EUROPEAN POLYMER JOURNAL
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2022
·
IF 5.546
Qingyi Lu,Dongkui Zhang,Feng Xu,Guohang He,Junning Qian,Jiangbin Xia
Porous organic polymers (POPs) have attracted widespread attention in many fields because of their large specific surface area, uniform pore size and high environmental stability. However, the rational synthetic strategy of POPs remains limited and challenging. Herein, the amine group ( NH 2 ) of 9,9′,9″-(benzene-1,3,5-triyl)tris(9H-carbazol-3-amine) (TCBA) and 9-(4-(bis(4-(3-amino-9H-carbazol-9-yl)phenyl)amino)phenyl)-9H-carbazol-3-amine (TCPA) is used as node via chemical oxidation polymerization to fabricate novel star-shaped porous fluorescent polyaminocarbazole (PTCBA and PTCPA). PTCBA and PTCPA not only have large surface area and high environmental stability but also exhibit excellent sensitivity toward Fe 3+ , Cu 2+ and Ru 3+ . Interestingly, Fe 3+ , Cu 2+ and Ru 3+ can be visibly recognized by fluorescent paper strip. We envisage that such porous fluorescent polyaminocarbazole is a promising material in chemsensors.
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GREEN CHEMISTRY
·
2022
·Vol. 24
·期 17
·6619-6630
·
IF 11.034
Haichuan Zhang,Shiyu Fu
Catalytic transfer hydrogenolysis (CTH) has emerged as a sustainable and carbon-neutral biorefinery process due to the decrease in the carbon footprint and high atom and energy efficiency. Herein, heteropoly acids (HPAs) as green catalysts were used for the CTH of Kraft lignin (KL) into lignin oil under mild conditions. It is found that all the types of HPAs, Pd/C, H-donor solvent and reaction temperature affected significantly the conversion of Kraft lignin. SiW12 and PW12, respectively, afforded 95.0% and 83.8% KL conversion in isopropanol with Pd/C at 190 °C for 5 h. However, the degradation of eucalyptus Kraft lignin (EKL) provided phenolic monomers with the highest yield of 42.6% using SiW12 and Pd/C. Molecular dynamics (MD) simulation showed that SiW12 and PW12 in isopropanol are more likely to be close to lignin compared to n-propanol. The relative average molecular weight of the obtained lignin oil ranges from 100 Da to 700 Da, including phenolic monomers, dimers and trimers. The lignin monomer products are mainly composed of guaiacols and syringols with 0 to 3 carbon side chains. The simultaneous depolymerization and deoxygenation of KL during CTH led to a high-boiling organic fraction, analyzed with a Fourier transform-ion cyclotron resonance mass spectrometer (FT-ICR MS) equipped with an electrospray negative ion source (ESI−), maintaining highly aromatic structures and having lower O/C and higher H/C ratios compared to initial lignin. This work exhibits a prospective application of the CTH for the conversion of technical lignin to chemicals and biofuels.
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Polymers
·
2022
·Vol. 14
·期 14
·2889
·
IF 4.967
Pengyang Bian,Yixuan Liu,Xiaoqin Zheng,Weibo Shen
A new type of biochar, called GBC, was prepared from silkworm excrement, and then modified by chitosan combined with pyromellitic dianhydride. The removal of mono-metal and polymetals (Pb, Cd and Cu) from an aqueous solution by GBC was investigated in this research. Compared to unmodified biochar, the removal rate of Pb and Cd by GBC was about 12% higher, while that of Cu was about 94.6% higher. It also shows the types of functional groups in biochar have a great impact on their adsorption. The removal of Pb is mainly involved in the N-C=O functional group, the removal of Cd is mainly involved in N-containing functional group and C=C bond, and that of Cu is mainly involved in N-containing functional group, carboxyl group, hydroxyl group, and a carbonyl group. Five adsorption–desorption cycles of GBC were carried out, and it was found that the adsorption capacities of GBC for Pb, Cd and Cu decreased by 7.28%, 10.78% and 6.07%, respectively, indicating that GBC had a good renewable performance. The adsorption capacity of GBC for Cu in different water samples is between 89.62 and 93.47 mg·g−1, indicating that GBC has great application potential for the removal of Cu in wastewater.Keywords:silkworm excrement biochar;functional modification;heavy metals;competitive adsorption;adsorption mechanism
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高影响因子
Materials
·
2022
·Vol. 15
·期 13
·4578
·
IF 3.748
Yu Wang,Tao Xing,Yongqi Deng,Kefu Zhang,Yihan Wu,Lifeng Yan
Hydrogen is a dangerous gas because it reacts very easily with oxygen to explode, and the accumulation of hydrogen in confined spaces is a safety hazard. Composites consisting of polymers and catalysts are a common getter, where the commonly used catalyst is usually commercial Pd/C. However, it often shows poor compatibility with polymers, making it difficult to form a homogeneous and stable composite. In this work, palladium chloride (PdCl2) was converted to palladium (Pd) nanoparticles by reduction reaction and supported on graphene oxide (GO) modified by silanization. Spherical Pd nanoparticles with a size of 2–36 nm were uniformly distributed over the Silanized graphene oxide (SGO) matrix. When mixed with Pd/SGO, polymethylvinylsiloxane can be cured to silicone rubber (SR) by B2O3. Afterwards, the vinyl in the polymer can interact with hydrogen under the catalysis of Pd through the addition reaction, thus achieving the purpose of hydrogen elimination. The polymer elastomers with excellent self-healing properties and improved hydrogen elimination performance were prepared and were superior to the commercial Pd/C. In addition, excellent environmental adaptability was also demonstrated. The new getter SR-Pd/SGO provides a new avenue for developing polymer getters with superior properties.Keywords:polysiloxane;modified graphene;hydrogen getter;self-healing
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高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Qiqi Lu,Xiu-Zhi Wei,Jianguo Liu,Longlong Ma
Zeolite-tailored encapsulation of metal nanoparticles exhibits prominent catalytic performance in many fields especially for selective hydrogenation reaction due to the modulation effect of the zeolite microenvironment. Here, Pd nanoparticles encapsulated in MFI zeolite by an in-situ encapsulation method were first used in the selective hydrogenation of nitrile into a primary amine. After introducing KOH for mediating the acid-base property of zeolite microenvironment, the as-synthesized [email protected] manifested an improved selectivity in the synthesis of primary amine from nitrile, while outperformed both commercial catalysts and conventional Pd supported on zeolite catalyst. The remarkable performance of [email protected] could be attributed to both the basic property of the S-1-K zeolite for inhibiting the side reactions and the highly dispersed and ultrasmall Pd clusters for superior catalytic activity. Besides, the best yield of 81% was achieved at 80 °C, 5 bar H 2 , 2 h in ammonia solution via optimization experiments, and the moderate applicability of [email protected] catalyst was obtained by substrate scope test.
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BIOCHEMICAL PHARMACOLOGY
·
2022
·
IF 6.1
Liangping Li,Pingping Li,Xuesong Ma,Shulan Zeng,Yan Peng,Guohai Zhang
p53 inactivation by disabling its function is a hallmark in lung carcinomas , emphasizing the significance of restoring p53 function as an attractive therapeutic strategy. However, the clinical efficacy of existing p53 activators is limited due to their inability to effectively activate p53 within the tumors. Here, we established a p53 activator screening assay in EGFR-driven lung cancer cells and identified a small molecular, MX-C4, as a promising candidate. Using high throughput compound screening and combination analyses, we found that MX-C4 effectively promoted the phosphorylation of p53 at serine-392 (s392). It exhibited potent antitumor activity in a variety of cancer cell lines, but only limited toxicity to NCI-H1299 (p53-null) and normal cell lines such as LX2 and HL-7702. Overexpression of p53 in NCI-H1299 cells by a p53 expressing virus vector sensitized cells to MX-C4 treatment, suggesting a p53-dependent anticancer activity. Furthermore, we demonstrated that MX-C4 bound to p53 and exerted its anticancer activity through cell cycle arrest at G2/M phase and apoptosis induction. Mechanistic study indicated that p53 activation regulated cell cycle and cell survival related targets at protein levels. Moreover, p53 activation raised phospho-p53 translocation to mitochondria and subsequently reorganized the Bcl-xl-Bak complex, thus conformationally activating Bak and inducing apoptosis. It is noteworthy that MX-C4 could effectively activate p53 within the tumors in EGFR-driven xenograft models, where tumor was significantly suppressed without obvious toxicity. Our study identified a promising candidate for lung cancer therapy by restoring p53 function.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Jiansu Ran,Ruixue YangCheng,Yuntong Cui,Jianjian Wang
Selective and efficient low-temperature hydrodeoxygenation (HDO) of lignin derivatives in water for the production of valuable biofuel and chemicals is still challenging. Herein, we reported biomass carbon-supported ultrafine Pd nanoparticles as highly active and stable catalysts for low-temperature HDO of vanillin (a typical lignin-derived compound) to 2-methoxy-4-methylphenol (MMP). We found that the abundant carboxyl groups on the resultant catalyst greatly accelerated the conversion of the generated intermediate (vanillyl alcohol, VAL), and then, the synergistic catalysis between carboxyl groups and Pd nanoparticles promoted the efficient production MMP through a free-radical pathway. Other lignin derivatives with different functional groups were also efficiently converted to the corresponding products over the prepared catalyst. This work may provide a new idea for designing a biomass-derived catalyst for efficient transformation of various lignin derivatives to produce value-added biofuels and chemicals.
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ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Heyu Li,Minghua Liu,Wenqi Zou,Yuancai Lv,Yifan Liu,Lihui Chen
In this study, Ni-metal–organic frameworks (MOFs) were used as precursors to obtain carbon-supported nickel composites (Ni@C) after calcination. The hydrodeoxygenation properties of the model compound and corncob lignin were investigated without an external hydrogenation source and initial pressure. Additionally, the effect of Ni@C on degradation of model compounds, corncob lignin, and benzyl phenyl ether (BPE) under different conditions was examined. The results showed that with isopropanol as the in situ hydrogen source, the conversion percentage of BPE was 90.2% and the yield of phenol was 88.3 wt % at 150 °C. The catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), NH3 temperature-programmed desorption (NH3-TPD), X-ray photoelectron spectroscopy (XPS), and thermogravimetry (TG), and the lignin and bio-oil were characterized by gas chromatography–mass spectrometry (GC–MS) and two-dimensional heteronuclear single quantum coherence (2D-HSQC). It was found that the Ni@C catalyst with well dispersion, high support rate, and rich acid sites was successfully synthesized. In the process of degradation, the C–O ether bond in the structure of lignin was successfully broken to generate the phenolic monomer, and the high-efficiency hydrodeoxygenation of lignin was realized under mild conditions.
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高影响因子
CARBOHYDRATE POLYMERS
·
2022
·
IF 10.723
Long Xia,Juguo Dai,Xiaohong Wang,Mingjin Xue,Yiting Xu,Conghui Yuan,Lizong Dai
Multifunctional cotton fabrics (M-CF) have important application prospects in intelligent home decoration and material packaging. In this work, nanoparticles (AgNC@BP) were prepared by coating the surface of silver nanocubes (AgNCs) with borate polymer. Subsequently, M-CF with electromagnetic wave (EMW) absorption, mechanical enhancement, flame-retardancy and antibacterial performances were prepared by immersing cotton fabrics (CF) into AgNC@BP/crosslinked chitosan (CS) solution. Expectantly, AgNC@BP endows AgNC@BP/CS-CF with good flame retardancy and low combustion heat release. That is, the char length of AgNC@BP/CS-CF is 7.9 cm after the vertical burning test (UL-94 V) and the peak heat release rate (pHRR) of AgNC@BP/CS-CF is reduced by 21.4% compared to pure CF. Meanwhile, the tensile strength of AgNC@BP/CS-CF is 18.8% higher than that of CF. Synchronously, the introduction of AgNC@BP can also endow M-CF with better EMW absorption, mechanical and antibacterial properties . In conclusion, this work provides a tactic for fabricating M-CF.
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PubMed
高影响因子
Minerals
·
2022
·Vol. 12
·期 5
·530
·
IF 2.818
Chenhu Zhang,Haijun Wu,Wei Sun,Yuehua Hu,Chengyong Wang,Shan Zhu,Peng Chen
The recovery of scheelite from calcium-bearing carbonate ores by foam flotation is challenging due to its low separation efficiency. This study investigated the effect of pentasodium diethylenetriaminepentaacetate (PD) on the surface properties of scheelite and fluorite. For this purpose, we performed micro-flotation tests and carried out zeta potential measurements, as well as Fourier transform infrared (FT-IR) and X-ray photoelectron (XPS) spectroscopic measurements, in order to analyze the surface properties of these minerals. The addition of PD as a novel depressor significantly improved the effect of fluorite and sodium oleate (NaOl) on the flotation-based scheelite recovery and separation from fluorite. PD was spontaneously adsorbed onto fluorite through electrostatic and chemical adsorption. By contrast, PD did not appear on the scheelite because of the reaction conditions, surface site, and steric hindrance. X-ray photoelectron spectroscopy measurements and a solution chemistry analysis were used for the determination of the PD-selective adsorption mechanism and key factors derived from multi-layer adsorption onto fluorite, which completely hindered that of NaOl.Keywords:scheelite;fluorite;selective flotation;pentasodium diethylenetriaminepentaacetate
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NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 19
·9024-9035
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IF 3.925
Jun Li,Yuehua Cong,Haozhou Huang,Qiankun Shi,Yinggang Jia,Baoyan Zhang
Multiple mesophases, including the smectic A phase (Sm A), chiral nematic phase (N*), and blue phase (BP I), were seen in a series of non-symmetric bent mesogenic dimers containing a cholesteryl benzoate group. FTIR, 1H-NMR, DSC, POM, UV, and XRD were used to analyze the chemical structure and liquid crystal characteristics of the dimers. The phase transition occurred when the azobenzene structure was treated with UV light, changing the structure of the molecules. There is evidence that when the length of the terminal alkoxy chain is longer than the flexible spacer, it exhibits a smectic A phase as well as a chiral nematic phase; however, when the length of the flexible spacer is shorter than the length of the terminal alkoxy chain, it only exhibits a chiral nematic phase.
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PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION
·
2022
·Vol. 39
·期 4
·2200013
·
IF 3.467
Xinyi Wei,Jinfeng Zhang,Chang Liu,Xiaopeng Han,Yida Deng,Wenbin Hu
The construction of binary metal Pd-based catalysts is an effective strategy to enhance the activity of methanol oxidation reaction. Herein, atomically dispersed Ir single atoms doped to cuboctahedral Pd nanoparticles (Ir-SAs/Pd) as efficient catalysts for alkaline methanol oxidation are prepared via a simple chemical reduction method. The synthetic Ir-SAs/Pd catalysts exhibit the outstanding mass activity of about 1717.3 mA mg Pd −1 compared with pure Pd and commercial Pd/C in electrooxidation for methanol. Meanwhile, the introduction of Ir single atoms enhances the CO tolerance of Pd nanoparticles to a large extent. On the basis of density functional theory results, the enhanced catalytic performance and CO tolerance rely on the effective improvement of the electron dominance near Fermi level and the negative shift of the d-band center for Pd as a result of the electron redistribution between Pd and Ir atoms. This article will provide new insight into the design of high-performance binary metal catalysts for methanol oxidation in alkaline media.
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