Preparation of polymer microspheres with reactive epoxy group and amino groups as stabilizers for gold nanocolloids with recoverable catalysis

Liu

et al. 2015

Colloid Polym Sci

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Superhydrophobic fluorinated polystyrene microspheres were prepared by distillation precipitation polymerization of 4-fluorostyrene (FSt), styrene (St), with divinylbenzene (DVB) as cross-linker in acetonitrile in the absence of any stabilizer. Both the fluorine contents and sizes of the polymeric microspheres were tuned via altering the feed ratio of the fluorinated monomers for polymerization. The films via casting the suspension with fluorinated microspheres exhibited a superhydrophobic behavior with contact angles larger than 150°. The resultant microspheres were characterized by transmission electron microscopy (TEM), Fouriertransform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS), ion chromatography, and contact angle system.

Section: Synthesis Of P(fst-co-st-co-dvb) Microspheressupporting

confidence: 86%

Synthesis of superhydrophobic fluorinated polystyrene microspheres via distillation precipitation polymerization

Liu

et al. 2015

Colloid Polym Sci

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“…To further understand the interaction nature between the amide groups and AuNPs, XPS of Au 4 f and N 1 s were measured for the as-synthesized microspheres as shown in Figure 5. XPS is an effective method for analyzing the interaction at the interface, in particular for the solid material, which has been extensively used to investigate the interaction between the stabilizer and Au particles [27,28]. Figure 5A showed the XPS spectra of N 1 s for SiO 2 @PMBA microspheres (curve a) and SiO 2 @PMBA@Au microspheres (curve b), respectively.…”

Section: Resultsmentioning

confidence: 99%

“…In order to test the catalytic ability and thermoresponsive property, the reduction of 4-NP to 4-AP with NaBH 4 as the reductant was used as the model reaction for the new nanoreactor. An aqueous solution of 4-NP in the presence of excess NaBH 4 has a distinct UV-vis spectral profile with the maximal absorption at 400 nm, while the maximal absorption of 4-AP aqueous solution in the same condition was at 300 nm [28]. When the catalyst was added into the solution, the yellow color of 4-NP faded gradually together with simultaneous decreasing of the absorption peak at 400 nm.…”

Section: Resultsmentioning

confidence: 99%

AuNPs-Based Thermoresponsive Nanoreactor as an Efficient Catalyst for the Reduction of 4-Nitrophenol

Liu

Zhu

et al. 2018

Nanomaterials

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A new AuNPs-based thermosensitive nanoreactor (SiO2@PMBA@Au@PNIPAM) was designed and prepared by stabilizing AuNPs in the layer of poly(N,N’-methylenebisacrylamide) (PMBA) and subsequent wrapping with the temperature-sensitive poly(N-isopropylacrylamide) (PNIPAM) layer. The new nanoreactor exhibited high dispersibility and stability in aqueous solution and effectively prevented the aggregation of AuNPs caused by the phase transformation of PNIPAM. The XPS and ATR-FTIR results indicated that AuNPs could be well stabilized by PMBA due to the electron transfer between the N atoms of amide groups in the PMBA and Au atoms of AuNPs. The catalytic activity and thermoresponsive property of the new nanoreactor were invested by the reduction of the environmental pollutant, 4-nitrophenol (4-NP), with NaBH4 as a reductant. It exhibited a higher catalytic activity at 20 °C and 30 °C (below LCST of PNIPAM), but an inhibited catalytic activity at 40 °C (above LCST of PNIPAM). The PNIPAM layer played a switching role in controlling the catalytic rate by altering the reaction temperature. In addition, this nanoreactor showed an easily recyclable property due to the existence of a silica core and also preserved a rather high catalytic efficiency after 16 times of recycling.

“…Poly(glycidyl methacrylate) (PGMA) microsphere, a polymer advantageous due to easy preparation, active surface for stable immobilization, and easy separation by simple centrifugation after reaction, has been extensively used as a support for noble metals. ,− Nam et al used amine-functionalized PGMA microsphere as the template to fabricate gold crystals with high catalytic activity in converting 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Li et al deposited gold nanoparticles (12 ± 3 nm) on the surface of poly(allylamine hydrochloride)-modified PGMA spheres.…”

Section: Introductionmentioning

confidence: 99%

In Situ Synthesis of Monodisperse Silver Nanoparticles on Sulfhydryl-Functionalized Poly(glycidyl methacrylate) Microspheres for Catalytic Reduction of 4-Nitrophenol

Sun

2015

Ind. Eng. Chem. Res.

Immobilization of silver nanoparticles (Ag NPs) to improve monodispersity and recyclability is crucial for applications in nanocatalysts. Herein, a novel protocol for stabilizer-free, effective, and in situ synthesis of Ag NPs on sulfhydrylfunctionalized poly(glycidyl methacrylate) microspheres (PGMA-SH) was proposed. Ag NPs of 16.97 ± 3.15 nm were successfully grown on PGMA-SH, and remained monodisperse and stable even after sonication, washing, and long-term storage. Moreover, the Ag NPs on PGMA-SH (Ag NPs@PGMA-SH) composite exhibited excellent catalytic activity with an average normalized activity parameter of 4.38 × 10 −3 L·mg −1 ·s −1 toward the reduction of 4-nitrophenol, which was 1.3−132 times higher than reported in literature. The composite can be easily recycled and showed excellent reusability as a conversion higher than 92% was achieved after 10 cycles. Thus, the preparation of Ag NPs@PGMA-SH has been proven a feasible, straightforward, and effective protocol, which would facilitate the applications of Ag NPs in environmental control.