resumo
Inverse gas chromatography (IGC) is a technique for evaluating surface properties. The current work emphasizes the use of IGC to evaluate the surface physicochemical changes during different bacterial cellulose (BC) processing methods as well as upon polyaniline (PANi) incorporation. The processing methods (oven-drying, freeze-drying, and regeneration) caused changes in the BC surface group distribution, where upon freeze-drying and regeneration, a more acidic behavior is obtained, compared to oven-drying (K (b)/K (a) decreased up to 24%). Through freeze-drying, the structural pore preservation increases (54%) the BC porosity, whereas through regeneration, the porosity decreases (23%), compared to BC oven-drying. Regarding the nanocomposites, with PANi incorporation, the overall properties evaluated by IGC were significantly changed. The increases up to 150%, indicating a more reactive surface in the nanocomposites. Also, is observed a sevenfold increase in the K (b)/K (a) and a less porous surface (up to 85%). Hence, the current work highlights the use of IGC as a viable technique to evaluate the physicochemical changes upon different BC modifications.
palavras-chave
INVERSE GAS-CHROMATOGRAPHY; BACTERIAL CELLULOSE; COEFFICIENTS
categoria
Materials Science; Polymer Science
autores
Alonso, E; Faria, M; Ferreira, A; Cordeiro, N
nossos autores
Artur Jorge Faria Ferreira
Professor Coordenadoragradecimentos
The authors would like to thank the Programa Nacional de Re-equipamento Cientifico, POCI 2010, for sponsoring IGC work (FEDER and Foundation for Science and Technology). Moreover, the help of Tomasia Fernandes and Igor Fernandes (Madeira University) in the laboratory work was appreciated.