Controlled Synthesis of Gold Nanoparticles in Copolymers Nanomolds by X-ray Radiolysis
We show by X-ray and neutron small-angle scattering that gold nanoparticles with controlled sizes and morphologies can be obtained by the metallic reduction of AuCl4- ions trapped in 3D organic molds by X-ray radiolysis. The molds are spherical frozen micelles of polystyrene-b-poly(dimethylaminoethy...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 36(2020), 22 vom: 09. Juni, Seite 6132-6144 |
|---|---|
| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2020
|
| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article |
| Zusammenfassung: | We show by X-ray and neutron small-angle scattering that gold nanoparticles with controlled sizes and morphologies can be obtained by the metallic reduction of AuCl4- ions trapped in 3D organic molds by X-ray radiolysis. The molds are spherical frozen micelles of polystyrene-b-poly(dimethylaminoethyl methacrylate) (PS-b-PDMAEMA) block copolymer in acidic aqueous solution with a PS spherical core surrounded by a corona of PDMAEMA chains in good solvent. The behavior of micelles is controlled by the [AuCl4-]/[DMAEMA] ratio RAuCl4-/DMAEMA. At low gold concentration, AuCl4- ions condense on the positively charged DMAEMA moieties without changing the behavior of the PDMAEMA chains. At intermediate gold concentration, the ions induce a progressive contraction of the corona's chains and dehydration of micelles. At large gold concentration, the corona becomes a fully dry phase loaded with gold ions, which induces micelle aggregation. Radiolysis of the solution by an intense X-ray beam produces different types of gold nanoparticles with respect to RAuCl4-/DMAEMA and irradiation time. At RAuCl4-/DMAEMA = 0.033, irradiation produces in the first step gold clusters in the micelle corona which in the second step merge to form nanoparticles of a similar size to that of the micelle. Conversely, at RAuCl4-/DMAEMA = 0.33, micelles do not operate as templates but only as nucleation zones and large nanoparticles grow outside the micelles |
|---|---|
| Beschreibung: | Date Revised 09.06.2020 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/acs.langmuir.0c00554 |