Study on improving the anion adsorption performance of spandex by using an adsorbent

Spandex fibres have characteristics such as high elongation and high recovery, and are widely used in sports and medical rehabilitation. However, spandex lacks the functional groups for binding with dyes and other anions. When its content is high, “grin-through” can appear, severely limiting its application. To address this issue, this study adopted a self-made spandex adsorbent (SX) and investigated the improvement in the adsorption properties of anionic Isolan dyes under its action. The structure of the adsorbent was studied by performing Fourier transform infrared (FTIR) spectroscopy, H 1 -nuclear magnetic resonance (H 1 -NMR), and mass spectrometry (MS). The mechanism of Spandex adsorption by Isolan Yellow NHF-S under the action of the adsorbent was assessed using chemical thermodynamics and chemical kinetics. The results showed that when the concentration of the adsorbent was 2%, the spandex dyeing depth (K/S value) and the adsorption capacity of Isolan dyes on the spandex increased significantly, which is closely related to the quaternary ammonium cation and long hydrophobic chain segment in the adsorbent structure according to FTIR spectroscopy, H 1 -NMR spectroscopy, and MS. The dyeing kinetics showed that under the action of the spandex adsorbent, the equilibrium adsorption capacity and dyeing rate constant increased, the half-dyeing time decreased, and the adsorption rate and adsorption percentage increased, the adsorption of dyes on the spandex followed pseudo-second-order kinetics, primarily involving chemical adsorption. According to the chemical thermodynamic analysis, the adsorption isotherm of Isolan Yellow NHF-S Spandex was basically consistent with the Langmuir+Freundlich binary adsorption model under the action of adsorbents. Compared with no adsorbent, the dyeing affinity, dyeing heat, and dyeing entropy of the spandex dyed with the Isolan dyestaff under the action of the adsorbent increased, which is significant to expand the range of applications for spandex and provide valuable insights into the use of anionic conductive materials for the preparation of highly elastic flexible sensors. Spandex fibre have obvious advantages in the fields of sports and medical rehabilitation; Spandex lacks functional groups that can combine with conductive materials. To address this issue, Firstly , a self-made Spandex adsorbent SX was adopted in this study, and the improvement in the adsorption properties under the action of this additive was studied using anionic Isolan dyes. Furthermore , the mechanism of Spandex adsorption by Isolan Yellow NHF-S under the action of the adsorbent was assessed using chemical thermodynamics and chemical kinetics. The Spandex dyed with the Solon dye under the action of the adsorbent increased, which is significant to the preparation of highly elastic flexible sensors, as shown in Fig. 1 .