title: Green synthesis of colloidal silver nanoparticles using natural rubber latex extracted from Hevea brasiliensis.
abstract: Colloidal silver nanoparticles were synthesized by an easy green method using thermal treatment of aqueous solutions of silver nitrate and natural rubber latex (NRL) extracted from Hevea brasiliensis. The UV-Vis spectra detected the characteristic surface plasmonic absorption band around 435 nm. Both NRL and AgNO(3) contents in the reaction medium have influence in the Ag nanoparticles formation. Lower AgNO(3) concentration led to decreased particle size. The silver nanoparticles presented diameters ranging from 2 nm to 100 nm and had spherical shape. The selected area electron diffraction (SAED) patterns indicated that the silver nanoparticles have face centered cubic (fcc) crystalline structure. FTIR spectra suggest that reduction of the silver ions are facilitated by their interaction with the amine groups from ammonia, which is used for conservation of the NRL, whereas the stability of the particles results from cis-isoprene binding onto the surface of nanoparticles. Therefore natural rubber latex extracted from H. brasiliensis can be employed in the preparation of stable aqueous dispersions of silver nanoparticles acting as a dispersing and/or capping agent. Moreover, this work provides a new method for the synthesis of silver nanoparticles that is simple, easy to perform, pollutant free and inexpensive.
authors.affiliation: Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirão Preto, SP, Brazil. ederguidelli@pg.ffclrp.usp.br
authors.forename: Eder José
authors.initials: EJ
authors.lastname: Guidelli
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Ramos
authors.forename: Maria Elisabete D
authors.initials: ME
authors.lastname: Zaniquelli
authors.forename: Oswaldo
authors.initials: O
authors.lastname: Baffa
mesh_terms: D000641:Ammonia / Q000737:chemistry; D003102:Colloids / Q000737:chemistry*; D055772:Green Chemistry Technology / Q000379:methods*; D028482:Hevea / Q000378:metabolism*; D007840:Latex / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission / Q000379:methods; D008956:Models, Chemical; D036103:Nanotechnology / Q000379:methods; D010936:Plant Extracts / Q000378:metabolism*; D012408:Rubber; D012834:Silver / Q000737:chemistry*; D012835:Silver Nitrate / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D020349:Surface Plasmon Resonance
chemical_list: D003102:Colloids; D007840:Latex; D010936:Plant Extracts; D012834:Silver; D000641:Ammonia; D012408:Rubber; D012835:Silver Nitrate