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Your search keyword '"Qiu, Xueqing"' showing total 108 results
Start Over Author "Qiu, Xueqing" Publisher american chemical society
108 results on '"Qiu, Xueqing"'

15. Encapsulating β‑Glucosidase within Nanoporous ZIF-8-Cu Nanoparticles Enables High-Temperature Activity.

Author

Jiao, Rui, Wang, Yanming, Pang, Yuxia, Yang, Dongjie, Lou, Hongming, and Qiu, Xueqing

Abstract

Recently, metal–organic frameworks (MOFs) have become a promising carrier for immobilized enzymes. However, the long transmission distance and microporous nature of traditional 3D ZIF-8 materials not only reduce the accessibility of the enzyme and the substrate, but also the enzymes "encapsulated" by microporous ZIF-8 suffer compromising enzyme activity (<10% of the original enzyme activity). In this article, a method is proposed to construct one kind of new-type mesoporous 3D ZIF-8-Cu composed of 2D nanostructures that utilize a metal competitive coordination-induced defect structure by adjusting a metal guide agent copper chloride (CuCl). In addition, the feasibility of in situ encapsulating β-G within the developed mesoporous 3D ZIF-8-Cu endows that the enzyme complex (β-G@ZIF-8-Cu) possessed remarkably enhanced synergistic catalysis ability. The enzyme activity of mesoporous β-G@ZIF-8-Cu (with respect to cellobiose) was up to 50.1%, while that of 3D microporous β-G@ZIF-8 was only 5.1% at 50 °C. Significantly, with the increase of temperature, the enzyme activity of mesoporous β-G@ZIF-8-Cu increased as high as approximately 178.3%, almost 34.2 times that of β-G@ZIF-8 (5.2%) at 90 °C. This improvement results from the expansion of pores (significantly increased at 10∼50 nm), promoting substrate diffusion, and the thinner 2D structure shortened the mass transfer distance, accelerating the transport rate of reactants. In addition, 3D mesoporous β-G@ZIF-8-Cu composed of multilayer 2D nanostructures with better high-temperature resistance. [ABSTRACT FROM AUTHOR]

Published
2023
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25. Pyrene-Functionalized Alkali Lignin to Disperse Hydroxylated Boron Nitride Nanosheets in Cellulose Nanofibers for Thermal Management.

Author

Hu, Zhaosong, Liu, Yingchun, Lin, Jinxin, Wu, Haohan, Liu, Bowen, Guo, Weiqi, Lin, Xuliang, Chen, Liheng, Qiu, Xueqing, and Qin, Yanlin

Abstract

High-thermal-conductivity (λ) nanocomposites have been thought to resolve thermal management issues in electronic development. However, use of these is still challenging due to the easy aggregation of micro/nanofillers in a matrix. Here, a high-efficiency, low-cost, environmental strategy was developed wherein pyrene-functionalized alkali lignin (AL-PPBA) dispersants were employed to disperse hydroxylated boron nitride nanosheets (BNNS) by π–π conjugation in a cellulose nanofiber (CNF) solution, following which a nanocomposite film was prepared via the vacuum-assisted self-assembly method. Experimental and simulation results show that an efficient interfacial interaction between AL-PPBA and BNNS was achieved successfully and a stable aqueous dispersion solution was obtained. The as-prepared nanocomposites thus show λ as high as 18.27 W m–1 K–1 with the loading of 10.4 vol % of BNNS and superior anisotropy. A potential thermal management capability was demonstrated when using nanocomposites as heat sink components for light-emitting diode (LED) chips. This study provides a route to promote the dispersity of micro/nanofillers via a noncovalent cross-linking strategy and address heat management issues. [ABSTRACT FROM AUTHOR]

Published
2023
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