基于AFM胶体探针测量液固界面DLVO力及表面电势

发布时间：2018-01-12 10:23

本文关键词：基于AFM胶体探针测量液固界面DLVO力及表面电势　出处：《实验流体力学》2017年04期 　论文类型：期刊论文

【摘要】：表面电势是微纳流控芯片中流体流动的重要参数。本文介绍了基于AFM胶体探针技术测量液固界面DLVO力并进一步测量表面电势及表面电荷密度的方法。本文改进了胶体探针制作的技术手段,并提出用双探针法测量胶体探针的弹性系数。在0.1~1mM浓度范围内的NaCl溶液中,测量了硅、二氧化硅和氮化硅液固界面双电层内的DLVO力及表面电势。实验结果表明胶体探针技术可以很好地测量液固界面的DLVO力,尤其对静电力指数变化段非常敏感。通过DLVO力曲线可以间接测量表面电势、表面电荷密度等重要参数,是微纳流动及界面属性测量的有效手段。此外,在不同硅基材料表面的测量结果显示了硅烷醇基密度对表面电势起主导作用,可以通过选用不同硅烷醇基密度的材料来有效调控表面电势,从而在硅基材料制作的微流控芯片中调控电动流动的强弱。
[Abstract]:Surface potential is an important parameter of fluid flow in micronanofluidic chip. This paper introduces the method of measuring DLVO force at liquid-solid interface based on AFM colloid probe technology and further measuring surface potential and surface charge density. In this paper, the technique of making colloidal probe is improved. The elastic coefficient of colloidal probe was measured by double probe method. Silicon was measured in NaCl solution with 0.1 渭 m of concentration. The DLVO force and surface potential in the double electric layer of the liquid-solid interface between silicon dioxide and silicon nitride. The experimental results show that the colloidal probe technique can measure the DLVO force of the liquid-solid interface very well. DLVO force curve can indirectly measure surface potential, surface charge density and other important parameters, which is an effective means to measure micro-nano flow and interface properties. The measurement results on the surface of different silicon based materials show that the silane alcohol-based density plays a leading role in the surface potential, and the surface potential can be effectively controlled by selecting the materials with different silane alcohol-based densities. In order to control the strength of electric flow in the microfluidic chip made of silicon-based material.
【作者单位】：大连理工大学机械工程学院;中国科学院力学研究所非线性力学国家重点实验室;
【基金】：自然科学基金项目(11202219) 辽宁省教育厅重点实验室基础研究项目(LZ2014005)
【分类号】：O363.2
【正文快照】： 0引言水和气体、固体间的界面问题无处不在,且在生活及大多数工业领域都十分重要[1]。近年来随着流动尺度的进一步减小,纳流控应运而生,在生物芯片技术、新能源领域及微纳尺度化学分析等方面都有广阔的应用前景[2]。溶液中,固体表面会从溶液中选择性地吸附离子或是固体表面的

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