School of Chemistry and Chemical Engineering, Key Laboratory of Resources Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha 410083, Hunan, China.
Waste Manag. 2013 Dec;33(12):2623-31. doi: 10.1016/j.wasman.2013.09.003. Epub 2013 Sep 29.
Flotation tests of 35 polymer materials were carried out to investigate their floatability modulated by frothers. Results of flotation tests demonstrated that polymer resins and soft PVC showed high floatability, floatability of hard PVC plastics was relatively low and was related to the frothers, and there exists significant difference in the floatability of different post-consumer plastics. Flotation rate of post-consumer plastics varies from 0% to 100%. Furthermore, three-category low-energy surface (LES) was defined based on the hydrophile index of the materials involved in this paper, and an adsorption model was proposed to explain the results of flotation and to discuss the floatability of polymer materials modulated by frothers. Frother molecules are prone to adsorb on the surface of bubble rather than LES at relatively low concentration, bubble adsorbed by frother molecules is prone to approach first-category LES rather than third-category LES, and the structure of liquid film is formed on the first-category LES at large concentration. Floatability of polymer materials modulated by frothers is further discussed: frothers increase the floatability of the first-category LES but decrease the floatability of the third-category LES, while the floatability of the second-category LES is related to the type of frothers.
进行了 35 种聚合物材料的浮选试验，以研究它们在起泡剂作用下的可浮性。浮选试验结果表明，聚合物树脂和软 PVC 表现出较高的可浮性，硬 PVC 塑料的可浮性相对较低，与起泡剂有关，不同消费后塑料的可浮性存在显著差异。消费后塑料的浮选率从 0%到 100%不等。此外，根据本文涉及材料的亲水指数，定义了三类低能表面（LES），并提出了一个吸附模型来解释浮选结果，并讨论了起泡剂对聚合物材料可浮性的调节。在较低浓度下，起泡剂分子更容易吸附在气泡表面而不是 LES 上，被起泡剂分子吸附的气泡更容易接近第一类 LES 而不是第三类 LES，并且在较大浓度下在第一类 LES 上形成液膜结构。进一步讨论了起泡剂对聚合物材料可浮性的调节作用：起泡剂提高了第一类 LES 的可浮性，但降低了第三类 LES 的可浮性，而第二类 LES 的可浮性与起泡剂的类型有关。
