【作者】 翟雪如； 辛霞； 谭业邦； 徐桂英；

【Author】 Xueru Zhai;Xin Xia;Yebang Tan;Guiying Xu;Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education;

【机构】 山东大学胶体与界面化学教育部重点实验室；

【摘要】 聚氧乙烯（PEO）-聚氧丙烯（PPO）嵌段聚醚是一类重要的非离子型两亲分子,在选择性溶剂中可以自组装成多种形貌的介观结构。由于PEO-PPO嵌段聚醚具有良好的界面吸附能力、生物相容性和环境友好性,被广泛应用于洗涤、润湿、分散、消泡、破乳等领域。PEO-PPO嵌段聚醚的聚集行为不但对自身分子特征、浓度、温度以及pH等因素具有强烈的依赖性,同时还受溶剂和添加剂等因素的影响。目前国内外对PEO-PPO嵌段聚醚的聚集行为及相关应用的研究主要集中在线型结构的嵌段聚醚,而对支状聚醚的报道相对较少。我们课题组已研究了一系列支状嵌段聚醚聚集行为,发现它们在碳纳米管分散、原油破乳、纳米材料合成等应用方面具有优越的性能[1-3]。本文采用Langmuir-Blodgett（LB）膜天平测量了七支状PEO-PPO-PEO嵌段聚醚（AE73,结构如图1所示）在纯水及CaCl₂、MgCl₂、NaCl、NaI和NaSCN五种无机盐亚相表面的π-A等温线,制备了AE73在以上亚相表面的LB单层膜,并通过原子力显微镜及接触角测量对LB膜的形貌和性质进行了简单表征。结果表明,AE73分子在气/液界面上形成的界面膜属于液态扩张膜,可压缩性较强。AE73在NaCl、MgCl₂和CaCl₂亚相表面的界面膜更加凝聚,NaI与NaSCN的加入则使AE73界面膜变得相对扩张。AE73在纯水和无机盐亚相表面的平均分子极限占据面积由小到大排列顺序为NaCl<CaCl₂<MgCl₂<纯水<NaI<NaSCN。AE73在盐析型无机盐亚相表面形成的聚集体之间易发生粘连,在盐溶型无机盐亚相表面易形成分散的圆形聚集体且数量较少。无机盐的加入均可以使AE73的LB膜厚度增大,但增厚的机理有所不同。更多还原

【Abstract】 Poly（ethylene oxide）-poly（propylene oxide）（PEO-PPO） block polyethers are important nonionic Amphiphiles. They can form multiple mesoscopic aggregates in selective solvent. PEO-PPO block polyethers have good interfacial adsorption ability, biocompatibility and environment-friendliness, they are widely applied in fields of deterging, wetting, dispersing, defoaming, demulsification and used as annexing agent in cosmetics, pharmaceuticals and food. The aggregation behavior of PEO-PPO polyethers are not only influenced by molecular character, concentration, temperature and pH（for the polyethers with an amine moiety）, but also by solvent and additive. The aggregation behavior of PEO-PPO polyethers in aqueous solution can be significantly affected with the addition of inorganic salt, alcohols, organic solvents, ionic liquids and surfactants. In this paper, the π-A isotherms of AE73, which the molecular structure of AE73 is illustrated in Fig. 1, on subphases of pure water and aqueous salt solution were measured by a Langmuir-Blodgett（LB） film balance, the LB monolayer films were prepared on the above subphases and then transferred onto solid substrates. The LB films were characterized by atomic force microscopy and contact angle measurements. The results show that the AE73 molecules form a liquid expansion film at air/water interface, which has a strong compressibility. The interfacial films of AE73 are more condensed in presence of NaCl, MgCl₂ and CaCl₂, while they are relatively more expansive on subphases of NaI and NaSCN aqueous solution. The average limiting areas of AE73 molecules on different subphases increase in the order of NaCl<CaCl₂<MgCl₂<pure water<NaI<NaSCN. The aggregates of AE73 formed on subphases of "salting out" salt solution usually adhere to each other to form web-like aggregates, however, those formed on "salting in" salt solution are usually disk-like and distribute scatteredly. The thickness of the LB film will increase with the addition of salts, but the mechanisms are different for salts with different types.更多还原