JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 133
·期 35
·
IF 1.866
Yuanzhu Long,Fuhua Sun,Chao Liu,Dong Huang,Xingyi Xie
To explore a new blowing agent for polyurethanes (PUs), palmitic acid was grafted onto a branched polyethyleneimine (bPEI; weight-average molecular weight = 25,000 Da) via N,N ′-carbonyldiimidazole condensation to form a hydrophobically modified bPEI [palmitic acid grafted branched polyethyleneimine (C 16 –bPEI)] with a grafting rate of 12%. A CO 2 adduct of C 16 –bPEI, which trapped 16.8% CO 2 in it, was synthesized from C 16 –bPEI. The long alkyl chain grafting improved the dispersibility of the CO 2 adduct in the PU raw materials and favored a homogeneous release of CO 2 to blow PUs during the exothermic foaming process. The preliminary results show that the foams possessed a density of 72.0 kg/m 3 and a compressive strength of 246 kPa; this matched the required values of foams for the thermal insulation of underground steel pipes. This new blowing agent emitted nothing but CO 2 to the atmosphere, so it will not promote ozone depletion and will avoid global warming problems that are associated with traditional blowing agents such as chlorofluorocarbons and hydrochloroflourocarbons. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43874.
研究领域:
高分子化学
·
材料科学
·
绿色化学
·
能源与环境材料
·
工业催化
✓ 已验证
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2023
·
IF 6.4
Jinhui Wang,Ruisong Wang,Xiaoxiao Ji,Chunde Jin,Yutao Yan
Phenol formaldehyde (PF) resin adhesives are widely used in the production of bamboo-based composites owing to their excellent bonding strength and durability. However, the inherent brittleness of cured PF resin may result in notable stress concentration at the interface between PF resin and bamboo bonding, leading to the generation of cracks. In this study, a hyperbranched compound polyethyleneimine (PEI) with high reaction activity was incorporated into a PF resin adhesive to toughen the adhesive and the bonding interface. And the effects of PEI incorporation on the properties of the adhesive and the bonding performance between PF resin and bamboo were comprehensively investigated. The results showed that introduction of flexible PEI chains could effectively facilitated stress transfer, avoiding stress concentration, thus enabling efficient energy release and play a toughening effect. In addition, PEI could react with PF resin and bamboo components during hot pressing, forming a three-dimensional network structure and enhancing the bonding interface, which was proved by FT-IR and XPS analysis. When 1 wt% PEI was incorporated, the bending strength and Charpy impact toughness of the modified PF resin was significantly increased by 38.88% and 76.02%, respectively, compared with the pure PF resin. While the dry and wet shear strength of the bamboo composite bonded by the PEI modified PF resin were also obviously increased. This study is expected to address the problem of cracking in the bonding interface of bamboo composite, and endow the composites with high strength and durability, which can prolong its service life and contribute to the healthy and sustainable development of the bamboo industry.
研究领域:
材料科学
·
木材科学与技术
·
高分子化学
·
复合材料工程
·
胶接与界面科学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2011
·
IF 2.13
Xin Tian,Zhengping Dong,Yifan Huang,Jiantai Ma
In this work, molecular logic element modified multifunctional silica nanoparticles having high magnetization have been successfully prepared. These multifunctional nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), Elementary analysis, X-ray powder diffraction (XRD) and Vibrating sample magnetometer (VSM). The characterization datum indicated that the organic ligand was successfully grafted on the surface of the magnetic silica nanoparticles . The fluorescent changes of the hybrid material upon the addition of cations (H + , F − and their mixture) is utilized as an INHIBIT logic gate at the molecular level, using the fluorescence intensity signal as output.
研究领域:
纳米医学
·
生物传感器
·
分子诊断
·
化学生物学
·
智能材料
✓ 已验证
DOI
高影响因子
BULLETIN OF THE KOREAN CHEMICAL SOCIETY
·
2018
·Vol. 39
·期 5
·657-664
·
IF 0.522
Nai-Di Tan,Jian-Hang Yin,Yaqing Yuan,Lei Meng,Na Xu
Herein, a novel bright-green and highly fluorescent polyethyleneimine capped copper nanoclusters (CuNCs@PEI) has been hydrothermally synthesized, which is employed as a fluorescence probe to determine rifampicin. Under optimum synthetic conditions, the morphology, surface chemistry and optical features of resulting CuNCs@PEI are well characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, UV–Vis absorption spectra, transient and steady-state fluorescence. In comparison to previous reports, the new species with a larger diameter of approximately 3 nm exhibit higher fluorescence quantum yield (QY) up to nearly 10.7%, and demonstrate tolerability to extreme pH, high ionic strengths as well as long-term UV irradiation. These excellent optical properties ascribe to unique grain size and surface chemical features of products, which are further discussed in this work. In addition, we employed as-prepared CuNCs@PEI to detect rifampicin based on fluorescence quenching phenomenon. The fluorescence intensity of probe is linearly proportional to rifampicin over the concentration rage from 0 to 20 μM, where the limit of detection (LOD) is 50 nM. Besides, this probe can be also used to assay rifampicin in serum samples with satisfactory recoveries.
研究领域:
分析化学
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纳米生物技术
·
药物分析
·
分子诊断
·
转化医学
·
药代动力学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 58
·53319-53323
·
IF 3.289
Tiantian Gu,Min Zhou,Mengyun Liu,Kangli Wang,Shijie Cheng,Kai Jiang
A polyimide–MWCNT composite (PNP@CNT) synthesized from 1,4,5,8-naphthalenetetracarboxylic-dianhydride (NTCDA) and phenylene diamine (PDA) was investigated as a novel anode for aqueous Na-ion batteries. This composite demonstrates a high reversible capacity of 149 mA h g−1 at quite a low potential of −0.65 V (vs. SCE), superior rate capability and long-term cycling stability. The feasibility of PNP@CNTs in aqueous Na-ion full batteries is also confirmed in conjunction with the Na0.44MnO2 cathode, possibly serving as a high performance aqueous Na host anode for large-scale electric energy storage applications.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米复合材料
·
电池技术
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
·
2014
·
IF 2.745
Teng Zhang,Xiao-Ling Xu,Yi-Ning Jin,Jian Wu,Zhi-Kang Xu
Carbon nanotubes are widely applied in electronics, which offers great potential for enhancing the activity of redox enzyme. In this work, polyimide (PI) was blended with multiwalled carbon nanotubes (MWCNTs) and then electrospun into nanofibers for the immobilization of horseradish peroxidase (HRP), a redox enzyme. SEM and TEM were used to characterize the surface morphology of the PI/MWCNTs nanofibers and to analyze the protruding parts induced by the blending of MWCNT. The results indicate that, compared to the virgin PI nanofibers, the blending of MWCNTs increases the retention activity of immobilized HRP from 2.38% to 12.50%. Circular dichroism and UV–vis molecular absorption spectrometry were used to explore the interactions between HRP and MWCNTs . It seems that MWCNTs increase the enzyme activity by the facilitation of electron transfer among the catalytic intermediates “HRP I”, “HRP II” and MWCNTs.
研究领域:
生物化学
·
纳米生物技术
·
酶工程
·
生物材料
·
分析化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Shengguo Zhou,Wentao Li,Wenjie Zhao,Chao Liu,Zhiwen Fang,Xiulei Gao
As one of the youngest graphene derivative, fluorinated graphene (FG) with excellent mechanical strength and lubricity was incorporated into polyimide polymer (PI) to strengthen the comprehensive performance of nanocomposite . This article gives a detailed characterization to investigate the tribological behaviors of PI/FG nanocomposite films under different friction conditions including both of dry sliding and seawater lubrication . Firstly, the chloroform-treated FG was proved to be stably dispersed in the PI matrix . Subsequently, mechanical properties, thermal stability and tribological properties of PI/FG nanocomposite films were greatly improved. Finally, analysis of the reasons for the significant improvement in wear resistance from the viewpoint of thermal, mechanical properties and the evolution of friction products. Meanwhile, the transfer of FG from polymer matrix to frictional duality was revealed during tribological testing. The above results suggest the potential application of FG in the field of reinforcing polymer friction properties.
研究领域:
材料科学
·
高分子材料
·
表面工程
·
摩擦学
·
纳米复合材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 52
·期 19
·11701-11714
·
IF 2.599
Wei Xiuzhen,Hong Jialiang,Zhu Shuangshuang,Chen Jinyuan,Lv Bosheng
Polyethyleneimine (PEI) of various molecular weights and trimesoyl chloride (TMC) were utilized to prepare composite nanofiltration (NF) membranes via interfacial polymerization. The changes in the surface structure and chemical composition of the prepared membranes were evaluated using SEM, ATR-FTIR, XPS and surface potential measurements. The pure-water flux and rejection rates of the inorganic salts (MgCl 2 , MgSO 4 , Na 2 SO 4 and NaCl) through the resultant NF membranes were also investigated. The results showed that the performance of the composite NF membranes was significantly affected by the molecular weight of the PEI. Notably, the permeate flux and rejection rate of the NF membranes increased with the PEI molecular weight. In addition, when the NF membranes were used to treat actual wastewater from the electroplating industry, the NF membranes presented high-efficiency separation properties for heavy metal ions. The rejection rates of the NF membranes at 0.4 MPa for chromium, nickel, zinc and copper ions reached 92.6, 89.6, 89.2 and 86.3%, respectively.
研究领域:
材料科学
·
膜分离技术
·
环境工程
·
高分子化学
·
水处理
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2018
·
IF 2.21
Fei Xu,Hongtao Wang,Mengyi Wu,Jiangsai Nan,Ting Li,Shun-an Cao
Redox-active organic materials are potential cathode materials for material-sustainable and environment-friendly Li-ion batteries. As is one of the most prominent features for organic compounds, isomerism has a significant influence on their properties. Herein, we synthesize two isomeric pairs of poly(anthraquinonyl imide)s ( PAQI s) by a simple one-pot reaction, and investigate their electrochemical properties as Li-ion battery cathodes by cyclic voltammogram and galvanostatic discharge/charge cycling. The PAQI materials exhibit a high reversible capacity of 202 mAh g −1 and a stable cyclability with 80% capacity retention over 200 cycles, and a remarkable rate performance, suggesting a potential feasibility of these organic cathode materials for high-capacity Li-ion batteries. The discharge/charge potentials of these PAQI s are slightly lower than the monomers . A further comparison of these four PAQI s indicates the isomerism plays a significant role in the electrochemical performance of these organic electrode materials .
研究领域:
电化学
·
材料科学
·
能源存储
·
有机电极材料
·
锂离子电池
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 12
·2982-2991
·
IF 2.137
Zhiyong Zhang,Miaojun Xu,Bin Li
The polymethacrylimide/silicate (PMI/silicate) composites were successfully prepared from the monomers of acrylonitrile (AN) and methacrylic acid (MAA) via the monomer in situ intercalation polymerization and free foaming. The formation of imide groups was monitored by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The results of FTIR and XPS indicated that the imide groups were gradually formed and cyano groups were dwindling but still existed during foaming and thermal treatment. The thermogravimetric analysis results revealed that the thermal stability of the PMI/silicate composites was improved, the rate of thermal degradation was reduced, and the residue was increased because of the addition of silicates. The results of dynamic mechanical analysis revealed that the rigidity and the glass transition temperature of the composites were improved. The limit oxygen index (LOI) and cone calorimeter (CONE) test showed that the fire-retardant properties were improved because of the barrier effect of silicates. The cell morphologies of the PMI/silicate composites were characterized by scanning electron microscopy (SEM), and the results showed that the silicate particles were distributed on the cell walls, but the cells slightly cracked. The mechanical properties were measured by tensile, flexural, and compressive strength. The mechanical strength, especially flexural strength, was significantly improved. The flexural strength of PMI/MMT, PMI/kaolin, and PMI/talc containing 8 wt% silicates was improved to 172%, 240%, and 233%.
研究领域:
高分子材料
·
复合材料科学
·
材料化学
·
防火材料
·
多孔材料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 27
·22908-22916
·
IF 3.289
Jianwen Tian,Xiaohui He,Jingyin Liu,Xiaodan Deng,Defu Chen
Palladium(II) and copper(II) chloride complexes bearing bulky 9,10-dihydro-9,10-ethanoanthracene-11,12-diimine ligands were synthesized and sufficiently characterized by elemental and spectroscopic analysis along with X-ray diffraction analysis. The X-ray diffraction demonstrated that palladium(II) complexes (C1–C2) and copper(II) complexes (C3–C4) were four-coordinated. All these complexes displayed catalytic activities up to 105 gpolymer molMt−1 h−1 for norbornene vinyl-addition polymerization on treatment with excess methylaluminoxane (MAO). The parameters of the reaction conditions, the type of metals and steric effects of coordinative ligands had influences on the catalytic properties. C2 was selected as a catalyst precursor for the copolymerization of norbornene (NB) with 2-butyloxymethylene norbornene (BN), which exhibited catalytic activities up to 1.1 × 105 gpolymer molPd−1 h−1 and produced copolymers with relatively high molecular weights. The fraction of BN in the copolymer could reach up to 9.8–62.1% by controlling the monomer feed ratio range from 10–80%. The achieved vinyl-addition type poly(NB-co-BN) displayed high thermal stability and was soluble in common organic solvents, such as CHCl3 and THF.
研究领域:
高分子化学
·
配位化学
·
催化化学
·
有机金属化学
·
功能高分子材料
✓ 已验证
DOI
高影响因子
Advanced Materials Technologies
·
2019
·Vol. 4
·期 10
·1900426
·
IF 5.395
Peng Bi,Xiaowei Liu,Yang Yang,Ziyu Wang,Jing Shi,Gaomin Liu,Fangfang Kong,Benpeng Zhu,Rui Xiong
Wearable devices have become very important for collecting health information and monitoring the condition of seriously ill patients. However, most recently developed wearable devices can only monitor limited signals within a very small range of values. A novel sensor is fabricated by modifying the surface of polyimide nanowires with silver nanoparticles. These nanowire sensors can sense both pressure and temperature changes and have antimicrobial properties. The fabricated sensor can detect a wide range of pressure variation from 5 KPa to 100 KPa. A theoretical model is developed to explain the sensing mechanism of the silver-nanoparticle-modified polyimide nanowires. The experimental and theoretical results for the nanowires are in good agreement. By attaching these sensors to human joints and fingers, real-time information can be detected for human motion, such as walking or holding a hot cup of water. The excellent performance of this device shows that it has great potential for use in artificial skins for detecting temperature and human motion.
研究领域:
生物医学工程
·
纳米医学
·
柔性电子
·
智能材料
·
转化医学
·
可穿戴传感器
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）