Production and characterization of chitosan and alginate multilayer membranes containing copper / Obtenção e caracterização de membranas multicamadas de quitosana e alginato contendo cobre

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Study of membranes has attracted much interest in recent years due to their applicability in areas such as medicine, microelectronics, water treatment, etc. rather than in traditional separation processes. As the application range arises, the need for establishing more elaborated structures also increases. In this context, the present study adapts the layer-by-layer technique for production of micro-scale multilayer membranes. Subsequent incorporation of copper ions is performed n these membranes. Morphological, chemical and crystalline characterizations, besides ion diffusion tests and evaluation of bacteriostatic ability were performed. The chemical analysis showed the interaction between the chains of chitosan and alginate, ensuring the dimensional stability of the membrane. Changes in crystallinity of membranes were also observed, as they became amorphous after the incorporation of copper ions in its structure. EXAFS analysis indicated that these atoms are linked preferentially to oxygen and nitrogen atoms, constituents of alginate and chitosan functional groups, respectively. Moreover, the amount of copper to the membrane caused remarkable changes in its diffusivity, reducing its value in comparison to membranes without copper. The bacteriostatic capacity was significantly influenced by the presence of metal in membranes: the samples with copper, regardless of its composition, provided inhibition of bacterial growth, both for E. coli and for S. aureus, while the untreated control samples showed no bacteriostatic capacity. These results show the potential of using these membranes in applications where this kind of capacity is required

ASSUNTO(S)

membranas (tecnologia) alginate membranes quitosana chitosan cobre alginatos copper

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