Hollow ZIF-67-derived Co@N-doped carbon nanotubes boosting the hydrogenation of phenolic compounds to alcohols

The selective hydrogenation of highly toxic phenolic compounds to generate alcohols with thermal stability,environmental friendliness,and non-toxicity is of great importance.Herein,a series of Co-based catalysts,named Co@NCNTs,were designed and constructed by direct pyrolysis of hollow ZIF-67(HZIF-67)under H_(2)/Ar atmosphere.The evolution of the catalyst surface from the shell layer assembled by ZIF-67-derived particles to the in situ-grown hollow nitrogen-doped carbon nanotubes(NCNTs)with certain length and density is achieved by adjusting the pyrolysis atmosphere and temperature.Due to the synergistic effects of in situ-formed hollow NCNTs,well-dispersed Co nanoparticles,and intact carbon matrix,the as-prepared Co@NCNTs-0.10-450 catalyst exhibits superior catalytic performance in the hydrogenation of phenolic compounds to alcohols.The turnover frequency value of Co@NCNTs-0.10-450is 3.52 h^(-1),5.9 times higher than that of Co@NCNTs-0.40-450 and 4.5 times higher than that of Co@NCNTs-0.10-550,exceeding most previously reported non-noble metal catalysts.Our findings provide new insights into the development of non-precious metal,efficient,and cost-effective metal-organic framework-derived catalysts for the hydrogenation of phenolic compounds to alcohols.

Prediction of Henry Constants and Adsorption Mechanism of Volatile Organic Compounds on Multi-Walled Carbon Nanotubes by Using Support Vector Regression

Support vector regression （SVR） combined with particle swarm optimization for its parameter optimization is employed to establish a model for predicting the Henry constants of multi-walled carbon nanotubes （MWNTs） for adsorption of volatile organic compounds （VOCs）. The prediction performance of SVR is compared with those of the model of theoretical linear salvation energy relationship （TLSER）. By using leave-one-out cross validation of SVR test Henry constants for adsorption of 35 VOCs on MWNTs, the root mean square error is 0.080, the mean absolute percentage error is only 1.19~, and the correlation coefficient （R2） is as high as 0.997. Compared with the results of the TLSER model, it is shown that the estimated errors by SVR are ali smaller than those achieved by TLSER. It reveals that the generalization ability of SVR is superior to that of the TLSER model Meanwhile, multifactor analysis is adopted for investigation of the influences of each molecular structure descriptor on the Henry constants. According to the TLSER model, the adsorption mechanism of adsorption of carbon nanotubes of VOCs is mainly a result of van der Waals and interactions of hydrogen bonds. These can provide the theoretical support for the application of carbon nanotube adsorption of VOCs and can make up for the lack of experimental data.

Structure and Properties of Self-assembled Narural Rubber/Multi-walled Carbon Nanotube Composites

Natural rubber （NR）/multi-walled carbon nanotube （MWCNTs） composites were prepared by combining self-assembly and latex compounding techniques.The acid-treated MWCNTs （H2SO4：HNO3=3：1,volume ratio） were self-assembled with poly （diallyldimethylammonium chloride） （PDDA） through electrostatic adhesion.In the second assembling,NR/MWCNTs composites were developed by mixing MWCNTs/PDDA solution with NR latex.The results show that MWCNTs are homogenously distributed throughout the NR matrix as single tube and present a great interfacial adhesion with NR phase when MWCNTs contents are less than 3 wt%.Moreover,the addition of the MWCNTs brings about the remarkable enhancement in tensile strength and crosslink density compared with the NR host,and the data peak at 2 wt% MWCNTs loadings.When more MWCNTs are loaded,aggregations of MWCNTs are gradually generated,and the tensile strength and crosslink both decrease to a certain extent.

熔融法制备纳米管Li-Ti-O化合物及其表征

在熔融的LiNO3中,以纳米管钛酸钠为母体进行锂-钠离子交换,制得了具有高表面积的纳米管Li-Ti-O化合物(198.6m·2g-1)。XRD、XPS、TG表征结果表明:此纳米管Li-Ti-O化合物包含两种晶型物质,即立方尖晶石结构的Li2Ti2O4和锐钛矿结构的LixTiO2(x<0.1)],Li+在这两种晶型物质中的结合能不同;在空气中此纳米管Li-Ti-O化合物具有较强的吸水性,化学吸附水在高于400℃时才开始脱附。

分子动力学模拟在碳材料增强复合材料中的研究进展

综述了近年来国内外学者使用分子动力学模拟对碳纳米管、碳纤维和石墨烯增强的两相及三相树脂基复合材料进行研究的进展。分别对界面结合能、基体分散、聚合物构象等方面的模拟计算进行概述,归纳总结了分子动力学模拟在树脂基复合材料中所能解决的各类技术难题,并对其应用前景和发展趋势进行了展望。

基于物理特性的环氧胶粘材料改性效果比较

为了提升胶粘材料的力学性能,考察了单独添加石墨烯(GPE)、单独添加多壁碳纳米管(MWCNTs)和复合添加GPE+MWCNTs对胶粘剂单搭接接头室温剪切强度和断裂伸长率的影响,并对断口形貌进行了观察。结果表明,5组未改性胶粘剂试样的室温剪切强度和断裂伸长率平均值分别为14.98 MPa和1.79%;随着GPE含量从0.25%增加至1.5%,试样的室温剪切强度和断裂伸长率先增加后减小。随着MWCNTs含量从0.25%增加至1.5%,试样的室温剪切强度和断裂伸长率先增加后减小而后又增加的趋势。随着GPE+MWCNTs含量从0.25%增加至1.5%,试样的室温剪切强度和断裂伸长率先增加后减小而后又增加。复合添加GPE+MWCNTs对胶粘剂试样的室温剪切强度和断裂伸长率的提升效果要优于单独添加GPE或MWCNTs的胶粘剂试样。

碳纳米管及其改性复合材料的研究进展与展望

本文重点介绍了近几年碳纳米管及其复合材料的研究进展,对碳纳米管的特性,以及功能填料与高分子材料制备成高性能复合材料的合成工艺、材料性能和具体应用进行了分类介绍,最后对碳纳米管及其改性复合材料今后的发展方向进行了展望。

复方四黄液联合Ag_(2)O-TiO_(2)-NTs调控TLRs信号通路对骨折术后感染炎性反应的实验研究

目的探讨复方四黄液联合Ag_(2)O-TiO_(2)-NTs通过调控TLRs信号通路,对骨折术后感染的炎性反应的调控作用。方法将32只SPF级新西兰大白兔建立闭合性骨折内固定术后感染模型,按随机数字法分为对照组、Ag_(2)O-TiO_(2)-NTs组、复方四黄素溶液组、Ag_(2)O-TiO_(2)-NTs溶液+复方四黄素溶液组。于骨折部位注入表面葡萄球菌悬液。注射菌液当天及注射1 d、5 d、10 d、15 d后记录所有大白兔肛温、CRP、ESR及PCT,并取钢板周围滑膜组织进行TLR2和4的免疫组化及Western blot检测。结果复方四黄液以及Ag_(2)O-TiO_(2)-NTs均可以降低CRP、ESR及PCT的表达,二者合用时,效果更为明显。复方四黄液对术后感染的体温升高,具有较好的控制作用。复方四黄液和Ag_(2)O-TiO_(2)-NTs两组的TLR2及TLR4均较对照组降低,而合用后降低更为明显,说明二者具有抑制TLRs信号通路始动环节TLR2和TLR4的作用。结论应用复方四黄液,并联合Ag_(2)O-TiO_(2)-NTs治疗兔子闭合性骨折内固定术后感染,明确复方四黄液及Ag_(2)O-TiO_(2)-NTs能有效抑制TLR2及TLR4相关信号传导的启动,并降低下游的炎症指标表达的作用。

Concurrent catalytic removal of typical volatile organic compound mixtures over Au-Pd/α-MnO2 nanotubes

α-MnO2 nanotubes and their supported Au-Pd alloy nanocatalysts were prepared using hydrothermal and polyvinyl alcohol-protected reduction methods, respectively. Their catalytic activity for the oxidation of toluene/m-xylene, acetone/ethyl acetate, acetone/m-xylene and ethyl acetate/m-xylene mixtures was evaluated. It was found that the interaction between Au-Pd alloy nanoparticles and α-MnO2 nanotubes significantly improved the reactivity of lattice oxygen, and the 0.91 wt.% Au0.48 Pd/α-MnO2 nanotube catalyst outperformed the α-MnO2 nanotube catalyst in the oxidation of toluene, m-xylene, ethyl acetate and acetone. Over the0.91 wt.% Au0.48 Pd/α-MnO2 nanotube catalyst,（i） toluene oxidation was greatly inhibited in the toluene/m-xylene mixture, while m-xylene oxidation was not influenced;（ii） acetone and ethyl acetate oxidation suffered a minor impact in the acetone/ethyl acetate mixture; and（iii） m-xylene oxidation was enhanced whereas the oxidation of the oxygenated VOCs（volatile organic compounds） was suppressed in the acetone/m-xylene or ethyl acetate/m-xylene mixtures. The competitive adsorption of these typical VOCs on the catalyst surface induced an inhibitive effect on their oxidation, and increasing the temperature favored the oxidation of the VOCs. The mixed VOCs could be completely oxidized into CO2 and H2 O below 320°C at a space velocity of 40,000 m L/（g·hr）. The 0.91 wt.% Au0.48 Pd/α-MnO2 nanotube catalyst exhibited high catalytic stability as well as good tolerance to water vapor and CO2 in the oxidation of the VOC mixtures. Thus, the α-MnO2 nanotube-supported noble metal alloy catalysts hold promise for the efficient elimination of VOC mixtures.

MWCNTs/PVP增强APA6复合材料的制备及性能研究

以阴离子开环聚合PA6(APA6)为基体,聚乙烯吡咯烷酮(PVP)表面修饰的多壁碳纳米管(MWCNTs)为增强填料,采用原位阴离子开环聚合法,制备MWCNTs/APA6复合材料。采用扫描电镜(SEM)、差示扫描量热法(DSC)、热重分析(TG)、电阻率测定仪和电子万能试验机等,来研究多壁碳纳米管在复合材料中的分散行为、界面强度、热稳定性和结晶熔融行为等。通过设定碳纳米管与PVP的含量,研究其对复合材料各方面性能的影响。结果表明:表面修饰剂(PVP)与未改性碳纳米管共同作用对复合材料增强效果更好,多壁碳纳米管与PVP的加入不仅能显著改善APA6复合材料的弯曲强度和冲击强度,还可较大程度降低APA6复合材料的体积电阻率。当MWCNTs与PVP含量同为1.5%时,复合材料其弯曲强度提高14.5%,无缺口冲击强度提高55.3%,所以此含量下复材综合性能最优。

Effect of co-existing organic compounds on adsorption of perfluorinated compounds onto carbon nanotubes

Co-existing organic compounds may affect the adsorption of perfluorinated compounds （PFCs） and carbon nanotubes in aquatic environments. Adsorption of perfluorooctane sulfonate （PFOS）, perfluorooctane acid （PFOA）, perfluorobutane sulfonate （PFBS）, and perfluor- ohexane sulfonate （PFHxS） on the pristine multi-walled carbon nanotubes （MWCNTs-Pri）, carboxyl functionalized MWCNTs （MWCTNs-COOH）, and hydroxyl functiona- lized MWCNTs （MWCNTs-OH） in the presence of humic acid, 1-naphthol, phenol, and benzoic acid was studied. Adsorption kinetics of PFOS was described well by the pseudo-second-order model and the sorption equilibrium was almost reached within 24 h. The effect of co-existing organic compounds on PFOS adsorption followed the decreasing order of humic acid 〉 1-naphthol 〉 benzoic acid〉phenol. Adsorbed amounts of PFOS decreased significantly in the presence of co-existing or preloaded humic acid, and both adsorption energy and effective adsorption sites on the three MWCNTs decreased, resulting in the decrease of PFOS adsorption. With increasing pH, PFOS removal by three MWCNTs decreased in the presence of humic acid and phenol. The adsorbed amounts of different PFCs on the MWCNTs increased in the order ofPFBS 〈 PFHxS 〈 PFOA 〈 PFOS. The increase of both initial concentrations and the number of aromatic rings of co-existing organic compounds suppressed PFOS adsorption on the MWCNTs.

Simultaneous determination of nitrophenol isomers at the single-wall carbon nanotube compound conducting polymer film modified electrode

Based on the molecular recognition ability of conductive polymer and the peculiar properties of carbon nanotubes,a novel single wall nanotubes(SWNTs)compound poly(4-aminopyridine)modified electrode(SWNTs/POAPE)is prepared at glass carbon electrode(GCE).The electrochemistry response of nitrophenol isomers is studied at the SWNTs/POAPE.The re-sult indicates that o-,m-and p-nitrophenol are separated entirely at the SWNTs/POAPE interface.The electrode present here can be easily used to determine nitrophenol isomers simultaneously with higher sensitivity.

碳纳米管复合材料结合分散固相萃取-高效液相色谱-串联质谱法检测环境水样中痕量全氟化合物

以碳纳米管-二氧化硅棒复合材料为吸附剂,基于分散固相萃取法和液相色谱-串联质谱法建立了一种高灵敏、快速分析环境水样中痕量全氟化合物(PFCs)的方法。该研究选择全氟己烷磺酸、全氟庚酸、全氟辛酸、全氟辛烷磺酸、全氟壬酸和全氟癸酸6种全氟化合物为目标分析物。采用单因素优化法对影响萃取效果的重要因素进行了优化。获得的最佳条件为:吸附时间为30 min、吸附剂用量为10 mg、样品溶液pH为6、萃取过程添加NaCl浓度为1.7 mol/L、解吸溶剂为丙酮、解吸时间为4 min、解吸液的体积为4 mL。采用高效液相色谱-三重四极杆质谱联用技术对水样品中全氟化合物进行定量分析。以5 mmol/L乙酸铵和甲醇为流动相进行梯度洗脱,经Kinetex C18色谱柱(100 mm×2.1 mm, 1.7μm)分离,采用电喷雾离子源、负离子扫描模式和质谱多反应监测,实现了环境水样中6种全氟化合物的快速定性和定量分析。在优化条件下,6种全氟化合物在各自的线性范围内线性关系良好,检出限(S/N=3)为0.10~0.26 ng/L。添加500 ng/L 6种PFCs进行重复性实验,日内相对标准偏差(RSD)为2.51%~7.48%,日间RSD为3.59%~9.63%。将方法应用于自来水、桶装饮用水和河水3种实际环境水样中全氟化合物的分析,在低、中、高3个水平下,6种全氟化合物的加标回收率为72.1%~109.6%,结果满意。本方法成功地应用于实际环境水样中全氟化合物的检测,为快速、有效地检测环境水样中痕量全氟化合物提供了良好的选择。

Chinese Medicine Single-Walled Carbon Nanotube Targeting Compound for Antitumor Therapy:A Feasible Way?

Malignant cancer is the leading cause of death in man,exceeding cerebrovascular disease and heart disease.More than half of the total mortality due to malignant cancer is from lung,liver,intestinal and gastric cancer.Chemotherapy is one of the effective treatments for cancer.However,the great majority of Western anticancer medicines have considerable side effects.Herbal medicines offer many more advantages than synthesized compounds because they are made from purely natural compounds and have less adverse effects.However,the single administration methods used as standard in herbal medicine,and deficient drug targeting,severely limit their anticancer activity.Single-walled carbon nanotubes（SWNTs）can be used as drug carriers.They have been modified to form Chinese anticancer medicine-SWNT compounds which can specifically target tumors,thereby significantly increasing the therapeutic effectiveness of these medicines.Water-soluble SWNTs have high stability.As a drug carrier,SWNTs functional modification of the anticancer medicine may improve the targeting and killing of tumor cells.SWNTs have been attached to the Chinese antitumor medicines paclitaxel and plumbagin and have achieved excellent therapeutic effects.Furthermore,choosing the best administration methods such as internal iliac arterial infusion,intravesical infusion and embedment of a hypodermic chemotherapeutic pump,may also improve the anticancer effects of Chinese medicine.

多壁碳纳米管GC-21在全钢巨型工程机械子午线轮胎胎面胶中的应用

研究多壁碳纳米管GC-21在全钢巨型工程机械子午线轮胎胎面胶中的应用。结果表明:在胎面胶中以多壁碳纳米管GC-21部分替代炭黑N234,可改善胶料的导热性能,提高胶料的定伸应力、拉伸强度、耐磨性能和抗撕裂性能,胶料生热降低;成品轮胎的内部温度降低,使用寿命延长。

柔性固态超级电容器凝胶复合材料的研究进展

柔性固态超级电容器因其具有功率密度高,柔韧性好,质量轻,体积小,安全性好和循环寿命长的优点得到了广泛的关注和应用。由于凝胶复合材料具有独特的三维网络结构,将其用作电极材料和电解液材料能够显著提高柔性固态超级电容器的电化学性能。笔者系统地介绍了凝胶复合材料作为电极材料和电解液材料在柔性固态超级电容器上的研究进展,探讨了凝胶复合材料对柔性固态超级电容器的电化学性能和力学性能等多样化功能特性方面的重要作用。最后,分析了凝胶复合材料在柔性固态超级电容器中的前景与挑战。

碳纳米管对酚类物质的吸附研究

研究了碳纳米管对甲酚、对苯酚、对硝基苯酚以及α-萘酚的吸附,测定了不同浓度下碳纳米管对这4种物质的吸附量,并采用Langmuir方程、Freundlich方程进行拟合,探讨了其可能的吸附机理。结果表明:碳纳米管对α-萘酚具有很好的吸附效果,而对苯酚的吸附效果最差;对甲酚和α-萘酚的吸附比较适合用Langmuir方程描述,而对硝基苯酚的吸附用Freundlich方程描述较为适合.

苯酚及取代酚在碳纳米管上的吸附研究

本文研究了水溶液中碳纳米管(CNTs)吸附苯酚、对甲酚和对甲氧基苯酚的热力学特性,测定了不同温度下的吸附等温线,并探讨了其可能的吸附机理。结果表明:在稀溶液中碳纳米管对三种酚类物质的吸附均符合Freund lich和Langmu ir方程,吸附均为放热、熵增的自发过程,并且都具有物理吸附特征;碳纳米管与三种酚类物质分子之间的л—л共轭作用的强弱决定了碳纳米管对三种酚类物质的吸附能力,顺序依次为:对甲氧基苯酚>对甲酚>苯酚。

不同纳米碳材料阻燃聚对苯二甲酸乙二醇酯复合材料性能的表征

以碳微球(CMSs)、碳纳米管(MWNTs)、碳微球(CMSs)与碳纳米管(MWNTs)复配的3种材料,通过熔融共混法分别对聚对苯二甲酸乙二醇酯(PET)进行阻燃改性,制备出不同纳米碳材料阻燃PET复合材料。采用极限氧指数(LOI)法、垂直燃烧法、热重分析、扫描电镜等方法,测试和表征了CMSs/PET、MWNTs/PET、CMSs/MWNTs/PET复合材料的阻燃性能、热稳定性能、分散性及力学性能。结果表明,质量分数为1%的CMSs可使PET的LOI明显提高到28.9%,但对其抗熔滴性能的改善并不明显;同质量分数的MWNTs的添加,可有效提高PET的抗熔滴性能,其熔滴数由原PET的24d/min减少为6d/min;且CMSs与MWNTs具有协同阻燃效应,当两者的质量比为1∶2时,CMSs/MWNTs/PET的LOI为27.3%,且其熔滴数仅为4d/min;三者的垂直燃烧级别都由原PET的V-2级上升为V-0级,热稳定性都有所提高,但力学性能都有一定程度的下降。