聚丙烯酸丁酯/磺化聚苯乙烯复合水基微乳液的制备

将聚苯乙烯制成磺化聚苯乙烯离聚体,利用相反转技术,将磺化聚苯乙烯离聚体制成具有纳米级稳定的水基微乳液,利用磺化聚苯乙烯颗粒内部作为反应场所,引发另一单体丙烯酸丁酯聚合, 制备聚丙烯酸丁酯/磺化聚苯乙烯复合水基微乳液.研究了聚合过程中的影响因素,并通过FI-TR,TEM等分析仪器对体系反应前后的颗粒形态、颗粒大小、分布及结构进行了研究.     

SPS及其离聚体的形态结构与热性能

通过ＤＳＣ、ＤＭＡ、ＴＥＭ、ＳＡＸＳ和ＴＧ对ＳＰＳ（磺化聚苯乙烯）及其离聚体的形态结构和热性能进行了研究。结果表明，在磺酸基含量为９．８３ｍｏｌ％的ＳＰＳ中有磺酸离子的聚集。金属离子的引入使ＳＰＳ离聚体的分子间作用力、微相分离程度增大。磺酸盐含量为４．７０ｍｏｌ％以上的ＳＰＳ离聚体中有离子聚集，离子簇直径为３～１０ｎｍ。在磺酸盐含量为１３ｍｏｌ％范围内，ＳＰＳＮａ离聚体基体的Ｔｇ１、离子微区的Ｔｇ２均随磺酸盐含量的增加而线性增大。ＰＳ磺化、中和成ＳＰＳ离聚体后，热稳定性增加，其顺序为：ＳＰＳＺｎ＞ＳＰＳＮａ＞ＳＰＳ＞ＰＳ。     

相互缠结的聚甲基丙烯酸甲酯/磺化聚苯乙烯复合水基微乳液的研究Ⅰ.复合水基微乳液的制备及影响因素

将聚苯乙烯制成磺化聚苯乙烯离聚体（SPS），利用相反转技术，将磺化聚苯乙烯离聚体加水制成具有纳米级的稳定的水基微乳液，利用SPS纳米微粒核内部作为反应场所，用引发剂引发亲油性单体甲基丙烯酸甲酯聚合，制备具有相互缠结结构的PMMA／SPS复合水基微乳液，研究了引发剂的用量，MMA的用量，溶剂极性对聚合反应及复合水基微乳液的影响。     

磺化聚苯乙烯锌盐离聚体对尼龙1010／聚苯乙烯共混体系增？…

利用动态粘弹谱，广角Ｘ射线衍射和扫描电镜分析了磺化聚苯乙烯锌盐离聚体（ＺｎＳＰＳ）对尼龙１０１０／聚苯乙烯烯（ＰＡ１０１０／ＰＳ）共混物形态结构的影响，结果表明，ＺｎＳＰＳ的加入对共混物起了增容作用，其中低离子含量（３．２５ｍｏｌ％）ＺｎＳＰＳ的加入有利于ＰＳ渗透尼龙要中，而对ＰＳ相无明显影响；高离子含量（１０．６７ｍｏｌ％，１３，８７ｍｏｌ％）ＺｎＳＰＳ的加入使ＰＳ与尼龙互相渗透的同时更有利于尼     

十二烷基硫酸钠／正戊醇／二甲苯／H2O微乳液及纳米Ni催化剂制备

以SDS／正戊醇／二甲苯／H2O微乳液为对象,考察了体系含水量与分散相和水核半径的关系,以及制备条件对纳米镍颗粒大小的影响。TEM、选区电子衍射和XRD对纳米镍进行了表征,结果表明,水核半径和体系含水量之间存在着线性关系,分散相和水核半径,分散相中表面活性剂分子随着含水量的增加而变大。     

反相微乳液法制备纳米羟基磷灰石及其表征

采用水溶液(W)/环己烷(O)/Triton X-100(S)/正戊醇(A)反相微乳液体系制备出粒径为20～60nm的球状羟基磷灰石(Hap)颗粒,并用TEM、XRD、IR和动态激光散射等手段对合成的样品进行形貌和结构表征.研究结果表明,合成的Hap具有弱结晶性,与人骨结构较相似.改变水油比可实现对纳米Hap颗粒尺寸的控制.微乳液经超声处理后,可制得尺寸为80nm×(5～15)nm的Hap纳米针状晶体.增加Hap微乳液的搅拌时间对纳米Hap的颗粒度、粒度分布影响不大.     

苯乙烯与丙烯酸酯在微乳液中的共聚合

分别以γ射线和过氧化苯甲酰（ＢＰＯ）引发苯乙烯（Ｓｔ）／丙烯酸甲酯（ＭＡ）,Ｓｔ／丙烯酸丁酯（ＢＡ）在微乳液中共聚合,微乳液共聚合与本体共聚合相比,两者之间存在明显的差异,两种引发剂之间也不相同,在微乳液共聚合的聚合初期,ＢＰＯ引发时,共聚合场所为大聚合物粒子的内核;而γ射线引发时,为单体溶胀胶束的乳化剂层。     

磺化聚苯乙烯锌盐离聚体对尼龙1010/聚苯乙烯共混体系增容作用研究

利用动态粘弹谱、广角Ｘ射线衍射和扫描电镜分析了磺化聚苯乙烯锌盐离聚体（ＺｎＳＰＳ）对尼龙１０１０／聚苯乙烯（ＰＡ１０１０／ＰＳ）共混物形态结构的影响。结果表明，ＺｎＳＰＳ的加入对共混物起了增容作用，其中低离子含量（３．２５ｍｏｌ％）ＺｎＳＰＳ的加入有利于ＰＳ渗进尼龙相中，而对ＰＳ相无明显影响；高离子含量（１０．６７ｍｏｌ％，１３．８７ｍｏｌ％）ＺｎＳＰＳ的加入在使ＰＳ与尼龙互相渗透的同时更有利于尼龙渗进ＰＳ相中。ＺｎＳＰＳ对尼龙１０１０分子链沿晶胞（００２），（１００）面的生长有抑制作用，这种抑制作用随ＺｎＳＰＳ加入量和离子含量的增大而愈加明显。ＺｎＳＰＳ的加入明显改善了ＰＡ１０１０／ＰＳ共混物的微观形态，使共混物力学性能得到了提高，初步实现了ＰＳ增韧尼龙１０１０的目的。     

CuFe梯度结构颗粒的合成研究

以铁、铜硝酸盐水溶液为前驱体,碳酸钠为沉淀剂,通过梯度沉淀的手段实现滴加液组成随时间梯度变化的特点,在微乳液中沉淀得到具有组成径向梯度分布结构的纳米CuFe颗粒。考察了油水比例对微乳液/乳液尺寸的影响以及对梯度结构形成的影响,并通过TEM图像观察到了梯度结构的存在,通过反应条件的调变,发现梯度结构的形成与微乳液/乳液各组元比例有很大的关系。     

相互缠结的PMMA/SPS复合水基微乳液的研究Ⅱ.体系反应前后的粒度分布及形态表征

将聚苯乙烯磺化制成聚苯乙烯离聚体（SPS），利用相反转技术，将磺化聚苯乙烯离聚体制成具有纳米级稳定的水基微乳液，利用SPS微粒核为反应场所，引发另一单体MMA聚合，制备具有相互缠结结构的PMMA／SPS复合水基微乳液。通过粒度分布仪、透射电镜等分析仪器对体系反应前后粒径形态、大小变化进行了探讨；用DSC仪器分析了复合材料的玻璃化转变，发现体系具有良好的相容性。     

Electrohydrodynamic atomization (EHDA) of high-conductivity pure solvent

ABSTRACT

In this study, the effects of flow rate, liquid conductivity and neutralizer strength on the operating and output characteristics are examined for an Electrohydrodynamic atomization (EHDA)-based aerosol generator system, designed and built in our laboratory. Ethylene glycol is used for generating the droplets. It is seen that stable cone-jet mode could be obtained for solvent conductivity as high as 240 μS/cm. While the output number concentration was found to increase with both flow rate and conductivity, the mean particle diameters decreased with increasing conductivity and increased with flow rate. The mean droplet size and output number concentration are found to be about three times more sensitive to changes in conductivity as compared to that of flow rate in the range of 26–150 μS/cm. It is also observed that throughput from the system is strongly dependent on the strength of the charge neutralizer. In the present setup, 8 μCi ²⁴¹Am bipolar neutralizer in axisymmetric configuration was found to be sufficient to neutralize the generated droplets.     

可生物降解高分子纳米微粒的制备及表征

以合成的聚己内酯（ＰＣＬ）、聚丙交酯（ＰＬＬＡ） 们的共聚物（ＰＣＬＬＡ）为材料,通过沉淀法制备了ＰＣＬ、ＰＬＬＡ、ＰＣＬＬＡ纳米微粒。透射电子显微镜和激光粒度仪分析表明,获得了纳米微粒具有较小的尺寸和粒径分布。同时还研究了水相温度、聚合物的分子量以及聚合物材料本身性质对纳米微粒粒径大小和分布的影响。     

纳米银-聚合物薄膜的制备及力电性能测试

聚合物基底上纳米银颗粒薄膜的制备工艺相对简单,成本较低,且该薄膜具有成为高敏感性压阻应力/应变传感材料的潜力。本文采用银镜制备法在聚酰亚胺(PI)和聚乙烯(PE)上合成了纳米银颗粒薄膜,系统研究了该薄膜制备工艺、结构特性、材料性能之间的关系。实验考察了材料“浸泡”时间及聚合物材料前处理等因素对材料表面吸附纳米颗粒含量的影响,研究了 “浸泡”时间对纳米银颗粒粒径大小、颗粒含量及分布的影响,并探讨了不同聚合物基体的颗粒特性对薄膜二维导电渗滤,压阻特性及拉伸性能的影响。研究表明,增加“浸泡”时间能够增加纳米银颗粒粒径大小,提高银颗粒的含量及分布均匀性；在相同的制备条件下,PI基底较PE基底对纳米银颗粒具有更加优异的吸附效果；在PI 和PE基底上的纳米银颗粒薄膜均表现出显著的压阻性能,且电阻对应变的敏感性随应变的增大及银颗粒含量的减少而显著提高。     

Synthesis of crosslinked poly(styrene-<Emphasis Type="Italic">co</Emphasis>-divinylbenzene-<Emphasis Type="Italic">co</Emphasis>-sulfopropyl methacrylate) nanoparticles by emulsion polymerization: Tuning the particle size and surface charge density

We have synthesized highly charged, crosslinked poly (styrene-co-divinylbenzene-co-sulfopropyl methacrylate) copolymer colloidal particles using emulsion polymerization. The effects of concentration of the emulsifier and the initiator on the particle size and the charge density of the colloidal particles are studied. Colloidal particle size is highly dependent upon the concentration of the emulsifier and the initiator. The colloidal particle diameter decreases with increasing concentration of the emulsifier and increases with increasing concentration of the initiator in the polymerization mixture. Number of particles, surface charge density and charges per particle are also functions of both the emulsifier and the initiator concentration. The surface charge density and the number of charges per sphere increase with increasing particle diameter. These copolymer colloid particles self assemble readily and diffract visible light. Polymer hydrogel imbibed with these colloids shows the light diffraction.     

电纺丝法制备聚环氧乙烯超细纤维

采用静电纺丝的方法制备出聚环氧乙烯超细纤维。通过场发射环境扫描电子显微镜(ESEM)对超细纤维的形貌及直径分布进行了表征。研究了纺丝过程中溶液浓度、不同溶剂和射流长度三个参数对纤维形态的影响。研究结果表明,水溶液的浓度对得到连续的超细纤维起决定性作用。在电纺丝的工艺参数中,混合溶液的性质对纤维的形态和直径分布影响很大;对于不同的溶液体系也要采取不同的射流长度。     

高固含量乳液(St/BA/AA)的合成、乳胶粒径及其分布

采用滴加预乳化液的半连续乳液聚合方法,合成了固含量高达65%的苯乙烯/丙烯酸丁酯/丙烯酸(St/BA/AA)共聚物乳液,并系统研究了乳化剂含量、固含量、单体配比、功能单体浓度对乳胶粒大小及分布的影响,利用透射电子显微镜对乳胶粒子的微观形态进行了表征.结果表明,乳化剂及功能单体浓度增加,乳胶粒粒径减小,分布变窄;增加固含量、单体BA用量,乳胶粒径增大,分布加宽.高固含量(St/BA/AA)乳液的平均粒径在150 nm～500 nm范围内,粒径分散系数为1.06～2.5,乳胶粒子呈多分散分布.     

Corona discharge neutralizer for electrospray aerosols used with condensation nucleation light-scattering detection

To obviate the use of radioactive materials, a simple unipolar electrical neutralizer based on a corona discharge was developed to neutralize electrospray aerosols used when coupling capillary liquid chromatography (CLC) and capillary electrophoresis (CE) to condensation nucleation light-scattering detection (CNLSD). The electrical neutralizer could be operated with either a positive or negative corona to generate ions to neutralize oppositely charged aerosols generated by electrospray and allow sensitive detection with CNLSD. The device could further be operated with organic solvents as well as aqueous buffer. The parameters affecting the corona discharge and neutralization process were studied and optimized. Compared to a CNLSD system using a radioactive neutralizer, the system with the electrical neutralizer showed higher signal and signal-to-noise ratio for test compounds, which indicated better neutralization efficiency of the charged aerosol. Highly reproducible results were obtained with the robust and durable electrical neutralizer with both CLC- and CE-electrospray-CNLSD systems.     

The synthesis and characterization of polymer coated iron oxide microspheres

For biomedical applications drug carrying polymers are coated around magnetic iron oxide particles to form microspheres. In the present study, the iron oxide powder was ball milled. Microspheres were then synthesized by solvent evaporation, resulting in iron oxide particles encapsulated in a polymer and drug coating. Various parameters, such as the duration of milling and agitation speed as well as the polymer concentration were varied. A milling time of 72 h was found to yield a small size and narrow size distribution of particles; the average particle size was about 600 nm. Measurements of the change in grain size and the magnetic properties of the powder with milling time were performed. It was determined that the size of the microspheres was not sensitive to the initial particle size, but it could be decreased by variation of agitation speed or polymer concentration. The agitation speed and polymer concentration of 400 rpm and 0.04 g poly(l-lactic acid) in 8 g dicholoromethane, respectively, was found to yield small, spherical microspheres with a narrow size distribution. The surface morphology and magnetic properties of the microspheres was also analyzed.     

Controlling foam morphology of polystyrene via surface chemistry,size and concentration of nanosilica particles

Controlling cell morphologies of polymeric foams is an important part of controlling foam properties. In this study, the effects of particle size, particle content, and particle surface chemistry on cell nucleation in nanosilica/polystyrene (PS) composites are investigated. A theoretical hypothesis on the effect of nanoparticle size on cell nucleation in PS matrix foam was examined. The surface chemistry of nanosilica particles was studied by modifying them with Vinyltriethoxysilane (VTES) silane coupling agent. The microcellular porous materials of neat and composite PS were prepared by batch foaming technique (pressure quench) using supercritical carbon dioxide (ScCO₂) as a blowing agent. It was found that the size of the pores decreases and the cell density increases with the decrease in nanosilica size and the increase of silica loading. It was also observed that the surface treatment of the nanosilica particles have substantial effect on the decrease of the cell size and the increase of the cell density.     

乳化添加非溶剂法微胶囊的缓释性能研究

利用Ｏ／Ｗ型乳化添加非溶剂法，制备了水溶性药物复合高分子微胶囊，实验所选择的核物质为茶碱，壳物质为乙基纤维素。本研究选用甲苯为溶剂，环己烷为非溶剂，探讨了高分子溶液浓度、核物质与壳物质比例等对核物质的溶出速率及动力学的影响。实验结果表明，核物质的溶出速率受高分子溶液的浓度及核物质与壳物质比值的影响较大，其速率随高分子溶液浓度及核物质与壳物质比值的增加而增加，其释放方式大多同时符合一阶动力学模式及Ｈｉｇｕｃｈｉ间质化模式。