CHEMICAL ENGINEERING JOURNAL
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2023
·
IF 15.1
Ziwei Qin,Yi Yang,Qingli Tian,Hao-Yang Mi,Heng Li,Runhao Guo,Ying Wang,Chuntai Liu,Changyu Shen
Developing protective materials with intelligent and stimuli-responsive properties is indispensable for safety protection. However, combining contradictory characteristics into a single polymer is challenging, such as high mechanical strength, impact protection, and self-healing properties. Herein, a strain-hardening supramolecular polyurethane nanocomposite (SPN) with high mechanical strength and unique impact protection characteristics is synthesized by incorporating quadruple hydrogen bonds (H-bonds), disulfide bonds, and modified silica nanoparticles into polyurethane elastomer. Benefiting from the dynamic break and re-form characteristic of quadruple H-bonds and the stress dissipation behavior of nanoparticles, SPN exhibits high energy absorption efficiency and impact protection properties. During the drop ball striking test, the impact energy absorption efficiencies reached 90%, and the buffer time of impact was significantly longer than common buffering materials. The SPN exhibited excellent stretchability and self-healing ability, ascribing to disulfide metathesis and H-bonds association. Moreover, the prepared SPN could be easily processed through a hot press and showed negligible creeping. The developed SPN could serve as a novel self-standing impact protective material that offers promising prospects in sports, transportation, and aerospace fields.
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Catalysis Science & Technology
·
2023
·Vol. 13
·期 15
·4400-4408
·
IF 5
Zhengxin Peng,Xiangbowen Du,Nan Lu,Jing Sui,Xiaofan Zhang,Renhong Li,Xiaoqing Yan
The rational design and fabrication of junction-based photocatalysts is of great importance to enhance the photocatalytic efficiency of water splitting. Herein, a new heterophase junction photocatalyst consisting of cubic bixbyite and rhombohedral corundum In2O3 (c-In2O3 and h-In2O3) was readily prepared by directly annealing an InOOH precursor in an inert atmosphere. The resulting c/h-In2O3 heterophase junction photocatalyst showed an optimal hydrogen production rate of 0.73 mmol g−1 h−1 in a 6 h period reaction from alkaline formaldehyde solution in the presence of molecular oxygen under visible light irradiation, which was approximately 5.6 and 3.4 times higher than that of single-component c-In2O3 and h-In2O3, respectively. The superior photocatalytic activity of the c/h-In2O3 heterophase junction was partially attributed to its appropriate band gap and band positions. Spectroscopic characterization and photoelectrochemistry experiments indicated that the heterophase junction photocatalyst could effectively enhance charge separation and transfer abilities between h-In2O3 and c-In2O3. Furthermore, molecular O2 was found to play a key role in mediating the photocatalytic H2 evolution from formaldehyde oxidation as a catalytic electron scavenger, and O2 was not consumed throughout the reaction. Thus, the photocatalytic activity was also greatly enhanced because the adsorption ability of oxygen species was effectively improved after the formation of heterophase junctions.
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CONSTRUCTION AND BUILDING MATERIALS
·
2023
·
IF 7.4
Chenchen Xiong,Yulin Wang,Yang Zhou,Xingyu Liu,JinHui Tang,Pan Feng
An ordered structure and high mechanical property of calcium silicate hydrate (C-S-H) gel has been always pursued in the field of cementitious materials. In this paper, compacted and layer-by-layer stacking C-S-H plates were fabricated based on Layer-by-Layer (LBL) method and H-cell penetration (HCP) method through cation exchange membrane templating. This new way changed the randomly packing structure of traditional C-S-H, and synthesized a high-orderly C-S-H platelets with denser structure. Based on molecular dynamics simulations, it can be attributed to the strong adsorption and nucleation sites contributed by sulfonic acid groups on the cation exchange membrane. Besides, AFM indentation experiments indicate this C-S-H owns significantly higher elastic modulus than traditional C-S-H, while the mechanical properties can be further increased by the addition of PVA and the regulation of reaction time. This new type C-S-H may pave the way to the preparation of high-performance concrete in the future.
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CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Qiuxia Zou,Hongshen He,Jie Xie,Shibo Han,Weijie Lin,Ajoy Kanti Mondal,Fang Huang
In this study, Sn modified molecular sieves with Lewis (L) acid center and Al modified molecular sieves with Brönsted (B) acid center were prepared by post-synthesis method. They were applied to the catalytic pyrolysis of Kraft lignin for the preparation of bio-oil. The acid properties of acid modified zeolites were systematically investigated by XRD, SEM, EDS and Py-FT-IR, and the bio-oil is analyzed by heteronuclear single quantum coherent nuclear magnetic resonance (HSQC-NMR). By separating L acid and B acid from zeolite molecular sieves, the conformational relationships between these two acids on the oxygen-containing functional groups in Kraft lignin bio-oil are investigated separately. The results show that acid modified molecular sieves’ L acid and B acid can effectively improve the cleavage of aromatic C-O bonds including methoxy and ether bonds. The L acid of Sn modified molecular sieve tends to break the O-C 4 bond and the natural methoxy bond, while the B acid of Al modified molecular sieve generates aliphatic hydrocarbon intermediates and phenolic compounds by breaking the C β -O bond and rearranging the methoxy bond. By chemical characterization of the acid modified molecular sieves and the bio-oil, the conformational relationship between the L acid and B acid of zeolite molecular sieves on the deoxygenation efficiency of Kraft lignin pyrolysis bio-oil is established.
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ChemSusChem
·
2019
·Vol. 12
·期 16
·3871-3877
·
IF 7.804
Dan Wu,Xing Yu,Xinqing Chen,Gan Yu,Kun Zhang,Minghuang Qiu,Wenjie Xue,Chengguang Yang,Ziyu Liu,Yuhan Sun
Graphical Stacks on ! H-type MFI zeolite catalysts with a unique stacked structure are synthesized in a one-pot procedure in the presence of NH 4 F with the help of zeolite confinement through a solvent-free route without further ion-exchange procedures. The catalysts display excellent catalytic performance in methanol-to-gasoline reactions. H-type aluminosilicate zeolites are extensively used as solid-acid catalysts and support materials in industrial catalysis. However, the conventional synthesis methods involving hydrothermal syntheses and ion-exchange processes suffer from severe water pollution and toxic gas emissions. Herein, H-type MFI zeolite catalysts with a unique stacked structure were directly synthesized in the presence of NH 4 F and with the help of zeolite confinement through a solvent-free route without further ion-exchange procedures. A range of ex situ and in situ characterization procedures were used to provide evidence of the simultaneous use of pre-made ZSM-5 and NH 4 F as a confined Al source and mineralizer, respectively. The confined zeolite framework of ZSM-5 prevented the formation of AlF x species between NH 4 F and Al atoms, ensuring that the prepared samples had desirable acidic properties. Moreover, the resulting morphology could be controlled by using different silica substrates. The obtained H-type MFI zeolites showed excellent catalytic performance in methanol-to-gasoline reactions owing to their unique structure and directly exposed acidic sites. The developed one-pot strategy provides an alternative method for the facile synthesis of H-type zeolites with defined morphology.
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高影响因子
EUROPEAN POLYMER JOURNAL
·
2025
·
IF 6.3
Zhen Huang,Shimin Geng,Yizhen Chen,Ying Li,Mingen Fei,Renhui Qiu,Tingting Chen,Wendi Liu
Traditional polyurethane hot-melt adhesives often fall short in achieving high bonding strength and recyclability, and their dependence on non-renewable resources poses a significant hurdle for sustainable development. In this study, a palm oil-based diethanolamide (POEA) containing a long aliphatic chain was synthesized to develop comb thermoplastic polyurethane hot-melt adhesives (POPUs) with high biobased content, superior adhesion strength, and reusability. The microphase separation structure of POPUs was manipulated through the incorporation of dangling fatty acid chains and hydrogen bonds, resulting in the adhesives with excellent mechanical properties, with an optimum tensile strength of 5.37 MPa and an elongation at break of 282 %. As a hot-melt adhesive, it achieved a maximum lap-shear strength of 7.34 MPa on steel and maintained an average strength of 95 % of its initial value across multiple bonding cycles. Moreover, its lap-shear strengths with wood and glass remained at 6.57 MPa and 3.57 MPa respectively, fully meeting the requirements for interior decoration. Additionally, it was unexpectedly discovered that the adhesives possessed fluorescence characteristics, which can be applied in fields such as cultural relic restoration and anti-counterfeiting.
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ANALYTICAL BIOCHEMISTRY
·
2016
·
IF 2.243
Wei Zhang,Min Zhu,Feng Wang,Danhui Cao,Jennifer Jin Ruan,Weike Su,Benfang Helen Ruan
Glutamate dehydrogenase (GDH) catalyzes the oxidative deamination of L-glutamate and is important for several biological processes . For GDH inhibitor screening, we developed a novel mono-sulfonated tetrazolium salt (EZMTT), which can be synthesized using H 2 O 2 oxidation and purified easily on silica gel in large quantities. The EZMTT detection method showed linear dose responses to NAD(P)H, dehydrogenase concentration and cell numbers. In E. coli GDH assay, the EZMTT method showed excellent assay reproducibility with a Z factor of 0.9 and caused no false positives in the presence of antioxidants (such as BME). Using the EZMTT-formazan-NAD(P)H system, we showed that EGCG is a potent E. coli GDH inhibitor (IC 50 45 nM) and identified that Ebselen , a multifunctional thioredoxin reductase inhibitor, inactivated E. coli GDH (IC 50 213 nM). In cell-based assays at 0.5 mM tetrazolium concentration, EZMTT showed essentially no toxicity after a 3-day incubation, whereas 40% of inhibition was observed for WST-8. In conclusion, EZMTT is a novel tetrazolium salt which provides improved features that are suitable for dehydrogenases and real-time cell-based high-throughput screening (HTS).
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Journal of the American Chemical Society
·
2015
·
IF 12.113
Xiao-Li Pei,Yang Yang,Zhen Lei,Shan-Shan Chang,Zong-Jie Guan,Xian-Kai Wan,Ting-Bin Wen,Quan-Ming Wang
The activation of C(sp3)–H bonds is challenging, due to their high bond dissociation energy, low proton acidity, and highly nonpolar character. Herein we report a unique gold(I)–silver(I) oxo cluster protected by hemilabile phosphine ligands [OAu3Ag3(PPhpy2)3](BF4)4 (1), which can activate C(sp3)–H bonds under mild conditions for a broad scope of methyl ketones (RCOCH3, R = methyl, phenyl, 2-methylphenyl, 2-aminophenyl, 2-hydroxylphenyl, 2-pyridyl, 2-thiazolyl, tert-butyl, ethyl, isopropyl). Activation happens via triple deprotonation of the methyl group, leading to formation of heterometallic Au(I)–Ag(I) clusters with formula RCOCAu4Ag4(PPhpy2)4(BF4)5 (PPhpy2 = bis(2-pyridyl)phenylphosphine). Cluster 1 can be generated in situ via the reaction of [OAu3Ag(PPhpy2)3](BF4)2 with 2 equiv of AgBF4. The oxo ion and the metal centers are found to be essential in the cleavage of sp3 C–H bonds of methyl ketones. Interestingly, cluster 1 selectively activates the C–H bonds in −CH3 rather than the N–H bonds in −NH2 or the O–H bond in −OH which is traditionally thought to be more reactive than C–H bonds. Control experiments with butanone, 3-methylbutanone, and cyclopentanone as substrates show that the auration of the C–H bond of the terminal methyl group is preferred over secondary or tertiary sp3 C–H bonds; in other words, the C–H bond activation is influenced by steric effect. This work highlights the powerful reactivity of metal clusters toward C–H activation and sheds new light on gold(I)-mediated catalysis.
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Soft Matter
·
2013
·Vol. 9
·期 48
·11585-11597
·
IF 3.909
Wenlong Li,Peiyi Wu
The dynamic thermally reversible phase transition behaviour of poly(ethylene oxide) (PEO) in 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) has been investigated by calorimetric measurements (DSC) and FT-IR, in combination with perturbation correlation moving window (PCMW) and two-dimensional correlation spectroscopy (2DCOS) for the first time. A relatively high lower critical solution temperature (LCST) was observed which is different from that of conventional thermo-sensitive polymers in aqueous solution. Four types of hydrogen bonds were found in this system, among which the type I (the hydrogen bonds between the unsaturated C–H on the imidazole ring and the oxygen atoms of PEO) and type II (the hydrogen bonds between the saturated C–H on the PEO backbone and the fluorine atoms of the IL anions) ones have a more predominant influence on the phase transition. Moreover, type I plays the predominant role in both the heating and cooling process. DSC revealed that the phase transition temperature of PEO–[EMIM][BF4] solutions decreases with the increasing concentration of PEO, as well as with a decreasing scanning rate. Through PCMW, the LCST was determined to be ca. 137 °C during heating and ca. 131 °C during cooling. Finally, 2DCOS was employed to elucidate the dynamic mechanism of PEO in [EMIM][BF4], which revealed hydrogen bond disruption, chain aggregation and exclusion of IL molecules. Solutions with a low PEO concentration tend to form loosely aggregated globules, compared to the more densely aggregated globules in samples with a high PEO concentration. Additionally, it is worth mentioning that several unusual and peculiar phenomena were also observed, such as opposite frequency shifts in C–H groups, a “tail-raising” phenomenon, critical PEO concentration for the phase transition temperature, and intersection of the frequency shift curves for samples with high concentrations of PEO during cooling.
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JOURNAL OF MATERIALS SCIENCE
·
2014
·Vol. 49
·期 22
·7730-7741
·
IF 2.305
Luo Yan-Ling,Huang Rui-Juan,Xu Feng,Chen Ya-Shao
pH-Sensitive biodegradable polymethacrylic acid- block -polylactic acid- block -polymethacrylic acid (PMAA 2 - b -PLA- b -PMAA 2 ) H-type multiblock copolymers were synthesized by atom transfer radical polymerization. The copolymer structure and molecular weight were characterized by FT-IR, 1 H NMR, and gel permeation chromatography. The physicochemical characterization revealed that the copolymers could spontaneously form spherical core–shell micelles in aqueous solution, with critical aggregation concentration of about 19.7–32.5 mg L −1 and the hydrodynamic diameters below 200 nm. Z eta potentials measurements disclosed that the copolymer micelles were negatively charged due to ionized carboxyl groups in various PBS solutions. The H-type block copolymer micelles exhibited pH- sensitivity, as expected; and the hydrophobic anticancer drugs, 10-hydroxycamptothecin, and paclitaxel, had faster release rate in PBS solution of pH 5.6–7.4 than in PBS of pH 1.4, which was important for applications in the therapy of small intestine cancers. The copolymer micelle aggregates were proved to be biodegradable, and the degradation rates changed with copolymer compositions and environmental media. The micelle drug formulation indicated pH-dependent cytotoxicity and was thus capable of effectively killing the intestinal cells while avoiding doing harm to stomach. The biodegradable pH-sensitive PMAA 2 - b -PLA- b -PMAA 2 H-type copolymer micelles can be used as water-insoluble drug targeting release carriers for targeted treatment of intestine cancers.
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TETRAHEDRON
·
2016
·
IF 2.645
Weijian Li,Guanghui Lv,Xu Cheng,Rui Sang,Xiaojun Ma,Yong Zhang,Ruifang Nie,Jie Li,Mei Guan,Yong Wu
A moisture- and air-stable palladium(II)-Schiff base complex supported on h-BN was simply prepared by using commercially available reagents. This nanomaterial was applied as an excellent and recyclable heterogeneous catalyst for the Suzuki and Heck cross-coupling reactions. And it has been characterized by FT-IR, XRD, SEM, XPS , TG and ICP-AES techniques. High yields, ligand-free, low reaction time, water as solvent, non-toxicity and recyclability of the catalyst are the main merits of these protocols. In addition, a series of pharmacologically relevant products were successfully synthesized using this catalyst. Above all, this work opens up an interesting and attractive avenue for the use of h-BN as an efficient support for heterogeneous catalysts.
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ACS Nano
·
2024
·
IF 15.8
Haijian Huang,Hao Feng,Ziyu He,Yanan Huang,Jiawei Xu,Chengzhi Hu,Zhangxian Chen,Zeheng Yang,Weixin Zhang
Enhancing proton storage in the zinc-ion battery cathode material of MnO2 holds promise in promoting its electrochemical performance by mitigating the intense Coulombic interaction between divalent zinc ions and the host structure. However, challenges persist in addressing the structural instability caused by Jahn–Teller effects and accurately modulating H+ intercalation in MnO2. Herein, the doping of high-electronegativity Sb with fully occupied d-orbital in MnO2 is reported. The Sb doping strategy engenders the formation of Mn–O–Sb path in the structure with a strong dipole polarization field, which facilitates the delocalization of eg orbital electron in Mn and thus mitigates the Jahn–Teller effects. Simultaneously, adjusting the level of Sb doping in MnO2 leads to modulation of the p-band center of O, optimizing its interaction with hydrogen and thereby enhancing proton storage. Consequently, MnO2 doped with 6% Sb exhibits commendable performance in both rate capability and cycling endurance, delivering 113 mAh g–1 at 2 A g–1 after 2000 cycles. This investigation underscores the crucial role of electronic structural engineering in elevating the electrochemical performance of cathode materials for zinc-ion batteries.
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