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日用化学工业 ›› 2019, Vol. 49 ›› Issue (12): 774-782.doi: 10.3969/j.issn.1001-1803.2019.12.002

• 科技讲座 • 上一篇    下一篇

表面活性剂-纳米颗粒相互作用与智能体系的构建(VI)相同电荷表面活性剂-纳米颗粒相互作用(ii)—— 新型乳状液的稳定机制和智能化

张婉晴1,许茂东1,2,蒋建中1,崔正刚1()   

  1. 1. 江南大学 化学与材料工程学院 合成与生物胶体教育部重点实验室,江苏 无锡 214122
    2. 安微工程大学 生物与化学工程学院,安徽 芜湖 241000
  • 收稿日期:2019-11-21 出版日期:2019-12-22 发布日期:2019-12-24
  • 通讯作者: 崔正刚
  • 作者简介:张婉晴(1995-),女,内蒙古呼和浩特人,硕士研究生,电话:18861822963,E-mail:1025056280@qq.com。
  • 基金资助:
    国家自然科学基金资助项目(21872064);国家自然科学基金资助项目(21573096);国家自然科学基金资助项目(21473080);中央高校基本科研业务费专项资金(JUSRP21937)

Interactions between surfactants and nanoparticles and the construction of smart systems(VI)Interactions between like-charged nanoparticles and surfactants(ii)Stabilization mechanism and intelligentialization of the novel emulsions

ZHANG Wan-qing1,XU Mao-dong1,2,JIANG Jian-zhong1,CUI Zheng-gang1()   

  1. 1. The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical & Material Engineering, Jiangnan University, Wuxi, Jiangsu 214122, China;
    2. School of Biological and Chemical Engineering, Anhui Polytechnic University, Wuhu, Anhui 241000, China
  • Received:2019-11-21 Online:2019-12-22 Published:2019-12-24
  • Contact: Zheng-gang CUI

摘要:

超低浓度的离子型表面活性剂和带相同电荷的纳米颗粒能够协同稳定一种新型O/W型乳状液,其中微量表面活性剂吸附于油/水界面,使油滴表面带电,而纳米颗粒分布于连续相水膜中,增加了油滴间的距离,进而显著降低了油滴间的范德华引力作用。纳米颗粒和油滴都存在一个临界Zeta电位,高于这一Zeta电位,才能确保乳状液的稳定。对纳米颗粒而言,这一临界Zeta电位约为±18 mV,而油滴的临界Zeta电位尚待确定。使用CO2/N2开关型表面活性剂DDMA与纳米氧化铝颗粒组合,可以获得开关性新型乳状液。向乳状液中通入N2,使DDMA转变为中性的烷基脒,即能解除其表面活性和油滴的Zeta电位,导致乳状液破乳;而向体系中通入CO2使DDMA转变为阳离子,则油滴的Zeta电位恢复,又能获得稳定的新型乳状液。对用常规离子型表面活性剂构建的新型乳状液,加入带相反电荷的离子型表面活性剂,与体系中已有的离子型表面活性剂形成离子对,即可消除油滴的Zeta电位,导致乳状液破乳,而再加入微量原有的离子型表面活性剂,则油滴的Zeta电位恢复,又能得到稳定的新型乳状液。由此得到刺激-响应性新型乳状液。本讲座将介绍有关最新的研究进展。

关键词: 新型乳状液, 临界Zeta电位, 开关性, 刺激-响应性, 协同效应

Abstract:

Ionic surfactants and same-charged inorganic nanoparticles can co-stabilize novel O/W emulsions both at extremely low concentration, in which trace amount of the ionic surfactants adsorb at the oil/water interface to endow droplets with surface charge whereas the charged nanoparticles disperse in the aqueous lamellae(continuous phase)which increases the distance between droplets and thus significantly reduces the wan der Waals attraction between droplets. There is a critical Zeta potential for both particles and droplets, above which stable emulsions can be obtained. For nanoparticles the critical Zeta potential is approximately ±18 mV, whereas for droplets it still needs to be determined. Switchable novel emulsion can be obtained by using a CO2/N2switchable surfactant DDMA in combination with positively charged alumina nanoparticles. By bubbling N2 into the emulsion, the DDMA is transformed from cationic to neutral form, and the surface activity of DDMA and the Zeta potential of droplets are eliminated, leading to demulsification. In contrast, by bubbling CO2 into the system to turn DDMA back to cationic form, the Zeta potential of droplets is recovered and the emulsion is re-stabilized. For the novel emulsions co-stabilized by conventional ionic surfactants and same-charged nanoparticles, they can be made stimuli-responsive. By adding an ionic surfactant charged oppositely to the ionic surfactant already present in the emulsion, ionic pairs are formed to eliminate the Zeta potential of droplets, leading to demulsification, whereas by further addition of extra original ionic surfactant, the Zeta potential of droplets is recovered and the emulsion is re-stabilized. This lecture will discuss the most recent research progress relevant.

Key words: novel emulsion, critical Zeta potential, switchable, stimuli-responsive, synergistic effect

中图分类号: 

  • TQ423