     

石墨烯／ZnO／聚苯胺复合材料的制备及其储锂性能的研究

以六水合硝酸锌、石墨及苯胺为原料,采用传统水热一原位聚合两步法首次制备了石墨烯／ZnO／聚苯胺复合材料．通过XRD、SEM、FT—IR、TG等分析方法对产物进行表征,并测试了该复合材料的储锂能力和循环稳定性．实验结果表明：ZnO以纳米棒状结构均匀分布在石墨烯表面,聚苯胺包裹在石墨烯／ZnO的表面形成石墨烯／znO／聚苯胺复合材料．电化学性能测试结果表明：石墨烯的存在可有效提高ZnO的导电性,同时聚苯胺柔性分子链可有效缓冲ZnO在充放电过程中的体积效应,对电极材料的循环稳定性起到了至关重要的作用．     

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 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.     

磁场环境下聚苯胺的合成与性能研究

在不同磁场强度下,用苯胺单体(An)和氧化剂过硫酸铵(APS),掺杂剂磺基水杨酸(SSA),乳化剂十二烷基苯磺酸钠(SDBS)合成了导电聚苯胺(PAn)。研究了氧化剂和掺杂剂用量对PAn掺杂率和电导率性能的影响;并采用红外光谱、X射线衍射、粒径分析、腐蚀电位曲线表征了PAn结构与性能的关系。结果表明:磁场对苯胺聚合的影响是正向的,磁场能减少掺杂剂的用量、提高产物的电导率;在乳化剂n(SDBS)/n(An)=0.45,氧化剂n(APS)/n(An)=0.8,掺杂剂SSA 0.3 mol.L-1时,合成的PAn电导率最大;在磁场环境中合成的PAn导电性、粒径、防腐性、规整性等各方面与无磁场作用的产品相比均具有明显的优势。     

Electro-rheological Effect of Barium Titanate Particles Coated with Urea and Suspended in Methyl Silicone Oil

Barium titanate nano-powders were synthesized under defined conditions.The surface of these particles was successfully modified by coating with urea.The characteristics of these composite particles were studied by X-ray diffraction, transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy.The electro-rheological (ER) effects of these particles suspended in methyl-silicone oil were measured.The particle, methyl-silicon oil ratio was 30%-35% weight percent.The experimental results indicate that these ER particles exhibit a remarkable ER effect.The ER fluid shows Bingham characteristics and the static shearing stress increases with an increase of the electric field strength.The highest static shearing stress under a 4 MV/m electric field is 13.2 kPa at room temperature, an increase of about 8.7 kPa compared to untreated BaTiO(C2O4)2 powders.     

PMMA／SiO2复合颗粒制备与表征

乳液聚合是对纳米颗粒改性的常用方法。但聚合效果不好且对改善纳米颗粒的分散作用不大。本实验引入硅烷自组装单分子层，采用无皂微乳液聚合法制备PMMA／SiO2复合颗粒。EDS、FTIR、TEM、LSS分析表明．纳米SiO2通过硅烷功能化，可以更有效地与MMA发生化学键合。复合颗粒在水中分散效果明显改善。不规则形状纳米SiO2通过组装而接近球形结构。复合颗粒具有很好的有机相容性和分散稳定性。