An Investigation into the Adsorption Mechanism of Organic Anions on a New Spandex

Abstract

In recent years, there has been significant interest in the study of spandex in high-elasticity sensors. As a new kind of special spandex, dyeable spandex shows strong adsorption capacity for anions. In this study, neutral red G was used as an anion adsorption simulator to study the adsorption mechanism of dyeable spandex on anionic materials. The structure of dyeable spandex was characterized by the modern instrumental analysis method, and the adsorption kinetics and thermodynamics of neutral red G on dyeable spandex were discussed. The results show that the use of mixed amines as chain extenders for dyeable spandex reduced the regularity of molecules and the crystallinity of spandex, which was beneficial to the diffusion adsorption of anions. On the other hand, the number of secondary amino groups increased, providing more adsorption sites under acidic conditions. The adsorption of neutral red G on dyeable spandex satisfied the quasi-second-order kinetics and the Langmuir adsorption model, indicating that dye adsorption on spandex was mainly electrostatic. The diffusion coefficient and equilibrium adsorption capacity of neutral red G on dyeable spandex increased significantly, whereas enthalpy and entropy decreased.

Bio-Based Polyurethane Foams for the Removal of Petroleum-Derived Pollutants: Sorption in Batch and in Continuous-Flow

“…These situations often occur in the initial stages of the sorption process. The second one is the ideal system to describe processes in which chemical interactions represent the driving force with respect to other purely physical processes, such as inclusion, occlusion and diffusion [ 48 , 49 ]. The intraparticle diffusion model is not the rate controlling step for this kind of process because the plot is not linear by the analysis of the correlation coefficients and does not pass through origin and C i ≠ 0 as reported in Table 2 and Supporting Information .…”