title: Facile synthesis of silver nanoparticles stabilized by cationic polynorbornenes and their catalytic activity in 4-nitrophenol reduction.
abstract: We report the facile one-pot single-phase syntheses of silver nanoparticles stabilized by norbornene type cationic polymers. Silver nanoparticles (AgNPs) stabilized by polyguanidino oxanorbornenes (PG) at 5 and 25 kDa and polyamino oxanorbornenes (PA) at 3 and 15 kDa have been synthesized by the reduction of silver ions with NaBH4 in aqueous solutions at ambient temperature. The four different silver nanoparticles have been characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and transmission electron microscopy (TEM) for their particle size distributions. Interestingly, PG stabilizes the silver nanoparticles better than PA as evident from our spectroscopic data. Furthermore, the AgNP-PG-5K (5K = 5 kDa) was found to serve as an effective catalyst for the reduction of 4-nitrophenol to 4-aminophenol in the presence of NaBH4. The reduction has a pseudo-first-order rate constant of 5.50 × 10(-3) s(-1) and an activity parameter of 1375 s(-1) g(-1), which is significantly higher than other systems reported in the literature.
authors: Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw, Georgia 30144-5591, United States. bbaruah@kennesaw.edu
authors: Bharat
authors: B
authors: Baruah
authors: Gregory J
authors: GJ
authors: Gabriel
authors: Michelle J
authors: MJ
authors: Akbashev
authors: Matthew E
authors: ME
authors: Booher
mesh_terms: D002384:Catalysis; D002412:Cations / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D015394:Molecular Structure; D009596:Nitrophenols / Q000737:chemistry*; D010084:Oxidation-Reduction; D010316:Particle Size; D010969:Plastics / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D002412:Cations; D009596:Nitrophenols; D010969:Plastics; C071464:polynorbornen; D012834:Silver; C024836:4-nitrophenol