title: Native and structurally modified gum arabic: exploring the effect of the gum's microstructure in obtaining electroactive nanoparticles.
abstract: Electroactive nanoparticles combining gum arabic (GA) and polyaniline (PANI) were prepared by chemical synthesis. The gum consists of highly branched anionic polysaccharides with some protein content. GA was structurally modified by Smith controlled degradation, in order to reduce its degree of branching (GAD), aiming the elucidation of the relationship between the structure and the properties of complex polysaccharides. The modification was studied by SEC, GC-MS, (13)C NMR and colorimetric methods. GAD has lower molecular mass, lower degree of branching and lower uronic acid content. Besides it is enriched in galactose and protein when compared with GA. The obtained composites (GA-PANI and GAD-PANI) were thoroughly characterized. Although the use of both polysaccharides (GA and GAD) produced highly stable electroactive nanoparticles, the best combination of properties was achieved for GA-PANI. The sample GAD was not able to prevent the occurrence of crosslinking between PANI chains, possibly due to its lower microstructural complexity which diminishes the occurrence of hydrogen bonds between the polymers.
authors.affiliation: Grupo de Pesquisa em Macromoléculas e Interfaces, Departamento de Química, Universidade Federal do Paraná-UFPR, CxP 19081, CEP 81531-980 Curitiba, PR, Brazil.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Cornelsen
authors.affiliation: Grupo de Pesquisa em Macromoléculas e Interfaces, Departamento de Química, Universidade Federal do Paraná-UFPR, CxP 19081, CEP 81531-980 Curitiba, PR, Brazil.
authors.forename: Ronaldo C
authors.initials: RC
authors.lastname: Quintanilha
authors.affiliation: Grupo de Pesquisa em Macromoléculas e Interfaces, Departamento de Química, Universidade Federal do Paraná-UFPR, CxP 19081, CEP 81531-980 Curitiba, PR, Brazil.
authors.forename: Marcio
authors.initials: M
authors.lastname: Vidotti
authors.affiliation: Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná-UFPR, CxP 19046, CEP 81531-980, Curitiba, PR, Brazil.
authors.forename: Philip A J
authors.initials: PA
authors.lastname: Gorin
authors.affiliation: Grupo de Pesquisa em Macromoléculas e Interfaces, Departamento de Química, Universidade Federal do Paraná-UFPR, CxP 19081, CEP 81531-980 Curitiba, PR, Brazil; Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná-UFPR, CxP 19046, CEP 81531-980, Curitiba, PR, Brazil.
authors.forename: Fernanda F
authors.initials: FF
authors.lastname: Simas-Tosin
authors.affiliation: Grupo de Pesquisa em Macromoléculas e Interfaces, Departamento de Química, Universidade Federal do Paraná-UFPR, CxP 19081, CEP 81531-980 Curitiba, PR, Brazil. Electronic address: izabel.riegel@ufpr.br.
authors.forename: Izabel C
authors.initials: IC
authors.lastname: Riegel-Vidotti
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D002850:Chromatography, Gel; D055664:Electrochemical Techniques; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006170:Gum Arabic / Q000737:chemistry*; D008027:Light; D008745:Methylation; D008970:Molecular Weight; D009005:Monosaccharides / Q000032:analysis; D053761:Nanocomposites / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D012031:Refractometry; D012542:Scattering, Radiation; D013059:Spectrum Analysis, Raman
chemical_list: D000814:Aniline Compounds; D009005:Monosaccharides; C416807:polyaniline; D006170:Gum Arabic
keywords: Electroactive properties; Gum arabic; Polyaniline nanoparticles; Structural modification