磁性Fe_3O_4/Beta沸石复合材料制备及其水体磷污染物吸附行为研究

自制得到磁性Fe3O4/Beta沸石复合材料,并通过SEM、XRD、FT IR,磁滞回线表征鉴定,相应最佳吸附除磷实验条件为:0.05g磁性Fe3O4/Beta沸石复合材料对5mL,50mg/L PO34-溶液(pH值为3.0)吸附率近100%,吸附平衡时间为6h,吸附行为符合Freundlich方程,可在碱性介质溶液中脱附再生。磁性Fe3O4/Beta沸石复合材料基于磁基质易于水体分离操作,过程简便可控,实际应用前景广阔。     

羧基化磁性Fe3O4复合材料的制备及其对水体中Pb2+的吸附研究

以采用共沉淀法制备的磁性Fe₃O₄为核,通过硅烷化及酰胺化反应,制备了羧基化磁性Fe₃O₄复合材料（Fe₃O₄?SiO₂?NH?COOH）,通过红外光谱仪（FTIR）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、磁强度计（VSM）和X射线衍射仪（XRD）等对复合材料的结构进行了表征,并对不同作用条件下Fe₃O₄?SiO₂?NH?COOH吸附Pb²⁺的效果及Fe₃O₄?SiO₂?NH?COOH的重复使用效能进行了研究。结果表明,具有Fe₃O₄?SiO₂?NH?COOH结构的复合材料已被成功被制备,且该材料仍然能够实现快速磁性分离;Fe₃O₄?SiO₂?NH?COOH对Pb²⁺的静态吸附动力学数据更符合准二阶动力学,吸附时间为100 min、pH=4.5、Fe₃O₄?SiO₂?NH?COOH用量为1.0 g/L时,Fe₃O₄?SiO₂?NH?COOH对Pb²⁺的最大吸附容量为208.7 mg/g,且Langmuir方程更能描述该吸附等温过程;Fe₃O₄?SiO₂?NH?COOH对Pb²⁺的吸附是吸热过程;Fe₃O₄?SiO₂?NH?COOH对Pb²⁺的吸附量随时间延长先增加后趋于稳定,随pH值的增加先增加后减小;相比于一价阳离子,溶液中二价Ca²⁺、Mg²⁺的存在对吸附反应具有一定抑制作用;Fe₃O₄?SiO₂?NH?COOH吸附Pb²⁺后可洗脱再生,连续重复使用6次后对Pb²⁺的去除率仍大于50 %。     

Fe3O4@SA/CTS凝胶球对亚甲基蓝及碱性品红的吸附

为解决染料对水体污染问题,本工作以海藻酸钠为骨架,结合Fe3O4及壳聚糖,制备了Fe3O4@SA/CTS凝胶球,并对制备的材料进行了微观表征。研究了不同影响因素下,吸附剂对MB及CB的吸附效果,同时研究了不同pH下对混合液的吸附性能,以及吸附剂循环利用性实验。结果表明,MB或CB初始浓度为100 mg/L、吸附剂投加量为1.0 g/L、MB的pH为11或CB的pH为8、反应时间4 h、MB和CB的去除率分别可以达到91.9%和21.5%。Langmuir模型能够更好反应对MB或CB的吸附,吸附以单分子物理吸附为主。吸附动力学符合伪二级动力学方程,吸附过程更容易受到化学吸附影响。不同pH下,Fe3O4@SA/CTS对混合液中的MB吸附优于CB,5次脱附循环使用后对MB保持在70%以上,对CB的去除率保持在15%以上。     

Rapid Removal of Toxic Remazol Brilliant Blue-R Dye from Aqueous Solutions Using Juglans nigra Shell Biomass Activated Carbon as Potential Adsorbent: Optimization,Isotherm, Kinetic,and Thermodynamic Investigation

Recently, the treatment of effluent by agricultural waste biomass has significantly attracted wide interest among researchers due to its availability, efficacy, and low cost. The removal of toxic Remazol Brilliant Blue-R (RBBR) from aqueous solutions using HNO₃-treated Juglans nigra (walnut) shell biomass carbon as an adsorbent has been examined under various experimental conditions, such as initial pH, adsorbate concentration, adsorbent dosage, particle size, agitation speed, and type of electrolyte. The experiments are designed to achieve the maximum dye removal efficiency using the response surface methodology (RSM). The optimum pH, adsorbent dosage, and particle size were found to be 1.5, 7 g L⁻¹, and 64 μm, respectively for maximum decolorization efficiency (98.24%). The prepared adsorbent was characterized by particle size, Brunauer–Emmett–Teller (BET) surface area, pore volume, zero-point charge (pH_zpc), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy/energy dispersive X-ray spectroscopy (FE-SEM/EDX), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Based on fitting the experimental data with various models, the isotherm and kinetic mechanism are found to be more appropriate with Langmuir isotherm and pseudo-second-order kinetics. The adsorption mechanism can be described by the intra-particle diffusion model, Bangham, and Boyd plots. The overall rate of adsorption is controlled by the external film diffusion of dye molecules. The maximum monolayer adsorption capacity, (q_max) 54.38 mg g⁻¹ for RBBR dye, was obtained at a temperature of 301 K. From a thermodynamic standpoint, the process is endothermic, spontaneous, and the chemisorption process is favored at high temperatures. Desorption studies were conducted with various desorbing reagents in various runs and the maximum desorption efficiency (61.78% in the third run) was obtained using the solvent methanol. Reusability studies demonstrated that the prepared adsorbent was effective for up to three runs of operation. The investigation outcomes concluded that walnut shell biomass activated carbon (WSBAC) is a cost-effective, eco-friendly, and bio-sustainable material that can be used for synthetic dye decolorization in aqueous media.     

Fe_3O_4@rGO复合磁性粒子对聚氨酯弹性体复合材料性能的影响

将3种不同的Fe3O4@还原氧化石墨烯(rGO)–四氢呋喃(THF)复合磁性粒子分散液分别与聚氨酯(PUR)弹性体进行原位聚合制备3种PUR弹性体/Fe3O4@rGO磁性复合材料,并对其组分和分散状态进行了表征,系统研究了Fe3O4@rGO复合磁性粒子对PUR弹性体磁性能、热性能和力学性能的影响。结果表明,仅掺入质量分数为0.5%的Fe3O4@rGO复合磁性粒子可以显著提高PUR弹性体的性能。随着Fe3O4@rGO复合磁性粒子中rGO含量的增加,PUR弹性体复合材料的饱和磁化强度逐渐下降,热稳定性和力学性能均逐渐提高。当复合磁性粒子中rGO质量分数为60%时,复合材料的力学性能最佳,拉伸强度、断裂伸长率和拉伸弹性模量分别为35.31MPa,438.90%和86.42MPa,玻璃化转变温度、最大损耗因子和在–60℃时的储能模量分别达10.64℃,0.41和3805.84MPa。此外,扫描电子显微镜观察发现,Fe3O4@rGO复合磁性粒子在基体中具有良好的分散性。     

蒙脱土壳聚糖复合材料对活性艳红KE-3B的吸附行为研究

采用壳聚糖和蒙脱土合成了纳米复合材料,在静态条件下,研究了蒙脱土壳聚糖对活性艳红KE-3B的吸附,探讨了蒙脱土壳聚糖吸附活性艳红KE-3B的最佳吸附条件。结果表明,蒙脱土壳聚糖对活性艳红具有较好的吸附性能,吸附的最佳pH值为6.0,最佳吸附时间为40 m in,最佳吸附温度为30℃,最佳吸附剂用量为50 mg,活性艳红KE-3B的最佳初始浓度为50 mg/L,吸附率最高可达91.6%以上。计算得出蒙脱土壳聚糖对活性艳红KE-3B的吸附符合Freund lich吸附等温式。实验表明,蒙脱土壳聚糖的吸附性能好,具有良好的应用价值。     

Fe_3O_4/SiO_2核壳复合磁性微球的制备和表征

以溶剂热法制备的高磁饱和强度Fe3O4纳米颗粒为核,正硅酸乙酯(TEOS)为前驱体,采用Stber方法,在乙醇/水溶液中,通过氨水催化水解硅醇盐,制得核壳结构的Fe3O4/SiO2复合磁性微球。对制备的样品的物相结构、形貌和磁性能进行了测试表征。结果表明:制备的Fe3O4/SiO2磁性微球呈球形,粒径分布均一,SiO2壳层圆整光滑,厚度为40~70nm。X射线衍射分析显示,Fe3O4/SiO2磁性微球具有尖锐的Fe3O4特征衍射峰,表明包覆过程没有破坏Fe3O4的晶体结构,其室温下的磁滞回线呈顺磁性,且比饱和磁化强度为30A·m2/kg。此外,对SiO2壳层的包覆机理进行了探究。     

High-Specific Surface Area Hierarchical Al2O3 Carbon Fiber Based on A Waste Paper Fiber Template: Preparation and Adsorption for Iodide Ions

In this work, a hierarchical Al₂O₃ carbon fiber (H-Al-CF) was successfully fabricated for application in the removal of iodide ions from water. High yields of Al₂O₃-coated carbon fiber were prepared by a sol–gel process using waste paper fibers as templates and carbon sources. The H-Al-CF is fabricated by an in-situ growth of AlOOH nanocrystals on the surface of carbon fibers following calcination. The synthesized H-Al-CF exhibits the developed porosity including mesopores and macropores, and has high-specific surface area (348.9 m² g^?1) and iodide ions' adsorption efficiency (92.3%). The in-situ growth process ensures that H-Al-CF has a more stable structure, further promoting higher adsorption efficiency.     

Fe3O4@PGMA-Arg磁性吸附剂的制备及对亚铁离子的吸附性能

为脱除油田采出水中的Fe(Ⅱ)合成磁性吸附剂,本文以溶剂热法制得亲水性Fe₃O₄纳米颗粒,使用盐酸多巴胺（DA）进行包覆得到Fe₃O₄@PDA,再以甲基丙烯酸缩水甘油酯（GMA）在其表面聚合接枝得到Fe₃O₄@PGMA,后经精氨酸（Arg）修饰后得到功能化的Fe₃O₄@PGMA-Arg。通过红外光谱、X射线光电子能谱、X射线衍射和磁化强度对制备的纳米颗粒进行表征,结果表明Fe₃O₄@PGMA-Arg中具有伯胺、亚胺双键、羟基和羧基官能团,其中伯胺基团和亚胺双键上的N可与Fe(Ⅱ)形成配位键,羟基和羧基的O可与Fe(Ⅱ)形成配位键,从而达到吸附Fe(Ⅱ)的目的。合成产物仍保持了Fe₃O₄的反尖晶石结构,具有好的磁响应性能。通过静态吸附实验探究吸附条件对Fe₃O₄@PGMA-Arg吸附Fe(Ⅱ)的影响因素,结果表明,Fe(Ⅱ)的吸附量随着温度和初始浓度的增加而增加,适宜的pH为4。动力学和热力学研究表明,吸附Fe(Ⅱ)过程符合准二级反应动力学模型,吸附等温线符合Langmuir模型,吸附过程活化能为45.60kJ/mol,为化学吸附。Fe₃O₄@PGMA-Arg经5次再生后,对亚铁离子仍保持较高的脱除率。     

核壳型Fe3O4-聚吡咯电磁屏蔽填料的制备与表征

采用一步刻蚀法制备了核壳Fe₃O₄-聚吡咯(Fe₃O₄-PPy)复合微球,并采用FT-IR、XRD、TG和矢量网络分析仪对其结构和电磁参数进行了表征。结果表明:盐酸刻蚀产生的Fe ³⁺引发了吡咯在Fe₃O₄微球表面的聚合。扫描电镜与透射电镜证实了其核壳结构;FT-IR谱图证明了聚吡咯的生成;XRD谱图证明了在反应过程中核的晶型没有变化。热重曲线与磁滞回线表明:随着反应时间的延长,Fe₃O₄的含量减少而聚吡咯的含量增加。当反应时间为5 min时,该样品的吸波性能最优,最低反射损耗为-41.9 dB,有效吸收带宽达到6 GHz。Fe₃O₄-PPy基电磁屏蔽涂层在30 MHz~1 GHz的电磁屏蔽效能≥36 dB。     

Fe3O4@mesoporouspolyaniline: A Highly Efficient and Magnetically Separable Catalyst for Cross‐Coupling of Aryl Chlorides and Phenols

A high surface, magnetic Fe₃O₄@mesoporouspolyaniline core‐shell nanocomposite was synthesized from magnetic iron oxide (Fe₃O₄) nanoparticles and mesoporouspolyaniline (mPANI). The novel porous magnetic Fe₃O₄ was obtained by solvothermal method under sealed pressure reactor at high temperature to achieve high surface area. The mesoporouspolyaniline shell was synthesized by in situ surface polymerization onto porous magnetic Fe₃O₄ in the presence of polyvinylpyrrolidone (PVP) and sodium dodecylbenzenesulfonate (SDBS), as a linker and structure‐directing agent, through ‘blackberry nanostructures’ assembly. The material composition, stoichiometric ratio and reaction conditions play vital roles in the synthesis of these nanostructures as confirmed by variety of characterization techniques. The role of the mesoporouspolyaniline shell is to stabilize the porous magnetic Fe₃O₄ nanoparticles, and provide direct access to the core Fe₃O₄ nanoparticles. The catalytic activity of magnetic Fe₃O₄@mesoporousPANI nanocomposite was evaluated in the cross‐coupling of aryl chlorides and phenols.     

Influence of Fe3O4 nanoparticles decoration on dye adsorption and magnetic separation properties of Fe3O4/rGO nanocomposites

Magnetite (Fe₃O₄) nanoparticles were prepared by solvothermal method and its composites with reduced graphene oxide namely FG1, FG2, and FG3 (changing magnetite precursor loading 0.1, 0.5, and 1 respectively) were used as adsorbents for the removal of methyl violet (MV) dye. The structural and morphological results confirm that rGO sheets were decorated with Fe₃O₄ and it ensures the variation of active sites toward dye removal property. The maximum adsorption capacity obtained for FG2 was 196 mg/g. The adsorption isotherms and kinetics better fit Langmuir and pseudo-second-order kinetic model for FG1 and FG2. Increasing of Fe₃O₄ loading on rGO reduces the dye adsorption sites and too low Fe₃O₄ loading affects the magnetic separation. The optimal loading of Fe₃O₄ on rGO is important parameter for the adsorption process and fast separation of adsorbent.     

改性果胶-Fe3O4磁性微球制备及对Pb 2+吸附性能

合成了一种琥珀酸酐改性果胶-四氧化三铁（Fe₃O₄）磁性微球吸附剂,分别采用扫描电镜（SEM）、红外光谱（FT-IR）、X射线衍射（XRD）等手段对样品进行了表征,并研究了其吸附铅离子（Pb ²⁺）的性能。研究结果表明：成功制备了琥珀酸酐改性果胶-Fe₃O₄磁性微球,改性果胶包覆四氧化三铁几乎没有改变Fe₃O₄的尖晶石结构,其表面疏松多孔;改性果胶-Fe₃O₄磁性微球对铅离子的吸附符合准二级动力学方程、Langmuir等温吸附方程,吸附过程主要为化学吸附。最佳吸附条件：吸附时间为600 min,吸附温度为40 ℃,溶液pH为5,吸附剂添加量为20 mg,溶液中Pb ²⁺质量浓度为800 mg/L。改性果胶-Fe₃O₄磁性微球吸附剂用于脱除毛蚶子、扇贝酶解液中的Pb ²⁺,Pb ²⁺去除率分别为76.47%和80.34%,效果良好。     

A Novel Yolk–Shell Fe3O4@ Mesoporous Carbon Nanoparticle as an Effective Tumor-Targeting Nanocarrier for Improvement of Chemotherapy and Photothermal Therapy

Owing to their good stability and high photothermal conversion efficiency, the development of carbon-based nanoparticles has been intensively investigated, while the limitation of unsatisfactory cellular internalization impedes their further clinical application. Herein, we report a novel strategy for fabrication of Fe₃O₄ yolk–shell mesoporous carbon nanocarriers (Fe₃O₄@hmC) with monodispersity and uniform size, which presented significantly higher cell membrane adsorption and cellular uptake properties in comparison with common solid silica-supported mesoporous carbon nanoparticles with core–shell structure. Moreover, the MRI performance of this novel Fe-based nanoparticle could facilitate precise tumor diagnosis. More importantly, after DOX loading (Fe₃O₄@hmC-DOX), owing to synergistic effect of chemo–phototherapy, this therapeutic agent exhibited predominant tumor cell ablation capability under 808 nm NIR laser irradiation, both in vitro and in vivo. Our work has laid a solid foundation for therapeutics with hollowed carbon shell for solid tumor diagnosis and therapy in clinical trials.     

A molecular imprinted polymer on the surface of superparamagnetic Fe3O4–graphene oxide (MIP@Fe3O4@GO) for simultaneous recognition and enrichment of evodiamine and rutaecarpine in Evodiae fructus

A composite material (MIP@Fe₃O₄@GO) based on molecular imprinted polymer (MIP), superparamagnetic Fe₃O₄ particles and graphene oxide (GO) was prepared by the chemical coprecipitation method, and used to simultaneously separate and enrich two alkaloids (evodiamine and rutaecarpine) in the extract of Evodiae fructus. The as‐prepared MIP@Fe₃O₄@GO was characterized by Fourier transform infrared spectroscopy (FT‐IR), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). The adsorption kinetics, isotherms, competitive adsorption, and reusability of MIP@Fe₃O₄@GO were also investigated. The results revealed that MIP@Fe₃O₄@GO was sensitive to the magnetic field and could be easily separated using an external magnet; MIP@Fe₃O₄@GO showed good recognition selectivity, as well as simultaneous enrichment and separation abilities for evodiamine and rutaecarpine in the extract of E. fructus with satisfactory recoveries. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44465.     

撞击流-旋转填料床制备纳米Fe3O4颗粒及其对重金属离子的吸附性能

FeCl2×4H2O和FeCl3×6H2O为原料、NaOH为沉淀剂,采用撞击流-旋转填料床制备Fe3O4纳米颗粒,考察了超重力因子、液体流量和反应物浓度对Fe3O4颗粒粒径的影响及其对Pb(II)和Cd(II)的吸附性能. 结果表明,随超重力因子、液体流量及反应物浓度增加,Fe3O4颗粒的粒径减小,最佳制备条件为超重力因子65.32、液体流量60 L/h及FeCl3×6H2O浓度0.321 mol/L,该条件下所制超顺磁性单分散Fe3O4纳米颗粒的平均粒径约为10 nm,饱和磁化强度为60.5 emu/g. Fe3O4纳米颗粒对Pb(II)和Cd(II)吸附过程符合Langmuir吸附等温模型,计算的最大吸附容量分别为30.47和13.04 mg/g.     

Composite Fe3O4/Humic Acid Magnetic Sorbent and its Sorption Ability for Chlorophenols and some other Aromatic Compounds

A composite magnetic sorbent with a relatively high content of humic substances (above 35% of organic carbon) was prepared by co-precipitation of Fe²⁺/Fe³⁺ salts with commercially available alkaline humate concentrate. Magnetite (Fe₃O₄) was identified as the main crystalline phase bearing the magnetic properties of the sorbent. Scanning electron microscope (SEM) images revealed the presence of uniform sub-micron structures on the surface of the sorbent grains. Due to the presence of humic substances, the sorbent exhibited good sorption ability towards low-polarity organic pollutants, namely chlorophenols. The sorption efficiency increased in the order of 4-mono- < 2,4-di- < 2,4,5-trichlorophenol in accordance with growing hydrophobicity of these compounds, confirming a hydrophobic nature of the interactions involved in the sorption process. Similar trends were found in the desorption study utilizing water and methanol as leachants. Some polycyclic aromatic hydrocarbons (naphthalene, anthracene, phenanthrene, fluoranthene, pyrene) were also retained on the sorbent. The chemical composition as well as the main physical characteristics (surface area, phase composition) of the sorbent remained virtually unchanged during the sorption process. The sorbent retained its magnetic properties during the sorption of organic substances from aqueous solutions, which provides an opportunity for its regeneration.     

Magnetic-field-induced Fe3O4@CNTs/PES/SPSf composite membrane for efficient removal of methylene blue by adsorption and catalytic degradation

Novel composite membranes are successfully developed for adsorption and catalytic degradation of methylene blue (MB) by blending Fe₃O₄-coated CNTs (Fe₃O₄@CNTs) nanoparticles in polyethersulfone (PES) and sulfonated polysulfone (SPSf) matrix via nonsolvent-induced phase separation (NIPS) method assisted by magnetic field. Fe₃O₄@CNTs nanoparticles migrate to the separation layer under the induction of magnetic field, thus Fe₃O₄@CNTs/PES/SPSf composite membranes prepared under magnetic field exhibit a better dye removal ability compared with that without magnetic field. The MB removal ratio by Fe₃O₄@CNTs/PES/SPSf composite membrane containing 8 wt% Fe₃O₄@CNTs (M2−M) can reach up to 99% in 30 min under the conditions of 0.25 g composite membrane, 20 mg/L MB, 0.1 mol/L H₂O₂, pH = 3 and 80°C. Furthermore, the composite membranes show excellent recycling performance, as the MB removal capacity remains at 99% even after four cycles.     

Ternary nanocomposite of SiO 2 /Fe 3 O 4 /Multi-Walled Carbon Nanotubes for Efficient Adsorption of Malachite Green: Response Surface Modeling,Equilibrium Isotherms and Kinetics

In the work, synthesis and application of the ternary nanocomposite of SiO2/Fe3O4/multi-walled carbon nanotubes (SFCNT) for adsorptive removal of malachite     

生物质焦油衍生氮掺杂多孔碳负载Co3O4纳米晶的制备及双功能氧反应催化

以生物质焦油活化多级孔碳为骨架,通过一步水热合成同时实现氮掺杂和Co₃O₄纳米粒子负载,获得Co₃O₄@N/C复合催化剂。对比研究结果表明,凭借复合材料中活性Co₃O₄和N掺杂结构之间的协同效应,Co₃O₄@N/C复合催化剂对氧还原（ORR）和析氧反应（OER）均表现出较高的催化活性,ORR和OER启动电位电势差ΔE为0.99V;其中,ORR极限扩散电流密度为-5.10mA/cm²,与贵金属Pt/C相当。此外,Co₃O₄@N/C具有优异的氧还原稳定性,在经3000次循环伏安法扫描后,Co₃O₄@N/C的极限扩散电流密度仍能保持89.9%。这一生物质焦油衍生碳所构筑的N掺杂多孔碳负载Co₃O₄纳米晶复合材料在燃料电池和金属空气电池等领域具有巨大的应用潜力。