磁场-温度双重响应性复合微球的制备与表征

采用部分还原共沉淀法制备了尺寸约为10 nm的Fe₃O₄磁性纳米粒子, 并用油酸对其进行表面改性, 通过无皂乳液聚合的方法将Fe₃O₄与温敏性N-异丙基丙烯酰胺-丙烯酰胺共聚物(PNIPAAm-co-Am)复合, 获得了具有磁场和温度双重响应的复合微球. 采用TEM, FTIR和XRD等方法研究了复合微球的结构与形貌, 分别采用动态激光光散射(DLS)和振动样品磁强计(VSM)表征了复合微球的温度响应性和磁场响应性. 结果表明, 所制备的Fe₃O₄/(PNIPAAm-co-Am)复合微球具有核壳结构, 尺寸约为100 nm, 该微球具有良好的磁响应性和温度响应性, 其最低临界溶解温度(LCST)约为40 ℃.     

Synthesis and characterization of a new magnetic bromochromate hybrid nanomaterial with triethylamine surface modified iron oxide nanoparticles

We describe a novel method for the synthesis a new magnetic bromochromate hybrid nanomaterial, Fe3O4@SiO2@TEA@[CrO3Br], as a catalyst. The physical properties, morphology and magnetic investigations of magnetic bromochromate hybrid nanomaterials are identified by transmission electron microscopy （TEM）, scanning electron microscopy （SEM） and vibrating sample magnetometer （VSM） techniques. Fourier transform infrared （FT-IR）, elemental analysis, X-ray fluorescence （XRF）, X-ray diffraction （XRD） were also used for structural identification. The quantity of chromium is approximately 0.38%, which confirms to the immobilization amount of [CrO3Br]- and is equal to 0.007 mol/100 g.     

导电聚苯胺与Fe3O4磁性纳米颗粒复合物的合成与表征

对十二烷基苯磺酸(DBSA)掺杂的导电聚苯胺(PAn-DBSA)的氯仿溶液,在pH为中性的条件下,采用“修饰-再掺杂(Modification-re-doped)法”合成了含有Fe₃O₄磁性纳米颗粒的导电聚苯胺复合物的有机溶液.用FTIR,XRD,TEM,UV-Vis和SQUID等对所得复合物进行了表征,结果表明,该复合物呈现超顺磁性和半导体的导电性,并具有较好的透明性.     

用于磁性靶向治疗肺纤维化的聚多巴胺包覆的Fe3O4/甲强龙/环磷酰胺复合超粒子

肺纤维化是一种致命性肺部疾病, 目前临床常规的甲强龙(MPS)联合环磷酰胺(CTX)治疗方法存在明显的不良反应. 基于降低药物毒副作用的目的, 本文设计了一种聚多巴胺(PDA)包覆的Fe₃O₄纳米粒子/甲强龙/环磷酰胺复合超粒子(Fe₃O₄/MPS/CTX@PDA SPs), 提出磁性靶向治疗肺纤维化的思路. 从预制的油溶性Fe₃O₄纳米粒子出发, 通过水包油微乳液模板法制备了Fe₃O₄ 超粒子(SPs), 并在进一步包覆PDA壳层的过程中引入MPS和CTX, 制备了Fe₃O₄/MPS/CTX@PDA SPs, 考察了Fe₃O₄/MPS/CTX@PDA SPs的稳定性、 磁性、 对MPS和CTX的负载及释放, 分析了其生物毒性, 并建立动物模型验证了其磁性靶向功能.     

聚(苯乙烯-马来酸酐)/Fe3O4纳米杂化材料的制备与表征

采用2,2,6,6-四甲基-1-哌啶氧化物(TEMPO)的溴盐对化学共沉淀法制备的Fe3O4纳米粒子进行表面修饰,以该粒子为过氧引发剂,苯乙烯(St)、马来酸酐(MA)为单体,采用"活性"/可控自由基聚合技术在粒子表面原位引发聚合,制备了聚(苯乙烯-马来酸酐)/Fe3O4纳米杂化材料,并对纳米Fe3O4及杂化材料进行了FT-IR、XRD、TGA、TEM和GPC表征。结果表明,所制备的纳米杂化材料的平均粒径约为70 nm,磁性粒子表面的聚合物分子链随着聚合时间的增长而增长。振动样品磁强计测试结果显示,在室温、外加磁场下,该纳米杂化材料呈现超顺磁性,饱和磁化强度随着包覆聚合物量的增加而降低。     

多孔Fe_2O_3纳米纤维用于高容量长寿命锂空气电池催化剂

采用静电纺丝技术,以乙酰丙酮铁[Fe(C5H7O2)3]、聚乙烯吡咯烷酮(PVP)和二甲基甲酰胺(DMF)为原料,制备了由Fe2O3纳米颗粒组成的高比表面积的多孔纳米纤维,并成功应用于锂氧气电池用催化剂.Fe2O3纳米颗粒为反应提供了充足的活性位点,提高了电池容量;而三维网状结构为反应物及产物提供了足够的反应及储存空间,避免了对电极孔道堵塞的问题,从而达到了锂空气电池长循环的目的.     

Magnetic Solid Base Catalyst Fe3O4@Gly Used as Acid‐Resistant Catalyst for Biodiesel Production

Fe₃O₄@Gly nanoparticles were synthetized by coprecipitation and studied in the transesterification of soybean oil and methanol to determine its performance for biodiesel synthesis. The magnetism and catalytic performance of Fe₃O₄@Gly alkaline catalyst were investigated in detail. With a catalyst dosage 1.5 wt %, methanol/soybean oil ratio of 15:1, reaction temperature of 65 °C, and a reaction time of 3 h, the highest yield of biodiesel was 95.8%. The strong base catalyst CaO was used as comparison, from which it was seen that Fe₃O₄@Gly was more hydrophobic than the former. Moreover, because of the complete dissolution of oleic acid in methanol, Fe₃O₄@Gly could make better contact with oleic acid, which made it perform far better than pure CaO in oleic acid. In addition, after four times recycling, the yield of biodiesel was still 86.6%. The results show that Fe₃O₄@Gly possesses excellent properties of acid resistance and recyclability. The catalyst can be a high‐efficiency alkaline heterogeneous catalyst for biodiesel production.     

A highly selective magnetic sensor with functionalized Fe/Fe3O4 nanoparticles for detection of Pb2+

A magnetic sensor for detection of Pb~(2+) has been developed based on Fe/Fe_3O_4 nanoparticles modified by3-(3,4-dihydroxyphenyl)propionic acid(DHCA). The carboxyl groups of DHCA have a strong affinity to coordination behavior of Pb~(2+) thus inducing the transformation of Fe/Fe_3O_4 nanoparticles from a dispersed to an aggregated state with a corresponding decrease, then increase in transverse relaxation time(T_2) of the surrounding water protons. Upon addition of the different concentrations of Pb~(2+) to an aq. solution of DHCA functionalized Fe/Fe_3O_4 nanoparticles(DHCA-Fe/Fe_3O_4 NPs)([Fe] = 90 mmol/L), the change of T_2 values display a good linear relationship with the concentration of Pb~(2+) from 40 μmol/L to 100 μmol/L and from 130 μmol/L to 200 μmol/L, respectively. Owing to the especially strong interaction between DHCA and Pb~(2+), DHCA-Fe/Fe_3O_4 NPs exhibited a high selectivity over other metal ions.     

Magnetic CuO nanoparticles supported on graphene oxide as an efficient catalyst for A3-coupling synthesis of propargylamines

Magnetically separable CuO nanoparticles supported on graphene oxide (Fe₃O₄ NPs/GO-CuO NPs) is synthesized and characterized for the preparation of propargylamines in EtOH, at 90℃. Fe₃O₄ NPs/GO-CuO NPs is found to be an efficient catalyst for the A³-coupling of aldehydes, amines, and alkynes through C-H activation. Both aromatic and aliphatic aldehydes and alkynes are combined with secondary amines to provide a wide range of propargylamines in moderate to excellent yields.     

Preparation for Magnetic Nanoparticles Fe3O4 and Fe3O4@SiO2 and Heterogeneous Fenton Catalytic Degradation of Methylene Blue

Dyestuff textile wastewater treatment has become a research hotspot due to its high chroma, poor biodegradability, and low toxicity characteristics. In this paper, we have synthesized magnetic Fe₃O₄ and core‐shell Fe₃O₄@SiO₂ materials by hydrothermal methods. These materials were characterized by XRD, TEM, N₂ adsorption‐desorption and so on. These materials’ heterogeneous Fenton has been applied to dye wastewater treatment. Methylene blue was used as a typical target of dye wastewater. Decolorization ratios of methylene blue were determined by different nanostructure composites catalysts. A serious of results of study showed that decolorization ratios of magnetic nanoparticles and core‐shell composites arrived at above 90 % under the weakly acidic or neutral conditions and room temperature. When these catalysts were reused, the results show that Fe₃O₄@SiO₂ materials were possessed with good cycle performance.     

Fast synthesis of dopamine-coated Fe3O4 nanoparticles through ligand-exchange method

A fast approach was described for the synthesis of water-dispersible monodisperse dopamine-coated Fe₃O₄ nanoparticles（DA-Fe₃O₄） with uniform size and shape via ligand-exchange of oleic acid on Fe₃O₄ using only 2 min.The prepared DA-Fe₃O₄ nanoparticles were characterized by transmission electron microscopy,Fourier transform infrared spectrometry,and vibrating sample magnetometer.The results indicated that the resulting DA-Fe₃O₄ nanoparticles had an average diameter of about 19.2 nm. The magnetic saturation value of the prepared DA-Fe₃O₄ nanoparticles was determined to be 72.87 emu/g,which indicating a well-established superparamagnetic property.     

磁性介孔纳米粒子的制备及对抗癌药紫杉醇的传输

以十六烷基溴化铵(CTAB)为结构导向剂, 正硅酸乙酯(TEOS)为硅源, 在碱性环境下经过自组装过程对单分散性磁性Fe₃O₄纳米粒子进行包覆, 制备出磁性硅基介孔纳米粒子Fe₃O₄@SiO₂. 结合X射线衍射、 傅里叶变换红外光谱(FTIR)、 透射电子显微镜(TEM)以及氮气吸附-脱附等技术对Fe₃O₄@SiO₂粒子进行表征. 结果表明Fe₃O₄@SiO₂纳米粒子具有球形形貌, 平均直径约为150 nm, 蠕虫状介孔结构, 比表面积为932 m²/g, 孔径为2.5 nm且分布较均匀, 包覆后Fe₃O₄的结构得以保持, 同时材料具有很好的磁响应能力. 以抗癌药紫杉醇(Paelitaxel, TXL)为模型药物进行负载, 实验结果表明, Fe₃O₄@SiO₂对TXL的负载能力为80 mg/g, TXL-Fe₃O₄@SiO₂对TXL的缓释时间持续120 h以上, 累积释放量达到30 mg/g. 通过噻唑蓝比色(MTT)法测量了TXL-Fe₃O₄@SiO₂粒子对体外培养的HeLa细胞的细胞毒性, 与相同浓度的TXL相比, TXL-Fe₃O₄@SiO₂对HeLa细胞的抑制率明显增高.     

General Preparation of Heme Protein Functional Fe3O4@Au‐Nps Magnetic Nanocomposite for Sensitive Detection of Hydrogen Peroxide

Stable magnetic nanocomposite of gold nanoparticles (Au‐NPs) decorating Fe₃O₄ core was successfully synthesized by the linker of Boc‐L‐cysteine. Transmission electron microscope (TEM), energy dispersive X‐ray spectroscopy (EDX) and cyclic voltammograms (CV) were performed to characterize the as‐prepared Fe₃O₄@Au‐Nps. The results indicated that Au‐Nps dispersed homogeneously around Fe₃O₄ with the ratio of Au to Fe₃O₄ nanoparticles as 5–10/1 and the apparent electrochemical area as 0.121 cm². After self‐assembly of hemoglobin (Hb) on Fe₃O₄@Au‐Nps by electrostatic interaction, a hydrogen peroxide biosensor was developed. The Fe₃O₄@Au‐Nps/Hb modified GCE exhibited fast direct electron transfer between heme center and electrode surface with the heterogeneous electron transfer rate constant (Ks ) of 3.35 s⁻¹. Importantly, it showed excellent electrocatalytic activity towards hydrogen peroxide reduction with low detection limit of 0.133 μM (S /D =3) and high sensitivity of 0.163 μA μM⁻¹, respectively. At the concentration evaluated, the interfering species of glucose, dopamine, uric acid and ascorbic acid did not affect the determination of hydrogen peroxide. These results demonstrated that the introduction of Au‐Nps on Fe₃O₄ not only stabilized the immobilized enzyme but also provided large surface area, fast electron transfer and excellent biocompatibility. This facile nanoassembly protocol can be extended to immobilize various enzymes, proteins and biomolecules to develop robust biosensors.     

磁性功能高分子材料的制备及其催化性能

以Fe3O4微粒作为载体,糠醛单体为主要原料通过酸催化聚合-热处理的方法制备了磁性功能高分子PFD/Fe3O4光催化材料.采用透射电子显微镜(TEM)、X-射线衍射(XRD)、红外光谱(IR)、热重分析(TG-DTA)以及紫外-可见光谱(UV-Vis)等技术对样品的形貌、结构、光吸收特性等进行了表征.以亚甲基蓝溶液的脱色降解为模型反应,考察了样品的光催化性能.结果表明,在自然光照射下,反应40min后,PFD/Fe3O4对亚甲基蓝溶液的脱色率达到85%左右,COD去除率为47.37%.     

4-叔丁基苯乙烯和甲基丙烯酸甲酯共聚物磁性吸油树脂

以4-叔丁基苯乙烯(t BS)和甲基丙烯酸甲酯(MMA)为单体,二乙烯基苯(DVB)为交联剂,与双键修饰的Fe3O4纳米粒子共聚,制备了一系列基于t BS和MMA的磁性高分子吸油树脂.用红外光谱(FTIR)、X-射线衍射(XRD)、光学显微镜(OM)、扫描电子显微镜(SEM)、接触角(CA)和比表面积测试等技术对样品进行了表征.详细考察了两单体配比、交联剂用量对树脂的吸附容量、吸附速率的影响规律.实验发现,当两单体用量分别为2 m L,交联剂为0.5 m L时,磁性吸油树脂的吸油性能达到最好.     

超磁性四氧化三铁纳米颗粒在大鼠脑积水模型磁共振及CT成像中的应用

目的旨在研究四氧化三铁纳米颗粒在大鼠脑积水模型中的磁共振及CT成像中的应用,为临床应用提供理论依据,为合理开发该纳米颗粒奠定实验基础。方法采用单纯随机分组法将60只分为空白对照组(20只,给予无菌生理盐水注入枕大池)和实验组(40只,利用高岭土制作大鼠脑积水模型,利用MR筛选大鼠脑积水模型,向模型蛛网膜下腔内注入四氧化三铁纳米颗粒,1h后行CT检查,并于1个月后在显微镜下观察空白对照组与实验组四氧化三铁纳米颗粒在脑、心、肝、脾肺、肾等器官蓄积情况。结果 (1)实验组手术和麻醉导致6只大鼠死亡,实验组死亡率15%。对照组死亡率10%。总死亡率为13.3%。(2)实验组32只大鼠形成脑积水,在存活大鼠中模型成功率为88.9%,模型总制作成功率80.0%。(3)四氧化三铁在大鼠椎管磁共振成像中显示欠佳,CT具有较好的对比效果;(4)蛛网膜下腔内注入四氧化三铁纳米颗粒1个月后在脑、肝、脾、肺、肾等器官无明显蓄积。结论椎管内注入超磁性四氧化三铁纳米颗粒是安全可靠的,可以作为脑积水颅脑CT检查的造影剂。     

磁性Fe3O4纳米晶的电化学制备及在线混凝过程研究

以铁片和碳纤维为电极,采用电化学法实现了磁性Fe3O4纳米晶混凝剂的快速制备、在线混凝和磁性过滤的预处理过程.采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)等对磁性Fe3O4纳米晶进行了表征.结果表明,所制备的磁性Fe3O4纳米晶具有均匀的晶体尺寸,粒子尺寸分布在30~100 nm之间.利用Fe3O4纳米晶对高浊度高岭土悬浊液进行了混凝研究,并在外加磁场的作用下实现了絮凝体和水体的快速分离.结果证实电化学法磁混凝技术能够快速高效去除污水浊度,省去了机械过滤过程.理论研究结果表明,磁性Fe3O4纳米晶去除浊度的过程是电荷中和与沉淀卷扫共同作用的结果,而电荷中和过程发生是由于电化学制备Fe3O4纳米晶时表面电荷种类的均一性.     

Double Magnetic Separation-assisted Fluorescence Method for Sensitive Detection of Ochratoxin A

A double magnetic separation-assisted fluorescence method was developed to rapidly detect ochratoxin A(OTA). The OTA aptamer functionalized magnetic nanomaterial(Fe3O4-Aptanier) and complementary DNA conjugated nitrogen-doped graphene quantum dots(NGQDs-cDNA) were used in this assay. Aptamer could hybridize with cDNA, which induced tlie NGQDs-cDNA to bind onto Fe3O4-Aptamer, and resulted in the fluorescence quenching of NGQDs. After the addition of OTA, the NGQDs-cDNA could release into the solution, and resulted in the recovery of fluorescence signal of NGQDs consequently. By utilizing the magnetic separation, the unbonded NGQDs-cDNA and residual Fe3O4-Aptamer were removed, which significantly increased the fluorescence signal intensity. OTA could be detected in the linear range of 10 nmol/L to 2000 nmol/L, with a limit of detection as 0.66 mnol/L. The advantages of this method include simple operation, good selectivity and high sensitivity, and this method can be used for the rapid detection of ochratoxin A in wheat and com.     

Decoration of Electrospun Nanofibers with Magnetic Nanoparticles via Electrospinning and Sol-gel Process

Polyacrylonitrile(PAN)/Fe 3 O 4 composite nanofibers were successfully obtained through electrospinning and sol-gel technology. The resulting magnetic Fe 3 O 4 nanoparticles were homogeneously distributed on the surface of PAN nanofibers and the diameters of polyacrylonitrile nanofibers and nanoparticles were easily controlled, respectively. The distribution of Fe 3 O 4 nanoparticles inside the nanofibrous composite was investigated by field emission scanning electron microscopy and transmission electron microscopy. X-ray diffraction reveals the presence of Fe 3 O 4 nanoparticles in the composite nanofiber. The resulting sample shows a super paramagnetic behavior.     

F33O4 Magnetic Nanoparticles for Cinnamic Acid Extraction from Ramulus Cinnamomi

A facile solid‐phase extraction (SPE) method based on bare Fe₃O₄ magnetic nanoparticles (Fe₃O₄ NPs) was developed to capture cinnamic acid (CA) from a well‐known traditional Chinese medicine, Ramulus cinnamomi, for high performance liquid chromatography (HPLC) analysis. The as‐prepared Fe₃O₄ NPs were characterized via Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Several parameters that influence CA extraction rate, such as the amount of Fe₃O₄ NPs, shaking time, methanol content, eluent pH, and elution time, were investigated. The experimental results show that the CA extraction was 86.9 % at optimal condition, and the mass yield of CA extraction was found to be 0.00021 %. This study demonstrates that the developed CA extraction method is simple, cheap and environmentally friendly. Therefore, the proposed method has a potential for CA separation and purification from complex biological samples.