Synthesized cellulose/succinic anhydride as an ion exchanger. Calorimetry of divalent cations in aqueous suspension

• Published in: Thermochimica acta Vol. 524; no. 1; pp. 29 - 34
• Main Authors: Melo, Júlio C.P., Silva Filho, Edson C., Santana, Sirlane A.A., Airoldi, Claudio
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 20-09-2011; Elsevier
• Subjects: Applied sciences; Calorimetry; Cellulose; Cellulose and derivatives; Chemistry; Exact sciences and technology; General and physical chemistry; Ion exchange; Natural polymers; Other ion exchangers: preparations and properties; Physicochemistry of polymers; Solvent-free; Succinic anhydride; Surface physical chemistry; Calorimetry; Ion exchange; Succinic anhydride; Solvent-free; Cellulose; Divalent metal Ions; Adsorption isotherm; Thermogravimetry; lon exchange; X ray diffraction; Solvent free; Preparation; Ion exchanger; Thermal analysis; Cellulose organic ester
• ISSN: 0040-6031; 1872-762X
• DOI: 10.1016/j.tca.2011.06.007

► Synthetic route based on anhydride melting point. ► Cellulosic biopolymer/anhydride as ion exchanger. ► Calorimetry of cation exchange at solid/liquid interface. ► Favorable thermodynamic data of exchanging process.
A synthetic route to a biopolymer/anhydride ion exchanger adds cellulose directly to molten succinic anhydride in a quasi solvent-free procedure. An amount of 3.07
±
0.05
mmol of pendant groups incorporated onto the polymeric structure, which was characterized by elemental analysis, solid state carbon NMR, infrared, X-ray and thermogravimetry. The new polysaccharide is able to exchange cations from aqueous solution through a batchwise methodology, to obtain 2.46
±
0.09
mmol
g
−1 for divalent cobalt and nickel cations. The net thermal effects obtained from calorimetric titrations gave endothermic values of 3.81
±
0.02 and 2.35
±
0.01
kJ
mol
−1. The spontaneity of this ion-exchange process reflected in negative Gibbs energies and also a positive entropic contribution. These thermodynamic data at the solid/liquid interface suggests a favorable ion exchange process for this anchored biopolymer, for cation removal from the environment.