Nano-sized graphene oxide as sole surfactant in miniemulsion polymerization for nanocomposite synthesis: effect of pH and ionic strength
Nano-sized graphene oxide as sole surfactant in miniemulsion polymerization for nanocomposite synthesis: effect of pH and ionic strength
复制标题
DOI：
10.1016/j.polymer.2014.06.005
复制
发表时间：
2014-08
期刊：
影响因子：
4.6
通讯作者：
S. H. Man;David Ly;M. Whittaker;Stuart C. Thickett;P. Zetterlund
中科院分区：
文献类型：
--
作者：
S. H. Man;David Ly;M. Whittaker;Stuart C. Thickett;P. Zetterlund
以AIBN为引发剂，以纳米氧化石墨烯（GO）片为表面活性剂（不使用常规表面活性剂），在70℃条件下进行了苯乙烯的微乳液聚合，探讨了pH和离子强度（NaCl浓度）对聚合反应的影响。乳液的pH值对聚合的影响相对较小，相对于pH = 2.4和5.2，在pH = 3.2时得到的粒径分布略窄。离子强度的影响更为显著——适当浓度的NaCl的存在提高了胶体稳定性，缩小了粒径分布。研究结果解释了pH值对氧化石墨烯羧基电离程度的影响以及离子强度对双电层的影响，并对多种应用的聚合物/石墨烯纳米复合材料的合成具有重要意义。
Miniemulsion polymerization of styrene using AIBN as initiator at 70 °C has been performed with nano-dimensional graphene oxide (GO) sheets as surfactant (no conventional surfactants employed) with a view to exploring the effects of pH and ionic strength (NaCl concentration). The pH value of the emulsion exerted a relatively minor influence on the polymerization, with a somewhat narrower particle size distribution being obtained at pH = 3.2 relative to pH = 2.4 and 5.2. The ionic strength had a more significant effect – the presence of a suitable concentration of NaCl resulted in increased colloidal stability and narrower particle size distribution. The results are explained in terms of the effects of pH on degree of ionization of COOH groups of GO and the influence of ionic strength on the electric double layer, and have implications with regards to synthesis of polymer/graphene nanocomposite materials for a variety of applications.