查找使用阿拉丁产品的科研文献

Green conversion of CO2 by N-heterocyclic carbene-CO2 adducts grafted hierarchical porous silica microspheres

Xueting Liu,Kuayue Li,Wenkui Liu,Peng Cui,Fengyu Wei

The multiphase catalysts DMSNs-Cb-X containing NHC-CO2 adducts were synthesized by soft template method that is, first preparing dendritic multi-model pore silica nanoparticles (DMSNs) with central-radial structure, and then grafting imidazoline functional groups, and finally allowing to react with dimethyl carbonate to graft NHC-CO2 adducts. The investigations had the scope to improve the performance and to elucidate the effect of NHC-CO2 adducts on the CO2 cycloaddition reaction. The optimum catalyst DMSNs-Cb-1 and the optimum reaction conditions (200 mg, 100 °C, 10 h) were obtained via thermogravimetric analysis. CO2 cycloaddition reaction with epoxide DMSNs-Cb-1 can convert CO2 and epoxide to cyclic carbonate at ambient pressure without solvent and co-catalysts (1 bar, 100 °C). The reaction proceeds with high yield and high conversion frequency (TOF = 27.4 h−1). The prepared catalyst is easily recovered and still has high activity after five cycles of experiments. The excellent catalytic performance of the obtained catalyst can be attributed to the synergy of hierarchical porous structure and NHC-CO2 adducts acting as CO2 adsorption sites as well as zwitterionic catalytic sites. This work demonstrates an efficient strategy for green conversion of CO2 into cyclic carbonates.

Discovery of N-hydroxy-4-(1H-indol-3-yl)butanamide as a histone deacetylase inhibitor

Jiang Bian,Yepeng luan,Chunbo Wang,Lei Zhang

Antibiotic-free antimicrobial functionalization of PEEK via UV-induced self-initiation and N-halamine grafting

Ziying Cheng,Yansheng Huang,Zhigang Zhao,Songnan Shao,Zitong Zhao,Xiaoshuai Peng,Baorong He,Zhen Chang

Background Implant-associated infection remains a major challenge in orthopedic surgery. Although polyether ether ketone (PEEK) is widely used owing to its favorable mechanical properties and radiolucency, its intrinsic bioinertness renders it highly susceptible to bacterial colonization. Developing a durable, antibiotic-free antibacterial surface modification for PEEK with translational relevance remains clinically desirable. Methods In this study, a covalently grafted N-halamine–functionalized PEEK surface (PEEK- g -PAM-NCl) was fabricated via a UV-induced self-initiated polymerization strategy. The antibacterial performance was systematically evaluated against Staphylococcus aureus and Escherichia coli using time–kill assays, live/dead staining, and antibacterial tests under protein-rich conditions. Biocompatibility and osteogenic potential were assessed in vitro using hBM-MSCs. In vivo antibacterial efficacy and biocompatibility were further investigated using subcutaneous implant-associated infection model in the C57BL/6J mice and femoral osteomyelitis model in the SD rat. Results PEEK- g -PAM-NCl exhibited sustained and effective antibacterial activity against both Gram-positive and Gram-negative bacteria, achieving >98% bacterial reduction in vitro, including under protein-rich conditions. Time–kill assays revealed a pronounced time-dependent bactericidal effect. In vivo, PEEK- g -PAM-NCl significantly reduced bacterial burden, inflammatory infiltration, and infection-associated tissue damage compared with pristine PEEK, effectively preventing chronic osteomyelitis features. Importantly, no abnormal systemic inflammatory response or local tissue toxicity was observed. In vitro osteogenic assessments demonstrated that the antibacterial modification did not adversely affect osteogenic differentiation. Conclusion This study demonstrates that covalent N-halamine functionalization endows PEEK with sustained, antibiotic-free antibacterial activity while preserving biocompatibility performance. PEEK- g -PAM-NCl represents a promising translational strategy for preventing implant-associated infections in orthopedic applications. The translational potential of this article This study presents an antibiotic-free antibacterial surface modification strategy for PEEK implants based on UV-induced covalent grafting of N-halamine polymers. The robust antibacterial efficacy, preserved cytocompatibility, and supportive bone-related biological responses suggest potential applicability in preventing implant-associated infections in orthopedic settings. This work provides a feasible surface engineering approach that may be further optimized and translated toward clinically relevant load-bearing implants.

Strong metal-support interaction enhanced acetylene hydrochlorination stability over Cu1-N-C single-site catalysts

Chang Liu,Jianlin Cao,Yuxiang Bao,Juncong Yuan,Yuanning Yue,Yibin Liu,Xiaobao Chen,Yinming Guo,Chaohe Yang,Baorui Li,Xiang Feng,De Chen

Cu-based catalysts present a promising alternative to toxic mercuric chloride (HgCl 2 ) in acetylene hydrochlorination owing to their cost-efficiency and environmental compatibility. However, the dispersion and leaching of active sites under operational conditions hinders its application. Herein, we designed a lignin-supported Cu 1 N single-site copper catalyst (Cu 1 /L-CN) by site-anchored strategy which employed pyrrolic N functional groups to anchor and inhibit the aggregation of Cu atoms by strong metal-support interaction. Based on kinetics study and in-situ characterizations, it is found that the Cu 1 /L-CN catalyst inhibits the formation of complexes between copper and acetylene, suppressing over-adsorption of acetylene and undesired side reactions. Accordingly, the Cu 1 /L-CN catalyst demonstrated excellent catalytic activity and a low deactivation rate constant (k D  = 0.016 h −1 ) with significantly reduced carbon deposition. This work will provide a new approach to the design of mercury-free catalysts toward industrial production of vinyl chloride from the acetylene hydrochlorination.

Interface-tuned capacitance enhancement in N-P Co-doped carbon membrane/PANI hybrids for supercapacitors

Cai Jiangtao,Liu Yi,Zhou Xiaonan,Hu Yehao,Yang Jin,Wang Zhiqiang,Sun Wenbin,Zhang Yating

Conducting polyaniline (PANI) and porous carbon fibrous membranes to construct composite electrode materials is one of the hotspots for preparing high-performance supercapacitors. The key is realizing the homogeneous dispersion of the two materials, carbon/PANI, and the connection interface with considerable firmness and strength. Therefore, based on the interfacial covalent bonding strategy, the N-P co-doped carbon membrane and PANI hybrid (NPCM@PANI) materials were designed and constructed. NPCMs were used as substrates to functionalize with nitric acid and ND42, and then co-aniline in situ on the surface of NPCMs. This approach aimed to obtain a hybrid material with high specific capacitance, using NPCM as the substrate. The resulting NPCM@PANI hybrids have a specific capacitance of up to 552 F/g (1 A/g), a small equivalent series resistance of 1.1 Ω and a low transfer diffusion resistance of about 1 Ω in 1 M H 2 SO 4 electrolyte. The capacitance performance is still 78% after 1,000 cycles, which provides excellent capacitance properties. Graphical abstract

The effect of different n-butanol-fatty acid methyl esters (FAME) blends on puffing characteristics

Yu Zhang,Ronghua Huang,Shijie Xu,Yuhan Huang,Sheng Huang,Yinjie Ma,Zhaowen Wang

The droplet suspension technology was used under the condition of atmospheric pressure and 873   K. The n -butanol concentration ranged from 0% to 75% to investigate the effect of n -butanol concentration on the puffing characteristics of a n -butanol-fatty acid methyl esters (FAME) droplet. Experimental results showed that BUT25, BUT50 and BUT75 (BUT’XX’ represented XX% n -butanol by mass fraction in the n -butanol-FAME blend) underwent three phases, namely the transient heating phase, fluctuation evaporation phase and equilibrium evaporation phase. The temperatures of BUT25, BUT50 and BUT75 were similar at the start and end of the transient heating phase. The duration of BUT75’s transient heating phase was much longer than that of BUT25 and BUT50. Therefore, the evaporation cooling of BUT75 was the most prominent because the temperature growth rate of BUT75 was significantly less than that of BUT25 and BUT50. Furthermore, the fluctuation evaporation phase could be divided into the strong and weak fluctuation stages. The violent fluctuation was only observed in the strong fluctuation stage. The weak fluctuation stage was similar as the stable evaporation. The active rupture was found in the strong fluctuation stage and the passive rupture was found in the weak fluctuation stage. The active and passive ruptures were caused by the fast bubble expansion and surface evaporation respectively. In addition, many periodic processes were contained in the strong fluctuation stage. The similarity degree of the periodic process showed a slump and a gradual increase, which were caused by bubble expansion and droplet recovery respectively. The bubble expansion of BUT50 was greater than that of BUT75. Significant bubble expansion led to the violent deformation after bubble rupture. The recovery time of BUT50 was longer than that of BUT75. Therefore, the similarity degree of BUT50 exhibited a wavy structure and BUT75 displayed a comb-like structure in the strong fluctuation stage.

Facile synthesis and catalytic activity of well-defined amphiphilic block copolymers based on N-vinylimidazolium

Chang Peng,Kai Huang,Mingsong Han,Wei Meng,Yuanqin Xiong,Weijian Xu

Well-defined amphiphilic block copolymers, poly(styrene)- b -poly( N -vinylimidazole) (PS- b -PVim), were successfully synthesized by macromolecular design via interchange of the xanthates/reversible addition–fragmentation chain transfer (RAFT) polymerization. The structure of the copolymer based on Vim can be well controlled, and the molecular weight distribution was relatively narrow (PDI = 1.24). The size and morphology of the aggregates of the amphiphilic copolymers were investigated by dynamic light scattering and transmission electron microscope, the results implied that the uniform spheroidal micelles consisting of PS core and PVim corona were assembled, and the catalytic activities of PS- b -PVim for the hydrolysis of p -nitrophenyl acetate at different temperatures were also investigated by high-performance liquid chromatograph (HPLC); the catalytic activities of diblock copolymers were prominently improved compared with that of PVim homopolymers. Moreover, the catalytic activities of the copolymers followed the Arrhenius behavior in the wide experimental temperature range. Copyright © 2013 John Wiley & Sons, Ltd.

Synthesis and characterization of multi-responsive poly(N-isopropylacrylamide)-sodium alginate-graphene oxide composite hydrogels

Zhang Yiqiang,Yang Fuguo,Huang Huabo,Zhao Rui,Huang Juan,Li Liang,Yu Xianghua

The multi-responsive ternary poly(N-isopropyl acrylamide) (PNIPAM)/ /sodium alginate (SA)/graphene oxide (GO) composite hydrogels were prepared. The influence of GO content on the microstructure and physical properties of the composite hydrogel was researched. The ternary composite hydrogels exhibited significantly larger mechanical strength and higher water uptake compared to binary PNIPAM/SA composite hydrogels. The effects of temperature, pH, and contact time on the adsorption capacity of rhodamine B (RB) for the PNIPAM/SA/GO ternary composite hydrogels were further investigated. The adsorption kinetic and isotherm for the adsorption behavior of the ternary composite hydrogel were well fitted with the pseudo-second-order kinetic model and Langmuir model, respectively. Besides, the PNIPAM/SA/GO ternary composite hydrogel could be easily removed from the dye solutions and reused without the obvious decrease of its performance. It indicated that the ternary composite hydrogel could serve as an effective adsorbent for the removal of organic pollutants.

Construction of N-loaded conjugated polymer for highly effective removal of iodine in organic solution

Qian Zheng,Bingyuan Huang,Xueying Du,Juan Zhang,Hongquan Fu,Hejun Gao,Yunwen Liao

Efficient capture of radioiodine is critical during nuclear fuel reprocessing and nuclear accidents. The development of material with excellent adsorption properties of radioiodine has always been a significant challenge. Three kinds of N-loaded conjugated polymers were prepared using the solvothermal method by changing the N-group in pyrrole . The effect of nitrogen type on the structure of conjugated polymers was investigated by SEM, BET, FT-IR, XPS , and EPR. Despite their low specific surface area, their mesoporous structure is conducive to transporting iodine molecules. The results showed that in the conjugated system , the adsorption capacity of alkyl tertiary amines for iodine was better than that of aminoethyl tertiary amines and secondary amines, and the maximum adsorption capacity could reach 737.4 mg/g. The adsorption mechanism of iodine on N-loaded conjugated polymer is mainly the interaction of charge transfer between iodine and N-aromatic in the organic solution.

Porous ball-in-ball N-doped carbon loading Co nanoparticles for high-performance asymmetric capacitor

Jiying Shi,Linlin Zang,Long Zhang,Jingzhen Wang,Qing Xu,Yanhong Zhang,Liguo Sun

Porous carbon supported metal nanoparticles as supercapacitor electrode materials have attracted extensive attention. In this paper, cobalt nitrate/polystyrene microspheres/chitosan(Co(NO 3 ) 2 /PS/CS) balls were fabricated by emulsion encapsulation and self-assembly process. After carbonization, Co nanoparticles (NPs) loaded on porous ball-in-ball N-doped carbon (Co/BNC) were prepared. Co/BNCs with high surface area profit formation of sufficient active sites and facilitate ion transport due to the interconnected and interpenetrating porous carbon structure. The electrochemical performances of Co/BNCs are affected by Co NPs content and the Co/BNC with the optimal Co NPs content (Co/BNC-2) possesses a commendable specific capacitance of 1120 F g −1 at 1 A g −1 . Moreover, the capacitance retention of the asymmetric supercapacitors assembled by Co/BNC-2 and activated carbon is about 85.38 % after 5000 cycles. Remarkably, the device exhibits a maximum energy density of 60.9 Wh kg −1 at 764 W kg −1 and maintains 37.8 Wh kg −1 at 7878 W kg −1 . Co/BNCs mentioned here have the potential to be candidates for high-performance supercapacitor electrode materials.

Synthesis, characterization, and performance comparison of boron using adsorbents based on N-methyl-D-glucosamine

Hui Jiang,Zijian Zhao,Ning Yu,Yi Qin,Zhengwei Luo,Wenhua Geng,Jianliang Zhu

Using N -methyl-D-glucosamine (NMDG) as the functional monomer , glycidyl methacrylate (GMA) as the connecting monomer, functionalized Fe 3 O 4 nano-particles (NPs) as the support, three adsorbents were prepared including direct polymer GMA-NMDG, magnetic GMA-NMDG polymer (MGN), and boron magnetic ion-imprinted polymer (BMIIP). Based upon the optimization of synthesis conditions, the prepared adsorbents and intermediate products were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscope, energy dispersive spectroscopy, X-ray diffraction, vibrating sample magnetometer, and Brunauer–Emmett–Teller to investigate the synthesis process, the morphological structure and the functional properties of the materials. The optimum performances of GMA-NMDG, MGN and BMIIP were obtained in the initial neutral solution (pH of 6.5). Moreover, GMA-NMDG and MGN reached the maximum adsorption capacity at 120 min, whereas BMIIP reached adsorption saturation at 60 min. The pseudo-second-order kinetic model was more suitable for the adsorption of boron using the adsorbents. The maximum adsorption capacity of GMA-NMDG was found to be 43.4 mg·g −1 , while those of MGN and BMIIP were 32.5 and 28.3 mg·g −1 , respectively. The Langmuir isotherm model was more appropriate to describe the adsorption process . The adsorbents maintained satisfactory adsorption performance within a certain temperature range. Competing ions had little effect on the adsorption of boron, and would be adsorbed simultaneously, due to which, the effect of co-adsorption can be considered. The adsorption capacity of GMA-NMDG was high, while the adsorption selectivity of BMIIP was much better. Furthermore, BMIIP showed good adsorption after five cycles of adsorption and desorption. The comparison of adsorbents showed that GMA-NMDG had the highest adsorption capacity and was suitable for co-adsorption. MGN had a high adsorption capacity, good comprehensive performance and magnetic properties. BMIIP had better adsorption rate, adsorption selectivity and recyclability. Through the optimization of synthesis conditions, the adsorption capacity of the traditional monomer NMDG polymer was increased, and the magnetism was given to facilitate rapid recovery. Combined with the ion imprinting technology, it showed higher boron adsorption selectivity in the presence of competitive ions.

Poly(N-heterocyclic carbene)-Protected Water-Soluble Gold Nanoparticles with Tunable Functions for Biosensing Applications

Xiujuan Qiao,Xing-Xing Gou,Yang Li,Jian-Li Li,Tianli Yue,Qinglin Sheng,Ying-Feng Han

Gold nanoparticles (Au NPs) are often susceptible to environmental changes, especially a complexly biological environment, significantly hindering the potential application of biosensors for practical detection. However, the controllable construction of ultrastable water-soluble Au NPs for biosensing applications remains a major challenge today. Here, ultrastable water-soluble Au NPs protected by tris-N-heterocyclic carbene (NHC) ligands (2·Au NPs) have been controllably designed and synthesized. The tris-NHC shell on the Au NP surface increases the chemical and electrochemical stability of the materials, making them stable in biological environments and even in excess biomercaptan. In addition, the ammonium salt substituent on the imidazolium nitrogen not only regulates the water solubility of Au NPs but also facilitates electrostatic interactions with biological substances. Ultimately, based on the controlled synthesis of ultrastable 2·Au NPs, it is convenient to build a probe for toxic substances of ochratoxin A detection with two signal readouts. A low limit of detection (0.66 pmol·L–1) and a wide linear response range (2.5 pmol·L–1 to 25 μmol·L–1) are achieved. Meanwhile, this proposed aptasensor exhibits excellent selectivity toward various potential interfering bioanalytes and sundry ions. This work demonstrates an efficient method to regulate the properties of Au NPs by functional NHC anchors and paves the way for practical biosensing application purposes.