ABC triblock copolymer-stabilized gold nanoparticles for catalytic reduction of 4-nitrophenol

Dai, Yu; Li, Yong; Wang, Shengping

doi:10.1016/j.jcat.2015.06.006

Cited by 52 publications

(32 citation statements)

References 38 publications

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“…To ensure uniformity in all the catalytic experiments, the concentration of AuNPs is maintained at 8 nM, which is calculated based on their SPR band intensity and molar extinction coefficient of 2.18 × 10 8 M −1 cm −1 . Complete reduction of 4‐nitrophenol to 4‐aminophenol occurs in just two minutes at this concentration as can be seen in the absorption spectra showing complete disappearance of the band at 400 nm, which is very fast compared to some of the reported work …”

Section: Resultsmentioning

confidence: 77%

Modulating the Catalytic Activity of Gold Nanoparticles through Surface Tailoring

Satapathy

Mohanta

2016

ChemistrySelect

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The present work describes the catalytic activity of gold nanoparticles towards the reduction of 4‐nitrophenol and their modulation through surface tailoring using various organic ligands. One step protocol is used to prepare CTAB capped gold nanoparticles of size 15 ± 2 nm and the catalysis reaction using these particles simultaneously follow both zero‐order and first‐order reaction kinetics. The zero‐order rate constant, k0=0.418 mol lit−1 min−1 and first‐order rate constant, k1=0.938 min−1 is achieved just by using 8 nM of gold catalyst. On the other hand citrate capped gold nanoparticles of similar sizes (13 ± 3 nm) follow only the first‐order kinetics with k1=0.243 min−1, which is about four times less compared to CTAB capped gold nanoparticles. Moreover, the reaction kinetics is changed to zero‐order rate with k0=0.345 mol lit−1 min−1 simply by replacing citrate with CTAB on the gold nanoparticles surface. On the other hand, replacing the citrate with PVP on the nanoparticles surface, the reaction rate still follows the first‐order kinetics, but with two‐fold increase in the rate constant with k1=0.587 min−1. Further, silica coating of the CTAB capped gold nanoparticles and their use as catalyst for 4‐nitrphenol reduction exclusively follows the zero‐order kinetics with k0=0.305 mol lit−1 min−1 and are better recyclable upto five cycles without affecting their conversion efficiency.

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Section: Resultsmentioning

confidence: 77%

Modulating the Catalytic Activity of Gold Nanoparticles through Surface Tailoring

Satapathy

Mohanta

2016

ChemistrySelect

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“…One of the classical categories, PEO‐based ABC triblock polymers have been summarized for their synthetic complexity and application benefits for controlled drug delivery . PEO‐based ABC triblock polymers, e.g., poly(ethylene oxide)‐ b ‐poly(2,3‐dihydroxypropyl methacrylate)‐ b ‐poly[2‐(diisopropylamino) ethyl methacrylate] (PEO‐PDHPMA‐PDPAEMA), poly(ethylene glycol)‐ b ‐linear polyethylenimine‐ b ‐poly(ε‐caprolactone) (PEG‐PEI‐PCL), poly(ethylene glycol)‐ b ‐poly( N ‐isopropylacrylamide)‐ b ‐poly((3‐acrylamidopropyl) trimethyl ammonium chloride), (PEG‐PNIPAM‐PN), and poly(ethylene oxide)‐ b ‐poly(2‐vinyl pyridine)‐ b ‐polystyrene) (PEO‐P2VP‐PS) have also been used as the stabilizers of AuNPs. For instance, Liu and co‐workers reported amphiphilic triblock polymer poly(ethylene oxide)‐ b ‐poly(lipoic acid 2‐hydroxy‐3‐(methacryloyloxy)‐propyl ester‐ co ‐glycidyl methacrylate)‐ b ‐polystyrene (PEO‐P(LAMP‐GMA)‐PS) for binding AuNPs in the middle block, as shown in Figure .…”

Section: Amphiphilic Polymers For Stabilizing Colloidal Aunpsmentioning

confidence: 99%

Recent Advances in Amphiphilic Polymers as the Stabilizers of Colloidal Gold Nanoparticles

Dai

Zhang

2018

Macro Materials & Eng

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Gold nanoparticles (AuNPs) exhibit high catalytic activity as catalysts and have potential applications in biomedicine. To prevent the aggregation of colloidal AuNPs, the stabilizers including organic small molecules, organic ligands, inorganic ligands, and polymers, are necessary to be added in the synthesis of colloidal AuNPs. Among these stabilizers, amphiphilic polymers have attracted significant attention from scientists in the development of polymerization and modification methods. To date, numerous efforts are employed to develop amphiphilic polymers as the stabilizers of colloidal AuNPs but are not well‐summarized yet. In this review, four parts (amphiphilic linear polymers, amphiphilic graft polymers, amphiphilic hyperbranched polymers, and amphiphilic dendrimers) according to the polymer architectures will be discussed. Comprehensive understanding of amphiphilic polymers that are used for stabilizing colloidal AuNPs is provided.

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“…Similar results have also been found in other research systems. 41,62,74 As is known, the metal NPs catalyze this reaction by facilitating electron relay from the donor BH 4 À to acceptor 4-NP to overcome the kinetic barrier. 62 The rate of electron transfer at the metal surface can be inuenced by two aspects:…”

Section: Synthesis Of Block Copolymer-stabilized Au Npsmentioning

confidence: 99%

“…Previous studies have shown that the gold nanoparticles of about 8 nm in diameter exhibited a relatively high catalytic efficiency. 41,62,74,75 Therefore, the block copolymer P1 can be used as a stabilizer in the preparation of Au NPs@P1 (MR ¼ 1/2) with a high catalytic activity for the reduction of 4-NP by NaBH 4 . The PNIPAM chains in the block copolymers can change their position with the shrinking and extension of the PNIPAM chains under thermal stimuli.…”

Section: Synthesis Of Block Copolymer-stabilized Au Npsmentioning

confidence: 99%

Facile synthesis of thermo-responsive episulfide group-containing diblock copolymers as robust protecting ligands of gold nanoparticles for catalytic applications

Wang

Liu

et al. 2016

RSC Adv.

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We herein report the synthesis of well-defined novel thermo-responsive diblock copolymers, poly(N-isopropylacrylamide-co-2,3-epithiopropyl methacrylate)-block-poly(poly(ethylene glycol) methyl ether methacrylate) P(NIPAM-co-ETMA)-b-P(PEGMA), bearing an episulfide moiety as a ligand via reversible addition fragmentation chain transfer (RAFT) polymerization, followed by assembly into micelles in aqueous solution. The diblock copolymer-stabilized gold nanoparticles (Au NPs@P) could be further obtained by a Au 3+ -induced episulfide opening reaction and in situ reduction of HAuCl 4 . The block copolymer played a great role in the stabilization of Au NPs. These Au NPs@P were employed as an efficient catalyst and presented excellent catalytic activity to reduce 4-nitrophenol to 4-aminophenol.The content of PETMA segments, different ratios of Au atoms to sulfur atoms (MRs) of Au NPs@P1 and the dosage of catalytic carriers and reductants had varying degrees of influence on the catalytic activity.It was found that the catalytic activity of Au NPs@P increased with the decreasing content of PETMA segments. The size of the diblock copolymer-stabilized Au NPs also increased and the catalytic activity became higher with the increase of the MRs. The Au NPs@block copolymer with PNIPAM blocks also exhibited excellent temperature-responsive behavior for the catalytic reduction of 4-nitrophenol.

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ABC triblock copolymer-stabilized gold nanoparticles for catalytic reduction of 4-nitrophenol

Cited by 52 publications

References 38 publications

Modulating the Catalytic Activity of Gold Nanoparticles through Surface Tailoring

Modulating the Catalytic Activity of Gold Nanoparticles through Surface Tailoring

Recent Advances in Amphiphilic Polymers as the Stabilizers of Colloidal Gold Nanoparticles

Facile synthesis of thermo-responsive episulfide group-containing diblock copolymers as robust protecting ligands of gold nanoparticles for catalytic applications

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