超声场中高分子乳液稳定性与多孔材料结构的调控机理研究  

Modulation Mechanisms of Polymeric Emulsion Stability and Porous Material Architecture within Ultrasonic Fields

作　　者：朱先念 陈芳[1] 翟薇[1] 魏炳波[1] Zhu Xiannian Chen Fang Zhai Wei Wei Bingbo(School of Natural and Applied Sciences, Northwestern Polytechnical University, Xi＇an 710129)

机构地区：[1]西北工业大学理学院,西安710129

出　　处：《化学学报》2017年第9期878-883,共6页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.51327901;51571164);陕西省科技新星项目(No.2016KJXX-85);陕西省自然科学基金面上项目(No.2016JM2023);陕西省科技统筹创新工程重点实验室资助项目~~

摘　　要：采用星型聚合物POSS-(PMMA)8作为乳化剂兼成膜基质,使用超声乳化法制备w/o型聚合物乳液,制备的乳液液滴初始直径受超声功率调控,阐明了超声功率对液滴直径大小的作用规律.结果表明乳液液滴直径呈双峰分布,且随超声功率的增大液滴直径增大.通过改变水相离子浓度制备聚合物乳液,得到的乳液液滴直径10μm左右且单分散性好,并发现随超声功率增大乳液的絮凝程度增大.探索了超声功率对乳液失稳机制的影响,当超声功率低于750 W时,奥氏熟化是乳液失稳的主要机制.通过浸渍法制备以玻璃纤维为基底的多孔膜材料,发现多孔材料的孔径变化与对应乳液的液滴直径变化基本一致.本研究证实了通过改变超声功率可以调控乳液的液滴直径,然后利用乳液模板法能获得结构和形貌可控的多孔材料.Ultrasonic emulsification has received great attention recently due to the great potential of tuning the emulsion droplets size compared to the traditional homogeneous mixing method. In this study, a series of polymeric emulsions were prepared by ultrasonic emulsification approaches. The relationships between ultrasonic power, emulsion destabilization mechanism and structure morphology of macroporous polymer material were studied. The water in toluene emulsion was prepared by mixing the polymer POSS-（PMMA）8 toluene solution（10 mg·m L^（-1）） and water or Na_2CO_3 aqueous solution（0.1 mol·L^（-1）） through different ultrasonic powers. The volume ratio of water/toluene was remained as 50∶50. The evolution of emulsion droplets diameter distribution over time was analyzed based on optical microscopy data. The initial droplets diameter increased with the increase of ultrasonic power, and all emulsion droplets diameter distributions followed the diauxie curve. By changing the ion concentration in aqueous solution, excellent monodisperse emulsions with droplets diameter around 10 microns were acquired. It was found out that flocculation degree of emulsions prepared with Na_2CO_3 aqueous solution was increased with increasing of ultrasonic power. The relationship between ultrasonic power and emulsion stability was clarified by fitting the emulsion droplets diameter variation as the function of time. When ultrasonic power was below 750 W, Ostwald ripening dominated the instability mechanism of emulsion. Once the ultrasonic power achieved to 1000 W, the instability mechanism of emulsion was attributed to Ostwald ripening and coalescence at the same time. The macroporous polymer materials with adjustable pore diameter were prepared by dipping the glass fiber into salt containing emulsions. In this approach, POSS-（PMMA）8 not only acted as emulsifier during emulsion preparation, but also treated as the skeleton of porous materials. The droplet-size of emulsions was monitored by changing ultrasonic powe

关 键 词：超声 乳化 高分子乳液 乳液模板法 多孔材料 

分 类 号：O648.23[理学—物理化学] TB383.4[理学—化学]