A Novel and Universal Route to SiO₂-Supported Organic/Inorganic Hybrid Noble Metal Nanomaterials via Surface RAFT Polymerization

Abstract

Polymer-encapsulated gold or silver nanoparticles were synthesized and sterically stabilized by a shell layer of poly(4-vinylpyridine) (P4VP) grafted on SiO(2) nanoparticles that acts as a scaffold for the synthesis of hybrid noble metal nanomaterials. The grafting P4VP shell was synthesized via surface reversible addition-fragmentation chain transfer (RAFT) polymerization of 4-vinylpyridine (4VP) using SiO(2)-supported benzyl 9H-carbazole-9-carbodithioate (SiO(2)-BCBD) as the RAFT agent. The covalently tethered P4VP shell can coordinate with various transition metal ions such as Au(3+) or Ag(+) and therefore stabilize the corresponding Au or Ag nanoparticles reduced in situ by sodium borohydride (NaBH(4)) or trisodium citrate. The SiO(2)-supported RAFT agent and the Au or Ag nanoparticles embedded in the P4VP shell layer were characterized by UV-vis spectrophotometer, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and surface-enhanced Raman spectroscopy (SERS).

Attapulgite grafted with polystyrene via a simultaneous reverse and normal initiation atom transfer radical polymerization

“…Attapuglite (ATP) characterized by a porous crystalline structure, also named as palygorskite, is a multifunctional clay mineral with abundant deposit in China. 9 As a kind of hydrated magnesium alumina silicate, ATP has a typical unit cell consisting of [(Mg,Al) 4 (Si) 8 (O,OH,H 2 O) 26 ÁnH 2 O] and natural virgulate micromorphology of compactly aggregated fiber clusters, which was illustrated by Bradley early in 1940. 10 The higher aspect ratio, excellent mechanical strength, thermal stability and low-cost endow ATP a wide application in V C 2015 Wiley Periodicals, Inc. the clay mineralogy, environmental protection and catalyst engineering.…”

“…The preparation of ATP-Cl is further affirmed by the high-resolution Cl2p spectra of ATP-Cl, where the peaks components at about 200 and 201.6 eV are attributed to Cl2p 3/2 and Cl2p 1/2 , respectively. 26 After surface grafting with PS, the intensity of C1s peak increases substantially due to the high carbon content of PS [ Fig. 3(e)].…”

Preparation of core–shell structural surface molecular imprinting microspheres and recognition of l-Asparagine based on [N1111]Asn ionic liquid as template

“…Iniferter has lower initiation activity, ATRP introduces a heavy metal ion into the system, and the NMP initiator is high cost. RAFT polymerization has been proven to be one of the most versatile systems because of its applicability in a wide range of monomers (most monomers are polymerizable by free radical methods) and mild reaction conditions [26]. Thus, RAFT is introduced into the polymerization system to form a neat structural polymer.…”

Preparation, Structure, and Properties of Hybrid Polymer Composites Containing Silver Clusters and Nanoparticles

“…Polymerization of 4-vinylpyridine (4VP) through the RAFT mechanism [50,51] on the surface of SiO 2 particles gives hybrid core-shell nanosystems (Fig. 2) [52]. The high affinity of the nitrogen heterocycles in poly(4VP) [52] and the amide groups in polyacrylamide (poly(AAm)) [53] toward silver provides for efficient immobilization of the SN, formed upon the reduction of the Ag + ions in the polymer layer, on the surface of highly-dispersed SiO 2 .…”

“…2) [52]. The high affinity of the nitrogen heterocycles in poly(4VP) [52] and the amide groups in polyacrylamide (poly(AAm)) [53] toward silver provides for efficient immobilization of the SN, formed upon the reduction of the Ag + ions in the polymer layer, on the surface of highly-dispersed SiO 2 . Hybrid composites with bactericidal properties may also be obtained upon the hybridization of SN stabilized by polystyrenesulfonic acid with CaCO 3 microparticles [54].…”