物理化学学报 >> 2014, Vol. 30 >> Issue (1): 102-110.doi: 10.3866/PKU.WHXB201311071

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X型与线型嵌段聚醚在空气/水和正庚烷/水界面上聚集行为的比较研究

陈贻建, 刘腾, 翟雪如, 徐桂英   

  1. 山东大学胶体与界面化学教育部重点实验室, 济南 250100
  • 收稿日期:2013-07-11 修回日期:2013-11-06 发布日期:2014-01-01
  • 通讯作者: 徐桂英 E-mail:xuguiying@sdu.edu.cn
  • 基金资助:

    国家自然科学基金(20573067,20873077)和国家科技重大专项(2011ZX05024-004-08)资助项目

Comparative Study on the Aggregation Behaviors of X-Shaped and Linear Block Polyethers at the Air/Water and n-Heptane/Water Interfaces

CHEN Yi-Jian, LIU Teng, ZHAI Xue-Ru, XU Gui-Ying   

  1. Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, P. R. China
  • Received:2013-07-11 Revised:2013-11-06 Published:2014-01-01
  • Contact: XU Gui-Ying E-mail:xuguiying@sdu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20573067, 20873077) and Special Program for Major Research of the Science and Technology, China (2011ZX05024-004-08).

摘要:

通过阴离子聚合方法合成了环氧乙烷(EO)含量和分子量均相同的线型聚氧丙烯(PEO)-聚氧乙烯(PPO) (LPE)和X型聚氧丙烯-聚氧乙烯(TPE)嵌段聚醚,考察了它们在空气/水及正庚烷/水界面上聚集行为的差异. 界面活性的研究结果表明,TPE降低水、正庚烷界面张力的效率和效能均低于LPE的. 聚醚分子在正庚烷/水界面达到吸附平衡的时间比在空气/水表面短. 由于正庚烷分子插入到聚醚吸附层中,聚醚分子可以在正庚烷/水界面上采取更为直立的状态,因此聚醚分子在正庚烷/水界面扩散较快. 聚醚在正庚烷/水界面的扩张弹性高于空气/水表面的.

关键词: X型嵌段聚醚, 界面活性, 界面扩张粘弹性, 界面聚集行为

Abstract:

Linear block polyethers, i.e., poly(ethylene oxide) (PEO)-poly(propylene oxide) (PPO)-PEO (LPE), and X-shaped block polyethers, i.e., PEO-PPO-PEO (TPE), with same EO/PO ratios and molecular masses were synthesized by anionic polymerization. The aggregation behaviors at air/water and n-heptane/water interfaces were systematically studied. The results show that LPE is more efficient at decreasing the surface tension of water and n-heptane than TPE is. The dynamic interfacial tension curves indicate that the lag-time of the adsorption of the block polyethers at the n-heptane/water interface is smaller than that at the air/water surface, implying that immersion of the PO groups in the oil phase is more energetically favorable than immersion in the air phase. The oil molecules can insert into the adsorption layer, and hydrophobic interactions between oil molecules and PO moieties lead to a relatively ordered arrangement of adsorbed polyether molecules. At the n-heptane/water interface, diffusion of the block polyethers is faster than that at the air/water surface. The dilatational elasticity at the n-heptane/water interface is much higher than that at the air/water surface.

Key words: X-shaped block polyether, Interfacial activity, Interfacial dilational viscoelasticity, Interfacial aggregation behavior

MSC2000: 

  • O641