A simple, inexpensive, one-step synthesis of graphene/PAA-Au nanocomposites was achieved by using polyallylamine (PAA) as a reducing and stabilizing agent. The synthetic process was carried out only in aqueous solution, which is versatile and environmentally friendly. The resulting nanocomposites could be dispersed into water stably without any additional protection by polymeric or surfactant stabilizers. The products were further characterized by UV-visible absorption spectroscopy, transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR) and photoelectron spectroscopy (XPS). The results indicate that graphene sheets played an important role as a support material to increase the active area of Au nanoparticles (AuNPs). And the resulting graphene/PAA-Au nanocomposites film exhibited good electrocatalytical activity towards reduction of both H(2)O(2) and O(2), which showed potential application in electrochemical sensors.
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http://dx.doi.org/10.1016/j.talanta.2011.12.049 | DOI Listing |
Nanomaterials (Basel)
December 2024
Department of Industrial and Information Engineering and Economics, University of L'Aquila, Piazzale E. Pontieri 1, Monteluco di Roio, Roio Poggio, 67100 L'Aquila, AQ, Italy.
The aim of the present paper is to propose an innovative, one-step and sustainable process allowing us to obtain almost 10 kg/week of pure and crystalline simonkolleite nanoparticles (SK NPs) in only 8 min of reaction, working in water, under ambient conditions of pressure/temperature, guaranteeing at the same time low environmental impact and a high yield of NP production. In addition, the obtained NPs can also act as ZnO precursors at ambient temperature, and this result supports the sustainability of the process considering that, generally, the production of ZnO from SK occurred via annealing at high temperatures. The SK NPs appeared pure and crystalline, characterized by a highly uniform hexagonal lamellar feature.
View Article and Find Full Text PDFOrg Lett
December 2024
Strait Institute of Flexible Electronics (SIFE, Future Technologies), Fujian Key Laboratory of Flexible Electronics, Fujian Normal University and Strait Laboratory of Flexible Electronics (SLoFE), Fuzhou 350117, China.
Isothiourea-catalyzed multicomponent cascade reactions are challenging due to the existence of competitive side reactions between multiple reaction partners and intermediates. Herein, we report a practical and efficient protocol for the stereoselective divergent synthesis of pyrazolone-derived β-amino acid esters and β-lactams by isothiourea catalysis. Two distinct reaction pathways are identified, which are controlled by esterification or lactamization of the zwitterionic intermediate.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
December 2024
Key Laboratory of Macromolecular Synthesis and Functionalization (Ministry of Education), Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China; Center of Healthcare Materials, Shaoxing Institute, Zhejiang University, Shaoxing 312000, China. Electronic address:
Polymethacrylate and its derivatives are widely used in food industry and biomedical applications for their plasticity, biocompatibility and optical transparency. However, susceptibility to bacterial growth on their surfaces limits their applications. In this study, linear and branched polyethyleneimine (PEI) molecules were grafted onto poly(ethyl methacrylate) (PEMA) via aminolysis using a simple one-step method to enhance the antibacterial properties of PEMA films.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Guangdong Provincial Laboratory of Chemistry and Fine Chemical Engineering Jieyang Center, Jieyang 515200, PR China; Guangdong Provincial Key Laboratory of Plant Resources Biorefinery, School of Chemical Engineering and Light Industry, Guangdong University of Technology, Waihuan Xi Road 100, Guangzhou, Guangdong 510006, PR China.
Lignin, a renewable and biodegradable polymer, offers a promising alternative to petroleum-based polyols for polyurethane elastomer synthesis. However, its complex structure poses challenges, such as poor dispersibility and reactivity. This study introduces a novel one-step and solvent-free method for synthesizing lignin-containing polyurethane elastomers (SF-LPUes-ONE) with a high lignin substitution rate of at least 30 wt%.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Research Laboratory of Dendrimers and Nanopolymers, Faculty of Chemistry, University of Tabriz, P.O. Box 51666, Tabriz, Iran.
Hydrogels are adaptable substances with a 3D framework able to hold large quantities of water, which is why they are ideal for use in the field of biomedicine. This research project focused on creating a new hydrogel combining carboxymethyl chitosan (CMCS), graphene quantum dots (GQDs), pectin (Pe), and MIL-88 for precise and controlled release of the cancer drug doxorubicin (DOX). The creation of CMCS/GQDs@Pe/MIL-88 hydrogel beads was achieved through an eco-friendly one-step synthesis method.
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