Institutional Repository of Institute of Process Engineering, CAS (IPE-IR)
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Fine Pore-Structure Engineering by Ligand Conformational Control of Naphthalene Diimide-Based Semiconducting Porous Coordination Polymers for Efficient Chemiresistive Gas Sensing
Exploring new porous coordination polymers (PCPs) that have tunable structure and conductivity is attractive but remains challenging. Herein, fine pore structure engineering by ligand conformation control of naphthalene diimide (NDI)-based semiconducting PCPs with pi stacking-dependent conductivity tunability is achieved. The pi stacking distances and ligand conformation in these isoreticular PCPs were modulated by employing metal centers with different coordination geometries. As a result, three conjugated PCPs (Co-pyNDI, Ni-pyNDI, and Zn-pyNDI) with varying pore structure and conductivity were obtained. Their crystal structures were determined by three-dimensional electron diffraction. The through-space charge transfer and tunable pore structure in these PCPs result in modulated selectivity and sensitivity in gas sensing. Zn-pyNDI can serve as a room-temperature operable chemiresistive sensor selective to acetone
Project for Improving the Research Ability of Postgraduate from Beijing Technology and Business University[19008022056]
Experimental and theoretical study on the extraction of keratin from human hair using protic ionic liquids
Keratin, the naturally derived biomaterials have been developed and widely applied in many different fields. Among the resources containing keratin, human hair is one of the most abundant natural fibers rich in keratin and one of the most abundant waste materials produced by humans. It is critical for both value-added human hair utilization and environmental protection if suitable solvents for the dissolution and regeneration of the keratin were developed. Ionic liquids (ILs) have been evidenced to be the green solvents to extract keratin from waste human hair. In this work, five novel Protic ILs were designed and synthesized in one step with inexpensive raw materials under mild conditions. The effect of different anions and cations, temperature, and water content on the dissolution ability of Protic ILs for human hair was investigated in depth. The best IL [MEA]HCOO with high solubilization capacity (9 h, 130 degrees C) for human hair was finally obtained by considering the time required for complete hair dissolution and the properties of regenerated keratin. The results of FTIR, XRD, and TGA showed that the a-helix structure of regenerated keratin was not destroyed. The recycling result indicates that the dissolution ability of [MEA]HCOO for human hair kept stable after 5 times recovery. Furthermore, the density functional theory (DFT) calculations and independent gradient model (IGM) analysis uncover the dissolution of human hair by ILs through synergistic interaction between the cations and anions of ILs. (c) 2022 Elsevier B.V. All rights reserved
Integrated microsphere-packed bed enzymatic membrane reactor for enhanced bioconversion efficiency and stability: A proof-of-concept study
Fabricating high-performance enzyme reactors is requested for achieving efficient and stable bioconversions, but remains challenging, because few of them can possess high enzyme loading, sufficient mixing, and efficient mass transfer at the same time. Herein, we propose to develop a novel enzymatic packed bed membrane reactor (EPBMR) by integrating the advantages of both packed bed reactor (PBR) and enzymatic membrane reactor (EMR). A prototype study is conducted with the simplified enzyme-loaded microsphere-ultrafiltration EMR model (Mic-UF EMR). Invertase and dextranase are used in this work to produce glucose and oligodextran by hydrolysis of sucrose and dextran, respectively. Specifically, the use of microspheres can enlarge the contact area between enzymes and substrates and mitigate membrane fouling induced by free enzymes. Thus, Free&Mic-UF EMR (with both free and immobilized enzymes) exhibits a higher sucrose conversion rate (84%) than the EMR with free invertase (34%) and a negligible decline in sucrose conversion for 36 h continuous operation. Membrane fouling is ameliorated by alkaline cleaning and implementation of covalent bonding strategy. In addition, commercial resins with larger sizes are employed to replace konjac glucomannan microspheres (KGM) which reduce the pressure drop of EMR. Finally, by selecting the OF membrane with proper molecular weight cut-off (MWCO), the dextranase-based Mic-UF EMR system successfully produces oligodextran with desired molecular weight (Mw) and narrow Mw distribution. The outcome of this work not only offers a novel enzyme reactor construction strategy but also provides guidance for regulating the performance of EMR
Hydrophobically modified mesoporous silica supported Pt as a dual-function adsorbent buffer-catalyst for toluene removal under low-temperature
A bifunctional adsorption-catalysis system for the abatement of trace amounts of toluene was developed and realized by loading different amounts of Pt on mesoporous silica synthesized with ionic liquid with hydrophobic modification. The textural properties were evaluated using BET, contact angle, XRD, IR, XPS, TEM, and H-2-TPR techniques. The capability of the synthesized catalysts for room-temperature adsorption and low-temperature catalysis of toluene was appraised. The hydrophobic sample exhibited better toluene adsorption capacity of 53.1 mg g(-1) than SiO2-350 and 3.0Pt/SiO2 samples with 28.3 mg g(-1) and 18.9 mg g(-1), respectively. Furthermore, the hydrophobic sample showed increased maximum desorption temperatures of 52 degrees C in comparison with those at 44 degrees C and 37 degrees C, which acted as a good adsorption buffering system. 3.0Pt/SiO2-H showed the best toluene conversion capacity at T-90 = 129 degrees C, together with superior water vapor resistance and sequential capture-destruction performances. The increased bifunctional adsorption-catalysis performance with hydrophobic modification may be ascribed to the change in surface functional groups. The prepared system could be a valuable candidate material for adsorption-catalysis integration and assistance for VOCs elimination technology in barren waste gases