高等学校化学学报 ›› 2018, Vol. 39 ›› Issue (9): 2003-2009.doi: 10.7503/cjcu20180167

• 物理化学 • 上一篇    下一篇

烷烃与疏水固体界面超小水滴的制备与生长规律

王瑶1, 王云鹏3, 蔡美荣2, 李焕荣1(), 杨忠强3()   

  1. 1. 中国人民大学化学系, 北京100872
    2. 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
    3. 清华大学化学系有机光电子与分子工程教育部重点实验室, 北京 100084
  • 收稿日期:2018-03-04 出版日期:2018-09-07 发布日期:2018-04-28
  • 作者简介:

    联系人简介: 杨忠强, 女, 博士, 副教授, 主要从事软物质和界面化学方面的研究. E-mail: zyang@tsinghua.edu.cn; 李焕荣, 男, 博士, 副教授, 主要从事有机合成化学方面的研究. E-mail: hrli@ruc.edu.cn

  • 基金资助:
    国家自然科学基金(批准号: 21872078)资助.

Preparation and Growth of Interfacial Ultrasmall Water Droplets Between Alkanes and Hydrophobic Solid

WANG Yao1, WANG Yunpeng3, CAI Meirong2, LI Huanrong1,*(), YANG Zhongqiang3,*()   

  1. 1. Department of Chemistry, Renmin University of China, Beijing 100872, China
    2. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
    3. Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, China
  • Received:2018-03-04 Online:2018-09-07 Published:2018-04-28
  • Contact: LI Huanrong,YANG Zhongqiang E-mail:hrli@ruc.edu.cn;zyang@tsinghua.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.21872078).

摘要:

在“水-油-固”多相体系中, 以液态直链烷烃为油相, 利用自发形成法制备了油-固界面超小水滴, 探究了油相性质对界面超小水滴生长规律的影响并系统表征了界面超小水滴随着时间的生长变化情况. 利用光学显微镜跟踪观察了从正庚烷到正十六烷10种直链烷烃与疏水玻璃构成的油-固界面, 发现油相上层的水分子能穿过油层抵达固体基底表面进而形成超小水滴, 但并未观察到烷烃碳链长度改变引起的超小水滴的规律性变化. 利用具有高分辨率的激光扫描共聚焦显微镜对界面超小水滴的形貌、 位置及生长情况进行了系统表征, 发现界面超小水滴位于油-固界面, 呈现球缺状形貌, 水滴尺寸随着时间的延长而增大, 相近水滴有融合现象, 当水滴与油膜厚度接近时水滴冲破油膜而消失. 结合Imaris软件统计界面超小水滴的总体积, 探究了界面总水量随时间变化情况, 发现界面超小水滴形成过程可分为生长、 稳定和退化3个阶段. 本文扩展了“水-油-固”多相体系自发形成界面超小水滴的油相选择范围, 建立了新模型, 为制备界面超小液滴提供了新方法, 也为微纳尺度润湿理论研究提供了实验依据.

关键词: 界面, 超小水滴, 自发形成, 多相,

Abstract:

In “water-oil-solid” multiphase system, linear alkanes in liquid form were chosen as oil phase, a spontaneous formation method was used to create interfacial ultrasmall water droplets, in order to investigate how the oil properties influence the interfacial ultrasmall water droplet growth and systematically characterize how the interfacial ultrasmall water droplets grow and change over time. First, the oil-solid interface between alkanes(heptane to hexadecane, in total ten linear alkanes) and hydrophobic glass was examined by optical microscope. It was found that water molecules above oil phase can diffuse through oil layer and adsorb to the underlying solid substrate, resulting in the formation of ultrasmall water droplets. However, by varying alkane carbon chain length, the growth of interfacial ultrasmall water droplets did not show obvious regular changes. The morphology, position and growth of interfacial ultrasmall water droplets were characterized by laser scanning confocal microscopy with high resolution. It was observed that the morphology of interfacial ultrasmall water droplets was spherical and localized at the oil-solid interface, the size of water droplets increased over time, and adjacent water droplets showed fusion phenomenon. When the thickness of water droplets and oil film was close, the water droplets disrupted the oil film and disappeared. Based on Imaris software, the total volume of interfacial ultrasmall water droplets was calculated, and the change of water volume over time was explored. It was found that the formation of interfacial ultrasmall water droplets can be divided into three stages: growth, stability and degradation. In this work, a new model was established by extending the oil phase selection range of the interfacial ultrasmall water droplets spontaneously formed in the “water-oil-solid” multiphase system, which provided a new method for the preparation of interfacial ultrasmall droplets and experimental basis for the study of micro-nano scale wetting theory.

Key words: Interface, Ultrasmall water droplet, Spontaneous formation, Multiphase, Oil

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