核壳高分子微球的制备

介绍了核壳高分子微还需的制备方法及影响因素，并制备出了核壳型聚苯乙烯/聚甲基丙烯酸甲酯微球，同时进行了表征。     

核壳结构有机/无机复合微球的制备与应用进展

根据核、壳的组成,核壳结构有机/无机复合微球可以分为2类:A类是核为无机材料,壳为高分子材料的核壳式结构;B类是核为高分子材料,无机材料作为壳层的核壳式结构.综述了B类复合微球的研究进展,详细讨论了复合微球的制备方法,如原位化学沉积法、溶胶-凝胶法、化学镀法、自组装法,并对各种制备方法的优缺点进行了总结,介绍了复合微球在轻质雷达吸波材料、光子晶体、生物医药载体材料、化妆品等领域的应用.最后指出了该研究领域未来的发展方向.     

高分子中空微球的制备及其在聚硫密封剂中的应用

以甲基丙烯酸及甲基丙烯酸酯类单体为核、苯乙烯单体为壳层,通过种子乳液聚合法合成核壳结构的聚合物微球。采用碱酸分步处理的方法,将富含羧酸的微球内核充分离子化,通过溶胀离开微球,得到高分子中空微球。通过种子制备阶段乳化剂用量的控制可调控最终中空微球的粒径,并获得两种不同粒径的中空微球(分别为551nm和156nm)。将两种高分子中空微球分别与聚硫橡胶共混,制备出相应的聚硫密封剂。采用透射电子显微镜(TEM)、傅里叶红外光谱仪(FTIR)、电子拉力机对其结构、形貌、成分及其力学性能进行研究。结果显示:所制备的中空微球粒径分布均匀,中空度较高。添加高分子中空微球可以降低密封剂密度,同时提升其力学性能。相比较而言,粒径较大的高分子中空微球具有更好的应用效果。     

含功能性基团“邻苯二甲腈”的核壳型及中空型聚合物微球的制备

通过无皂乳液聚合成功制备了含有功能性邻苯二甲腈基团的核壳型和中空型聚合物微球。首先,通过两步投料的方法制备含邻苯二甲腈的核壳型聚合物微球,然后利用DMF溶解掉聚苯乙烯核层,从而制备出中空型聚合物微球。为了分析所制备微球的组成和结构,进行了FT-IR和TEM测试。实验表明,成功制备了核壳型及中空型聚合物微球,且将功能基团邻苯二甲腈结构成功引入到制备的聚合物微球中。     

微流体技术光/热聚合可控制备Janus核-壳微球

Janus核壳微球是一种结合Janus微球以及核壳微球结构特点的复杂结构微球。它独特的性能在某些领域例如药物的定向输送方面具有潜在的应用。然而由于结构的复杂性以及传统制备方法的局限性,该微球的制备存在一定挑战,目前国内外尚无制备该微球的报道。本文利用基于毛细管的微流体控制技术,结合光/热聚合等手段,成功制备出了单分散的Janus核壳微球,并实现了对其大小、形貌以及核数目的控制。     

乳液聚合法制备核壳纳米粒子研究进展

核壳结构纳米复合颗粒因其特殊的结构而呈现出独特的物理、化学性能,具有广阔的应用前景。介绍核壳纳米复合材料的2类制备方法,综述了乳液聚合法制备核壳结构纳米微球的研究近况,主要分析了传统乳液聚合、微乳液聚合、细乳液聚合以及无皂乳液聚合等制备技术,展望了乳液聚合法制备核壳结构纳米微球的发展趋势。     

Fe_3O_4/聚苯乙烯磁性复合微球的制备与应用前景

采用改进的乳液聚合法,制备了磁性Fe3O4为核、苯乙烯和丙烯酸的共聚物为壳的磁性高分子复合微球。在透射电镜下观察磁性微球的粒径在130 nm左右;并用FT-IR、XPS和热失重方法表征了复合微球的组成成分、羧基(-COOH)的含量及所含Fe3O4的百分量。结果表明,微球的粒径分布均匀,大小可控,稳定性好,具有一定的抗溶剂性能,可长时间存放,是纳米磁性高分子聚合物网络的雏形。     

表面含羧基磁性高分子复合微球的制备

用化学共沉淀法制备了F e3O4纳米微粒,并对F e3O4微球表面进行改性,以磁性F e3O4为核,通过苯乙烯和丙烯酸的乳液共聚,制备了粒径均匀、以苯乙烯和丙烯酸共聚物为壳、表面含有一定羧基的磁性高分子纳米复合微球。测定了此微球的形态、结构和粒径,探讨了聚合单体、乳化剂等因素对微球合成的影响。     

分散聚合法制备SiO2/PAM核壳复合微球

采用分散聚合法制备出以SiO2为核、PAM为壳的核壳复合微球。根据Stber法制备了单分散SiO2微球,粒径随着TEOS、氨水浓度的增加而增大。采用硅烷偶联剂对SiO2微球进行表面处理,TEM显示处理后的微球继续保持单分散性,粒径有所增加。以SiO2微球或处理后的SiO2微球为核,采用分散聚合法在其上包覆AM,借助TEM、IR对其进行表征;研究发现,以处理后的Si O2微球为核能得到核壳结构,这种SiO2/PAM核壳微球的粒径大约为163 nm,包覆层30 nm左右。     

一种新型填料在97％盐酸小檗碱原药测试中的应用

诱导聚合胶体团聚法(PICA)以其简单快捷、成本低的优点被广泛应用于SiO_2核壳微球的制备,但制备过程中易出现团聚和二次成核现象,所制备的核-壳微球单分散性差,粒径不均一,必须进行分级筛分才能够投入使用。通过改进实验方法,优化实验条件,成功解决了上述问题,制备出单分散的核壳SiO_2微球。将制备的核壳微球经十八烷基三氯硅烷(C18)改性后装填色谱柱,并将其应用于97%盐酸小檗碱原药测试中,取得了较好的测试效果。     

Synthesis and Photoluminescence Properties of Eu3+‐Doped Silica@Coordination Polymer Core–Shell Structures and Their Calcinated Silica@Gd2O3:Eu and Hollow Gd2O3:Eu Microsphere Products

The conjugation of Eu³⁺‐doped coordination polymers constructed from Gd³⁺ and isophthalic acid (H₂IPA) with silica particles is investigated for the production of luminescent microspheres. A series of doping ratio‐controlled silica@coordination polymer core–shell spheres is easily synthesized by altering the amounts of metal nodes used in the reactions, where the ratios of Gd³⁺ and Eu³⁺ are 10:0 ( 1a ), 9:1 ( 1b ), 8:2 ( 1c ), 7:3 ( 1d ), 5:5 ( 1e ), and 0:10 ( 1f ). The formation of monodisperse uniform core–shell structures is achieved throughout the entirety of a series. Investigations of the photoluminescence property of the resulting series of silica@coordination polymer core–shell spheres reveal that 20% Eu³⁺‐doped product ( 1c ) has the strongest emission intensity. The subsequent calcination process on the silica@coordination polymer core–shell structures ( 1a ‐ f ) results in the formation of a series of doping ratio‐controlled silica@Gd₂O₃:Eu core–shell microspheres ( 2a ‐ f ) with uniform shell thickness. During the calcination step, the coordination polymers within silica@coordination polymer core–shells are transformed into metal oxides, resulting in silica@Gd₂O₃:Eu core–shell structures. The final etching process on the silica@Gd₂O₃:Eu core–shell microspheres ( 2a ‐ f ) produces a series of hollow Gd₂O₃:Eu microspheres ( 3a ‐ f ) as a result of the elimination of silica cores. The luminescence intensities of silica@Gd₂O₃:Eu core–shell ( 2a ‐ f ) and hollow Gd₂O₃:Eu microspheres ( 3a ‐ f ) also vary depending upon the doping ratio of Eu³⁺ ions.     

Hollow MCM-41 microspheres derived from P(St-MMA)/MCM-41 core/shell composite particles

In soap-free latex media, poly(styrene-methyl methacrylate)/MCM-41 core/shell composite microspheres have been fabricated by adding silicate source in batches. In this process, silicate species and the surfactant micelles were self-assembled into 2-dimensional hexagonal arrangement on the surface of P(St-MMA) microspheres. Hollow MCM-41 microspheres were obtained via removing polymer core by solvent. XRD, TEM, IR and N₂ adsorption-desorption analysis were applied to characterize products. The results showed that average diameter and wall thickness of hollow MCM-41 microspheres is about 240 nm and 20 nm, respectively. Results of N₂ adsorption-desorption indicate that hollow MCM-41 microspheres possess a highly ordered mesoporous structure and a narrow pore distribution with a mean value of 2.34 nm.     

Space‐Confined Polymerization: Controlled Fabrication of Nitrogen‐Doped Polymer and Carbon Microspheres with Refined Hierarchical Architectures

The construction of refined architectures plays a crucial role in performance improvement and application expansion of advanced materials. The synthesis of carbon microspheres with a refined hierarchical structure is still a problem in synthetic methodology, because it is difficult to achieve the necessary delicate control of the interior structure and outer shell across the microscale to nanoscale. Nitrogen‐doped multichamber carbon (MCC) microspheres with a refined hierarchical structure are realized here via a surfactant‐directed space‐confined polymerization strategy. The MCC precursor is not the traditional phenolic resol but a new kind of 2,6‐diaminopyridine‐based multichamber polymer (MCP) with a high nitrogen content up to 20 wt%. The morphology and sizes of MCP microspheres can be easily controlled by a dual‐surfactant system. The as‐synthesized MCC with a highly microporous shell, a multichamber inner core, and beneficial N‐doping can serve as a promising supercapacitor material.     

Preparation of magnetic nanoparticles modified by amphiphilic copolymers

Coordination method was used to prepare magnetic nanoparticles. Magnetic hysteresis loop studies showed that the obtained nanoparticles are categorized as soft magnetic materials. Microspheres prepared by the coordination method had PBMA core and hydroxylated PGMA shell bonded with Fe ion. The magnetic content and response decreased with the adding rate of the ferrous salt, while the size and size distribution of the microspheres increased. The magnetic response increased with the concentration of the ferrous salt. Also, the influence of the polymer content was studied, which indicated the particle size decreased with the polymer concentration and its distribution increased.     

核壳结构复合材料合成技术述评

文中综述了核壳结构材料的特点,如能提高材料的稳定性、包裹功能性核以及制备功能性栽体等,并详细论述了核壳结构制备方法(如乳液聚合、包裹技术和自组装等)的原理、优缺点及改进方法和发展前景.     

Hydrodynamically Formed Uniform Thick Coatings on Microspheres

Forming uniform thick coatings on microspheres remains a significant challenge in various surface modification and drug delivery applications. In this work, a hydrodynamic method is demonstrated for centering microspheres in droplets with sizes ranging from tens to hundreds of micrometers. The core microspheres stay at the center of the droplets due to the hydrodynamic pressure generated in the surrounding liquid shells, despite the significant density difference between the core microsphere and the liquid shell. Therefore, by using polymerizable liquids that can be solidified thermally or by illumination as the shell layer, core–shell particles with gas, liquid, or solid cores can be surrounded with uniform coatings using the present method.     

核-壳式聚苯乙烯/二氧化硅复合微球及空腔硅球的制备

利用层层自组装的方法制备了粒径和组成可裁剪、具有核-壳式结构的单分散聚苯乙烯(PS)/二氧化硅(SiO₂)复合微球.对复合微球进行热处理除去有机物中心,制备出壁厚可剪裁的空腔硅球.透射电镜(TEM)照片显示二氧化硅纳米颗粒在中心外生成均匀壳层,而煅烧后则可得到轮廓分明的球形空腔;热重分析(TG)说明复合球体的硅含量随着所组装的纳米二氧化硅的粒径的增加而增加;比较PS、SiO₂、复合球体及热处理后的粉体的红外光谱,可分别验证二氧化硅的成功组装和热处理过程中作为中心的PS的完全去除.在吸附相同层的前提下,随着所选用的二氧化硅纳米粒子(10um,20um,40um)的粒径的增大,复合微球的粒径增大,空腔球体的壁厚增加.