磁性镁铝类水滑石的制备及其对甲基橙的吸附研究

采用液相非稳态共沉淀法制备了磁性镁铝类水滑石(Fe_3O_4@HTlc),通过透射电子显微镜、粉末X射线衍射仪、傅里叶变换红外光谱仪、振动样品磁强计、比表面分析仪、微电泳仪等对样品的形貌和结构进行了表征,并比较了Fe_3O_4@HTlc和HTlc对甲基橙的吸附性能。结果表明,Fe_3O_4@HTlc为顺磁性的具有核-壳结构和较大比表面积并带有正电荷的近球状颗粒。甲基橙在Fe_3O_4@HTlc和HTlc上的吸附动力学曲线均符合准一级动力学方程,吸附等温线均符合Langmuir吸附等温式;298K时Fe_3O_4@HTlc和HTlc对甲基橙的饱和吸附量分别为138.89和147.06mg/g,且Fe_3O_4@HTlc对甲基橙有较强吸附推动力和较短的吸附平衡时间。二者对甲基橙的吸附量均随温度的升高和pH(5~11)的增加而降低。     

纳米Fe3O4@壳聚糖材料的制备及吸附性能的研究

以废弃的虾壳为原料制备壳聚糖,以壳聚糖为壳、磁性Fe_3O_4为核、液体石蜡为分散剂、T-80为乳化剂、戊二醛为交联剂制备了纳米Fe_3O_4@壳聚糖材料。利用扫描电镜、热重分析仪、红外光谱仪、X射线衍射仪对其进行了表征。结果显示,纳米Fe_3O_4@壳聚糖材料为表面光滑的球形结构,直径约75.82nm,壳聚糖和Fe_3O_4的质量比为2∶1。吸附动力学实验研究表明,纳米Fe_3O_4@壳聚糖材料对Cu~(2+)吸附符合准二级动力学,以化学吸附为主,平衡吸附容量为17.32mg/g。吸附等温线实验研究表明,吸附符合Freundlic模型,纳米Fe_3O_4@壳聚糖材料与Cu~(2+)之间的交互作用强烈,最大吸附容量为213.68mg/g。     

磁性氧化石墨烯/聚苯胺纳米复合材料的制备 及再生循环吸附性研究

由氧化法和原位合成法成功制备了磁性氧化石墨烯/聚苯胺(Fe_3O_(4 )/GO/PANI,MPGO)纳米复合材料,使用X射线衍射、热重分析、红外光谱、VSM、BET等对所得材料进行了结构表征和性能测试,研究了复合材料对甲基橙染料的吸附性能。结果表明:pH为4时,MPGO吸附量最大,为198 mg·g~(-1);450 min达到吸附平衡,吸附量为211.08 mg·g~(-1)。MPGO对甲基橙的吸附行为符合Langmuir等温模型和准二级动力学模型;经过7次再生循环后,MPGO对甲基橙的吸附量保持为初始吸附量的72.2%,具有较好的重复利用性。     

多层组装聚苯胺@硅磁复合物的制备及对磺酸基染料的选择性吸附

以硅磁粒子(Fe_3O_4@SiO_2)为核,采用低温-原位氧化聚合-共沉淀法制备了多层核壳聚苯胺硅磁复合物(Fe_3O_4@SiO_2@PANI).通过X射线衍射分析(XRD)、傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等对Fe_3O_4@SiO2_@PANI复合物的结构、形貌和性质进行了表征.以磺酸基偶氮染料甲基橙、刚果红和蒽醌染料茜素红溶液模拟染料废水,对其在Fe_3O_4@SiO_2@PANI上的吸附进行了研究,讨论了pH值、吸附时间、染料初始浓度及吸附剂用量对吸附过程的影响,优化了吸附条件.实验结果表明,弱酸性(p H6. 0)条件下,Fe_3O_4@SiO_2@PANI对甲基橙、刚果红和茜素红具有优异的选择性吸附性能,其平衡吸附量分别为26. 05,34. 0和69. 58 mg/g.该复合物对染料的吸附过程更接近Langmuir等温吸附的单分子层吸附机理,其对染料废水的去除率高达96. 5%,易于分离,且重复使用性能良好.     

壳聚糖改性磁性碳基吸附剂的制备及其对水中Cr(Ⅲ)-EDTA的吸附机理

利用二茂铁制备磁性碳基材料(Fe_3O_4@C),通过壳聚糖(CS)功能化,制备CS改性Fe_3O_4@C复合吸附材料(Fe_3O_4@C-CS)。利用红外光谱(FTIR)、X射线衍射(XRD)、振动样品磁强计(VSM)、热重分析(TGA)和X射线光电子能谱(XPS)等对Fe_3O_4@C-CS表征分析,并通过改变浓度、温度、时间、pH和阳离子等条件系统研究对水中已配位的三价铬(Cr(Ⅲ)-EDTA)的吸附性能。结果表明Fe_3O_4@C已经成功被CS功能化,在pH=4.0、反应温度25℃、投加量0.4 g·L~(-1)时,吸附等温线符合Langmuir模型,理论最大吸附量为12.63 mg·g~(-1),吸附动力学符合拟二级动力学模型,吸附行为是自发进行的吸热过程。结合吸附实验结果和XPS表征分析,静电吸附和配位作用是Fe_3O_4@C-CS吸附剂去除水中Cr(Ⅲ)-EDTA的主要机制。4次吸附-脱附循环后,Fe_3O_4@C-CS对水中Cr(Ⅲ)-EDTA仍具有较高的吸附效率。     

Fe3O4/GO/PPy复合材料的制备及其对2-硝基-1,3-苯二酚的吸附性能

采用改进的Hummers法制备了氧化石墨烯,用水热法首次制备了Fe_3O_4/GO/PPy(聚吡咯)三元复合粒子用于处理含2-硝基-1,3-苯二酚(NRC)的废水,研究了其对水中NRC的吸附性能。采用紫外-可见吸收光谱(UV-Vis)、透射电子显微镜(TEM)、傅里叶变换红外光谱(FT-IR)、X射线衍射(XRD)、振动样品磁强计及ζ电位等对所制备复合粒子的结构进行了表征;研究了溶液pH值、吸附剂用量、NRC的初始浓度、吸附时间和温度对吸附NRC的吸附性能的影响,并对吸附过程进行了吸附动力学模拟。结果表明:制备的Fe_3O_4/GO/PPy复合材料为层状分散结构,PPy及Fe_3O_4颗粒无规则地镶嵌在石墨烯片层之间。Fe_3O_4颗粒为多面体晶体结构,尺寸为100～300 nm。Fe_3O_4/GO/PPy具有超顺磁性,40 s可以磁分离,NRC移除率达91.6%;在NRC浓度为200 mg·L~(-1)、pH=5±0.05、温度T=318 K、吸附剂用量10 mg·L~(-1)和吸附时间6 h的条件下Fe_3O_4/GO/PPy对NRC的吸附量最大,达到163.3mg·g~(-1)。NRC吸附动力学符合二级动力学模型,吸附等温线符合Langmuir模型。循环使用5次后,NRC的移除率由最初的91.6%下降至77.6%,说明Fe_3O_4/GO/Ppy磁性复合物的结构具有较好的稳定性,且可以再重复利用。     

Fe3O4@HTlc的制备及其对甲基橙的吸附研究

采用液相非稳态共沉淀法制备了磁性镁铝类水滑石(Fe3O4@HTlc),采用透射电子显微镜、粉末X射线衍射仪、傅里叶变换红外光谱仪、振动样品磁强计、比表面分析仪、微电泳仪等对样品的形貌和结构进行了表征,并比较了 Fe3O4@HTlc和HTlc对甲基橙的吸附性能。结果表明,Fe3O4@HTlc为顺磁性、具有核-壳结构和较大比表面积、带有正电荷的近球状颗粒。甲基橙在Fe3O4@HTlc和HTlc上的吸附动力学曲线均符合准一级动力学方程;吸附等温线均符合Langmuir吸附等温式;298 K时Fe3O4@HTlc和HTlc对甲基橙的饱和吸附量分别为138.89和147.06 mg/g,但Fe3O4@HTlc对甲基橙有较强吸附推动力和较短的吸附平衡时间。二者对甲基橙的吸附量均随温度的升高和pH (5~11)的增加而降低。     

Fe_3O_4/PAA/ATP纳米复合磁性微凝胶吸附剂对Pb(Ⅱ)吸附动力学和吸附热力学研究

用γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)对纳米Fe_3O_4磁性粒子和凹凸棒黏土纳米棒晶进行表面改性,通过KH-570的桥接,在纳米Fe_3O_4磁性粒子和凹凸棒纳米棒晶的表面原位接枝聚合丙烯酸单体,制备Fe_3O_4/PAA/ATP纳米复合磁性微凝胶。将该复合微凝胶用作吸附剂,处理水体中的Pb(Ⅱ),研究其对Pb(Ⅱ)的吸附动力学和吸附热力学。     

高分散纳米薄水铝石和纳米氧化铝的制备及其对甲基橙的吸附性能

以硝酸铝为铝源,尿素为沉淀剂,采用无模板水热法合成纳米薄水铝石(γ-AlO(OH))。在不同温度下煅烧后,得到氧化铝产物(γ-Al2O_3和θ-Al2O_3)。利用X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)、傅里叶变换红外光谱(FTIR)、氮气吸附-脱附法和紫外-可见分光光度计(UV-Vis)对产物进行了表征分析。并且研究了产物对甲基橙(MO)的吸附性能,系统地考察了吸附时间、溶液的pH值、甲基橙浓度及循环使用对产物吸附性能的影响。此外,还对吸附过程进行了相关吸附理论研究。结果表明:与其他方法所制备的产物相比,通过该方法获得的产物的分散性更高,形态更均匀和完整。产物为高度分散的纳米捆扎状结构。γ-AlO(OH)对甲基橙的最大吸附量达1 492.5 mg·g~(-1)。另外,产物的吸附机制包含化学作用吸附机制和静电作用吸附机制等。3种产物对甲基橙的吸附均符合Langmuir单分子层吸附模型,吸附过程均符合二级动力学特征。     

具有染料选择吸附性的衍生于沸石咪唑酯骨架-67的NiCo-层状双氢氧化物设计与合成

以沸石咪唑类金属有机骨架(ZIF-67)为模板合成了一种新型的中空吸附剂NiCo-LDH@ZIF-67,该吸附剂对甲基橙具有良好的选择吸附性以及可循环性。 通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线粉末衍射仪(XRD)、红外光谱、电子能谱和氮气吸附-脱附等手段对样品进行了表征。 研究了溶液的pH值、甲基橙的初始浓度以及染料与吸附剂作用时间对NiCo-LDH@ZIF-67吸附性能的影响。 结果表明,该吸附剂对甲基橙的吸附动力学符合准二级动力学模型,且吸附等温线符合朗缪尔方程。 当pH值等于4, 吸附时间15 min,吸附剂用量为2400 mg/L时,该吸附剂对甲基橙的最大吸附量可达1766 mg/g,高于之前文献报道的类似吸附剂。 此外,NiCo-LDH@ZIF-67能从甲基橙和亚甲基蓝的混合溶液中选择性吸附甲基橙。     

Fe3 O4@(TF-LDHs)纳米复合体的制备及药物缓释性能

采用共沉淀法, 以替加氟(Tegafur, TF)插层层状双金属氢氧化物(LDHs)纳米杂化物(TF-LDHs)包覆磁性基质Fe3O4, 得到了具有核/壳结构的纳米复合体[Fe3O4@(TF-LDHs)], 采用XRD, FTIR, TEM, VSM和元素分析等技术对样品的化学组成、 晶体结构\, 形貌及磁性等进行了表征, 探讨了药物分子在LDHs层间的存在状态, 考察了其药物释放行为. 结果表明, Fe3O4@(TF-LDHs)纳米复合体具有顺磁性, 其比饱和磁化强度随磁性基质含量的增大而增强; TF分子在LDHs层间以长轴略倾斜于LDHs层板的方式呈双层排布; Fe3O4@(TF-LDHs)纳米复合体具有明显的药物缓释性能, 其释放动力学过程符合准二级动力学方程, 颗粒内部扩散为释放过程的速率控制步骤.     

MgFe2O4@(TF-LDHs)磁性纳米复合体的制备与表征

以镁铁尖晶石(MgFe2O4)颗粒为磁性基质, 采用共沉淀法制备了替加氟(TF)插层层状双金属氢氧化物(LDHs)包覆MgFe2O4的核-壳结构磁性纳米复合体[MgFe2O4@(TF-LDHs)], 并对其化学组成、 晶体结构和磁性等进行了表征, 探讨了TF在LDHs层间的存在状态, 考察了TF的释放行为. 实验结果表明, MgFe2O4@(TF-LDHs)纳米复合体具有顺磁性, 其比饱和磁化强度随磁性基质含量的增大而增强; TF分子在LDHs层间以长轴略倾斜于LDHs层板的方式呈双层排布; MgFe2O4@(TF-LDHs)纳米复合体具有明显的药物缓释效果, 其释放动力学过程符合准二级动力学方程, 释放机理为Fick扩散; 增大磁性基质含量或施加外加磁场均可减缓其药物释放过程.     

Magnetic carbon nanotubes synthesis by Fenton's reagent method and their potential application for removal of azo dye from aqueous solution

We report a simple and easy method to fabricate magnetic carbon nanotubes (CNTs) by Fenton's reagent method without the addition of any cations. H(2)O(2) was added slowly into the FeSO(4) solution mixed with purified CNTs, and the resulting reactants were placed into a quartz tube to undergo heat treatment under a nitrogen/hydrogen flow. Iron oxide (Fe(2)O(3)) nanoparticles were uniformly dispersed on CNTs without any pretreatment such as strong acid or covalent functionalization processes. The as-produced magnetic CNTs were used as an adsorbent for removal of methyl orange (MO) dye from aqueous solutions. Adsorption experiments indicated that the magnetic CNTs have good adsorption capacity (q(e)) of MO (28 mg/g). The Freundlich isotherm model fitted the experiment data better than the Langmuir isotherm mode. The mean energy of adsorption was calculated as 3.72 kJ/mol based on the Dubinin-Radushkevich model, which suggests that the removal process was dominated by physical adsorption. Kinetic regression results showed that the adsorption kinetics was more accurately represented by a pseudo second-order model. Intra-particle diffusion was involved in the adsorption process, but it was not the only rate-controlling step. More importantly, a new photocatalytic regeneration technology can be enabled by the high nanoscale iron oxide loading (50%). The magnetic CNT adsorbents could be effectively and quickly separated by applying an external magnetic field and regenerated by UV photocatalysis. Therefore, CNTs/λ-Fe(2)O(3) hybrid is a promising magnetic nanomaterial for preconcentration and separation of organic pollutants for environmental remediation.     

Study on the adsorption of heavy metals by a new magnetic hydrogel based on acrylic acid/ acrylamide/ sodium p-styrenesulfonateEI北大核心CSCD

通过水溶液法将Fe₃O₄@SiO₂负载到丙烯酸（AA）-丙烯酰胺（AM）-对苯乙烯磺酸钠（SSS）三元共聚水凝胶上,制备了具有高吸附能力的磁性水凝胶P（AA/AM/SSS）/Fe₃O₄@SiO₂。通过傅里叶变换红外光谱,X射线衍射光谱,拉曼光谱和比表面孔径分析表征了磁性水凝胶的微观结构。该磁性水凝胶平均孔径3.1 nm,属于介孔材料,且具有较好的热稳定性。吸附性能研究发现其对重金属离子Pb²⁺,Cu²⁺,Co²⁺,Cd²⁺和Ni²⁺均显示出较高的去除率,其中对Pb²⁺表现出优异的选择性,最大吸附量为497 mg/g。吸附动力学研究表明,吸附过程遵循拟二级动力学模型。再生实验发现该水凝胶经过7次吸附-解吸循环后,磁性水凝胶饱和吸附容量仍保持在265 mg/g。     

纳米金与磁性纳米复合物构建电流型免疫传感器的研究

制备了易于磁性分离、硫堇(Thi)包覆的四氧化三铁(Fe3O4)纳米复合物。通过静电吸附作用,将萘酚(Nafion)、Thi包覆的Fe3O4复合纳米粒子层层修饰到玻碳电极表面,再利用Thi分子中的氨基吸附纳米金,最后固载甲胎蛋白抗体,从而制得灵敏度高、稳定性好的无试剂电流型甲胎蛋白免疫传感器。实验通过透射电子显微镜(TEM)对该复合纳米粒子进行表征,并用循环伏安法考察了电极的电化学特性。结果表明,Fe3O4/Thi复合纳米粒子修饰的电极在实验过程中呈现出良好的氧化还原活性,其检测范围为0.05～20μg/L,检出限为0.03μg/L。     

Multifunctional nanocomposites constructed from Fe3O4-Au nanoparticle cores and a porous silica shell in the solution phase

This work is directed towards the synthesis of multifunctional nanoparticles composed of Fe(3)O(4)-Au nanocomposite cores and a porous silica shell (Fe(3)O(4)-Au/pSiO(2)), aimed at ensuring the stability, magnetic, and optical properties of magnetic-gold nanocomposite simultaneously. The prepared Fe(3)O(4)-Au/pSiO(2) core/shell nanoparticles are characterized by means of TEM, N(2) adsorption-desorption isotherms, FTIR, XRD, UV-vis, and VSM. Meanwhile, as an example of the applications, catalytic activity of the porous silica shell-encapsulated Fe(3)O(4)-Au nanoparticles is investigated by choosing a model reaction, reduction of o-nitroaniline to benzenediamine by NaBH(4). Due to the existence of porous silica shells, the reaction with Fe(3)O(4)-Au/pSiO(2) core/shell nanoparticles as a catalyst follows second-order kinetics with the rate constant (k) of about 0.0165 l mol(-1) s(-1), remarkably different from the first-order kinetics with the k of about 0.002 s(-1) for the reduction reaction with the core Fe(3)O(4)-Au nanoparticles as a catalyst.     

Sonochemical formation of iron oxide nanoparticles in ionic liquids for magnetic liquid marble

Ionic liquids (ILs)-stabilized iron oxide (Fe(2)O(3)) nanoparticles were synthesized by the ultrasonic decomposition of iron carbonyl precursors in [EMIm][BF(4)] without any stabilizing or capping agents. The Fe(2)O(3) nanoparticles were isolated and characterized by X-ray powder diffraction, transmission electron microscopy and susceptibility measurements. The physicochemical properties of ILs containing magnetic Fe(2)O(3) nanoparticles (denoted as Fe(2)O(3)@[EMIm][BF(4)]), including surface properties, density, viscosity and stability, were investigated in detail and compared with that of [EMIm][BF(4)]. The Fe(2)O(3)@[EMIm][BF(4)] can be directly used as magnetic ionic liquid marble by coating with hydrophobic and unreactive polytetrafluoroethylene (PTFE), for which the effective surface tension was determined by the puddle height method. The resulting magnetic ionic liquid marble can be transported under external magnetic actuation, without detachment of magnetic particles from the marble surface that is usually observed in water marble.     

Synthesis and Study of the Properties of Magnetic Adsorbents Based on Hydrophobized Silica

Moscow University Chemistry Bulletin - We proposed a method for producing magnetic nanocomposite adsorbents, based on the adsorption of Fe3O4 magnetic nanoparticles (MNPs) on hydrophobized silicas...     

Magnetically recoverable Cu2O/Fe3O4 composite photocatalysts：Fabrication and photocatalytic activity

A magnetically separable Cu2O/Fe3O4 magnetic composite photocatalyst was synthesized in large quantities by a fast and simple route. The as-prepared photocatalysts were characterized by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, X-ray photoelectron spectroscopy （XPS） and X-ray diffraction （XRD）. Furthermore, the Cu2O/Fe3O4 composite photocatalysts were tested using methyl orange （MO） degradation reaction under visible light irradiation （100 mW/cm2） and demonstrated to have a high photocatalytic efficiency toward the decomposition of MO under visible light irradiation with good recyclability.