Gold‐Loaded Carbon Nanoparticles from Poly(vinyl alcohol)‐b‐poly(acrylonitrile) Non‐Shell‐Cross‐Linked Micelles

Abstract

Herein we show that a new amphiphilic poly(vinyl alcohol)-b-poly(acrylonitrile) block copolymer dispersed in water can be easily loaded with gold nanoparticles by addition of chlorauric acid followed by reduction by sodium borohydride. After deposition of the so-loaded micelles onto a silicon wafer, followed by an appropriate thermal treatment, the poly(acrylonitrile) core of the micelles is carbonized, while the poly(vinyl alcohol) shell is completely decomposed and volatilized, leading to gold encapsulated in carbon nanoparticles. The morphology of the micelles is maintained during thermal treatment without requiring shell-cross-linking of the micelles prior to pyrolysis.

Antibacterial activity of poly(vinyl alcohol)-b-poly(acrylonitrile) based micelles loaded with silver nanoparticles

“…The solution of PVOH 269 -b-PAN 216 block copolymer in DMSO (a good solvent for both blocks), followed by the addition of silver nitrate aqueous solution ensures the coordination of silver cations with nitrile (-CN) and hydroxyl groups (-OH) arising from PAN and PVOH sequences [26,27]. Micellization of amphiphilic PVOH-b-PAN block copolymers loaded with silver cations was further performed by the slow addition of the dissolved copolymer into water at a controlled rate ($8 ml/h) [24]. Dialysis against water allowed removing the excess of silver nitrate.…”

“…The synthesis of amphiphilic poly(vinyl alcohol)-b-poly(acrylonitrile) (PVOH-b-PAN) copolymers was carried out by preparing first poly(vinyl acetate)-b-poly(acrylonitrile) (PVAc-b-PAN) block copolymer by cobalt mediated radical polymerization (CMRP) [23,25], followed by the selective hydrolysis of the PVAc sequence into PVOH as described elsewhere [24]. The solution of PVOH 269 -b-PAN 216 block copolymer in DMSO (a good solvent for both blocks), followed by the addition of silver nitrate aqueous solution ensures the coordination of silver cations with nitrile (-CN) and hydroxyl groups (-OH) arising from PAN and PVOH sequences [26,27].…”

“…[24]. In brief, PVAc-b-PAN block copolymer (1.0 g) was dissolved in DMSO (5 ml) and added into a solution of potassium hydroxide (4.5 g) in methanol (50 ml, p.a).…”

Tailoring environment friendly carbon nanostructures by surfactant mediated interfacial engineering

“…Block copolymers can have been a good tool to prepare a layer of carbon spheres on substrates [52,53]. Well-defined carbon nanoparticles were developed through pyrolysis of shell cross-linked poly(acrylic acid)-b-poly(acrylonitrile) nanoparticles prepared by micellization and crosslinking of amphiphilic block copolymers in aqueous systems [52].…”

Cobalt‐Mediated Radical Polymerization

“…Despite the low polyolefin content of the final material, 1-octene was used successfully as the comonomers of VAc in the block, and statistical radical polymerization processes were carried out in the presence of cobalt complexes [51]. Moreover, the resumption of styrene polymerization from a PVAc-Co(acac) 2 macroinitiator was also considered, which led to the expected PVAc-b-polystyrene (PS) copolymer; unfortunately, however, a poor control of the styrene block was observed in this case [52]. As CMRP is unable to impart any control over the styrenic and methacrylic monomers, a direct synthesis of the parent block copolymers appeared problematic when using this technique alone.…”