Measuring the Stability of Supramolecular Complexes in the Proximity of Single-Walled Carbon Nanotubes

The decoration of SWNTs with supramolecular motifs is a common strategy for their subsequent noncovalent functionalization. However, due to the lack of a standard methodology, there are no quantitative measurements showing the extent to which the supramolecular equilibria are affected by one of the host-guest couple being anchored to the SWNT. Here, we use a method we initially developed to quantify association of small organic molecules to the walls of SWNTs to compare association constants of two host-guest systems, a Hamilton receptor-cyanuric acid derivative and a crown ether-ammonium couple, in solution and when the host is covalently attached to the SWNTs. Our data show that association does occur, but the stability of the complexes is significantly affected, as reflected in a sizable reduction in their association constant, when compared to solution.     

Single‐gap Microelectrode Functionalized with Single‐walled Carbon Nanotubes and Pbzyme for the Determination of Pb2+

Lead is a highly toxic metal, which can persist in the natural environment and enrich in biological bodies. It can cause many severe diseases in the human body even at extremely low concentration. Here, we developed a new biosensor using single‐walled carbon nanotubes (SWNTs) modified with a specific Pbzyme (Pbzyme/SWNTs/FET) to detect lead ion (Pb²⁺), which can monitor the lead pollution. This biosensor used 3‐aminopropyltriethoxysilane to immobilize SWNTs on the area between the source and the drain of single‐gap microelectrode (FET), and the duplex DNA (Pbzyme) consisted of DNAzyme (GR‐5) and complementary DNA (CS‐DNA) was functionalized with the SWNTs’ surface through a peptide bond. The use of GR‐5 DANzyme and Pb²⁺ to form a stable complex structure to cleave the CS‐DNA can change radically the Pbzyme's structure on the SWNTs’ surface, which will further affect the number of carriers in SNWTs and the conductivity of the Pbzyme/SWNTs/FET. The change in conductivity can be used to evaluate the Pb²⁺ concentration. Under the optimal conditions, the relative resistances presented a positive correlation with the Pb²⁺ concentrations, showing a good linear relationship in the range of 10 pM to 50 nM, where the linear regression equation was y=10.104log [C_Pb]+5.8656, and the detection limit was 7.4 pM. Finally, the biosensor was applied to measure the Pb²⁺ contents in the soil collected from the forest grass green belt and paint, and the results were compared with the results of atomic fluorescence spectrometry.     

碳纳米管和碳纳米管-四氢呋喃水合物的储氢特性

研究了单壁碳纳米管(SWNTs)干法储氢和碳纳米管(SWNTs)-四氢呋喃(THF)水合物法储氢的过程. 结果表明, 实验所用的SWNTs在16.5 MPa压力下, 温度为0.5 ℃时, 氢气的吸附存储量为0.75%(质量分数), 经浓酸处理后, 氢气的存储量可以达到1.15%, SWNTs-THF水合物法储氢量为0.37%, 与碳纳米管干法储氢相比, 储氢量有所降低.     

Purification of Single-walled Carbon Nanotubes Grown by a Chemical Vapour Deposition (CVD) Method

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单壁碳纳米管的轴向能带工程

单壁碳纳米管具有优异的电子学特性,是制备新一代高性能集成电路的重要材料.碳纳米管芯片之路存在诸多挑战,包括直径和手性的控制生长方法、金属性和半导体性单壁碳纳米管的分离方法、器件加工与集成方法等.这些课题从本质上讲大多属于化学问题,因此碳纳米管芯片研究为化学家们提供了新的机遇与挑战.过去10年来,我们围绕单壁碳纳米管的轴向能带工程这一研究思路,开展了一系列碳纳米管芯片的基础探索工作,发展了若干有效的单壁碳纳米管局域能带的调控方法,包括温度阶跃生长法、脉冲供料生长法、基底调控法以及形变调控法等.本文系统地阐述了这些局域能带调控方法,为使读者对该领域的研究进展有一个较为全面的了解,文中对其他课题组开展的代表性工作也给予了综述性介绍.     

一种基于SWNTs/Nafion/CuNPs纳米复合材料的

通过电沉积金属铜于SWNTs/Nafion修饰的玻碳电极表面构建了一种经济且简单易制备的非酶尿酸传感器.采用扫描电镜和能谱仪表征了纳米材料的形貌和成分,并考察了不同扫速和pH值对修饰电极的影响.在优化条件下,尿酸的线性范围为0.1～1000 μmol·L-1,检出限(S/N =3)为0.058 5iμmol·L-1.采用标准加入法检测人体血清中尿酸的回收率为97.2％～103.9％,相对标准偏差(RSD)为0.04％～0.11％.该非酶法与GOD-POD酶法的结果高度一致,且传感器经济易制备、灵敏性高、稳定性好、重现性高.     

meso‐Tritolylcorrole‐Functionalized Single‐walled Carbon Nanotube Donor?Acceptor Nanocomposites for NO2 Detection

meso‐Tritolylcorrole‐functionalized single‐walled carbon nanotubes (TTC‐SWNT) donor‐acceptor (D–A) heterojunction nanocomposite film was fabricated on a polycarbonate membrane through filtration and non‐covalent functionalization, providing an excellent sensing platform with low‐cost, high flexibility and good gas accessibility. The TTC‐SWNTs nanocomposite displays a fast and sensitive response to nitrogen dioxide with a limit of detection of 10 ppb (S/N=3). The sensing response was significantly amplified compared to the unmodified one, which was ascribed to a D–A heterojunction at the interface between electron donor TTC and electron acceptor SWNTs. This study provides a simple route to fabricate low‐cost and highly sensitive donor‐acceptor nanocomposite‐based gas sensors.     

活性碳纤维阴极电芬顿反应降解微囊藻毒素研究

以具有高比表面积的活性碳纤维作为阴极,通过电芬顿反应降解水中微囊藻毒素(MCRR,MCLR)的电化学方法系统考察了电流密度、pH值和Fe2+浓度等因素对微囊藻毒素降解效果的影响.实验结果表明,在Fe2+浓度为1.0mmol/L和电流密度为6.6mA/cm2条件下,电化学处理60min,MCRR(8.81mg/L)去除率为75%,MCLR(6.36mg/L)去除率为94%.证明过氧化氢可以通过电化学还原在活性碳纤维阴极表面高效产生,微囊藻毒素可被高效降解去除.     

碳纳米管/超支化重氮盐自组装膜的制备及性能研究

利用静电吸附自组装技术将酸化处理后的单壁碳纳米管(SWNTs)与超支化重氮盐(DAS)组装成多层膜.利用紫外光谱、椭偏仪、原子力显微镜、扫描电镜、拉曼光谱等对自组装膜的生长过程、膜厚增长、自组装膜表面形貌以及纳米管在膜中的存在状态等进行了检测,并利用纳米压痕仪测试了自组装膜的硬度和弹性模量.研究结果表明,SWNTs与DAS不仅发生了静电吸附,而且还发生了化学交联.同时碳纳米管均匀分散在自组装膜中.这两种因素的共同作用使得自组装膜表现出良好的纳米力学性能,硬度达到2.0GPa左右,弹性模量达到10.0GPa左右,而且可以从基底上剥离下来成为独立支撑膜.     

可快速充放电聚吡咯/碳纳米管复合材料电化学聚合与表征

采用恒电流法制备了具有可快速充放电性能的对甲基苯磺酸根(TOS-)掺杂聚吡咯/功能化单壁碳纳米管(PPy-TOS/F-SWNTs)复合材料,扫描电镜(SEM)结果表明该复合材料呈纳米棒状构成的多孔结构,棒径约为70nm;比表面积(BET)测试分析表明该复合材料有着较高的比表面积(12.64m2.g-1)和大的介孔孔隙率(20-40nm).循环伏安(CV)、电化学阻抗谱(EIS)和恒电流充放电(GC)电化学分析表明该材料具有优异的快速充放电性能,在800mV的电位窗和2.5A.g-1(功率密度为2kW.kg-1)的电流密度下该材料具有211F.g-1的比容量(能量密度为18.7Wh.kg-1),而当充放电电流高达80A.g-1(功率密度为60kW.kg-1)时比容量仍可达141.8F.g-1(能量密度为12.6Wh.kg-1),同时该材料还表现出优异的稳定性,在10A.g-1大电流下经历10000圈循环后容量仍保持95.2%.