Park Seok Ho, Kim Jin-Chul
Department of Medical Biomaterials Engineering, College of Biomedical Science and Institute of Bioscience and Biotechnology, Kangwon National University, 192-1, Hyoja 2 dong, Chuncheon, Kangwon-do 200-701, Korea.
Polymers (Basel). 2020 Feb 24;12(2):498. doi: 10.3390/polym12020498.
Oxidation-responsive emulsions were obtained by stabilizing mineral oil droplets using amphiphilic poly(vinyl pyrrolidone-co-allyl phenyl sulfide) (P(VP-APS)). H nuclear magnetic resonance (NMR) spectroscopy revealed that P(VP-APS) whose APS content was 0%, 3.28%, 3.43% and 4.58% were successfully prepared by free radical reaction and the sulfide of APS was oxidized by HO treatment. X-ray Photoelectron Spectroscopy (XPS) also disclosed that the sulfide of APS was oxidized to sulfone by the oxidizing agent. The optical density of copolymer solutions and the interfacial activity of the copolymers markedly decreased by HO treatment possibly because the sulfide of APS was oxidized and the amphiphilicity of the copolymers were weakened. The increase rate of the oil droplet diameter of the emulsions was outstandingly promoted when HO solution (10%, v/v) was used as an aqueous phase. The phase separation of the emulsions was also expedited by the oxidizing agent. The oxidation of APS and the weakened interfacial activity were thought to be a main reason for the demulsification of P(VP-APS)-stabilized emulsions.
通过使用两亲性聚（乙烯基吡咯烷酮 - 烯丙基苯基硫醚）（P(VP - APS)）稳定矿物油滴获得了氧化响应乳液。氢核磁共振（NMR）光谱表明，通过自由基反应成功制备了APS含量为0%、3.28%、3.43%和4.58%的P(VP - APS)，并且APS的硫化物通过HO处理被氧化。X射线光电子能谱（XPS）也表明，APS的硫化物被氧化剂氧化为砜。HO处理使共聚物溶液的光密度和共聚物的界面活性显著降低，这可能是因为APS的硫化物被氧化且共聚物的两亲性减弱。当使用HO溶液（10%，v/v）作为水相时，乳液油滴直径的增加速率显著提高。氧化剂也加速了乳液的相分离。APS的氧化和界面活性的减弱被认为是P(VP - APS)稳定乳液破乳的主要原因。
