碳纳米管表面绿原酸印迹固相萃取材料的制备及应用

在多壁碳纳米管表面接枝的双键键合,以绿原酸为模板,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用沉淀聚合技术,在碳纳米管表面成功制备绿原酸印迹材料.采用红外光谱、扫描电镜和热重分析研究此印迹材料的性能.结果表明,在碳纳米管表面接枝一层稳定、均匀、30～40 nm厚的印迹材料.采用高效液相色谱研究此印迹材料的吸附动力学及吸附容量,实验结果表明,此印迹材料对绿原酸的结合存在两个结合位点,最大吸附容量Qmax分别为21.5和32.7 μmol/g.以此印迹材料作为固相萃取剂,优化萃取条件,成功应用于金银花提取液中绿原酸的富集分离研究,富集因子达25.     

多壁碳纳米管表面对硝基苯酚印迹复合材料的制备与吸附性能

以多壁碳纳米管表面接枝的L-苯丙氨酸为结合位点, 甲基丙烯酸为功能单体, 乙二醇二甲基丙烯酸酯为交联剂, 采用沉淀聚合技术, 在碳纳米管表面制备了对硝基苯酚印迹复合材料. 采用红外光谱和扫描电镜研究了该印迹复合材料的结构和形貌, 结果表明, 在碳纳米管表面接枝了一层稳定的印迹材料. 采用高效液相色谱研究了该印迹材料的等温吸附性能, 结果表明, 该印迹材料对模板分子具有较大的吸附容量(Qmax=80.5 μmol/g)和良好的选择吸附性能(选择因子达2.5). 以该印迹材料作为固相萃取吸附剂, 研究了它对对硝基苯酚和其它结构类似物混合溶液的动态吸附性能, 结果表明, 印迹复合材料对对硝基苯酚的吸附容量不受结构类似物浓度的影响, 能较好地应用于对硝基苯酚的分离富集检测.     

多壁碳纳米管表面邻苯二甲酸二(2-乙基)己酯印迹聚合物的制备及其在固相萃取中的应用

以苯基修饰的多壁碳纳米管为载体,邻苯二甲酸二(2-乙基)己酯为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,在碳纳米管表面接枝一层塑化剂邻苯二甲酸二(2-乙基)己酯印迹聚合层.采用红外光谱和扫描电镜对聚合物进行表征和分析.结果表明,在碳纳米管表面成功接枝一层20～30 nm厚的印迹聚合层.采用高效液相色谱研究该印迹聚合物的吸附性能,结果表明,碳纳米管分子印迹聚合物对邻苯二甲酸二(2-乙基)己酯最大吸附量为69.1 μmol/g,达到吸附平衡时间约为60 min.选择性吸附实验表明,与其它结构类似物相比,该印迹复合材料对邻苯二甲酸二(2-乙基)己酯有良好的识别能力.作为固相萃取材料装填于固相萃取柱中,该印迹聚合物能对芒果汁样品中塑化剂进行有效的分离和富集.     

多壁碳纳米管表面大黄素印迹材料制备及吸附性能研究

以表面硅烷修饰的碳纳米管为基材,甲基丙烯酸为功能单体,二甲基丙烯酸乙二醇酯为交联剂,采用表面印迹技术成功制备了大黄素印迹复合材料。采用扫描电镜和透射电镜研究该印迹复合材料的形貌,结果表明,在碳纳米管表面接枝了1层稳定的约40nm厚的印迹层。在pH=8.5时,该印迹材料对大黄素具有较大吸附容量和良好选择吸附性能,最大理论吸附量(Qmax)为20.8mg/g。以该印迹材料作为固相萃取吸附剂,在85%乙醇水溶液淋洗和10%乙酸的乙醇溶液洗脱下,可实现对猕猴桃根样品粗提取液中大黄素固相萃取分离富集,回收率达到85%以上。     

磁性碳纳米管表面新型壬基酚印迹纳米复合材料制备及吸附性能

采用聚苯胺包覆的磁性多壁碳纳米管为载体,以壬基酚(NP)为模板分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂制备新型磁性壬基酚印迹复合萃取材料。 采用扫描电子显微镜(SEM)、红外光谱(FT-IR)和样品振动磁强计(VSM)等技术手段对该磁性印迹复合材料进行表征和分析,结果表明,在磁性碳纳米管表面成功接枝厚度为60~70 nm的印迹聚合层。 采用高效液相色谱(HPLC)技术对该印迹复合材料的吸附性能进行探讨,结果表明,该磁性印迹复合材料对壬基酚具有特异性吸附性能,最大吸附量为38.46 mg/g。 结合HPLC检测技术,该磁性印迹复合材料成功用于分离富集饮用水中的壬基酚。     

核壳式氯霉素分子印迹聚合物碳纳米管复合材料的制备及应用

本文以多壁碳纳米管(MWCNTs)为载体,采用溶胶-凝胶法先在MWCNTs表面包覆硅层,得到MWCNTs@SiO2,再以氯霉素(Chloramphenicol,CAP)为模板,无水乙醇为溶剂,氨丙基三乙氧基硅烷(APTES)和苯基三甲氧基硅烷(PTMOS)为双功能单体,四乙氧基硅烷(TEOS)为交联剂,采用表面分子印迹技术合成具有核壳结构的CAP分子印迹聚合物包覆的碳纳米管复合材料。采用透射电镜(TEM)、红外(IR)光谱和热重(TG)分析技术对CAP分子印迹聚合物复合材料的结构、形貌进行了表征,并对其吸附性能进行了详细研究。结果表明,制备的分子印迹聚合物吸附动力学快,吸附容量大,选择性好,印迹因子达到4.2,并且可循环使用。将制备的分子印迹聚合物材料应用于实际样品鸡蛋中CAP含量的测定,回收率可达72.3%~84.1%。     

碳纳米管芹菜素印迹聚合物的制备及应用

本文以羧基化多壁碳纳米管为基材,结合芹菜素、丙烯酰胺、丙酮和乙二醇二甲基丙烯酸酯,在多壁碳纳米管表面合成对芹菜素具有特异性识别的分子印迹聚合物(MWCNTs-MIPs),并利用扫描电镜(SEM)、傅里叶变换红外(FT-IR)光谱和比表面积分析(BET)对该印迹聚合物进行表征。结果表明,在碳纳米管表面能均匀稳定地接枝一层厚度约为10~20nm的印迹材料。对聚合物的静态吸附性能和选择性进行研究,表明MWCNTs-MIPs的吸附效果优于其非印迹材料(MWCNTs-NIPs)。固相萃取实验表明该方法不仅重现性好,并能使芹菜素的纯度由0.53%增高至90.93%,回收率可达95.84%,富集因子高达171.6。可作为复杂天然产物中芹菜素分离提取材料。     

表面印迹法制备钴(Ⅱ)离子印迹硅胶及性能

采用表面印迹技术, 以Co(Ⅱ)离子作为印迹离子, 二乙烯三胺基丙基三甲氧基硅烷为功能分子, 硅胶为支撑物, 环氧氯丙烷为交联剂, 在硅胶表面制备Co(Ⅱ)离子印迹硅胶材料, 利用红外光谱仪、扫描电镜和热重分析仪等进行了表征, 采用平衡吸附法研究了印迹硅胶材料的吸附性能和选择识别能力. 结果表明, 印迹硅胶材料和非印迹硅胶材料的最大吸附量分别为35.2和6.5 mg/g; 印迹硅胶材料对Co(Ⅱ)离子的吸附行为符合Langmuir模型; 20 min即可达到吸附平衡; 当pH=3.9~7.8时, 印迹硅胶材料保持了较好的吸附容量; 印迹硅胶材料对Co(Ⅱ)离子具有较强的选择性识别能力; 重复使用时性能稳定.     

活性自由基聚合法制备多壁碳纳米管表面槲皮素分子印迹聚合物及其应用

为了制备能有效分离富集药草中槲皮素的固相萃取柱,以丙烯酰胺(AM)修饰的碳纳米管为载体,三硫代碳酸酯(DBTTC)为可逆加成-断裂链转移剂(RAFT试剂),槲皮素为模板,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,乙腈为致孔剂,制备了槲皮素分子印迹聚合物,采用红外光谱、扫描电镜和热重分析对印迹材料进行表征,通过高效液相色谱(HPLC)研究聚合物的吸附性能和对底物的特异性识别能力。结果表明,通过活性自由基聚合法合成的多壁碳纳米管表面槲皮素分子印迹聚合具有更好的形态结构和吸附性能,且对槲皮素有很好的特异性识别能力。     

基于壳聚糖修饰碳纳米管表面铅离子印迹材料的制备及其性能研究

以壳聚糖修饰的多壁碳纳米管为基材.Pb2+为模板分子,乙烯化壳聚糖(CS)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,在碳纳米管表面枝接一层Pb2+印迹聚合物.采用红外光谱、热重分析和扫描电镜对聚合物进行表征和分析.结果表明.在碳纳米管上成功制备了一层15～20 nm厚的Pb2+印迹聚合材料.采用原子吸收法...     

Surface covalent encapsulation of multiwalled carbon nanotubes with poly(acryloyl chloride) grafted poly(ethylene glycol)

Multiwall carbon nanotube (MWNT) was grafted with polyacrylate‐g‐poly (ethylene glycol) via the following two steps. First, hydroxyl groups on the surface of acid‐treated MWNT reacted with linear poly(acryloyl chloride) to generate graft on MWNT; secondly, the remaining acryloyl chloride groups were subjected to esterification with poly(ethylene glycol) leading the grafted chains on the surface of MWNTs. Thus obtained grafted MWNT was characterized using Fourier transform infrared spectrometer, transmission electron microscopy, and X‐ray photoelectron spectroscopy. Thermogravimetric analysis showed that the weight fraction of grafted polymers amounted to 80% of the modified MWNT. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6880–6887, 2006     

Polymer-functionalized multiwalled carbon nanotubes as lithium intercalation hosts

Multiwalled carbon nanotubes (MWNTs) functionalized with a hyperbranched aliphatic polyester and two different poly(ethylene glycol)s were synthesized by the reactions of carbonyl chloride groups on the surface of MWNTs and hydroxyl groups of polymers. Electrochemical intercalation of lithium in the three materials was investigated with galvanostatic charge-discharge experiments. The hyperbranched polymer-functionalized MWNT as an electrode material for lithium batteries showed a significant improvement over linear polymer-functionalized MWNTs in lithium insertion/deinsertion capacity and cycle stability. The MWNT functionalized with linear poly(ethylene glycol) showed a high initial capacity of lithium insertion/deinsertion but had the highest capacity fade rate among the materials. Because the polymers were chemically localized in the electrode-electrolyte interface, the comparison between hyperbranched and linear polymer-modified MWNTs manifested the important influence of the electrode-electrolyte interface on the electrochemical properties of lithium batteries.     

聚丙烯酸功能化多壁碳纳米管

Covalent functionalization of multiwalled carbon nanotubes （MWNT） with poly（acrylic acid） has been successfully achieved via grafting of poly（acryloyl chloride） on nanotube surface by esterification reaction of acyl chloride-bound polymer with hydroxyl functional groups present on acid-oxidized MWNT and hydrolysis of polymer attached to nanotubes. Polymer-functionalized MWNT could possess remarkably high solubility in water, and their aqueous solution was very stable without any observable black deposit for a long time. Characterizations of such functionalized MWNT samples using Fourier transform infrared spectrometer, transmission electron microscopy and nuclear magnetic resonance techniques indicated that poly（acrylic acid） was covalently attached to the surface of MWNT.     

Pyrenyl Carbon Nanotubes for Covalent Bilirubin Oxidase Biocathode Design: Should the Nanotubes be Carboxylated?

Understanding the characteristics of nanomaterials in the context of electrode designs for bio‐electrocatalysis is an emerging research direction. Applications for fuel cells, batteries, and biosensors are directly benefited. The objective of this study is to understand the influence of unfunctionalized multiwalled carbon nanotubes (MWNT) in comparison to carboxylated nanotubes (MWNT?COOH) for pi‐pi stacking with 1‐pyrenebutyric acid (Py) and covalent immobilization of bilirubin oxidase (BOD) enzyme toward the resulting oxygen reduction currents. We designed pyrolytic graphite‐edge electrodes modified with MWNT/Py, MWNT?COOH/Py, or only MWNT?COOH for carbodiimide activation and BOD immobilization. The relative increase in surface ?COOH groups as we move from MWNT to MWNT/Py to MWNT?COOH/Py modification is voltammetrically estimated. Although the MWNT?COOH/Py displayed the highest relative amount of surface ?COOH groups, the oxygen reduction current was the largest for the BOD‐immobilized MWNT/Py electrode than others. Results indicate that unfunctionalized MWNT is the optimal choice for pi‐pi stacking with pyrene linkers and covalent BOD immobilization as biocathode for energy devices. Favorable hydrophobic MWNT surface to interact more closely with the electron‐receiving T1 Cu site of BOD, as opposed to the relatively polar and more defective MWNT?COOH material due to functionalization, is suggested to be one of the underlying factors for the observed electrocatalytic trend.     

Rheological Behaviors of Nanofluids Containing Multi-Walled Carbon Nanotube

Stable nanofluids containing multi-walled carbon nanotubes (MWNTs) treated by concentrated acid and mechanical mill technology have been prepared. Water, ethylene glycol, glycerol, and silicone oil were used as base fluids. The rheological behaviors of the obtained nanofluids with different MWNT volume fractions and at different temperatures were investigated in details. The glycerol based and silicone oil based fluids behave Newtonian manner in all studied MWNT volume fractions and temperatures. The dispersant hexamethyldisiloxane added in silicone oil decreases the silicone oil viscosity but has no effect on the rheological properties of nanofluids. For the water based nanofluids, MWNTs act as lubricative function when the MWNT volume fraction is lower. Furthermore, for the ethylene glycol based and glycerol based fluid, almost no viscosity augmentation appears when the temperature is higher than 55°C.     

电纺丝法制备聚乳酸/多壁碳纳米管/羟基磷灰石杂化纳米纤维的研究

电纺丝是一种利用聚合物溶液或熔体在强电场中进行喷射纺丝的加工技术,所制得的纤维、直径一般在数十纳米至几微米之间,比传统方法制得的纤维直径小几个数量级,是获得纳米尺寸长纤维的有效方法之一．     

Influences of poly(lactic acid)‐grafted carbon nanotube on thermal,mechanical, and electrical properties of poly(lactic acid)

Poly(lactic acid)‐grafted multiwalled carbon nanotubes (MWNT‐g‐PLA) were prepared by the direct melt‐polycondensation of L ‐lactic acid with carboxylic acid‐functionalized MWNT (MWNT‐COOH) and then mixed with a commercially available neat PLA to prepare PLA/MWNT‐g‐PLA nanocomposites. Morphological, thermal, mechanical, and electrical characteristics of PLA/MWNT‐g‐PLA nanocomposites were investigated as a function of the MWNT content and compared with those of the neat PLA, PLA/MWNT, and PLA/MWNT‐COOH nanocomposites. It was identified from FE‐SEM images that PLA/MWNT‐g‐PLA nanocomposites exhibit good dispersion of MWNT‐g‐PLA in the PLA matrix, while PLA/MWNT and PLA/MWNT‐COOH nanocomposites display MWNT aggregates. As a result, initial moduli and tensile strengths of PLA/MWNT‐g‐PLA composites are much higher than those of neat PLA, PLA/MWNT, and PLA/MWNT‐COOH, which stems from the efficient reinforcing effect of MWNT‐g‐PLA in the PLA matrix. In addition, the crystallization rate of PLA/MWNT‐g‐PLA nanocomposites is faster than those of neat PLA, PLA/MWNT, and PLA/MWNT‐COOH, since MWNT‐g‐PLA dispersed in the PLA matrix serves efficiently as a nucleating agent. It is interesting that, unlike PLA/MWNT nanocomposites, surface resistivities of PLA/MWNT‐g‐PLA nanocomposites did not change noticeably depending on the MWNT content, demonstrating that MWNTs in PLA/MWNT‐g‐PLA are wrapped with the PLA chains of MWNT‐g‐PLA. Copyright © 2008 John Wiley & Sons, Ltd.     

Controlled functionalization of multiwalled carbon nanotubes with various molecular-weight poly(L-lactic acid)

Multiwalled carbon nanotubes (MWNT) were functionalized with poly(L-lactic acid) (PLLA) with different molecular weights using a "grafting to" technique. The oxidized MWNT (MWNT-COOH) were converted to the acyl-chloride-functionalized MWNT (MWNT-COCl) by treating them with thionyl chloride (SOCl2) and reacting them with PLLA to prepare the MWNT-g-PLLA. FTIR and Raman spectroscopy revealed that the PLLA was covalently attached to the MWNT, and the weight gain due to the functionalization was determined by thermogravimetric analyses (TGA). The Raman signals of the MWNT were greatly weakened as a result of the PLLA grafting. The morphology of the grafted PLLA was examined by using SEM and TEM. The amount of grafted PLLA depended on the molecular weight of the PLLA. The PLLA coated on the MWNT became thicker and more uniform with increasing PLLA molecular weight from 1000 to 3000. However, the amount of grafted PLLA became lower when the molecular weight of PLLA was further increased to 11,000 and 15,000, and the PLLA attached to the MWNT showed a squid leglike morphology forming blobs and leaving much of the MWNT surface bare.