Preparation method of thermosensitive microgel asymmetric supported nano silver catalyst

Abstract

A preparation method of a thermosensitive microgel asymmetric supported nano silver catalyst comprises the steps of preparing poly-(N-isopropylacrylamide-styrene) / poly-(N-isopropylacrylamide-methacrylic acid) core-shell microgel by a soap-free emulsion polymerization method and a seed emulsion polymerization method, and then synthesizing the asymmetric supported nano silver catalyst taking the microgel as a template by a pickering emulsion template method. The thermosensitive microgel asymmetric supported nano silver catalyst prepared by the method shows good thermosensitivity, and good catalytic activity as the catalytic reaction efficiency is regulated and controlled by temperature and the thermosensitivity of the microgel simultaneously during catalytic reduction of p-nitrophenol.

Description

technical field [0001] The invention relates to a preparation method of a temperature-sensitive microgel asymmetrically loaded nano-silver catalyst. Background technique [0002] In recent years, Janus particles with an asymmetric double-sided structure have been used in Molecular recognition, self-assembly, photoelectric biosensors, interface modification, electronic paper, anisotropic imaging probes, solar energy conversion, and surfactants have shown attractive application prospects. [0003] The preparation of Janus particles by the pickering emulsion template method is to form an oil / water interface by stabilizing the emulsion with solid particles. Symmetrical Janus particles. The advantage of the Pickering emulsion template method is that the toxicity to the human body is far less than that of surfactants, the emulsion has good stability, and it can be controlled to change the conditions for demulsification to release the granular emulsifier. The solid particle emul...

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Problems solved by technology

[0004] Nano-metals have attracted much attention due to their unique properties. However, due to the high surface energy of nano-metal particles, metal nanoparticles are prone to aggregation during synthesis and application, which reduces the actual utilization rate.

Using the polymer microgel with sensitive properties as the carrier of metal nanoparticles, the volume of the microgel and the hydrophilicity and hydrophobicity of the chain segment can be changed by changing the environmental conditions, which provides the possibility to realize the controllability of the catalytic reaction activity. , however, the symmetrical full loading of nano-metals on the substrate will greatly limit the unique properties of the original substrate

Melanie Bradley et al. (Journal of Colloid and Interface Science, 2011, 355, 321-327) used the Pickering emulsion template method to N-isopropylacrylamide and N(3-dimethylaminopropyl)methacrylamide The copolymer microgel is used for asymmetric loading of gold nanoparticles. The pre-synthesized gold nanoparticles are added to the paraffin / water Pickering emulsion, and the pre-synthesized gold nanoparticles are strongly adsorbed by the amino group on the surface of the microgel. function, it can adsorb nano-gold to the part of the microgel distributed in the water phase, so as to obtain an asymmetrically loaded nano-gold composite material, which not only solves the problem of agglomeration of nano-metals, introduces the unique properties of nano-metals, but also maintains The original performance of the matrix, but this method has many synthesis steps, which is relatively cumbersome and difficult to control

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