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磁性液体是由纳米级的强磁性粒子高度分散于基液之中所形成的稳定的胶体体系。介绍了磁性液体的性质及其在机械和化工行业中在动态密封方面的应用 相似文献
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本文阐述了磁性液体的特性,介绍采用化学共沉淀法制备纳米级(10 nm)Fe3O4微粒的技术,并采用表面活性剂和自制的ZDW基液制备了新型憎油基磁性液体,探讨了该磁性液体在动态密封、选矿分离、扬声器以及作为磁记录材料等方面的应用,并分析了目前国内外磁性液体技术的研究水平以及该技术在国内外的发展概况. 相似文献
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张秀敏 《精细与专用化学品》2012,20(11):8-14
作为一类在航空、机械、电子、汽车、生物医疗等领域均有着广泛应用前景的新型材料——磁性流体近年来受到了国内外的广泛重视,成为磁性材料研究领域内的热点课题之一,并且逐步发展成为一类新兴产业。综述了磁性流体及其关键材料的产业化发展历程、现状以及未来的发展趋势,着重介绍了磁性流体及其关键材料磁性纳米粒子的产业发展情况,对磁性流体产业的未来发展前景进行了展望。 相似文献
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磁流体在肿瘤中的扩散和能量在肿瘤中的传递是磁流体热疗中的关键过程,并直接影响到治疗的效果。本文针对这些关键过程,建立了靶区内球形肿瘤的多物理场耦合模型,并采用有限元方法,对其进行了数值求解,获得了肿瘤靶区组织的压力分布、温度分布及磁流体浓度分布。分析了扩散时间、注射点以及磁流体比吸收率等关键因素对温度分布的影响。结果表明,延长扩散时间、在注射总量一定的情况下增加注射点数及增大比吸收率,均可使肿瘤中达到细胞坏死温度的体积增大,从而提高肿瘤的治愈率。但增大比吸收率的同时也会使正常组织的温升增加。 相似文献
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磁流体在肿瘤中的扩散和能量在肿瘤中的传递是磁流体热疗中的关键过程,并直接影响到治疗的效果。本文针对这些关键过程,建立了靶区内球形肿瘤的多物理场耦合模型,并采用有限元方法,对其进行了数值求解,获得了肿瘤靶区组织的压力分布、温度分布及磁流体浓度分布。分析了扩散时间、注射点以及磁流体比吸收率等关键因素对温度分布的影响。结果表明,延长扩散时间、在注射总量一定的情况下增加注射点数及增大比吸收率,均可使肿瘤中达到细胞坏死温度的体积增大,从而提高肿瘤的治愈率。但增大比吸收率的同时也会使正常组织的温升增加。 相似文献
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Utilizing yield‐stress fluids to suppress chaining during magnetic alignment of microdisks via rotating fields
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Mingyang Tan Adam L. Lambert Britany M. Swann Han Song Pallavi Dhagat Albrecht Jander Travis W. Walker 《American Institute of Chemical Engineers》2018,64(8):3215-3226
Inkjet printing can be used to deposit photopolymerizable magnetic inks for the creation of functionalized composites. Anisotropic properties in the composites can be achieved when inkjet printing is combined with external magnetic fields to align magnetically orientable particles (MOPs). When a MOP is induced by an external magnetic field, it will create its own magnetic field that can attract neighboring particles. The coarsening of particles into higher‐order structures like chains and sheets is unwanted in certain areas, such as high‐frequency applications. We show that this particle–particle attraction and subsequent particle migration can be inhibited with the introduction of a yield stress into the suspending medium, while still allowing the alignment of the particle to proceed. For magnetically induced rotational and translational motions for oblate spheroids in a rotating magnetic field, theoretical scalings are presented for the characteristic timescales in a linear fluid and for the characteristic stresses in a yield‐stress fluid. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3215–3226, 2018 相似文献
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微流体技术良好的可控性为制备均一可控的微液滴提供了新的途径,而非牛顿流体因广泛的应用而受到关注。综述了近年来剪切变稀和黏弹性两类典型非牛顿流体中液滴生成机理的研究进展。围绕流动聚焦型和T型微通道两种典型微通道构型,介绍了非牛顿流体分别作为分散相和连续相时液滴生成过程的界面演化动力学,并与牛顿流体液滴生成过程进行了对比,分析了剪切变稀特性和弹性对主液滴和卫星液滴生成的影响。展望了非牛顿流体液滴生成过程待解决的关键科学问题,为进一步的模拟和实验研究提供了借鉴和参考。 相似文献
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Yulei Tai Li Wang Guangqing Yan Jin‐min Gao Haojie Yu Lei Zhang 《Polymer International》2011,60(7):976-994
Magnetic nanospheres have numerous applications in biomedicine, biotechnology and wastewater treatment, due to their high surface area, tunable sphere size and superparamagnetic properties. Magnetic nanoparticles can be designed and endowed with optical, electronic and fluorescent properties, allowing a wide range of functionality. Multifunctional magnetic particles with heterodimer structures allow various kinds of target molecules to be attached onto their specific parts via affinity or coordinate bonding, etc. The abilities of these nanodevices, including the encapsulation of target molecules in magnetic hybrid nanostructures and easy magnetic separation in the presence of external magnetic fields, show much promise for magnetic imaging, magnetic separation and drug delivery. Consequently, magnetic particles offer excellent potential future uses in disease diagnosis, hyperthermia, immunoassays, electrochemical biosensors, contaminated water treatment and optical detection. In this article, we review the preparation and application of inorganic and organic magnetic composite spheres in the fields of magnetic separation, drug delivery, hyperthermia, magnetic resonance imaging, and others. The size, specific surface area, structure, magnetic properties and surface functional groups of nanospheres have a great influence on their effectiveness in these applications. The encapsulation of target molecules in magnetic hybrid nanostructures and their easy separation using an external magnetic field show promise for the fabrication of novel nanodevices for many applications. Copyright © 2011 Society of Chemical Industry 相似文献
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超临界流体药物微粒化技术的研究进展 总被引:1,自引:0,他引:1
超细微粒特别是纳米粒子的研制,已成为药物输送系统研究中的一个热门领域。控制药物微粒的粒径和粒径分布,能够提高或改善药物的药效、增加药物的靶向性等作用,因此药物微粒化技术越来越受到制药行业的广泛关注。本文对超临界流体药物微粒化技术的研究进行了综述。 相似文献
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How to find early gastric cancer cells in vivo is a great challenge for the diagnosis and therapy of gastric cancer. This study is aimed at investigating the feasibility of using fluorescent magnetic nanoparticle (FMNP)-labeled mesenchymal stem cells (MSCs) to realize targeted imaging and hyperthermia therapy of in vivo gastric cancer. The primary cultured mouse marrow MSCs were labeled with amino-modified FMNPs then intravenously injected into mouse model with subcutaneous gastric tumor, and then, the in vivo distribution of FMNP-labeled MSCs was observed by using fluorescence imaging system and magnetic resonance imaging system. After FMNP-labeled MSCs arrived in local tumor tissues, subcutaneous tumor tissues in nude mice were treated under external alternating magnetic field. The possible mechanism of MSCs targeting gastric cancer was investigated by using a micro-multiwell chemotaxis chamber assay. Results show that MSCs were labeled with FMNPs efficiently and kept stable fluorescent signal and magnetic properties within 14 days, FMNP-labeled MSCs could target and image in vivo gastric cancer cells after being intravenously injected for 14 days, FMNP-labeled MSCs could significantly inhibit the growth of in vivo gastric cancer because of hyperthermia effects, and CCL19/CCR7 and CXCL12/CXCR4 axis loops may play key roles in the targeting of MSCs to in vivo gastric cancer. In conclusion, FMNP-labeled MSCs could target in vivo gastric cancer cells and have great potential in applications such as imaging, diagnosis, and hyperthermia therapy of early gastric cancer in the near future. 相似文献
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磁性靶向制剂具有制备工艺简单,可提高药效,降低毒副反应,定向给药,提高生物利用度及药物稳定性等优点,目前国内外此类制剂成为研究热点。通过查阅文献资料,进行系统的分析、归纳,对磁性靶向制剂的组成、特点进行探讨,主要从目前磁性靶向制剂研究的三个方向:磁性微球、纳米微粒、磁性脂质体入手,对磁性靶向制剂的研究进展进行综述。 相似文献