超疏水磁性Fe3O4_聚多巴胺复合纳米颗粒及其油_水分离

研究论文（DOI:10.6023/A13010137）

超疏水磁性Fe3O4/聚多巴胺复合纳米颗粒及其油/水分离

梁伟欣a, b 王贵元a, b 王奔a, b 张亚斌a, b 郭志光a, b*

（a.湖北大学功能材料绿色制备与应用教育部重点实验室 武汉 430062）

(b.中国科学院兰州化学物理研究所固体润滑国家重点实验室 兰州 730000）

摘要  借助于多巴胺在Fe3O4纳米颗粒表面自聚合形成聚多巴胺薄膜制备出Fe3O4/聚多巴胺（Fe3O4/PD）复合纳米颗粒，利用扫描电子显微镜、透射电子显微镜、X射线衍射仪对样品的形貌、结构及成分进行分析。所制备的颗粒经1H, 1H, 2H, 2H-全氟癸基三氯硅烷化学修饰后表现出超疏水性。有趣的是，超疏水性的Fe3O4/PD纳米颗粒包裹在水滴表面能形成磁性液珠，该液珠(4 µl)在亲水性玻璃表面上的接触角高达164°、滚动角为8°。这些磁性液珠具有良好的机械稳定性和强度，同时研究了外部磁场驱动液珠在平面、曲面、油相中运动。结果表明，磁性液珠能够有效应用于操作微流体装置中的液体输送。水滴在Fe3O4/PD纳米颗粒构成表面的接触角超过150°，而油滴则接近0°，因此，在磁场存在下，这些颗粒能用于吸收油水混合物中的油滴而实现油水分离。此外，回收的Fe3O4/PD纳米颗粒能保持着超疏水性且能再次利用。

关键词 Fe3O4/聚多巴胺纳米复合颗粒; 超疏水; 磁性; 液珠; 油/水分离µ

Superhydrophobic and Magnetic Fe3O4/polydopamine Composite

Nanoparticle and it’s Oil/water Separation

a,b* Liang,Weixin a,b Wang, Guiyuan a,b Wang, Ben a,b Zhang, Yabin a,b Guo, Zhiguang

（a. Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei

University, Wuhan 430062, China）

(b.State Key Laboratory of Solid Lubrication, Lanzhou Insitute of Chemical Physics, Chinese Academy of Sciences, Lanzhou

730000, China）

Abstract A simple approach to creating bifunctional Fe3O4/polydopamine (Fe3O4/PD) composite nanoparticles (NPs) with both superparamagnetic and superhydrophobic properties is presented. The Fe3O4/PD NPs were prepared by virtue of dopamine self-polymerization under mild conditions. Their morphology, structure and composition of nanocomposites were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), respectively. The Fe3O4/PD NPs have uniform sizes in a narrow range of 100-300 nm. Magnetic measurement reveals the Fe3O4/PD NPs are superaramagnetic with saturation magnetization of 73.40emu/g. The as-prepared particles showed superhydrophobicity after being modified by 1H, 1H, 2H, 2H-Perfluorodecyltrichlorosilane. The Fe3O4 particles were also modified by fluoroalkylsilane, and surface composed of the particles present a water contact angle(CA) of 117°. This result indicated that plenty of phenolic hydroxyl groups in polydopamine can conduce to the modification of fluorosilane. In this study, the magnetic liquid marble was obtained by coating some superhydrophobic Fe3O4/PD NPs on a water droplet. The CA of a liquid marble(4 µl) on the hydrophilic slide glass is 164°, and the sliding angle is 8°. Meanwhile, the mechanical strength and robustness of the liquid marbles were demonstrated, The liquid marbles are facilely controlled to move on various surfaces, such as flat surfaces, on curved surfaces, in oil phase under an external magnetic field control. These results indicate that the magnetic liquid marbles are effective application for manipulation of liquid transport in microfluidic devices. The Fe3O4/PD NPs composed surface has a water CA more than 150°, while the CA of oil is nearly 0°. Therefore, these particles

Project supported by the National Nature Science Foundation of China (No. 31070155 and 11172301), “Distinguished Young Scientists Project”of Hubei Province (2012FFA002) and the ‘‘Top Hundred Talents’’ Program of Chinese Academy of Sciences.

can be used to oil/water separation and the separated oil can be easily transported in the water with an external magnetic field. Impotrantly, the particles could be facility retrieved on the basis of their superaramgnetic properties. Moreover, the reclaimed Fe3O4/PD NPs after washed and dried can still be superhydrophobicity and can be reused.

Keywords Fe3O4/polydopamine composite nanoparticles, Superhydrophobic, Magnetic, Liquid marble, Oil/water separation

1.引言

近年来，因受荷叶表面的自清洁特性的启发人们已经制备出大量的仿生超疏水表面

[1-6]，并探索出实现仿生超疏水表面的两种基本途径：一种是在微纳米粗糙表面修饰低表面能物质，另一种是在低表面能的疏水材料表面构筑粗糙结构。然而随着研究的不断深入，研究热点倾向于制备出多功能一体化的仿生超疏水表面，如机械稳定性[7]、透明性[8,9]、润湿转换[10,11]、抗结霜[12]等功能。

控制和输送小体积的液滴对于化学和生物应用中的微型系统具有重要意义[13-16]，但是如何对液滴进行驱动是近年来研究的难点和热点。目前，已有文献报道在外部声音、电、磁等

[17-19]条件下能够对液滴进行控制和驱动。例如，Bormashenko课题组将超疏水聚偏二氟乙烯纳米粉末包裹着铁磁流体液滴在超疏水表面上形成磁性液珠，并在磁场的控制下能够驱动液珠[19]。在本实验中，我们利用多巴胺在温和条件下就能在很多材料表面自发聚合形成聚多巴胺膜的性质[20-23]制备出 Fe3O4/PD复合纳米颗粒，这些颗粒经含氟化合物修饰后呈现出超疏水性。随后，将超疏水性的颗粒包裹在水滴表面形成磁性液珠，并证实这种液珠具有良好的机械性能，且在外界磁场能操纵液滴的定向运动。

另外，随着工业含油废水排放的增加和海洋石油泄漏的频繁发生，如何高效实现油水分

离成为当今研究的热点之一。近年来研究发现，同时兼具超疏水性和超亲油性的固体表面是解决油水分离的有效方法[24-26]例如，我们课题组制备出超疏水的织物和海绵能多次循环利用于油/水分离[26]。本实验所制备的超疏水Fe3O4/PD复合颗粒能吸附在水表面上的油，在磁场的存在下能轻易把水中的油分离出来且在水中输送所分离的油。

2. 实验部分

2.1 Fe3O4微球的制备

根据Li课题组所报道的方法制备出Fe3O4微球[27]，实验过程为：将 FeCl3﹒6H2O(1.35g,

5 mmol)分散在 40 ml的乙二醇中形成澄清透明溶液，接着往透明溶液加入 3.6 g的醋酸钠和 1.0 g聚乙二醇剧烈搅拌 30 min，而后将混合溶液密封在 50 ml反应釜中于200 ℃下放置一夜，经室温冷却后，最后将黑色产物用乙醇清洗3-5次后在 60 ℃下 …… 此处隐藏：10820字，全部文档内容请下载后查看。喜欢就下载吧 ……