A smart synthesis of gold/polystyrene core–shell nanohybrids using TEMPO coated nanoparticles

Abstract

We propose a novel route for preparation of core–shell nanostructures based on the macroradicals coupling with nitroxides attached to the nanoparticle surface.

Nitroxide-coated silver nanoparticles: synthesis, surface physicochemistry and antibacterial activity

“…A similar component was observed for tetraoctylammonium bromide-capped gold nanoparticles labelled 50 with 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) derived nitroxides, where it was responsible for less than 1% of total intensity, 26 but it was not observed for the gold nanoparticles covered solely with nitroxides. 28 Therefore, it seems that in systems obtained in this work there is a significant amount of 55 strongly interacting radicals. Combined with the abovementioned increase in linewidth of the singlet signal, as compared with the gold nanoparticles coated with nitroxides, it is an additional support for the hypothesis of lower nanoparticle coverage of silver nanoparticles versus gold ones, but with 60 stronger average interactions between radicals.…”

“…Table 1 summarizes the effects of the reaction conditions (a molar ratio of Ag + to NaBH 4 , a molar ratio of Ag + to DiSS, reaction temperature, NaBH 4 dropping velocity, its concentration 85 in DMF and kind of environment (air or argon) on the synthesis of N-AgNPs. The first attempts at N-AgNPs synthesis have been based on the procedure, recently developed by our group, [26][27][28] for the preparation of gold nanoparticles stabilized with nitroxides. However, proceeding according to this protocol led to 90 aggregation during the synthesis (see Table 1, sample 1).…”

“…26,27 Moreover, we have shown that the nitroxide-coated gold nanoparticles 65 obtained in this way are efficient as mediators in a coupling reactions with free radicals. 28 In this work we describe the synthesis of nitroxide-coated silver nanoparticles (N-AgNPs), the physicochemical characteristic of the obtained material and their antibacterial 70 activity against representatives of Gram-negative bacteria -E. coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Gram-positive strains S. aureus, Staphylococcus epidermidis. 90 As a typical procedure, 38 mg AgNO 3 (223 µmol) has been dissolved in 60 ml of dimethylformamide (DMF), the appropriate amount of DiSS (required to achieve the assumed Ag + : DiSS molar ratio (see Table 1)) was added and the mixture was stirred using magnetic stirrer for 30 minutes.…”

Tunable Fluorophobic Effect Determines Nanoparticle Dispersion in Homopolymers and Block Polymers

“…In both cases, the entropic driving forces determined the final NP placement. We note that yet longer polymers grafted to NP surfaces do enable NP placement away from the block polymer (BCP) interface, however such NPs are mostly composed of stabilizing ligand, e.g., a recent report delivered 10 wt% of the functional NP core with the remaining 90 wt% polymer‐graft . The NP‐core often delivers desirable properties such as mechanical strength, optical response, electronic properties, or catalytic activity.…”

Advanced microemulsion synthesis and characterization of wollastonite (CaSiO3)/polystyrene one-dimensional nanorods with core–shell structures

“…ferric oxide (Bach, Islam, Kim, Seo, & Lim, 2012), using polymers such as poly(methylmethacrylate) (Avolio et al, 2010;Bach et al, 2012;Bhanvase et al, 2011;Chakkalakal et al, 2012;Jiang et al, 2006;Kwon et al, 2011;Liu et al, 2011;Tang et al, 2006;Xie, Li, Liu, & Mai, 2006;Yang & Dan, 2005;Zhu et al, 2008) and polystyrene (Chen et al, 2015;Chevigny et al, 2009;Choi et al, 2007;Chuayjuljit & Boonmahitthisud, 2010;Chuayjuljit & Luecha, 2011;Faridi-Majidi & Sharifi-Sanjani, 2007;Rong et al, 2002Rong et al, , 2005Tang et al, 2007;Zawada et al, 2014;Zeng et al, 2005), have been studied intensively and have received interest in a wide range of industrial fields. Core-shell nanoparticles consisting of an inorganic core and a polymer shell sometimes combine the desired properties of the different constituent materials (Toskas et al, 2011;Zhong & Maye, 2001).…”