Fe3O4/羧基改性壳聚糖复合纳米粒子的制备、表征及生物学应用

采用氧化水热法,以H2O2为氧化剂制备了磁性Fe3O4纳米颗粒.以磁性Fe3O4为核,通过反相悬浮聚合法对Fe3O4颗粒表面进行改性,在碳二亚胺的活化作用下,与壳聚糖衍生物-α-酮戊二酸缩壳聚糖(KCTS)反应制备了表面含有一定羧基的磁性Fe3O4/KCTS纳米粒子.经XRD、TEM、VSM、IR、TGA等手段对复合材料进行了表征及性能研究.结果表明,该磁性Fe3O4/KCTS纳米粒子的平均粒径为26nm,比饱和磁化强度为24.8A·m2/kg.其性能优良,具备超顺磁性,能很好的应用于生物分离,蛋白吸附等领域.     

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.     

四氧化三铁纳米粉在水溶液中分散稳定性的研究

采用液相共沉淀法制备了Fe3O4粒子,选用柠檬酸铵、白蛋白、PEG200和柠檬酸等作为分散剂,对Fe3O4纳米粉体进行表面修饰和改性,研究了分散剂种类、添加量及粉体含量等对Fe3O4纳米粉稳定性的影响.研究结果表明,白蛋白和柠檬酸铵是水溶液中纳米粉体很好的分散剂;电解质柠檬酸铵作为分散剂时,溶液分散处理都能达到很好的稳定效果;用白蛋白分散时,最佳工艺条件为:纳米Fe3O4粉体含量为40mL标准溶液/100mL溶液,白蛋白添加量为1.6mL.最后采用HRTEM、FT-IR等对其结构和包裹性能进行表征,结果表明,纳米粒子表面包覆了柠檬酸铵,柠檬酸铵包覆的Fe3O4纳米粒子基本呈球形,单个晶粒粒径约为10nm,制得的磁性液体分散稳定效果很好.     

多聚磷酸钠改性水基Fe_3O_4磁流体的制备与表征

采用多聚磷酸钠(STPP)对Fe3O4磁性纳米粒子进行表面改性,制备稳定的水基磁流体。通过傅里叶变换红外光谱(FTIR)、热重分析(TG)、透射电镜(TEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)、振动样品磁强计(VSM)及Zeta电位仪对所制备的磁流体进行表征。结果表明,STPP包覆于Fe3O4磁性纳米粒子的表面,当pH>3时,粒子表面带有负电荷;磁性测试结果表明,STPP/Fe3O4磁性纳米粒子具有超顺磁性,其饱和磁化强度为62.3 A.m2.kg-1。     

超声辅助磁性纳米Fe3O4粒子表面有机改性研究

采用超声粉碎分散团聚磁性纳米Fe3O4粒子,用油酸对分散好的磁性粒子表面进行改性.结果表明,在纳米Fe3O4中油酸用量为0.5mL、超声次数为15次、每次2min、间隔时间为15s、pH值为7.5的条件下,改性效果最好,改性指数为0.87.红外光谱分析证明,油酸通过-COOH的"均化"与纳米Fe3O4粒子的表面结合实现了包覆改性,无分解和其它化学反应发生,改性效果良好.     

改性Fe3O4纳米粒子在磁性复合超滤膜中的应用

为解决Fe3O4纳米粒子在磁性复合超滤膜中发生团聚和分布不均匀的问题,文中以市售20nm的Fe3O4粒子为对照,添加自制的改性Fe3O4纳米粒子制备出Fe3O4-聚砜(PSF)磁性复合超滤膜(改性复合超滤膜)。经扫描电镜观察膜表面形貌、能谱仪扫描复合膜中Fe元素分布以及铸膜液中Fe3O4纳米粒子分布情况分析和复合膜孔径分布测试后表明,改性后复合超滤膜中纳米粒子的分布较改性前更为均匀,且未出现粒子团聚现象,改性效果明显。由改性前后的复合膜在不同磁场下对聚乙二醇6000和10000的截留率呈现几乎相同的变化趋势可知,添加改性粒子并未改变磁性复合膜的分离特性。     

高稳定性导热油基磁性流体的制备

以氨水为沉淀剂、油酸为表面改性剂制备了高稳定性导热油基磁性流体.研究了所制备的Fe3O4粒子和磁性流体的各项性能.结果表明,制备的Fe3O4粒子晶型完整、粒径均一,具有很高的饱和磁化强度.通过表面改性油酸成功地包覆到Fe3O4粒子表面.所制备的导热油基磁性流体具有强磁性和高稳定性.     

超顺磁性Fe3O4纳米颗粒的制备及修饰

利用2-吡咯烷酮和乙酰丙酮铁为原料制备出Fe3O4磁性纳米粒子,选择偶联剂γ-氨丙基三乙氧基硅烷(NH2C3H6Si(OC2H5)3)对磁性材料进行了表面修饰.经XRD、TEM、VSM、FT-IR测试结果表明,制备出的Fe3O4磁性纳米粒子粒径均一(8～10nm)、结晶度高、磁响应较强;通过控制反应回流时间,可以改变粒子的大小;经表面改性以后,-OH、-NH、-NH2、-C-O、-C-OH等多种功能基团负载到磁性Fe3O4纳米粒子表面,增强了微球的生物相容性.     

复印显影剂用Fe3O4的表面改性

Fe3O4是亲水的,为了使其用于显影剂中,必须进行表面改性.选择油酸钠对Fe3O4进行改性,用SEM、IR、TG和XPS对Fe3O4改性前后的形貌和结构进行表征.结果表明,油酸钠使Fe3O4由亲水性变为疏水性,有效改善其与显影剂单体的润湿性.温度、时间、pH和油酸钠用量是影响润湿性的主要因素.油酸钠对Fe3O4的吸附为单分子层的化学吸附,符合Langmuir吸附等温式,饱和吸附量为0.94×10-5mol/m2,吸附自由能为-29.49kJ/mol.磁性能分析表明,改性后磁性能基本无变化.     

巯基表面修饰磁性复合纳米粒子用于重金属离子去除的研究

采用化学共沉淀法合成磁性Fe3O4纳米粒子,并且利用正硅酸乙酯(TEOS)的水解和凝聚作用在Fe3O4纳米粒子表面沉积包覆一层SiO2,合成核壳式的Fe3O4@SiO2复合纳米粒子。以Fe3O4@SiO2纳米粒子为基体,将(3-巯基丙基)三乙氧基硅烷嫁接到纳米粒子表面,制备出巯基功能化的纳米材料,将其应用于对重金属离子的吸附。由于功能化纳米粒子具有超顺磁性,为纳米粒子吸附重金属粒子后的分离提供了便利。通过TEM、XRD、FTIR、VSM等手段对Fe3O4@SiO2复合纳米粒子进行表征。     

表面活性剂对磁流体稳定性及外层包覆结构的影响

采用化学共沉淀法制备粒径分布均匀的纳米Fe3O4颗粒,用油酸钠和聚乙二醇4000(PEG4000)对纳米Fe3O4颗粒进行表面修饰,制得分散稳定的纳米Fe3O4磁流体,通过电动电位(Zeta电位)、粒径测试、离心沉淀、红外光谱分析(FT-IR)和热分析(TG)对修饰后的纳米Fe3O4颗粒进行了稳定性能评价与结构表征。结果表明,油酸钠与纳米Fe3O4颗粒存在两种不同类型的化学键作用;增大油酸钠加入量不会改变Fe3O4颗粒表面包覆结构,但是,其在纳米Fe3O4颗粒表面的吸附量呈先增加后降低的趋势;PEG4000物理吸附于油酸钠包覆的纳米Fe3O4颗粒表面,PEG4000的加入会进一步提高磁流体的稳定性。     

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.     

Fe3O4／Ag复合纳米材料的制备及SERS研究

采用乙酰丙酮铁作为有机前驱体盐,在二苄基醚溶液中,以油酸、油胺为表面活性剂,十六醇作为“分解促进剂”,分解前驱体乙酰丙酮铁,制备四氧化三铁纳米颗粒。以四氧化三铁纳米颗粒为“种子”,加入醋酸银,以油胺为还原剂,制备Fe3O4/Ag复合磁性纳米材料。利用透射电子显微镜对纳米材料的形貌进行了表征,通过紫外～可见吸收光谱和拉曼光谱仪对纳米材料的表面增强拉曼散射光谱进行表研究,采用铷硼磁铁对磁性纳米材料的磁性进行初步研究。实验结果表明：FelO2／Ag复合磁性纳米颗粒既具有磁性又具有贵金属光谱特性;相对Fe304而言,Fe3O4/Ag复合纳米粒子具有更好的s隙S增强效果。     

Preparation and characterization of Ni-nitrilotriacetic acid bearing poly(methacrylic acid) coated superparamagnetic magnetite nanoparticles

Stable superparamagnetic magnetite (Fe3O4) nanoparticles were synthesized via co-precipitation in the presence of poly(methacrylic acid) (PMAA) in aqueous solution. The polymer coated Fe3O4 nanoparticles were characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, thermal analysis, and vibrating sample magnetometry (VSM) techniques. These measurements reveal the presence of magnetite nanoparticles with a size of approximately 8 nm inside the PMAA matrix. The magnetization value of these superparamagnetic nanoparticles at room temperarure and 7 T was measured as about 40 emu/g. PMAA-coated Fe3O4 nanoparticles were further assembled with Ni-chelate through a reaction between a primary amine-bearing NTA (nitrilotriacetic acid) ligand and carboxy-functional groups of PMAA. NTA-PMAA-coated magnetite nanoparticles were then loaded with nickel ions and characterized using FTIR. The average amount of binded Ni on the surface of the NTA-modified PMAA coated Fe3O4 was calculated as 1.65 +/- 0.3 x 10(-6) mol nickel(II) ions per g of the magnetic particles from the inductively coupled plasma optical emission spectroscopy (ICP-OES) measurements.     

Fe3O4磁性纳米颗粒的合成与接枝聚合修饰（英文）

以氨水作为沉淀剂并控制溶液的pH值,采用Fe3+和Fe2+共沉淀法制得了磁性四氧化三铁纳米颗粒。合成的磁性纳米颗粒通过高分辨透射电镜、X射线衍射仪、傅里叶变换红外光谱仪进行了表征。四氧化三铁纳米颗粒的粒径约为10nm,其表面含有丰富的羟基。为了增强磁性四氧化三铁纳米颗粒和聚合物基质之间的相互作用,在纳米颗粒的表面接枝上乙烯基单体。傅里叶变换红外光谱仪和热重分析仪的测试结果显示,聚合物链共价结合在纳米颗粒表面。表面接枝聚合后,四氧化三铁纳米颗粒由极性转变为非极性。     

Fe3O4/CdTe磁性荧光纳米复合物的逐步杂凝聚法合成及其表征

采用逐步杂凝聚法合成了Fe3O4/CdTe磁性荧光纳米复合物.以化学共沉淀法制备Fe3O4纳米颗粒,经油酸修饰后分散在表面活性剂中形成磁流体.CdTe量子点以巯基乙酸为稳定剂制得.最后以聚乙烯亚胺(PEI)为联接剂,成功制备了Fe3 O4 /CdTe磁性荧光双功能纳米复合物颗粒.该复合物颗粒平均尺寸为(30±5)nm,荧光产率为0.186,饱和磁化强度为15.745emu/g,该纳米粒子既具有优异的荧光特性,也具有较强的超顺磁性.     

Fast removal of copper ions by gum arabic modified magnetic nano-adsorbent

A novel magnetic nano-adsorbent was developed by treating Fe(3)O(4) nanoparticles with gum arabic to remove copper ions from aqueous solutions. Gum arabic was attached to Fe(3)O(4) via the interaction between the carboxylic groups of gum arabic and the surface hydroxyl groups of Fe(3)O(4). The surface modification did not result in the phase change of Fe(3)O(4), while led to the formation of secondary particles with diameter in the range of 13-67nm and the shift of isoelectric point from 6.78 to 3.6. The amount of gum arabic in the final product was about 5.1wt%. Both the naked magnetic nanoparticles (MNP) and gum arabic modified magnetic nanoparticles (GA-MNP) could be used for the adsorption of copper ions via the complexation with the surface hydroxyl groups of Fe(3)O(4) and the complexation with the amine groups of gum arabic, respectively. The adsorption rate was so fast that the equilibrium was achieved within 2min due to the absence of internal diffusion resistance and the adsorption capacities for both MNP and GA-MNP increased with increasing the solution pH. However, the latter was significantly higher than the former. Also, both the adsorption data obeyed the Langmuir isotherm equation. The maximum adsorption capacities were 17.6 and 38.5mg/g for MNP and GA-MNP, respectively, and the Langmuir adsorption constants were 0.013 and 0.012L/mg for MNP and GA-MNP, respectively. Furthermore, both the adsorption processes were endothermic due to the dehydration of hydrated metal ions. The enthalpy changes were 11.5 and 9.1kJ/mol for MNP and GA-MNP, respectively. In addition, the copper ions could desorb from GA-MNP by using acid solution and the GA-MNP exhibited good reusability.     

纳米金磁颗粒的组装法制备及其核酸分离性能

以丙烯酰胺为单体,采用原位聚合法制备了Fe3O4/聚丙烯酰胺纳米磁粒(Fe3O4/PAM);利用胺基与金的相互作用,借助自组装法在Fe3O4/PAM表面组装金胶体制备了草莓型纳米金磁颗粒(Fe3O4/PAM/Au);用TEM、VSM、UV-vis对其进行了表征,并考察了表面修饰核酸探针的金磁颗粒对核酸靶分子的分离能力。结果表明,Fe3O4/PAM/Au粒子的粒径为36～56nm,具有超顺磁性,饱和磁化强度为31.2emu/g,分散在磷酸盐缓冲液中的Fe3O4/PAM/Au完全磁分离的时间为6min。修饰核酸探针的Fe3O4/PAM/Au粒子可以借助核酸杂交作用分离核酸靶分子,分离能力为118pmol/mg。     

接枝聚阳离子磁性微球的合成及抗菌活性

共沉淀法合成Fe3O4纳米颗粒,经硅烷偶联剂3-(异丁烯酰氧)丙基三甲氧基硅烷(MPS)表面双键功能化,与季铵盐化(苄基溴化或溴己烷化)甲基丙烯酸二甲基氨基乙酯(DMAEMA)单体自由基共聚,获得可循环利用的聚阳离子接枝的磁性抗菌微球(pQAC-Fe3O4)。颗粒形貌及表面性质通过X射线衍射(XRD)、红外(FT-IR)、动态光散射粒径分析(DLS)、透射电镜(TEM)、热重分析(TGA)等表征。测试pQAC-Fe3O4微球对革兰氏阳性、革兰氏阴性菌及真菌的抗菌活性,结果表明两种具有外磁场响应性的pQAC-Fe3O4颗粒均具有高效广谱杀菌性,且经磁分离回收循环利用10次后对大肠杆菌的杀菌率仍可达95%以上。颗粒杀菌效果不仅与接枝季铵盐基团的多少有关还与季铵盐取代基团有关。