Understanding kinetics and thermodynamics of the interactions between amitriptyline or eosin yellow and aminosilane-modified cellulose

A new adsorbent matrix (Cel-SiN) for the adsorption of the dye eosin yellow (EY) and the drug amitriptyline (AMI) from aqueous media has been synthesized. The Cel-SiN matrix was obtained via chemical modification of cellulose with (3-aminopropyl)trimethoxysilane. Successful modification was confirmed using Fourier transform infrared (FTIR) and C-13 and Si-29 solid state nuclear magnetic resonance (SSNMR) spectroscopies, thermal analysis (TG/DTG), X-ray diffraction (XRD), and elemental analysis. The effects of pH, contact time, concentration, and temperature were evaluated in batch adsorption tests. Cel-SiN efficiently adsorbed AMI and EY in aqueous media, with maximum adsorption capacities of 92.28 +/- 1.34 mg g(-1) for AMI (pH = 7, time = 240 min, and temperature = 318 K) and 61.0 +/- 0.36 mg g(-1) for EY (pH = 5, time = 80 min, and temperature = 298 K). The adsorption process occurs mainly via hydrogen bonding interactions for AMI and electrostatic interactions for EY.