title: In situ characterization of silver nanoparticle synthesis in maltodextrin supramolecular structures.
abstract: The use of maltodextrin supramolecular structures (MD SMS) as a reducing agent and colloidal stabilizing agent for the synthesis of Ag nanoparticles (Ag NPs) identified three key points. First, the maltodextrin (MD) solutions are effective in the formation of well-dispersed Ag NPs utilizing alkaline solution conditions, with the resulting Ag NPs ranging in size from 5 to 50 nm diameter. Second, in situ characterization by Raman spectroscopy and small angle X-ray scattering (SAXS) are consistent with initial nucleation of Ag NPs within the MD SMS up to a critical size of ca. 1 nm, followed by a transition to more rapid growth by aggregation and fusion between MD SMS, similar to micelle aggregation reactions. Third, the stabilization of larger Ag NPs by adsorbed MD SMS is similar to hemi-micelle stabilization, and monomodal size distributions are proposed to relate to integer surface coverage of the Ag NPs. Conditions were identified for preparing Ag NPs with monomodal distributions centered at 30-35 nm Ag NPs.
authors.affiliation: Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185, United States. Electronic address: nsbell@sandia.gov.
authors.forename: Nelson S
authors.initials: NS
authors.lastname: Bell
authors.affiliation: University of New Mexico, Center for Microengineered Materials, Department of Chemical and Nuclear Engineering, Albuquerque, NM 87131-0001, United States.
authors.forename: Darren R
authors.initials: DR
authors.lastname: Dunphy
authors.affiliation: Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185, United States.
authors.forename: Timothy N
authors.initials: TN
authors.lastname: Lambert
authors.affiliation: Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185, United States.
authors.forename: Ping
authors.initials: P
authors.lastname: Lu
authors.affiliation: Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185, United States.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Boyle
mesh_terms: D003102:Colloids; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D056004:Molecular Dynamics Simulation; D011134:Polysaccharides / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*
chemical_list: D003102:Colloids; D011134:Polysaccharides; D012834:Silver; C008315:maltodextrin
keywords: In situ; Maltodextrin; Nanoparticles; Silver; Synthesis