碳纳米管对羟基磷灰石基复合材料力学性能的影响

将力学性能优良的碳纳米管(CNTs)与羟基磷灰石(HA)生物陶瓷相复合,发展CNTs/HA复合材料来应用于骨组织修复领域,有望解决HA生物陶瓷力学性能的不足。通过3种不同的制备方法,即通过表面活性剂将CNTs分散在HA基体中、通过酸碱中和反应将CNTs与HA共沉淀以及通过体外浸泡在CNTs上矿化生长HA等方法来获得CNTs/HA复合材料。深入研究CNTs的表面结构和分散状态对CNTs/HA复合材料力学性能的影响。结果表明,CNTs的添加改变了HA的脆性,导致复合材料抗压力学性能得到提高。但是,由于复合材料制备方法的不同,导致CNTs在HA基体中的分散状态、表面结构的完整性以及与HA的界面结合情况不同,导致其抗压力学性能不同。其中,通过表面活性剂将CNTs分散在HA基体中而获得复合材料的抗压力学性能表现最好,而CNTs与HA通过共沉淀法所获得复合材料的抗压力学性能表现最差。     

碳纳米管对羟基磷灰石基复合材料力学性能的影响

将力学性能优良的碳纳米管(CNTs)与羟基磷灰石(HA)生物陶瓷相复合,发展CNTs/HA复合材料来应用于骨组织修复领域,有望解决HA生物陶瓷力学性能的不足.通过3种不同的制备方法,即通过表面活性剂将CNTs分散在HA基体中、通过酸碱中和反应将CNTs与HA共沉淀以及通过体外浸泡在CNTs上矿化生长HA等方法来获得CNTs/HA复合材料.深入研究CNTs的表面结构和分散状态对CNTs/HA复合材料力学性能的影响.结果表明,CNTs的添加改变了HA的脆性,导致复合材料抗压力学性能得到提高.但是,由于复合材料制备方法的不同,导致CNTs在HA基体中的分散状态、表面结构的完整性以及与HA的界面结合情况不同,导致其抗压力学性能不同.其中,通过表面活性剂将CNTs分散在HA基体中而获得复合材料的抗压力学性能表现最好,而CNTs与HA通过共沉淀法所获得复合材料的抗压力学性能表现最差.     

羟基喜树碱在单壁碳纳米管修饰电极上的伏安行为及应用

试验发现修饰电极上的单壁碳纳米管层能显著提高羟基喜树碱的氧化峰电流,通过选择和优化各项参数,提出了一种直接而灵敏测定羟基喜树碱的伏安分析方法.该方法的线性范围为0.05-2.5μmol·L-1.富集3 min后,检出限(3S/N)为0.02 μmol·L-1.1.0μmol·L-1羟基喜树碱平行测定10次的相对标准偏差为4.8%.分剐加入3种不同浓度的羟基喜树碱标准溶液进行方法的回收试验,测得回收率在95.5%-104.0%之间.该方法应用于羟基喜树碱注射液中羟基喜树碱的含量测定,所得结果与UV-分光光度法所测得结果相符.     

单壁碳纳米管短管的制备

分别通过控制CVD生长时间的方法和在混合的硝酸硫酸中超声氧化碳纳米管的化学剪裁法制备了单壁碳纳米管短管.两种方法都能将大多数碳纳米管的长度控制在500 nm以下.拉曼光谱结果表明: 在化学剪裁过程中,单壁碳纳米管部分被破坏产生无定形碳杂质;用控制CVD反应时间得到的单壁碳纳米管短管样品比长时间反应得到的长管样品杂质少,且不存在后处理时碳纳米管的破损问题,其纯度比化学剪裁法得到的产品纯度高.     

电化学沉积制备羟基磷灰石涂层及机理研究

控制电沉积溶液中钙 /磷离子的浓度 ,在钛合金表面直接沉积羟基磷灰石 (HAP)陶瓷涂层 .XRD、SEM实验证实 ,制备的HAP晶粒完整 ,粒度均匀 .热力学计算表明HAP比TCP更易于生成 .文中讨论了羟基磷灰石 (HAP)涂层电沉积的机理 ,指出电沉积是一个二步过程 ,HAP的形成是从溶液中离子到固体的直接过程 ,没有前驱体的生成     

碳纳米管纳米分子印迹聚合物传感器的制备及对血液中葡萄糖的测定

以葡萄糖为模板分子,通过电聚合邻苯二胺,在多壁碳纳米管修饰的GC电极表面制备了一种对葡萄糖具有选择性响应的分子印迹聚合薄膜传感器,优化了制备方法。通过循环伏安法(CV)和交流阻抗法对该分子印迹传感器对葡萄糖的响应性能进行了表征。在最优实验条件下,该印迹电极能在6.0~560.0μmol/L浓度范围内对葡萄糖进行检测,检出限为8.0×10~(-7) mol/L,并可在其他物质存在下选择性识别葡萄糖。此传感器可用于血液中葡萄糖的测定,加标回收率为98.5%~103.3%。     

基于单壁碳纳米管-十二醛复合材料的DNA电化学传感器

将单壁碳纳米管(SWNTs)和十二醛(DA)混合超声分散,得到均匀、稳定的无机-有机纳米复合材料(SWNTs-DA)。将其滴涂在玻碳电极表面晾干得到复合材料修饰电极(SWNTs-DA/GCE),再通过胺醛缩合反应将末端修饰氨基的单链DNA探针共价固定在SWNTs-DA/GCE表面,构建了一种新型的DNA电化学传感器。以[Fe(CN)6]3-/4-为电活性探针,采用循环伏安法和电化学阻抗法对传感器的层层组装过程进行表征。以亚甲基蓝(MB)作为杂交指示剂,考察了传感器分析性能。实验结果表明,MB在传感器上的峰电流值(Ip)与互补序列浓度对数值(lgcS2)在1.0×10-15～1.0×10-10mol/L范围内呈良好的线性关系(r=0.998)。根据3倍信噪比(S/N=3),计算得检出限为2.0×10-16mol/L。选择性实验表明该传感器能对互补序列、三碱基错配序列和非互补序列进行很好的识别。     

电位阶跃法沉积羟基磷灰石的研究

采用电化学方法在钛金属基底上沉积羟基磷灰石(HA)。系统考察了阶跃电位、沉积时间等实验条件对涂层质量的影响。在一定温度下经碱液处理后获得的羟基磷灰石(HA)涂层的形貌和结构分别用扫描电子显微镜(SEM)和X-射线衍射(XRD)进行了表征；用粘结拉伸法测得涂层的界面结合强度达7．44MPa，并在模拟生物体液中考察了生物活性以及电化学腐蚀性能。     

单壁碳纳米管的手性测量

单壁碳纳米管的制备方法主要包括物理法和化学法两种,不同制备方法的产物中包含很多种不同手性指数的单壁碳纳米管及杂质,而不同手性的单壁碳纳米管其作用完全不同,从而有不同的应用。采用化学方法——钴钼催化剂气相沉积法和物理方法——激光烧蚀气相沉积法制备单壁碳纳米管,用紫外–可见–近红外吸收光谱、荧光光谱及拉曼光谱法分别对其进行手性测量。结果表明,钴钼催化剂气相沉积法制得样品富含半导体型单壁碳纳米管,而激光烧蚀气相沉积法制得样品中主要为金属型单壁碳纳米管。分别得到了两种制备方法样品的手性分布。     

单壁碳纳米管与卤代烷的亲电加成反应

主要考察了以路易斯酸为催化剂,几种卤代烷烃为反应试剂的单壁碳纳米管侧壁的亲电加成反应,并通过傅立叶红外光谱、热失重分析和拉曼光谱验证了实验所得产物。此反应的目的是在单壁碳纳米管的侧壁连上烷基基团以提高其溶解性和分散性,并可使其更好地与聚烯烃相结合从而提高复合材料的性能,因而具有较高的研究和应用价值。     

碳纳米管/聚二烯丙基二甲基氯化铵/磷钼酸复合膜的组装及其在溴酸盐检测中的应用

通过静电层层组装技术在玻碳(GC)电极表面制备{多壁碳纳米管(MWCNT)/聚二烯丙基二甲基氯化铵(PDDA)}n多层膜,并采用循环伏安法在多层膜的表面电化学修饰一层磷钼酸(PMo12)膜,构筑GC/{MWCNT/PDDA}n-PMo12复合膜修饰电极.利用SEM对比观察{MWCNT/PDDA}n和{PDDA/MWCNT}n-PMo12的微观结构,并研究该复合膜修饰电极的电化学及其对溴酸盐(BrO3-)电催化还原性质.在此基础上研发一种基于GC/{MWCNT/PDDA}n-PMo12复合膜修饰电极的电流型BrO3-传感器,该传感器表现出明显增大的响应电流.在最优的实验条件下,采用电流时间曲线(i-t)法考察该复合膜修饰电极对BrO3-的安培响应.实验结果表明,该传感器在BrO3-浓度为50～400nmol/L的范围内具有良好的线性关系,相关系数R2为0.9950,响应时间为1.53s,检出限为20nmol/L,灵敏度为13.81mA(mmol/L)-1cm-2.     

Multiwalled carbon nanotube based ion imprinted polymer as sensor and sorbent for environmental hazardous cobalt ion

By using molecular imprinting approach, a highly selective multiwalled carbon nanotube based electrochemical sensor for Co(II) ion was fabricated. The sites for binding of Co(II) ion was created with cobalt ion as template, NNMBA-crosslinked polyacrylic acid as the solid polymer matrix which is coated on functionalized MWCNTs. For the comparison, system without template was also created (MWCNT-NIP). In order to check the importance of MWCNTs, imprinted (IIP) and non-imprinted (NIP) polymer without MWCNTs were also produced. The developed systems were successfully characterized by different analytical techniques. The selectivity of the systems was checked with different metal ions. The electrochemical response of the nanostructures modified platinum electrode were investigated and optimized. The MWCNT-IIP/Co/PE exhibit fast sensing and high selectivity towards Co(II) ion. The detection limit of the sensor was explored with differential pulse voltammetry and it was found to be at 1.01 × 10^?5µM. The practical applicability of the sensor was successfully applied for the trace sensing and extraction of Co(II) ion from real samples such as fertilizer and battery. The recoveries of Co(II) ion from the samples were very high, that revealed the efficiency of the systems for environmental applications.     

Direct electron transfer of hemoglobin on dihexadecyl hydrogen phosphate/single-wall carbon nanotubes film modified Au electrode and its interaction with taxol

Direct electrochemistry of hemoglobin (Hb) immobilized on the dihexadecyl hydrogen phosphate (DHP)/single-wall carbon nanotubes (SWNTs) film modified Au electrode is investigated. The immobilized Hb displays a couple of stable and well-defined redox peaks, whose formal potential (E ⁰) is −0.434 V (SCE) in a phosphate buffer solution of pH 7.0. The formal potential of the heme Fe(III)/Fe(II) couple shifts negatively linearly with increased pH with a slope of −42.3 mV/pH, denoting that one electron transfer accompanies single proton transportation. Both SWNTs and DHP can accelerate the electron transfer between Hb and the electrode. Using DHP/Hb/SWNTs-film-modified Au electrode, the interaction between Hb and taxol is investigated. The voltammetric response of Hb decreases with increasing concentration of taxol. The peak currents decreases proportionally to the taxol concentration at 1.4 × 10⁻⁵ to 1.3 × 10⁻⁴ M, the linear regression equation being Δi (A) = 2.9603 − 0.4225 c_taxol (M), with a correlation coefficient (r) 0.9985, and the detection limit 6.95 × 10⁻⁶ M (signal-to-noise ratio of three). Published in Russian in Elektrokhimiya, 2007, Vol. 43, No. 7, pp. 801–807. The text was submitted by the authors in English.     

Chitosan and multi-walled carbon nanotube composite rods

<正>Multi-walled carbon nanotubes(MWNTs) and chitosan(CS) composite rods with layer-by-layer structure were prepared via in situ precipitation method.On the one hand,some MWNTs fragments with open tips played the role of nuclear agent to improve the crystallinity of CS.On the other hand,MWNTs embedded in CS matrix to absorb energy when the composite rods were destroying.Nanotubes pulled out from CS matrix,and lots of holes remained,so MWNTs could endure external stress effectively.The bending strength and bending modulus of CS/MWNTs rods(100/0.5,W/W) arrived at 130.7 MPa and 4.4 GPa respectively,increased by 34.3%and 7.3%compared with those of pure CS rods.Consequently, CS/MWNTs composite rods with excellent mechanical properties could be a novel device used for bone fracture internal fixation.     

An electrochemiluminescent sensor for glucose employing a modified carbon nanotube paste electrode

A carbon nanotube paste (CNTP) electrode and a carbon nanotube paste/glucose oxidase (CNTP/GOx) electrode were prepared, and the electrochemiluminescent (ECL) behavior of luminol in the presence of glucose was investigated in detail at each of these electrodes. Compared to the classical carbon paste (CP) electrode, the CNTP electrode incorporating glucose oxidase greatly enhanced the response of the ECL sensor to glucose due to the electrocatalytic activity of the carbon nanotubes, the specificity of the enzymatic reaction, and the sensitivity of the luminol ECL reaction. Under optimal conditions, the electrode was found to respond linearly to glucose in the concentration range 1.0x10(-6) approximately 2.0x10(-3) mol/L, and the detection limit (defined as the concentration that can be detected at a signal-to-noise ratio of 3) was found to be a glucose concentration of 5.0x10(-7) mol/L. The method used to prepare the CNTP/GOx electrode was very convenient, and the electrode surface could be renewed in the case of fouling by simply polishing or cutting it to expose a new and fully active surface. The relative standard deviations (RSD) were found to be 6.8% and 8.9% for the CNTP electrode and the CNTP/GOx electrode (n=6). The electrode retained 95% of its initial response after two weeks.     

Electrochemistry and voltammetric determination of tannic acid on a single-wall carbon nanotube-coated glassy carbon electrode

The voltammetric behavior of tannic acid (TA) on a single-wall carbon nanotubes (SWNTs) modified glassy carbon electrode has been investigated by cyclic voltammetry. TA can generate a well-defined anodic peak on the modified electrode at around 0.42 V (vs. SCE) in 0.10 M phosphate buffer solutions (pH = 4.0). The electrochemical reaction involves 1e transfer, accompanied by one proton. The electrode process is controlled by adsorption. The parameters affecting the response of TA, such as solution pH, accumulation time and accumulation potential are optimized for the determination of TA. Under the optimum conditions, the peak current changes linearly with the TA concentration in the range of 5.0 × 10⁻⁸–1.0 × 10⁻⁶ M. The lowest detectable concentration of TA is 8.0 × 10⁻⁹ M after 180 s accumulation. This method has been successfully applied to the determination of TA in tea and beer samples. In addition, the influence of potential interferents is examined. In the presence of bovine serum albumin, the peak current of TA decreases linearly due to the formation of a super-molecular complex.     

对苯二酚在碳纳米管修饰玻碳电极的电化学行为及电化学动力学研究

碳纳米管(Carbon Nanotubes,CNT)自1991年发现以来,因其结构所具有的高比表面,高电导率,稳定的化学性质与超常的机械强度已成为世界范围内的研究热点,并应用于催化、气体储藏和电极材料等领域。用CNT修饰的电极具有良好的电化学性能并且已经取得了很好的实验结果[1],因此研究碳     

Investigation of the electrocatalytic behavior of single-wall carbon nanotube films on an Au electrode

The voltammetric behavior of uric acid (UA) was studied with an Au electrode modified with single-wall carbon nanotubes (SWNTs). In 0.1 M HAc-NaAc buffer solution (pH 5.0), the SWNT-modified electrode shows high electrocatalytic activity toward UA oxidation. The electro-oxidation of UA is an irreversible diffusion-controlled process with a diffusion coefficient (D) of 8.85×10⁻⁶ cm² s⁻¹. The peak current increases linearly with the concentration of UA in the range of 4.0×10⁻⁶-7.0×10⁻⁴ M. The detection limit is 1.0×10⁻⁶ M. The SWNT was characterized with scanning electron microscopy (SEM). Furthermore, the SWNT-modified electrode has favorable electrocatalytic activity toward dopamine and norepinephrine. This SWNT-modified electrode can also separate the electrochemical responses of uric acid, norepinephrine and ascorbic acid.     

基于氧化锌/碳纳米纤维材料的氧氟沙星电化学传感器的构建及应用

通过静电纺丝技术合成碳纳米纤维,以循环伏安法在此碳纤维上电聚合乙酸锌制备复合纳米材料作为一种新型的电化学增敏剂,用于修饰玻碳电极,开发了一种基于碳纤维和氧化锌复合材料的新型电化学传感器(ZnO/CNF/GCE)。使用循环伏安法、差分脉冲伏安法等进行电化学催化性能的研究,并优化实验条件。结果表明,与裸电极相比,在pH 5.5磷酸盐缓冲溶液中,ZnO/CNF/GCE修饰电极能使氧氟沙星的峰电流明显提升,线性范围1~200μmol/L,检测限为0.33μmol/L。该ZnO/CNF/GCE修饰电极已用于氧氟沙星滴耳液中氧氟沙星的含量测定。     

Direct electron transfer of glucose oxidase on the carbon nanotube electrode

The direct electrochemistry of redox enzymes (or proteins) has received more and more attention[1—9]. These studies developed an electrochemical basis for the investigation of enzyme structure, mechanisms of redox transformations of enzyme molecules and metabolic processes involving redox transformations. From these studies, one can also find potential appli-cations of enzymes in biotechnology. For example, if an enzyme immobilized on electrode surface is ca-pable of the direct electron tra…