超疏水材料制备及其在油水分离中的应用研究进展

仿生界面油水分离材料的研究主要集中在超疏水超亲油材料,其具有高吸油能力和油品回收方便快捷等特性。本文评述了近几年超疏水材料制备及其在油水分离中应用的研究进展。     

超疏水石墨烯/甲醛-三聚氰胺-亚硫酸氢钠共聚物海绵的制备及其在油水分离中的应用

采用两步法合成了石墨烯（GE）改性的超疏水超亲油甲醛-三聚氰胺-亚硫酸氢钠（FMS）共聚物海绵,首先在FMS海绵基质上进行GE原位聚合,然后通过聚甲基苯基硅氧烷构筑超疏水结构。采用FTIR、SEM、TGA、光学接触角测量仪对海绵结构进行表征分析。结果表明,GE成功地修饰了FMS海绵,制备出的GE/FMS共聚物海绵的接触角达158.9°。将GE/FMS共聚物海绵用于油水分离,经20次对机油吸附-解吸附测定后仍能保持稳定的超疏水性质。改性后的GE/FMS海绵具有良好的可重复利用性且对油和有机溶剂具有高度选择吸收性,对氯仿和机油的吸收量分别达到自身质量的约125倍和90倍,对油或有机溶剂的回收率达到87%以上。进一步对油或有机溶剂与水的分离进行了应用模拟,结果表明:改性后的GE/FMS海绵可以高效快速地将油或有机溶剂从水中分离出来,对于投入生产及吸附应用具有实际意义。      

电火花线切割制备超疏水多孔钛及其油水分离的应用

利用电火花线切割的方法制备具有双尺度结构的超疏水多孔钛表面,用于实现油水混合物的分离.以多孔钛为基材,通过电火花线切割的方法在表面加工出阵列微沟槽结构,该表面经过全氟癸基三乙氧基硅烷的低表面能修饰后,制得超疏水多孔钛表面.利用接触角测试仪和电子显微镜等手段对超疏水多孔钛表面进行润湿性测量和形貌特征的分析,利用油水分离器...     

超疏水铜网的制备及其在油水分离中的应用

将铜网浸渍于一定浓度的氯化铜和硫代硫酸钠的混合液中反应一定时间,从而在铜网表面构筑了微米级颗粒粗糙表面,并用一定浓度的正十二硫醇对其进行疏水修饰,制备出了具有超疏水特性的铜网。并探讨了浸渍温度、浸渍时间、浸渍液配比、修饰浓度、修饰时间对铜网疏水性的影响。在浸渍温度50℃,浸渍时间4h,浸渍液配比1∶1,修饰浓度10mmol/L,修饰时间10min的条件下得到了疏水性最好的铜网。用扫描电子显微镜、X射线粉末衍射仪、接触角测量仪对所制备的铜网表面形貌、化学组成、疏水性能进行了表征,并用4种油水混合物探究了所制备铜网的分离效果。结果表明,所制备的铜网具有超疏水性,接触角可达154°,并且成功应用于不同油水混合物的分离,分离效率均在96%以上。     

超疏水复合海绵材料的制备及在油水分离的应用

含油污水的治理已经成为世界性的难题,如何有效分离油水混合物成为亟待解决的问题。本研究通过绿色环保、简单浸蘸的表面修饰法,以三聚氰胺海绵(MS)作为基底材料,选择氧化石墨烯溶液(GO)与聚四氟乙烯浓缩分散液(PTFE)的混合液对MS改性,成功制备出性能优异的超疏水材料(GPMS)。采用X射线衍射仪(XRD),热重分析仪(TG)、傅立叶变换红外光谱仪(FT-IR)和扫描电子显微镜(SEM)对制备的GPMS进行结构、形貌和组分分析,并对其表面浸润性、压缩循环性、选择吸附性能以及连续油水乳浊液分离性能进行了系统研究。结果表明,制备的GPMS具有超疏水性(疏水角可达168°);机械性能优越,可以完成50次压缩循环实验;能够选择性地吸附水上浮油与水下重油,还可对油水乳浊液实现高效分离,是一种具有实际应用价值的含油污水治理材料。     

超疏水超亲油三聚氰胺海绵的制备及其油水分离性能

利用正十二硫醇和氯化铜反应制备十二烷基硫铜,然后将其配制成乙醇悬浮液;将表面涂覆有聚多巴胺的三聚氰胺海绵浸入上述悬浮液中成功制备出超疏水三聚氰胺海绵,并用它来分离油水混合物.采用扫描电镜观察海绵表面形貌,利用接触角测量仪表征其润湿性能,借助红外分光测油仪测定水中含油量.研究结果表明,三聚氰胺海绵表面形成了凹凸不平的微纳米结构,呈超疏水超亲油状态;测得它对水的静态接触角为152°,而油滴能在1 s内被完全吸收.该样品对油水混合物具有良好的分离能力,分离后水中菜籽油含量从约25 g/L降到15.20 mg/L;对同一大豆油水混合物连续分离五次后其含油量可从36.45 mg/L降低至5.12 mg/L.该超疏水海绵具有良好的吸附油的能力,可吸收约自身质量54～77倍的有机溶剂或油品;在重复使用100次后仍能保持145°的接触角和达自身质量68.6倍的吸油能力;在海水中浸泡36 h后仍保持约147°的接触角和73.4倍的吸油能力.     

超疏水吸油性聚二乙烯基苯的制备及其油水分离性能

在我国,水污染已经严重破坏了自然生态环境并危害人体健康,液态油类物质是其中重要的水体污染源。为解决含油污水处理过程中最重要的油水分离问题,本文采用简单易行的溶剂热法低成本合成了具有微米和纳米级粗糙结构的超疏水吸油性多孔性聚二乙烯基苯有机固体材料并对其油水分离性能进行了研究。由于其内部的亲油基链段与油分子可发生溶剂化作用,多孔性聚二乙烯基苯具有吸油速率快、容量大、再生性好,只吸油不吸水等特点,可很好地吸附脱除水中油类有机物,在油水分离方面具有很好的应用前景。     

低成本超疏水棉布的制备及其应用于油水混合物分离的研究

近年来因仿生界面材料特殊的表面效应,将其应用于油/水混合物高效分离领域引起了国内外研究者的极大关注。采用TiO_2和月桂酸对棉布进行表面改性,制备出超疏水/超亲油棉布,其表面水接触角高达156°,通过搭建连续分离装置,可实现油/水混合物的快速、高效、连续分离,且经过20次循环分离,分离效率仍高达94%。超疏水棉布制备工艺简单、成本低廉、环境友好,无需特殊的设备,在海上石油及有机化学品泄漏导致的水污染处理领域具有良好的应用前景。     

超疏水超亲油304不锈钢网的制备及其油水分离性能

目前,用于油水分离的材料成本高,制备工艺复杂且效果较差,针对这一现象,选用304不锈钢网作为基体材料,通过氯化铁溶液刻蚀法获得粗糙表面,随后用十七氟癸基三甲氧基硅烷对该表面进行改性,成功制备出具有优异油水分离特性的超疏水超亲油不锈钢滤网,并对其结构及性能进行了测试表征.结果表明:超疏水不锈钢网与水的接触角达到151°,...     

Synthesis of porous NiFe2O4 microparticles and its catalytic properties for methane combustion

In this paper, we report the obtention of agglomerate porous NiFe₂O₄ microparticles type-spinel with uniform size of 1-2 μm by the oxalic acid co-precipitation method. The structure, morphology and surface of microparticles as-synthesized were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), respectively. Fixed bed reactor test confirmed that the NiFe₂O₄ microparticles exhibit a good catalytic activity for methane combustion with the methane light-off temperature below 350 °C. XPS spectrum revealed that the excellent catalytic activity may be attributed to the surface oxygen vacancies arising from the peculiar inverse spinel structure with octahedral (Oh) site occupied by Fe²⁺ and Ni²⁺ cations.     

Fabrication of porous Al2O3-MgAl2O4 ceramics using combustion-synthesized powders containing in situ produced pore-forming agents

Novel pore-forming agents as well as other starting materials were produced in situ via a solution combustion process and were used to fabricate porous Al₂O₃-MgAl₂O₄ ceramics. The relative fuel-to-oxidant ratios (φ_e) of 1.06, 1.28, 1.49 and 1.70 were achieved by varying the amount of starch in the precursors. Effects of φ_e on the weight percent of the pore-forming agents in the powders, open porosity and Vickers hardness of the as-prepared porous ceramics were investigated. Experimental results revealed that the weight percent of the pore-forming agents in the powders increased significantly_, while porosity of the as-prepared ceramics first increased and then decreased as φ_e rose from 1.06 to 1.70. Meanwhile, pore size distribution became far narrower and the Vickers hardness of the porous ceramics increased as φ_e increased.     

Fabrication of superhydrophobic TPU film for oil-water separation based on electrospinning route

In this work, we described an electrospinning process for creating superhydrophobic thermoplastic polyurethanes (TPU) mat with bead-on-string morphologies. The initially hydrophobic TPU electrospun film presented superhydrophobic trait after treatment with hydrophobic nanosilicas, which was pre-fabricated by refluxing nanosilicas in a toluene solution of hexadecyltrimethoxysilane (HDTMS). The relationship between the microstructures and wettability was also discussed. This superhydrophobic TPU film turned out to be benign materials for separating oil and water mixture. The development of the electrospun process described in this paper, as well as the extension of our method, will no doubt facilitate the achievement of other functional superhydrophobic films for various applications.     

High-pressure modifications of CaAl2O4 and CaGa2O4

The modifications of CaAl₂O₄ and CaGa₂O₄ with the stuffed tridymite structure were examined under high temperatures (600 ～ 1500 °C) and high pressures (10 ～ 40 kb). Calcium monoaluminate CaAl₂O₄ was found to transform to three kinds of high-pressure modifications. The original CaAl₂O₄ (CA-I) changed to the phase CA-II which had m-CaGa₂O₄ type structure with a different array of tetrahedra in the six-membered rings of tetrahedron. The phase CA-II transformed either to the phase CA-IV with CaFe₂O₄ type structure or to an unknown phase (CA-III) under high pressures. The phase CA-IV was obtained under the pressures above 30 kb and at the temperatures above 1000 °C. Calcium monogallate CaGa₂O₄ transformed to the CaFe₂O₄ type structure above 30kb and 700 °C. No phases such as CA-II and CA-III were found. The structural relations among these modifications were discussed.     

Synthesis of nano B2O3/TiO2 composite material as a new solid phase extractor and its application to preconcentration and separation of cadmium

A new solid phase extractor, nano-scale diboron trioxide/titanium dioxide composite material, was synthesized and used for separation and/or preconcentration of trace cadmium ion from various samples. The characterization of the synthesized material was performed by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffractometer methods (XRD). The specific surface area of the material was also determined and found as 3.4 m²/g. Analytical parameters including pH of sample solution, sample volume, flow rate of sample solution, volume and concentration of eluent for the column solid phase extraction (SPE) procedure were examined. The effect of common matrix ions on the recovery of the cadmium has also been investigated and found that they did not interfere on cadmium preconcentration. Under the optimum experimental conditions, preconcentration factor and analytical detection limit were determined as 50 and 1.44 μg/L, respectively. The reusability (stabile up to 100 run) and adsorption capacity (49 mg/g) of the sorbent were excellent. The accuracy of the method was confirmed by analyzing certified reference materials (Tea leaves GBW-07605). The results demonstrated good agreement with the certified values (relative error <10%). The precision of the method was also satisfactory. The recovery of cadmium under the optimum conditions was found to be 96 ± 3% at 95% confidence level. The method was applied for the determination of cadmium in tap water and tea leaves.     

Fabrication of porous TiO2 nanofiber and its photocatalytic activity

Porous TiO₂-based nanofiber was fabricated via a combined electrospinning and alkali-dissolution method. TiO₂/SiO₂ composite nanofiber was firstly prepared by electrospinning and sintering, and then silica was leached out with alkaline solution from the bulk of TiO₂/SiO₂ composite nanofiber to produce porous microstructure. The thermal decomposition and phase structure of the composite nanofiber precursor was investigated with TG/DSC and XRD, and optimal sintering temperature was obtained. SEM-EDX and FT-IR characterization show that most silica can be dissolved out from the composite nanofiber and thus porous nanofiber with excellent microstructure can be spontaneously formed. The effect of composite nanofiber composition on porous microstructure was studied, and it is found that the composite nanofiber with 20wt% silica can produce better porous microstructure compared to those with 10wt% and 30wt% silica. Meanwhile, porous TiO₂ nanofiber with 20wt% silica shows higher degradation efficiency to Congo Red.     

Fabrication and electrochemical characterization of HRP-lipid Langmuir-Blodgett film and its application as an H2O2 biosensor

The formation of horseradish peroxidase-lipid Langmuir-Blodgett film and its applicability as a biosensor have been studied. HRP was spread directly onto the subphase covered with a layer of lipid in LB trough. Our experimental results showed that surface pressure of this film from liquid to solid state ranged between 15 to 25 mN/m. At surface pressure of 25 mN/m, the monolayer was successfully transferred onto the gold surface. In addition, electrochemical properties of this film showed that protein molecules still kept their natural structure and can give a well electrocatalytic activity to H₂O₂. As an H₂O₂ biosensor, this LB film was able to detect concentration of H₂O₂ which were 3 × 10^− 7 M.     

MgAl2O4:Mg荧光粉的合成及其发光性能

用超声辅助聚丙烯酰胺凝胶法合成了MgAl₂O₄:Mg荧光粉。在MgAl₂O₄体系中引入的Mg金属颗粒抑制了MgAl₂O₄相的形成,在900℃及以上的温度烧结MgAl₂O₄:Mg干凝胶粉末,镁颗粒氧化成MgO。Mg金属颗粒的引入使MgAl₂O₄:Mg荧光粉的形貌由细小的纳米颗粒变为方便面型;MgAl₂O₄:Mg荧光粉的颜色由在600℃烧结时的暗棕色变为在800℃烧结时的白色,在1000℃烧结时白色变暗。随着烧结温度的提高MgAl₂O₄:Mg荧光粉的能带先增大后略微减小。引入镁颗粒使荧光光谱中位于395和425 nm的两个荧光峰淬灭,在650、656和680 nm出现三个新的荧光发射峰,且随着烧结温度的提高发光强度减弱。金属颗粒的表面等离子体共振导致MgAl₂O₄主晶格荧光淬灭,缺陷能级使MgAl₂O₄:Mg荧光粉产生了新的荧光发射峰。     

Magnetic and Mössbauer studies of FeNi2BO5 and FeNiBO4

Single crystals of boron ferrites Fe^IIINi^II₂BO₅ and Fe^IIINi^IIBO₄ were grown by CVT method using HCl carrier gas. The measurements of magnetic susceptibility and Fe⁵⁷ Mössbauer effect were performed on the powdered samples in the temperature range from 4.2 K to 295K. FeNi₂BO₅ (FeNiBO₄) exhibits antiferromagnetic transition at T_N=54 K (13 K) giving asymptotic Curie temperature of ?220 K (?900 K) and the Curie constant agrees well with what is expected from Fe³⁺ and Ni²⁺ ions in the compounds. However, Zeeman splitting appears in the Mössbauer spectrum of FeNi₂BO₅ (FeNiBO₄) below ca. 102 K (26 K), far above the T_N. Further, the Zeeman pattern of FeNi₂BO₅ shows the presence of spin relaxation in the temperature range of ca. 94 ～ 107 K, and the quadrupole splitting decreases an order in magnitude and the line width becomes broader compared to the paramagnetic pattern. The origin for these remarkable features are discussed relating to the crystal structures and the magnetic interactions in the compounds.     

Spray-drying technology for the synthesis of nanosized LiMn2O4 cathode material

Spinel LiMn₂O₄ cathode material has been synthesized by a spray-drying method for lithium ion batteries. During the entire process, the as-prepared powders were characterized using TGA/DTA, XRD, FTIR, SEM and TEM. The results showed that this method not only reduces the sintering time to 5 h at 750 °C, but also decreases the average particle size of LiMn₂O₄ powders to the order of nanometers. The electrochemical performance of nanosized LiMn₂O₄ was investigated by the galvanostatic charge-discharge tests. The data indicate that the nanosized LiMn₂O₄ has a specific capacity of about 130 mA h g^− 1 (1/5 C), and at higher rate (1 C), still has good cycling stability.