Ali Bilgiç
ABSTRACT This study reports the synthesis and comparative adsorption performance of pillararene‐functionalized sporopollenin microcapsules ( Sp‐P[5]‐PCA ) and their magnetic derivatives ( MSp‐P[5]‐PCA ) for methylene blue (MB) removal from aqueous solutions. The prepared microcapsules were systematically characterized using FTIR, SEM, XRD, EDX, and TGA to elucidate their structural, morphological, and physicochemical properties. The results confirmed that magnetic modification coupled with surface functionalization significantly modified the surface characteristics and crystallinity of the pristine sporopollenin matrix. The effects of solution pH and adsorbent dosage on MB adsorption were investigated, revealing an optimal adsorbent dose of 0.0015 g for both materials. MB removal efficiency increased with increasing pH and reached a maximum in the pH range of 8–9. Kinetic studies demonstrated that adsorption followed the pseudo‐second‐order model for both microcapsules. Isotherm analysis showed a good fit with the linear Langmuir model, yielding high maximum adsorption capacities of 208.33 mg g −1 for Sp‐P[5]‐PCA and 270.16 mg g −1 for MSp‐P[5]‐PCA at 298 K. Thermodynamic parameters indicated a feasible and exothermic adsorption process favored at lower temperatures. The adsorption mechanism involves π–π interactions, hydrogen bonding, and host–guest encapsulation. Notably, magnetic microcapsules retained 69.15% efficiency after ten reuse cycles, demonstrating their sustainability and potential for wastewater remediation.