Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
595885 | Colloids and Surfaces A: Physicochemical and Engineering Aspects | 2009 | 8 Pages |
Abstract
This investigation explores the chemical modification of cellulose by using a quasi solvent-free procedure, in which the biopolymer was added to molten maleic anhydride, producing a mixture of maleated and fumarated celluloses. Using this pathway mainly surface modifications are observed and more than 2.82 ± 0.05 mmol of modifier per gram of synthesized polymer were obtained. These chemically modified materials were characterized by elemental analysis, solid-state 13C NMR CP/MAS, FTIR, XRD, TG and SEM. The chemically modified polysaccharides are able to adsorb cations. The data were adjusted to a modified Langmuir equation to give 1.75 ± 0.09 and 2.40 ± 0.12 mmol/g of Co2+ and Ni2+, respectively. The net thermal effects obtained from calorimetric titration measurements were also adjusted to a modified Langmuir equation and the enthalpy of the interaction was calculated to give the endothermic values of 0.29 ± 0.02 and 0.87 ± 0.02 kJ/mol for Co2+ and Ni2+, respectively. The thermodynamic data for these systems are favorable for cation adsorption from aqueous solutions at the solid/liquid interface, suggesting the use of this anchored biopolymer for cation removal from the environment.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Colloid and Surface Chemistry
Authors
Júlio C.P. de Melo, Edson C. da Silva Filho, Sirlane A.A. Santana, Claudio Airoldi,