AOUADA, F. A.

MATTOSO, L. H. C.

MOURA, M. R. de

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NANO - 2008,t.,! .'tr!r· .I,..r.' ...t.'IIi. '··9th InternationalConferen·on Nanostructured:/'Materiaisij "IIRIORIORIORIO';'.,o,eL • .,;'; • .,,, • -.... •• ~ ".'h.01 .. 0'6 June 2ClUJ8'Riu,de:,l'ãll'élto- BrazU• • ••.• 1&.. .•.•.. ...,~:•• "~'. '. G • '.6/3/2008 The-P0006 15h15Synthesis and thermal analysis of chitosan nanoparticlesF. A. Aouada'' 2, M. R. de Moura'", L. H. C. Mattoso 2J Chemistry Dept. - UFSCar, São Carlos, São Paulo, Brazil2 National Nanotechnology Laboratory for Agriculture, EMBRAPA-CNPDIA, São Carlos, São Paulo, BrazilNanoparticle synthesis is currently intensely investigated due to its wide variety of potentialapplications [1,2], including food processing, biomedical, optical, and electronic devices. Theuse of natural polysaccharides in the preparation of nanoparticles has attracted attentionbecause of their biocompatibility, biodegradability, and hydrophilic properties. ln this work,chitosan nanoparticles (eS-PMAA) were obtained in different conditions by thepolymerization of methacrylic acid (MAA) in the presence of chitosan (Câ), The forrnationand therrnal stability of eS-PMAA nanoparticles was investigated by nuclear magneticresonance (NMR), differential scanning calorimetry (DSe), and therrnogravimetric analysis(TGA). The complex molar ratios used in the syntheses (in monomer unit) of ncoOH/nNH2are4.8:1 (0.2 in-wt%), 1.9:1 (0.5 in-wt%) and 1.2:1 (0.8 in-wt%). Particle size values of es-PMAA nanoparticles prepared at pH 4.0 for this compositions were 111 ± 4; 82 ± 2 and 60 ±4 nrn, respective1y. For eS-PMAA nanoparticles, the NMR peaks obtained were very close tothose of es and PMAA, showing some shift associated with the forrnation of eS-PMAAnanopartic1es, which is an indication of the interaction between the two systems. The energyrelated to the cleavage of the e1ectrostatic interactions between carboxylate and amide groups(é>H) was based as total area of endotherrnic peak between 180 - 290°C, as suggested in theliterature [3]. Results showed that é>H values are strongly influenced by the amount of es.For nanopartic1es prepared with 0.2, 0.5, and 0.8 (in-wt%) of Cô, the values were 188.5,64.3,and 36.8 J g-l, respective1y. The temperature of degradation (Td) obtained using TGAtechnique for raw es and nanopartic1es with 0.2% of es was 240 ± 2.0 and 143 ± 2.3 "C,respectively. When the amount of es is increased, a pronounced increase in Ta can beobserved. For nanopartic1es prepared with 0.5, and 0.8 (in-wt%) of CS, the values of T, were242 ± 2.5 and 251 ± 2.3 "C, respectively. These results indicate that eS-PMAA nanopartic1esare more therrnally stables than raw es.Work supported by CNPq (proeess: FAA-141695/2005-6 and MRM- 14169412005-0), Embrapa-Brazil (LabexProgram and MPI Projeet) and FINEPILNNA (01.06.0096.00).[I] Y. Wang, X. Wang, G. Luo, and Y. Dai, Bioresouree Teehno!. 99, 3881 (2008).[2] J. Z. Jiang, and C. Cai, J. Colloid Interfaee Sei. 299, 938 (2006).[3] O. Borges, G. Borehard, J.C. Verhoef, A. de Sousa, and H. E. Junginger, Int. J. Pharm. 299, 15 (2005).Corresponding author: Fauze Ahmad Aouada, fauze(áknpdia.embrapa.brKevwords: Natural polymer, biopolymer, nanoparticles forrnation, chitosan, thennal stability.159

Synthesis and thermal analysis of chitosan nanoparticles.

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http://www.alice.cnptia.embrapa.br/alice/bitstream/doc/27115/1/1030001.pdf

Synthesis and thermal analysis of chitosan nanoparticles.

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