Application of halo polyhydroxy polyurethane foam for the extraction of cobalt from cobalamin drugs and urine

Abstract

<p>Polyhydroxy polyurethane sorbent was modified by the addition of halogen atoms to its matrix to produce a new sorbent distinguished by high surface polarity, enhanced capacity, and improved stability in both acidic and alkaline media. Halo polyhydroxy polyurethane foam (X-PPF) was characterized by NMR, FTIR, UV–Vis, Raman spectroscopy, pH_ZCP values, and scanning electron microscopy images. Experimental studies have proven that X-PPFs have a great potential for the extraction and recovery of cobalt ions and this was attributed to the presence of halogen, phenolic, and urethane groups. The pH_ZCP value of X-PPFs was determined to be 0.91 and the maximum metal recovery was achieved at a pH range of 6–7. The kinetics of the process was best described by pseudo-second-order model (<i>R</i>² = 1). Δ<i>H</i>, Δ<i>S</i>, and Δ<i>G</i> values were calculated to be −57.2 kJ mol⁻¹, −172.6 J K⁻¹ mol⁻¹, and −5.8 kJ mol⁻¹, respectively. A perfect isotherm curve with zero intercept (0.002), good correlation (<i>R</i>² = 0.999), and capacity of 246.8 mg g⁻¹ was obtained.</p