物理化学学报 >> 2016, Vol. 32 >> Issue (5): 1214-1220.doi: 10.3866/PKU.WHXB201602176

研究论文 上一篇    下一篇

支链化甜菜碱和阳离子表面活性剂在聚甲基丙烯酸甲酯表面的吸附及其润湿性质

吴伟1,刘丹丹2,徐志成2,宫清涛2,黄建滨3,张磊2,*(),张路2,*()   

  1. 1 中国石化胜利油田分公司油气开发管理中心,山东东营257001
    2 中国科学院理化技术研究所,北京100190
    3 北京大学化学与分子工程学院,北京100871
  • 收稿日期:2015-12-23 发布日期:2016-05-07
  • 通讯作者: 张磊,张路 E-mail:zl2558@163.com;luyiqiao@hotmail.com
  • 基金资助:
    国家科技重大专项(2016ZX05011-003)

Adsorption and Wettability of Branched Betaine and Cationic Surfactants on a Poly(methyl methacrylate) Surface

Wei WU1,Dan-Dan LIU2,Zhi-Cheng XU2,Qing-Tao GONG2,Jian-Bin HUANG3,Lei ZHANG2,*(),Lu ZHANG2,*()   

  1. 1 Oil and Gas Development Management Center of Shengli Oilfield Co. Ltd, SINOPEC, Dongying 257001, Shandong Province, P. R. China
    2 Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
    3 College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
  • Received:2015-12-23 Published:2016-05-07
  • Contact: Lei ZHANG,Lu ZHANG E-mail:zl2558@163.com;luyiqiao@hotmail.com
  • Supported by:
    the National Science and Technology Major Project, China(2016ZX05011-003)

摘要:

利用座滴法研究了两性离子表面活性剂支链十六烷基(聚氧乙烯)n醚羟丙基羧酸甜菜碱(n = 0, 3)和阳离子表面活性剂支链十六烷基(聚氧乙烯)n醚羟丙基季铵盐溶液在聚甲基丙烯酸甲酯(PMMA)表面上的润湿性质,考察了表面活性剂类型、结构及浓度对接触角的影响趋势。研究发现,表面活性剂浓度低于临界胶束浓度(cmc)时,分子通过氢键以平躺的方式吸附到PMMA界面,亲水基团靠近固体界面, PMMA表面被轻微疏水化;表面张力和粘附张力同时降低,导致此阶段接触角随浓度变化不大。浓度高于cmc时,表面活性剂通过疏水作用吸附,亲水基团在外, PMMA表面被明显亲水改性,接触角随浓度升高显著降低。由于具有相同的支链烷基,表面活性剂类型变化和聚氧乙烯基团的引入对接触角影响不大。

关键词: 支链化, 甜菜碱, 阳离子表面活性剂, 聚甲基丙烯酸甲酯, 接触角, 吸附

Abstract:

The wetting properties of the poly(methyl methacrylate) (PMMA) surface by aqueous solutions of the branched zwitterionic surfactants, hexadecanol glycidyl ether glycine betaine and hexadecanol polyoxyethylene(3) glycidyl ether glycine betaine, and branched cationic surfactants, hexadecanol glycidyl ether ammonium chloride and hexadecanol polyoxyethylene (3) glycidyl ether ammonium chloride, were investigated using sessile drop analysis. The influence of the surfactant type, structure, and concentration on contact angle was explored. The results indicate that the PMMA surface was slightly hydrophobically modified with the bulk concentration of surfactant before reaching the critical micelle concentration (cmc) because the adsorbed surfactant molecules are parallel to the substrate surface through hydrogen bonding and the hydrophilic groups are close to the surface. At this stage, the contact angle stays almost constant because of the simultaneous decrease in the surface tension and adhesional tension. However, at concentrations higher than the cmc, the surfactant molecules can adsorb on the PMMA surface through the hydrophobic interactions and the hydrophilic groups toward the bulk phase of solution. This leads to the increase in the hydrophilic character of the PMMA surface. The contact angle decreases dramatically with the increase in bulk surfactant concentration. The variation in the surfactant type and the introduction of ethylene oxide units has little effect on the contact angle because the alkyl chain in these four surfactant molecules is branched in the same way.

Key words: Branch-chain, Betaine, Cationic surfactant, Poly(methyl methacrylate), Contact angle, Adsorption

MSC2000: 

  • O647