刻蚀压强对制备碳纳米管形貌的影响

采用等离子体增强化学气相沉积技术,以C2H2、H2和N2为反应气体,制备出碳纳米管薄膜,利用扫描电镜(SEM)对其进行表征。结果表明:催化剂刻蚀压强对碳纳米管薄膜的生长起着重要作用,获得定向性好、密度适中、杂质缺陷少的碳纳米管的最佳的刻蚀压强为200 Pa。     

微型碳纳米管低压传感器工作性能研究

对于X射线管等小型真空器件,其内部真空监测还缺乏可靠的方法.基于碳纳米管的气体吸附影响场电子发射的特性,我们开发了一种微型低压传感器,本工作是对该传感器的场发射性能、传感性能、重复性和应用性进行研究.实验结果表明:合金材料制备的碳纳米管分布均匀、晶体性高,有良好的场发射性能;传感器对氮气和水汽具有传感效应,场发射电流能...     

阵列式碳纳米管对聚苯胺导电性能影响

用原位聚合法制备了聚苯胺／碳纳米管复合材料,研究了碳纳米管加入时间、搅拌速度等工艺因素对复合材料导电性能的影响。用四极电子电位差计和HT600透射电子显微镜对该复合材料的导电性能和微观形态作了检测。试验结果表明：在原位复合条件下,聚苯胺可以完全包覆在碳纳米管上,而且碳纳米管在聚苯胺基体中呈网状分布,使复合材料的导电性能得到改善。     

AEP作用下溶胶-凝胶法制备纤维素基炭气凝胶及其对水溶液中Cu2+吸附性能

以微晶纤维素为前驱物, 在表面活性剂异辛醇聚氧乙烯醚磷酸酯(AEP)作用下进行溶胶-凝胶反应, 经过真空冷冻干燥后得到纤维素气凝胶, 再在600℃惰性气氛中碳化反应制备成炭气凝胶。通过扫描电镜、BET比表面测定和红外光谱表征制备的炭气凝胶孔隙结构及表面官能团, 并采用静态吸附法考察了炭气凝胶对水溶液中铜离子的吸附性能。结果表明, 溶胶-凝胶反应中的AEP能够有效调节和改进制备的炭气溶胶孔隙结构及其吸附性能。添加2%的AEP得到的纤维素凝胶制备炭气凝胶CCA₂孔隙结构发达、均匀, 具有655.4 m²/g的比表面积和0.73 cm³/g的孔容, 对水溶液中Cu²⁺的吸附容量最大可达到86.27 mg/g, 吸附等温线符合Langmiur模型, 吸附过程遵循准二级动力学方程。     

Distinct Mechanisms of DNA Sensing Based on N‐Doped Carbon Nanotubes with Enhanced Conductance and Chemical Selectivity

N‐doped capped carbon nanotube (CNT) electrodes applied to DNA sequencing are studied by first‐principles calculations. For the face‐on nucleobase junction configurations, a conventional conductance ordering is obtained where the largest signal results from guanine according to its high highest occupied molecular orbital (HOMO) level, whereas for the edge‐on counterparts a distinct conductance ordering is observed where the low‐HOMO thymine provides the largest signal. The edge‐on mode is shown to operate based on a novel molecular sensing mechanism that reflects the chemical connectivity between N‐doped CNT caps that can act both as electron donors and electron acceptors and DNA functional groups that include the hyperconjugated thymine methyl group.     

碳纳米管及碳纳米管纤维的性能与应用

碳纳米管是由单层或多层石墨片卷曲而成的无缝纳米级管状壳层结构。扼要介绍了碳纳米管、碳纳米管纤维的合成方法及近几年来国内外制备的各种碳纳米管产品。碳纳米管、碳纳米管纤维由于其优良的力学、电学特性可以制成气体吸附体、生物模板、传动装置、增强复合体、催化剂载体、探测器、传感器、纳米反应器等产品，在航空、能源、医药、化学等技术领域广泛应用。     

碳气凝胶的制备及其电除盐性能的研究

在常压条件下通过溶胶-凝胶法和碳化、活化工艺制备碳气凝胶材料.用SEM和BET比表面积测量等手段对材料的表面形貌和微观结构进行分析表征,通过循环伏安法对材料的电化学性能进行研究.联系材料的微观结构和电化学性能,对碳气凝胶的电除盐过程和除盐机理进行了研究和分析,发现碳气凝胶是一种具有很大应用潜力的多孔电极吸附材料.     

Preparation and Characterization of Silica Aerogels Derived from Ambient Pressure

Silica aerogels were prepared by sol-gel technique from industrial silicon derivatives (polyethoxydisiloxanes, E-40), followed by silylation and drying under ambient pressure. The specific surface area, pore size distribution and thermal conductivity of the silica aerogels were investigated and the results showed that the diameter of the silica particles is about 6 nm and the average pore size of the silica aerogels is 14.7 nm. The specific surface area of which is about 1000 m2·g-1 and the thermal conductivity is about 0.014 wm-1·K-1 at room temperature and pressure of 1.01×105 Pa. The Si-CH3 groups were also detected on the internal surface of the silica aerogels, which show hydrophobic. Silica aerogels derived by this technique is low cost and have wide applications.     

石墨烯/炭气凝胶的制备及其结构与性能研究

以间苯二酚(R)和甲醛(F)为炭前驱体原料, 通过溶胶-凝胶法制备石墨烯/炭气凝胶复合材料。采用XRD、Raman、SEM和N₂吸附/脱附等对样品进行结构表征。结果表明: 石墨烯为R和F的聚合提供形核场所, R和F首先在氧化石墨烯(GO)表面聚合, 随着RF含量的增加, 复合炭气凝胶(RF)结构从石墨烯薄片层为骨架的三维网络, 经RF基炭球包裹于石墨烯的网络结构, 最终转变为球形团簇交联的三维网络。石墨烯/炭气凝胶复合材料的比表面积随着RF的增加先增大后减小。当GO与RF质量比为1︰100时, GO/RF-100用作超级电容器电极材料, 在6 mol/L KOH电解液中的比电容达169 F/g, 具有较好的电容特性。     

碳纳米管的特性及应用

介绍了巴基球及碳纳米管的发现和历史 ,重点介绍了碳纳米管的基本性能和晶体结构 ,描述了碳纳米管电传导和热传导的机理。文中还介绍了碳纳米管的主要生产方法和各自的优点。根据全球碳纳米管应用研究的方向 ,对碳纳米管的应用领域进行了探讨 ,展望了碳纳米管的应用前景及商业开发价值     

A Supercompressible,Elastic, and Bendable Carbon Aerogel with Ultrasensitive Detection Limits for Compression Strain,Pressure, and Bending Angle

Ultralight and compressible carbon materials have promising applications in strain and pressure detection. However, it is still difficult to prepare carbon materials with supercompressibility, elasticity, stable strain–electrical signal response, and ultrasensitive detection limits, due to the challenge in structural regulation. Herein, a new strategy to prepare a reduced graphene oxide (rGO)‐based lamellar carbon aerogels with unexpected and integrated performances by designing wave‐shape rGO layers and enhancing the interaction among the rGO layers is demonstrated. Addition of cellulose nanocrystalline and low‐molecular‐weight carbon precursors enhances the interaction among rGO layers and thus produces an ultralight, flexible, and superstable structure. The as‐prepared carbon aerogel displays a supercompressibility (undergoing an extreme strain of 99%) and elasticity (100% height retention after 10 000 cycles at a strain of 30%), as well as stable strain–current response (at least 10 000 cycles). Particularly, the carbon aerogel is ultrasensitive for detecting tiny change in strain (0.012%) and pressure (0.25 Pa), which are the lowest detection limits for compressible carbon materials reported in the literature. Moreover, the carbon aerogel exhibits excellent bendable performance and can detect an ultralow bending angle of 0.052°. Additionally, the carbon aerogel also demonstrates its promising application as wearable devices.     

辉光放电和压强对准直碳纳米管生长的影响

利用负偏压增强热丝化学气相沉积系统在沉积有过渡层Ta和催化剂层NiFe的Si村底上制备出准直碳纳米管，并用扫描电子显微镜研完了它们的生长和结构，结果表明辉光放电和压强对其生长和结构有极大的影响。若无辉光放电产生，碳纳米管是弯曲的，有辉光放电时，碳纳米管是准直的。当压强较大时，准直碳纳米管较容易生长，并且随着压强的减小，其平均直径减小和平均长度增大。但压强为5Pa时，准直碳纳米管却不能够生长。最后，分析和讨论了辉光放电和压强对准直碳纳米管生长和结构的影响。     

碳纳米管增强陶瓷基复合材料研究进展

碳纳米管因其独特的结构而具有许多独特的性能,除了在半导体器件、储氢、传感器、吸附材料、电池电极、催化剂载体等领域具有非常广阔和诱人的应用前景外,碳纳米管在制备结构、功能以及结构/功能一体化复合材料方面也将大有作为.本研究对国内外碳纳米管增强陶瓷基复合材料的研究状况进行了综合分析,指出了存在的问题及以后的发展方向.     

Toward High Strength and High Electrical Conductivity in Super‐Aligned Carbon Nanotubes Reinforced Copper

The miniaturization of electronic products is drawing higher demand in the strength and conductivity of conductors. This work demonstrates the possibility of substantially increasing the dislocation density in copper to enhance the strength of super‐aligned carbon nanotubes (SACNTs) reinforced copper matrix composites (SACNT/Cu) without compromising the electrical conductivity. High strain is introduced into pure copper and SACNT/Cu by accumulative roll‐bonding (ARB) process up to 16 cycles at ambient temperature. SACNTs with initial laminated distribution turn out to be dispersed uniformly with maintained directional arrangement inside the copper matrix after ARB, which can then effectively block the motion of dislocations. Therefore, large number of dislocations propagated by large strains can be accumulated without subdivision. The accumulated dislocations will result into strain hardening, which is the major strengthening mechanism in SACNT/Cu after ARB. Furthermore, the contribution of dislocations to resistivity increase is little, thus maintaining high electrical conductivity. As a result, a high tensile strength (505 MPa) combined with a high electrical conductivity (90% IACS) is achieved in large‐sized composite sheet.

     

碳/掺杂碳气凝胶及其研究进展

经溶胶-凝胶、超临界干燥和高温碳化过程制备的碳气凝胶及通过掺杂获得的掺杂碳气凝胶是一种新型的轻质纳米多孔材料,具有许多优异的性能和广阔的应用前景.介绍了溶胶-凝胶法的反应机理,综述了碳/掺杂碳气凝胶的制备方法、发展现状,指出了目前存在的问题并提出了新的可行的制备掺杂碳气凝胶的方法.     

碳纳米纤维气凝胶的制备及其吸油性能

先用静电纺丝-液相接收技术制备蓬松的聚丙烯腈(PAN)三维纳米纤维,然后将其进行热稳定化处理得到超轻纳米纤维气凝胶(CNFAs)。CNFAs内部是碳纳米纤维交叠形成的开孔网络,发生80%应变后能回弹到原形。用聚二甲基硅氧烷(PDMS)气相沉积疏水化处理后,CNFAs的水接触角增大到145°。研究了静电纺丝纳米纤维的原始堆积密度对CNFAs的体积收缩率、密度、吸油容量以及循环吸附量的影响,结果表明：这种气凝胶的机械性能优异。纳米纤维合适的初始堆积密度为4 mg·mL^-1,制备出的CNFAs对油类污染物的吸附量可达到自重的185倍;用燃烧和挤压方法10次循环回收吸附饱和的CNFAs,其吸附容量仍保持稳定。     

碳纳米管共价键连接体的制备和表征

为提高碳纳米管的可操作性和可应用性,采用一种新方法制备了碳纳米管共价键连接体.将-COCl功能化碳纳米管和-COOCH2-CH2OH或-COOCH2一(CH3)2-CH2OH功能化碳纳米管进行混合,利用功能体之间的反应实现碳纳米管之间的共价键连接,从而制得了碳纳米管连接体.通过扫描电镜观察到了反应产物中大量存在的T型、Y型以及端部连接型碳纳米管连接体.通过高分辨透射电镜对连接部位进行了观察,证实了碳纳米管之间的连接.使用傅里叶转换红外光谱对中间产物和最终产物进行了分析,证实了官能团在碳纳米管表面的成功嫁接和官能团之间的反应.     

窄直径分布竹节状纳米碳管膜的制备和表征

采用短时间一次阳极氧化法制备了纳米级孔氧化铝(AAO)模板,有效地缩短了模板的制备时间,获得的AAO模板孔洞排列有序程度虽有所下降,但分布依然均匀.该模板有效地增加了表面积,为金属沉积提供了均匀的纳米孔洞.采用电沉积法在AAO模板上沉积了颗粒尺寸一致且分布均匀的钴催化剂层后,用CVD法在该模板上生长纳米碳管.经SEM和TEM观察,所制得的纳米碳管密度高直径分布均匀,具有单一的竹节状结构,而且直径远小于孔径.试用了生长动力学来解释这种竹节状纳米碳管的形成原因.