酸碱渗透溶胀法制备微米/亚微米级中空聚合物微球

介绍了酸碱渗透溶胀法制备微米／亚微米级中空聚合物微球，以该方法制备中空聚合物微球的具体步骤为顺序，综述了现阶段该方法制备中空聚合物微球的研究现状，分析了该方法中有关微球中空形态及性质控制的影响因素，并对中空聚合物微球未来的研究方向和应用前景进行了展望。     

模板法技术制备中空聚合物微球的进展

介绍了模板法制备中空聚合物微球的原理、技术及其最新进展 ,总结了目标中空微球形态的影响规律。     

中空聚合物微粒的研究进展

介绍了目前国内外在空心核壳结构聚合物粒子的制备及应用方面的研究现状,并简要地对中空聚合物微球的发展前景进行了展望。     

产品开发

正聚合物中空微球成研发热点聚合物中空微球外壳与内部空腔结构的折光指数有显著差异,光散射性能良好,可应用于遮光材料。聚合物中空微球质量小强度高,具有特殊的光学性能和优良的力学性能,用作复合材料填充剂,可显著提高产品的力学性能,降低材料密度。聚合物中空微球的内部空腔可封装水、气体和特定     

碱溶胀法制备核壳中空微球研究进展

综述了碱溶胀法合成核壳中空微球的国内外研究进展,重点介绍了核壳中空结构的合成以及各种因素如聚合物组成,碱处理条件、乳化剂用量、单体瞬时转化率以及玻璃化温度对微球形态的影响。     

聚合物中空微球的研究进展

中空结构聚合物微粒具有低密度、高比表面积、稳定性好且可以容纳客体分子等特点在众多领域受到广泛关注。本文对聚合物中空结构微球的制备方法进行了综述,并简要介绍了聚合物中空微球在多个行业中的应用。     

中空微球对聚硫密封剂性能的影响

通过中空微球降低聚硫密封剂的密度,讨论了中空微球的种类及含量对密封剂力学性能和粘接性能的影响,同时研究了不同中空微球对聚硫密封剂的耐热、耐油、耐腐蚀及耐热破裂性能的影响。结果表明:中空微球可有效降低密封剂的密度,但体系的力学性能和粘接性能也有所下降,并随着微球含量的增加而下降明显。聚合物微球体系密封剂的耐油、耐腐蚀及耐热破裂性能较差,而玻璃微球性能优于聚合物微球,其中使用K15玻璃微球的聚硫密封剂综合性能较好。     

聚合物中空微球研究进展

综述了近几年聚合物中空微球在国内外的研究现状,介绍了不同种的该类聚合物的制备方法,以及不同制备方法赋予空心聚合物纳米球粒径、形态和性能等的影响的机理,并简单介绍了聚合物中空微球的应用。     

亚微米中空微球聚合物的制备及其形貌调控

采用乳液聚合协同碱渗透溶胀法，制备了亚微米中空微球聚合物。通过SEM、TEM、DLS分别对中空微球的形貌和粒径进行表征，并考察了中空微球聚合物的遮盖性能。研究了引发剂用量对核粒径的影响，中间层和壳层聚合物配比对微球形貌结构及其遮盖性能的影响。结果表明，在核制备过程中，核的粒径随引发剂用量的增加而减小；对于平均粒径为148 nm的核，当中间层甲基丙烯酸丁酯（BMA）用量为10 wt%、甲基丙烯酸（MAA）用量为3 wt%，甲基丙烯酸甲酯（MMA）用量为87 wt%，壳层苯乙烯（St）用量为97 wt%，交联剂用量为3 wt%时，可制备平均粒径414 nm，中空率为40.6 %的聚合物微球，且微球表面较为光滑，此时中空微球聚合物具有优异遮盖性能，遮盖度达到66 %。     

碱渗透溶胀法制备中空结构聚合物微球

采用预乳化饥饿型滴加方法结合碱溶胀处理制备了聚(甲基丙烯酸-甲基丙烯酸甲酯-丙烯酸正丁酯)/聚(甲基丙烯酸甲酯-苯乙烯-甲基丙烯酸)中空聚合物微球。试验集中讨论了种子阶段粒子大小,种子阶段引发剂用量、扩径时不同核壳比及不同碱进行碱处理时对形成中空聚合物微球的影响。同时采用TEM观察聚合物微球结构。试验所得的聚合物微球外径约为400 nm,内径约为220 nm。     

生物模板法制备磁性中空微球的方法和应用

磁性中空微球在功能性吸附、酶固定化载体、物质的分离纯化、活性物质和药物的封装与控释、靶向给药、污染防治、食品和材料学等领域有突出的应用价值。文章综述了利用生物模板法制备磁性中空微球的制备原理和最新研究成果,并主要分析了软模板法和自模板法两种制备工艺。软模板法工艺主要通过吸附-高温炭化法除去生物模板材料获得固定外形的磁性中空微球。自模板法制备磁性中空微球可依据生物材料自身成分经水热碳化反应或在惰性气体氛围保护下的高温炭化反应生成具有特殊官能团结构的中空碳微球,并将磁性物质溶入或吸附到中空微球中,具体分为水热碳化法和浸渍-高温炭化法;也可将制备好的磁性物质吸附于经过特殊处理过的生物模板材料表面,如吸附-共沉淀法和高温炭化-共沉淀法。总之,生物模板法制备磁性中空微球条件较为温和、无污染,生物模板材料对人体无毒,特别适合于食品、医药等行业的应用,具有很好的生产应用前景。     

宽频轻质吸波涂料的研究与应用进展

综述了目前国内外宽频轻质吸波涂料的研究动态,详细介绍了具有发展前景的空心微珠吸波材料、碳纳米管吸波材料、导电高聚物吸波材料、纳米吸波材料和智能隐身材料等新型宽频轻质吸波涂料的最新研究状况,并对雷达隐身材料应用技术的未来做了展望。     

功能隔热型弹性质感涂料的制备及其性能研究

通过弹性聚合物微球和进口空心玻璃微珠对弹性质感涂料进行改性增强,制得功能隔热型弹性质感涂料,对其性能进行了测试和验证,并对机理进行分析,也结合建筑基层的实际需要阐述了其于应用中的切实意义和实效性。     

B4C/SiC ceramic hollow microspheres prepared by slurry-coating and precursor conversion method

In this work, a new approach to fabricate B₄C/SiC ceramic hollow microsphere was established through combination of slurry-coating and precursor conversion method. Firstly, different slurries were prepared using modified B₄C powder with addition of PCS and LPCS. Subsequently, slurry was coated on a POM microsphere, followed by crosslinking, POM decomposition and heat-treatment at 1100 °C. Finally, the B₄C/SiC hollow microspheres with average diameter of 1.6–1.9 mm and thickness of 10–60 μm were obtained. The roughness (Ra) of outer surface was as low as 40.3 nm with high sphericity of 99.6%. Deoxidation was also explored by heat treatment at 1700 °C. The oxygen content was decreased from 11.06 wt.% to 0.37 wt.%, and crush load was promoted from 1.73 N to 4.50 N. The preparative method of B₄C/SiC ceramic hollow microspheres in this work can be easily extended for large-scale production.     

Controllable morphology and wettability of polymer microspheres prepared by nonsolvent assisted electrospraying

Polymethylmethacrylate (PMMA) microspheres with various morphologies are fabricated by nonsolvent assisted electrospraying. The morphology evolution is determined by nonsolvent properties including the solubility parameter, surface tension and viscosity, and nonsolvent induced phase separation is the main reason for the formation of the porous and/or hollow structures. It is found that nonsolvent possessing a high surface tension is beneficial to the formation of a hollow structure, while the large phase separation tendency between nonsolvent and the polymer can promote pore generation on the sphere surface. The nanosized pores, especially hierarchical pores, can enhance the hydrophobicity of the substrate surface coated with these microspheres. On the other hand, nonsolvent with a large viscosity could prevent the growth of the phase separated nuclei, leading to the presence of relatively small and discontinuous pores on the microsphere surface, which can finally cause the decrease of the contact angles. The surface pores of the electrosprayed microspheres are even eliminated if polymer additive, i.e., PVP, is incorporated into the polymer-solvent-nonsolvent solution. The addition of PVP renders the microsphere coated surface hydrophilic, which can be completely wetted by water droplets.     

Preparation and characterization of hollow microcapsules for use as ultrasound contrast agents

A laboratory-scale method of producing micron-sized hollow microscapsules from a biodegradable polymer such as 50/50 poly(D, L-lactide-co-glycolide) (PLGA), for use as a diagnostic ultrasound contrast agent, was developed. The technique involved microencapsulation of a volatile solid core material, and subsequent sublimation of the core to leave a hollow microsphere. A core material, such as ammonium carbonate, was ground to a suitable size distribution and encapsulated by a modified solvent evaporation or coacervation technique. This study investigated process parameters to produce diagnostically viable microscapsules by these two en-capsulation methods, such as polymer molecular weight (from 10,000 to 50,000), initial polymer concentration, agitation method, and stabilizer type. Polymer solution viscosity, polydispersity, and agitation rates significantly controlled the mean size of the microcapsules. Stabilizers were essential in solvent evaporation, but corrupted the morphology of spheres made by coacervation. Zeta potential values of microsphere dispersions revealed differences in surface characteristics between both encapsulation methods. Incubation of microcapsules with serum improved their dispersion in aqueous media. Preliminary in vivo ultrasound studies with the New Zealand white rabbit model, using color Doppler, showed that the microcapsules gave significant contrast in the right kidney.     

水性隔热涂料的制备与研究

采用化学沉积法使TiO2以纳米粒子的形式包覆于空心玻璃微珠表面,成功制备了TiO2纳米晶/空心玻璃微珠复合填料,并以改性微珠及空心玻璃微珠作为填料制备隔热涂料,对其光反射性能、隔热效果、隔热效果的影响因素进行了研究。结果表明,TiO2在空心玻璃微珠表面包覆效果良好,且经过热处理后空心玻璃微珠破损率很低。以改性微珠作为填料制备的涂料,涂膜对太阳光主要能量波段的光反射性能得到显著提高,其隔热效果较普通外墙涂料和空心玻璃微珠涂料相比有了明显的提高,且改性微珠添加量的多少对隔热温差的影响要大于厚度和白度对隔热温差的影响。