磁性羧甲基化壳聚糖纳米粒子的制备与表征

以化学共沉淀法制备了Fe3O4纳米粒子,壳聚糖经羧甲基化改性后接枝在Fe3O4颗粒表面,得到了磁性羧甲基化壳聚糖(Fe3O4/CMC)纳米粒子.利用透射电镜(TEM)、X射线衍射(XRD)、傅立叶红外光谱(FT-IR)及磁性测试对产物进行了表征.TEM表明Fe3O4纳米粒子被CMC包覆,粒径约10 nm;XRD分析表明复合纳米粒子中磁性物质为Fe3O4;FT-IR表明壳聚糖发生羧甲基反应以及在Fe3O4表面的接枝反应.Fe3O4/CMC纳米粒子具有超顺磁性,比饱和磁化强度25.73 emu/g,有良好的磁稳定性.     

反相微乳液法制备壳聚糖季铵盐/四氧化三铁复合磁性纳米粒子

以环氧丙基三甲基氯化铵(ETA)为季铵化试剂,制备了壳聚糖季铵盐(QC)———N-2-羟丙基三甲基氯化铵壳聚糖,采用AgNO3电位滴定法测定了季铵化度。以柠檬酸钠为改性剂,一步法制备了水基Fe3O4磁性纳米粒子。基于静电自组装作用,采用反相微乳液法制备了QC/Fe3O4复合磁性纳米粒子。通过多种手段对所制备的复合磁性纳米粒子的结构进行了表征、对其性能进行了研究。红外光谱(FT-IR)、热重分析(TG)及X射线光电子能谱(XPS)的结果表明,QC主要包覆于Fe3O4的表面。透射电镜(TEM)、X射线衍射(XRD)结果表明,复合磁性纳米粒子磁核为Fe3O4晶体结构,平均粒径大约为50 nm~60 nm。VSM结果表明,所制备的复合磁性纳米粒子仍具有超顺磁性,比饱和磁化强度为19.4emu/g。     

Fe3O4／羧甲基化壳聚糖纳米粒子的制备与表征

磁性壳聚糖纳米粒子可用于药物载体及废水处理吸附剂。以化学共沉淀法制备Fe3O4纳米粒子，壳聚糖先进行羧甲基化改性，再经碳二亚胺活化，包履在Fe3O4颗粒表面,透射电镜（TEM）表明，Fe3O4纳米粒子被CMC包履，粒径约10nm；X射线衍射（XRD）分析表明复合纳米粒子中磁性物质为Fe3O4；傅立叶红外光谱（FTIR）表明壳聚糖发生羧甲基反应；磁性测试表明，Fe3O4／CMC具有超顺磁性，饱和磁化强度25.73emu／g，且有良好的磁稳定性。     

新型氨基化磁性树状分子纳米颗粒的制备与表征

采用化学共沉淀法,以FeC13.6H2O和FeSO4·7H2O为原料制备磁性Fe3O4纳米颗粒,采用3-氨丙基三乙氧基硅烷(APTES)、丙烯酸丁酯(BA)和无水乙二胺(EDA)对其进行修饰,制备了三代表面氨基化的磁性Fe3O4树状分子纳米颗粒,并对其进行结构表征与性能测试.结果表明:树状分子逐代修饰在磁性颗粒表面,氨基含量逐代增加,分别为0.41、0.69和0.87mmol/g; Fe3O4纳米颗粒平均尺寸在12nm左右,修饰后的三代磁性纳米颗粒的粒径逐代增加,分别为14、27和40nm左右;三代产品仍具备较高的饱和磁化强度,展现出了典型的超顺磁性.这种氨基功能化的磁性纳米粒子在细胞分选、固定化酶和靶向药物等诸多领域有着巨大应用潜力.     

纳米Fe3O4/聚苯胺复合粒子的制备及其磁性能研究

用水解沉淀法制备纳米Fe3O4,然后在其溶液中原位合成聚苯胺,得到纳米Fe3O4/聚苯胺复合粒子.通过XRD、TEM、JDM等测试对纳米复合粒子的形态、结构及磁性能进行了研究.实验制备的纳米Fe3O4粒子粒径为30nm左右,在其表面沉积聚苯胺后,复合粒子的粒径达到了50nm左右.与纳米Fe3O4粒子相比,纳米Fe3O4/聚苯胺复合粒子的XRD峰形变得更为明锐.纳米复合粒子的磁性能表现出软磁性,与纳米Fe3O4粒子相比,矫顽力减小为0,这可以大大减小材料的磁滞损耗和退磁难度,性能得到改善.     

磁性SiO_2/Fe_3O_4复合粒子的制备研究

采用共沉淀法在硅酸钠溶液中将磁性Fe3O4纳米粒子进行包裹处理,得到表面包覆SiO2薄层的复合粒子,并通过XRD、TEM、穆斯堡尔谱、磁性能测试等手段对包裹样品进行了表征。实验结果表明,共沉淀法制备的复合粒子由磁性Fe3O4粒子核和外部的SiO2包裹层组成,复合粒子的粒径分布为介于20~30nm,包裹后的样品具有典型的铁磁性特征,比饱和磁化强度Ms为23.250emu/g。与单一的Fe3O4纳米颗粒相比,磁性SiO2/Fe3O4复合粒子除了具有良好的磁学性能、较小的矫顽力、较小的剩余磁化强度外,有着非常好的耐酸性和抗氧化性。     

Fe_3O_4/Au复合磁性纳米颗粒的制备及其表征

首先通过化学共沉淀法制备出Fe3O4磁性纳米颗粒,考察了表面活性剂的用量、碱的用量、陈化时间以及三价铁与二价铁的摩尔比等因素对Fe3O4纳米颗粒性能的影响。制备出饱和磁化强度为73.85A.m2/kg、粒径大小为10nm以下的Fe3O4纳米颗粒。在此基础上,制备出Fe3O4/Au复合纳米颗粒,通过VSM、TEM、XRD、XPS对产物进行了表征,研究了HAuCl4的用量、还原剂的种类、硅烷偶联剂以及包金之前的Fe3O4纳米颗粒对复合颗粒的影响,结果表明所制得的Fe3O4/Au复合磁性纳米颗粒包覆良好,粒径大小为50～200nm,饱和磁化强度为10.08A.m2/kg。     

3-氨丙基三乙氧基硅烷表面修饰的磁性Fe3O4纳米粒子合成与表征

以FeCl3、FeSO4为铁源,利用改进共沉淀法合成磁性纳米Fe3O4,在其制备的过程中加入水合肼充当还原剂和沉淀剂,采用3-氨丙基三乙氧基硅烷(APTES),通过硅烷化反应以化学键的方式结合Fe3O4纳米颗粒,获得表面氨基化的磁性Fe3O4纳米复合颗粒。并用XRD、IR、TEM、VSM等分析手段深入研究了APTES修饰前后磁性纳米颗粒结构和性能影响。结果表明APTES成功包覆到磁性纳米粒子表面,其包覆率为21%;磁性颗粒粒径为20nm,晶型为反立方尖晶石型;磁性颗粒具有很好的分散性,其磁化率为2.36×10-6,饱和磁化强度达60.8mT。     

交联β-环糊精聚合物/Fe3O4核壳结构复合纳米颗粒的制备和性能研究

以羧甲基-β-环糊精为表面修饰剂对Fe3O4纳米粒子进行包覆修饰,以环氧氯丙烷为交联剂,在β-环糊精的碱性溶液中通过Fe3O4纳米粒子表面进行的交联反应制备了交联β-环糊精聚合物/Fe3O4复合纳米颗粒.利用FTIR、XRD、TEM和TGA分剐对复合纳米颗粒的结构、形貌和尺寸进行了表征.结果表明,制备的复合纳米颗粒为近球形、核壳结构,粒径约为10～20nm,环糊精聚合物含量为29%,在水中的分散性良好.磁性能测试和包合性能测试表明,复合纳米颗粒为超顺磁性,对特定分子具有一定的包合能力,可用于靶向给药系统和特定物质分离的载体.     

Fe3O4/SiO2/CMCH/CdTe荧光磁性微球的合成与表征

利用St ber法和交联法制备出具有荧光和磁性功能的Fe3O4/SiO2/CMCH/CdTe微球,并对其性能和应用效果进行了分析讨论.首先以正硅酸四乙酯为前躯体,Fe2＋和Fe3＋物质的量的比为1∶2,利用超临界干燥法制备出了Fe3O4/SiO2复合微球;并通过透射电镜对其进行观察,Fe3O4颗粒粒径为10 nm,SiO2层厚度为5 nm;其次羧甲基化的壳聚糖（CMCH）被嫁接在Fe3O4/SiO2表面上;然后利用水热法制备出CdTe荧光颗粒,通过壳聚糖与CdTe之间的静电吸引作用,CdTe被吸附在壳聚糖表面;最后利用戊二醛对壳聚糖的选择性交联作用制备出粒径在200 nm以内,饱和磁化强度为22.16 A.m2/kg,且具有良好荧光性能的Fe3O4/SiO2/CMCH/CdTe微球.荧光光谱分析表明最大发射波长从519 nm红移到528 nm,也证实了荧光颗粒CdTe成功吸附在Fe3O4/SiO2/CMCH表面.在动物实验中,该复合微球也显示出良好的荧光性、磁性及稳定性.     

Fe3O4／壳聚糖纳米微球的制备与表征

采用原位聚合法制备分散性良好、粒径在300nm以下、兼具磁性能与荧光性能的Fe3O4／壳聚糖纳米微球,通过XRD、IR和SEM等对产物的组成、结构和微观形貌进行表征,利用荧光光谱分析Fe3O4壳聚糖纳米微球进行光学性能测试,实验结果表明,通过交联反应,Fe3O4被壳聚糖所包覆,产物显示出了非常好的荧光性能,并且在外加磁场下具有明显的磁响应行为。     

Characteristic of a novel composite inorganic polymer coagulant-PFAC prepared by hydrochloric pickle liquor

A novel magnetic nano-adsorbent has been developed by the covalent binding of polyacrylic acid (PAA) on the surface of Fe(3)O(4) nanoparticles and the followed amino-functionalization using diethylenetriamine (DETA) via carbodiimide activation. Transmission electron microscopy image showed that the amino-functionalized Fe(3)O(4) nanoparticles were quite fine with a mean diameter of 11.2+/-2.8 nm. X-ray diffraction analysis indicated that the binding process did not result in the phase change of Fe(3)O(4). Magnetic measurement revealed they were nearly superparamagnetic with a saturation magnetization of 63.2 emu/g Fe(3)O(4). The binding of DETA on the PAA-coated Fe(3)O(4) nanoparticles was demonstrated by the analyses of Fourier transform infrared (FTIR) spectroscopy and zeta potential. After amino-functionalization, the isoelectric point of PAA-coated Fe(3)O(4) nanoparticles shifted from 2.64 to 4.59. The amino-functionalized magnetic nano-adsorbent shows a quite good capability for the rapid and efficient adsorption of metal cations and anions from aqueous solutions via the chelation or ion exchange mechanisms. The studies on the adsorption of Cu(II) and Cr(VI) ions revealed that both obeyed the Langmuir isotherm equation. The maximum adsorption capacities and Langmuir adsorption constants were 12.43 mg/g and 0.06 L/mg for Cu(II) ions and 11.24 mg/g and 0.0165 L/mg for Cr(VI) ions, respectively.     

Synthesis of size-controlled Fe3O4@SiO2 magnetic nanoparticles for nucleic acid analysis

We present a systematic study on the preparation, characteration and potential application of Fe3O4 and Fe3O4@SiO2 nanoparticles. Fe3O4 nanoparticles of controllable diameters were successfully synthesized by solvothermal system with tuning pH. The magnetic properties of nanoparticles were measured by vibration sample magnetometer. Fe3O4@ SiO2 nanoparticles were obtained via classic St?ber process. Streptavidin coated Fe3O4@SiO2 nanoparticles were prepared by covalent interaction. The quantity of streptavidin bound to nanoparticles was determined by UV-Vis spectrometer. To evaluate the binding efficiency and capacity of nucleic acid on nanoparticles, the capture of biotinylated oligonucleotide on streptavidin coated Fe3O4@SiO2 nanoparticles at different concentration was estimated by fluorescence detection. Both Fe3O4 and Fe3O4@SiO2 nanoparticles exhibited well crystallization and magnetic properties. The maximal amount of streptavidin immobilized onto the Fe3O4@SiO2 nanoparticles was 29.3 microg/mg. The saturation ratio of biotinylated oligonucleotides captured on streptavidin coated Fe3O4@SiO2 nanoparticles was 5 microM/mg within 20 minutes, indicating that FeO4@SiO2 nanoparticles immobilized by streptavidin were excellent carriers in nucleic acid analysis due to their convenient magnetic-separation property. Therefore, the synthesized Fe3O4 and Fe3O4@SiO2 nanoparticles with controllable size and high magnetic saturation have shown great application potentials in nucleic acid research.     

静电纺丝法制备PAN/Fe3O4磁性纳米纤维

采用化学共沉淀法制备纳米四氧化三铁,选用曲拉通X-100为分散剂,利用静电纺丝法制备PAN/Fe3O4磁性纳米复合材料。X射线衍射仪(XRD)验证了四氧化三铁在复合纳米纤维中的存在。同时使用扫描电镜(SEM)和透射电镜(TEM)对复合纳米纤维的微观形貌和Fe3O4在纤维中的分布进行了观察,利用热重(TGA)对纳米复合材料的热稳定性进行分析;通过磁性实验分析了纳米复合材料的磁性性能。结果表明,所制备PAN/Fe3O4磁性纳米纤维成型良好,且Fe3O4磁性颗粒在纤维中分散均匀,其与PAN是物理复合。纳米复合材料具有一定磁性,并可由磁性颗粒的加入量进行控制。     

纳米Fe3O4/聚苯胺复合粒子的制备及其在交变磁场下的发热性能

用水解沉淀法合成了纳米Fe₃O₄粒子,并在其悬浮液中原位包覆聚苯胺,制备出纳米Fe₃O₄/聚苯胺复合粒子。研究了两种纳米粒子在交变磁场下的发热性能,对它们在定向集热治疗肿瘤中的应用前景进行了评价。纳米Fe₃O₄粒子的粒径为10~30nm,表面包覆聚苯胺后,复合粒子的粒径为30~50nm。纳米Fe₃O₄粒子的比饱和磁化强度为50.05Am2/kg,矫顽力为10.9kA/m;纳米Fe₃O₄/聚苯胺复合粒子的比饱和磁化强度为26.34Am2/kg,矫顽力为0。在10mg/mL的生理盐水悬浮液中,在外加交变磁场作用30min后,纳米Fe₃O₄粒子悬浮液的温度为63.6℃,纳米Fe₃O₄/聚苯胺悬浮液的温度为52.4℃,二者均达到了医学上定向集热治疗肿瘤用热籽的发热要求,是很有应用前景的医用纳米材料。      

交联P（St-r-AA）包覆Fe3O4粒子的制备及对Cu2＋的吸附

用乳液聚合的方法合成了交联P（St-r-AA）包覆的Fe3O4粒子,研究了该类粒子对Cu2＋离子的吸附性能。透射电镜（TEM）表明,交联的P（St-r-AA）包覆的Fe3O4磁性粒子粒径约100 nm;X射线衍射（XRD）分析表明,磁性粒子中磁性物质为尖晶石结构的Fe3O4;红外光谱（FT-IR）表明,Fe3O4表面的...     

Synthesis and characterization of SiO2/(PMMA/Fe3O4) magnetic nanocomposites

Magnetic silica nanocomposites (magnetic nanoparticles core coated by silica shell) have the wide promising applications in the biomedical field and usually been prepared based on the famous St?ber process. However, the flocculation of Fe3O4 nanoparticles easily occurs during the silica coating, which limits the amount of magnetic silica particles produced in the St?ber process. In this paper, PMMA/Fe3O4 nanoparticles were used in the St?ber process instead of the "nude" Fe3O4 nanoparticles. And coating Fe3O4 with PMMA polymer beforehand can prevent magnetic nanoparticles from the aggregation that usually comes from the increasing of ionic strength during the hydrolyzation of tetraethoxysilane (TEOS) by the steric hindrance. The results show that the critical concentration of magnetic nanoparticles can increase from 12 mg/L for "nude" Fe3O4 nanoparticles to 3 g/L for PMMA/Fe3O4 nanoparticles during the St?ber process. And before the deposition of silica shell, the surface of PMMA/FeO4 nanoparticles had to be further modified by hydrolyzing them in CH3OH/NH3 x H2O mixture solution, which provides the carboxyl groups on their surface to react further with the silanol groups of silicic acid.     

Magnetic controllable biorecognition process of doxorubicin detected by electrochemical contact angle measurement

Fe3O4 nanoparticles are the most commonly used magnetic materials with promising applications in biomedical and biochemical engineering. In this study, a novel application of the tetraheptylammonium capped Fe3O4 nanoparticles in controllable biorecognition process of anticancer drug doxorubicin through combination with external static magnetic field has been demonstrated. Our AFM and electrochemical studies illustrate that the presence of the tetraheptylammonium capped Fe3O4 nanoparticles could promote the binding behavior of doxorubicin to DNA. And the results of the electrochemical contact angle measurements indicate that the controllable biomolecular recognition of doxorubicin could be readily achieved by combining these functionalized Fe3O4 nanoparticles with changing the positions of external magnetic field.