磁性多孔聚苯乙烯微球的制备

在磁流体存在的情况下,采用改进了的乳液聚合法合成了具有磁核的微米级高分子聚苯乙烯微球。以该微球为种子,采用分散聚合法,以乙二醇／水为分散介质、聚乙二醇为分散剂、甲苯为制孔剂,进行苯乙烯-丙烯酸-二乙烯苯的三元共聚物的合成,最终合成出粒径分布均匀、磁响应性强的磁性多孔聚苯乙烯微球。     

乳液聚合法制备单分散性PS磁性微球的研究

用改进的乳液聚合法，以乙醇／水为反应介质，十二烷基苯磺酸钠为乳化剂，过硫酸钾为引发剂，制备出单分散性聚苯乙烯磁性微球。通过SEM观察其表面形貌、粒径大小及分布，表明具有良好的球形度和一定均匀性。为了制备出粒径小、粒径分布均匀的聚苯乙烯磁性微球，设计了正交实验来优化实验条件；探讨了反应聚合温度、引发剂用量、乳化剂用量及醇水比对微球粒径及粒径分布的影响。实验表明在实验范围内，较低的反应温度、较低的引发剂用量、较高的乳化剂用量、较低的醇水比有利于得到小粒径、高均匀性的PS磁性微球。     

大粒径磁性高分子微球的合成

本文研究了苯乙烯、丙烯酸等单体在磁性氧化铁(E_((?)3)O_4)的醇/水分散体系中的聚合行为。为了改善磁性氧化铁粒子与苯乙烯单体间的亲合性,加入聚乙二醇作为分散剂和稳定剂,制备出粒径为30～1000μm的具有磁响应性的聚苯乙烯微球。研究了控制聚合区域的方法,考察了分散稳定剂、分散介质、引发剂种类和用量、反应时间等因素对聚合行为及微球形成的影响。     

大粒径磁性高分子微球的合成

本文研究了苯乙烯，丙烯酸等单体在磁性氧化铁的醇／水分散体系中的聚合行为。为了改善磁性氧化铁粒子与苯乙烯单体间的亲合性，加入聚乙二醇作为发散剂和稳定剂，制备出业径为３０－１０００μｍ的具有磁响应性的聚苯乙烯微球。     

含锰铁氧化物磁性中空微球的制备与性能表征

用沉积表面反应法制备了以聚苯乙烯为核、Mn-Fe氧化物为壳的磁性核-壳微球. 考察了锰含量对核-壳球磁性的影响,分别采用烧结法和溶剂萃取法去除核-壳球内的聚苯乙烯以制取中空微球. 讨论了烧结温度与所形成的中空微球比表面积的关系,考察了溶剂萃取法去除聚苯乙烯的效果,比较了两者所形成的中空微球的性能. 结果表明,烧结法所得微球性能优于溶剂萃取法所得微球. 探讨了烧结法形成中空磁性球的最佳条件,在400℃下煅烧核-壳微球可以得到饱和磁化强度为68.66 emu/g、比表面积为27.8438 m2/g的含锰铁氧化物磁性中空微球.     

铁琼脂糖磁性微球的制备和表征

采用反相悬浮包埋法制备了以纳米铁粉为磁核、琼脂糖为壳层的铁琼脂糖磁性微球,其磁响应性比以四氧化三铁为磁核的琼脂糖磁性微球好得多;并对不同粒径的琼脂糖磁性微球表面的活性基团进行了测定,粒径为8.3 μm的铁琼脂糖磁性微球的表面活性羟基数目是4.02×1015个·mg-1.     

P(St-GMA-DVB)/Fe3O4高分子磁性微球的合成与表征

以FeCl3×6H2O和FeCl2×4H2O为原料,采用化学共沉淀法制备了Fe3O4油基磁流体,设计的合成工艺克服了合成磁流体过程中Fe3O4磁性粒子易团聚的缺点,合成了具有很好分散性和稳定性的磁流体,比饱和磁化强度达72.60 emu/g. 采用悬浮聚合方法合成了聚苯乙烯-甲基丙烯酸缩水甘油酯-二乙烯基苯[P(St-GMA-DVB)]高分子磁性微球,搅拌转速对磁性微球粒径影响大,磁性微球粒径在55~300 mm范围内,外形为具有单分散性的球形,表面环氧基团含量达17 mmol/g.     

纳米聚合物微球对石蜡的表面修饰

采用乳液聚合法制备得到单分散且粒径为80～100nm的聚苯乙烯(PS)种子微球,使聚苯乙烯与石蜡进行共聚,合成石蜡聚苯乙烯微球.通过实验对微球合成的因素进行分析,找到了影响微球合成产率及粒径分布的因素.结果表明,乳液聚合法合成的聚苯乙烯粒径较为均匀,分散性好.通过聚苯乙烯对石蜡的修饰得到微米级粒径、分布均匀且高产率的石...     

磁性高分子微球制备研究进展

磁性高分子微球作为一种新型功能材料,具有强磁响应性、易生物降解、生物相容性好、无毒、可通过其他手段进行友好改性等特性。介绍了近年来磁性高分子微球的制备方法,对各种方法进行了简要分析,指出不同的制备方法可以制备出具有不同性能的磁性高分子微球。最后对磁性高分子微球的制备方法的发展趋势进行了展望。     

新型磁性聚苯乙烯微球的制备及表征

为了制备一种以四氧化三铁磁性纳米粒子为壳、聚苯乙烯为核的新型高分子功能材料,并有望应用于磁稳定流化床反应器,采用悬浮聚合法制备了四氧化三铁纳米粒子包覆聚苯乙烯的磁性微球。运用扫描电镜（SEM）、红外光谱（FT-IR）、振动样品磁强计（VSM）、热失重（TGA）等测试手段,分析并表征了磁性聚苯乙烯微球的形貌特征、粒径、磁学性能及四氧化三铁包覆量。实验结果表明,所得磁性聚苯乙烯粒子为球状微球,粒径为150~200 μm且分布较窄;磁性聚苯乙烯微球的四氧化三铁包覆量达到7.81%（质量分数）,最高饱和磁化强度为3.97 A·m2/kg。     

磁性琼脂糖复合微球的制备和性质

采用乳化复合技术制备出粒径为２０～３００ｎｍ、分散系数为０．０９０～０．６０１、Ｆｅ３Ｏ４含量（ｗ）为７．５％～６１．３％的具有磁核的琼脂糖复合微球。该微球呈珠形,在４～９０℃的水介质中形成均匀稳定的分散液,在０．０５Ｗｂ／ｍ２的弱磁场中具强磁响应性。制备微球的最佳条件是：琼脂糖用量１２．５～８７．５ｍｇ／ｍｌ,氯化亚铁用量１５～１２０ｍｇ／ｍｌ,ｐＨ＞１０。     

Materials Characterization of Feraheme/Ferumoxytol and Preliminary Evaluation of Its Potential for Magnetic Fluid Hyperthermia

Feraheme, is a recently FDA-cleared superparamagnetic iron oxide nanoparticle (SPION)-based MRI contrast agent that is also employed in the treatment of iron deficiency anemia. Feraheme nanoparticles have a hydrodynamic diameter of 30 nm and consist of iron oxide crystallites complexed with a low molecular weight, semi-synthetic carbohydrate. These features are attractive for other potential biomedical applications such as magnetic fluid hyperthermia (MFH), since the carboxylated polymer coating affords functionalization of the particle surface and the size allows for accumulation in highly vascularized tumors via the enhanced permeability and retention effect. This work presents morphological and magnetic characterization of Feraheme by transmission electron microscopy (TEM), Energy dispersive X-ray spectroscopy (EDX), and superconducting quantum interference device (SQUID) magnetometry. Additionally, the results of an initial evaluation of the suitability of Feraheme for MFH applications are described, and the data indicate the particles possess promising properties for this application.     

磁性Fe3O4纳米粒子用作靶向药物载体的制备及分析

Fe3O4 magnetic nanoparticles were prepared by the aqueous co-precipitation of FeCl3·6H2O and FeCl2·4H2O with addition of ammonium hydroxide. The conditions for the preparation of Fe3O4 magnetic nanoparticles were optimized, and Fe3O4 magnetic nanoparticles obtained were characterized systematically by means of transmission electron microscope (TEM), dynamic laser scattering analyzer (DLS) and X-ray diffraction (XRD). The results revealed that the magnetic nanoparticles were cubic shaped and dispersive, with narrow size distribution and average diameter of 11.4nm. It was found that the homogeneous variation of pH value in the solution via the control on the dropping rate of aqueous ammonia played a critical role in size distribution. The magnetic response of the product in the magnetic field was also analyzed and evaluated carefully. A 32.6 mT magnetic field which is produced by four ferromagnets was found to be sufficient to excite the dipole moments of 0.05g Fe3O4 powder 2cm far away from the ferromagnets. In conclusion, the Fe3O4 magnetic nanoparticles with excellent properties were competent for the magnetic carriers of targeted-drug in future application.     

Theoretical Analysis of a Magnetic Separator Device for Ex‐Vivo Blood Detoxification

Abstract

The feasibility of a magnetic separator device for ex‐vivo blood detoxification was studied. This blood detoxification approach entails administering functionalized magnetic microspheres (FMMSs) into a patient's body by transdermal injection to capture and remove toxins from the blood using highly specific receptors attached to the surface of the FMMSs. These toxin‐loaded FMMSs are then removed from the body using extracorporeal blood circulation through a specially designed magnetic separator, based on high gradient magnetic separation principles. The performance of the magnetic separator, in terms of its collection efficiency (CE) of the FMMSs, was evaluated theoretically using a streamline analysis of a 2‐D model. The effects of blood velocity (1 to 20 cm/s), magnetic field strength (0.1 to 2.0 T), wire size (0.125 to 2.0 mm in radii), separator unit size at a fixed ratio of tube to wire diameter of one, tube length (2.0 to 20 cm), wire material (nickel, SS 430 and wairauite), and magnetic material comprising the FMMSs (iron, typical magnetite and weaker magnetite) on the CE were evaluated. Provided that the blood velocity was below 2 cm/s, CEs >80% could be attained under reasonable conditions, like when using FMMSs 400 nm in diameter and containing 60 wt% magnetite in a magnetic field of 0.5 T using a magnetic separator with 0.5 mm radii wire (at a fixed ratio of tube to wire diameter of close to one) that was 10 cm in length (same as the tube) and made of SS 430. CEs of between 30% and 80% could also be attained at blood velocities up to 20 cm/s without compromising the magnetic separator design. The magnetic separator performance improved by reducing the size of the unit with tubes and wires of equal radii, increasing the applied magnetic field strength, utilizing magnetic materials with the highest magnetizations, and increasing the length of the unit. Overall, the results from this study delineated the physically realistic conditions that make ex vivo blood detoxification possible with this magnetic separator device.     

A Parametric Study of a Portable Magnetic Separator for Separation of Nanospheres from Circulatory System

A portable magnetic separator was proposed for in-vivo biomedical applications. In this prototype design, a matrix of alternating, parallel magnetizable wires, and biocompatible tubing is immersed into an externally applied magnetic field. The wires are magnetized and high magnetic fields as well as field gradients are created to trap blood-borne flowing magnetic nanospheres in the tube. In this paper, a parametric investigation was carried out to evaluate the capture efficiency of flowing magnetic nanospheres by a separator unit consisting of single tubing and four wires. The parameters include: mean blood velocity (1 to 20 cm/s); magnetic field strength (0.1 to 2.0 T); sphere size (500 nm to 1000 nm in radii); sphere magnetic material (iron, two types of magnetite) and magnetite content in the spheres (0.05 to 0.8 by weight); wire material (nickel, stainless steel 430, and Wairauite); wire length (2.0 to 20 cm); wire size (0.125 to 1.0 mm in radii); tubing size at a fixed ratio of tubing to wire diameter of unity. The results show that capture efficiencies of the spheres of well over 90% were achievable under reasonable human physiological conditions, provided that the mean blood velocities were below about 5.0 cm/s. The results also show that the magnetic separator performance could be improved by maximizing the applied magnetic field strength up to about 1.0 T and by reducing the size of the unit with tubing and wires of equal radii. The results help further optimize a prototype magnetic separator suitable for rapid sequestration of magnetic nanospheres from the human blood stream while accommodating necessary clinical boundary conditions.     

磁性导向柔红霉素白蛋白微球的研究

:采用乳化交联技术将磁性超微粒子及柔红霉素包埋于白蛋白内 ,化学交联固化后制得柔红霉素磁性白蛋白微球。该微球呈球形 ,平均粒径为 2 32 μm ,大小分布均匀 ,在 0 0 5T磁场中具强磁响应性 ,在水中分散性好。磁性微球载药量为 11 2 6 % (mg/mg) ,包封率为 75 0 % ;临界相对湿度CRH =81 6 %。含药微球在体外 12h释放完全 ,具一定的缓释作用。体内外磁定位实验表明 ,DNR磁性白蛋白微球制剂可浓集于靶区。稳定性考察表明所制微球稳定性良好。     

磁性纤维直径对捕集Fe基细颗粒影响数值模拟

为了实现对钢铁行业微细颗粒的超低排放,提出磁性纤维提高对 Fe基细颗粒物的捕集。 基于计算流体力学?离散相模型CFD-DPM对比研究了传统纤维、磁性纤维直径对Fe基细颗粒捕集效率以及过滤阻力的影响。结果表明：当风速为0.10 m/s时,对于直径为35~45 μm范围的纤维,直径的增大能够明显增加过滤阻力。对于粒径小于2.5 μm的颗粒,磁性纤维直径的增加对捕集效率提高的影响相对较小,当颗粒粒径大于2.5 μm时,增大纤维直径能够显著提高捕集效率。风速处于0.01~0.05 m/s范围时,增大纤维直径对提高磁性纤维捕集效率作用明显;当风速为0.08~0.10 m/s时,纤维直径变化对捕集效率的影响较小。磁性纤维质量因子随纤维直径增大而下降。     

NCC负载纳米Fe_3O_4磁膜材料的交替沉积自组装及表征

以纳米纤维素(NCC)为组装模板,基于氢键的交替沉积自组装磁膜材料。X射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)和能量色散X射线光谱(EDX)分析结果表明,NCC负载纳米Fe3O4磁膜材料表面形貌和断面形貌规整,含有Fe3O4粒子为纳米级,且仅分布在NCC层。性能分析结果表明,NCC负载纳米Fe3O4磁膜材料为超顺磁性材料,与PVA膜相比,具有较好的紫外光阻隔性、较高的热稳定性和特殊的氧化降解能力;在Fe3O4固含量为1.1%时,磁性膜拉伸强度较PVA膜提高了17.0%。     

磁性二氧化钛-磷钨酸复合催化剂的制备及光催化性能研究

采用层层自组装法成功制备了兼具磁性和光催化活性的双功能Fe_3O_4@SiO_2/(TiO_2/PW_(12))_(10)复合微球,利用扫描电镜、红外光谱和X-射线能谱仪对所得微球进行了结构和形貌的表征。以甲基橙为模型污染物,研究了紫外光下Fe_3O_4@SiO_2/(TiO_2/PW_(12))_(10)的光催化性质,系统考察了甲基橙溶液的初始浓度、溶液pH和无机氧化剂碘酸钾对复合膜催化效率的影响。动力学研究表明,在不同浓度甲基橙溶液中,染料的光催化降解遵循表观一级反应动力学。磁性Fe_3O_4纳米粒子的使用实现了反应后催化剂方便、快速和高效地分离回收。