PP/碳纳米管复合材料的制备及电性能

采用原子转移自由基(ATRP)活性聚合方法在多壁碳纳米管(MWNT)表面接枝丙烯酸丁酯聚合物(PBA),并以此对聚丙烯(PP)进行改性。红外光谱(FT-IR)及透射电子显微镜(TEM)测试结果表明,采用ATRP法成功地将PBA接枝到多壁碳纳米管(MWNT)表面。对PP/MWNT复合材料电性能研究表明,MWNT-PBA的添加比MWNT-COOH更能降低复合材料的电阻率。MWNT-PBA的加入可使PP从绝缘材料转变为抗静电材料。MWNT-PBA和MWNT-COOH加入PP都能提高材料的电性能,而MWNT-PBA比MWNT-COOH的作用更加明显。     

PP/碳纳米管复合材料的结构与性能

采用原子转移自由基(ATRP)活性聚合方法在多壁碳纳米管(MWNT)表面接枝丙烯酸丁酯聚合物(PBA),并以此对聚丙烯(PP)进行改性。红外光谱(FT-IR)及透射电子显微镜(TEM)测试结果表明,采用ATRP法成功地将PBA接枝到多壁碳纳米管(MWNT)表面。采用熔融共混法制备了PP/MWNT复合材料,对其力学性能和耐热性能进行了研究,结果表明,接枝聚合物的碳纳米管提高了复合材料的拉伸强度和冲击强度,提高了PP的耐热性。MWNT-PBA和MWNT-COOH加入PP都能提高材料的性能,而MWNT-PBA比MWNT-COOH的作用更加明显。     

原子转移自由基聚合的最新研究进展

介绍了关于原子转移自由基聚合(ATRP) 引发-活化-失活过程的最新研究进展,包括RATRP 体系克服了常规ATRP 体系中低价态过渡金属催化剂容易氧化的问题,AGET ATRP 体系显著降低了过渡金属化合物的用量,ARGET ATRP体系中残存的过渡金属催化剂仅为(1～50)×10-6, 很多情况下不需要进行后处理,使其适合工业化生产成为可能.同时介绍了ATRP在表面接枝上的应用,表面引发ATRP反应能改善材料的表面特性,同时具有接枝链分子量及分布可控和高接枝率的优点,使其在很多方面都获得了广泛的应用,包括使材料表面图案化、提高材料表面的生物相容性、制备梳型的聚合物刷以及在纳米磁铁矿和真丝表面引发的ATRP反应.     

ATRP表面接枝在功能膜制备中的应用

ATRP表面引发接枝聚合是功能膜制备中一个重要而有效的方法.近年来,随着原子转移自由基聚合(ATRP)研究的快速发展,将ATRP应用于功能膜制备的研究已取得了显著的进展.详细介绍了在膜表面固定ATRP引发剂的方法及将ATRP表面接枝法应用于制备抗污染能力强,抗菌性好,环境响应迅速等多种功能性膜方面的研究进展情况.     

ATRP方法可控合成碳纳米管/PMMA纳米复合材料

通过多壁碳纳米管的表面改性合成了ATRP引发剂,利用合成的ATRP引发剂进行ATRP活性聚合,成功地在碳纳米管表面接枝聚合物PMMA。利用红外(IR)、透射电镜(TEM)、热重(TGA)以及核磁共振(NMR)表征接枝的碳纳米管,考察了碳纳米管用量对碳纳米管/PMMA纳米复合材料力学性能的影响,结果表明,碳纳米管表面成功接枝聚合物PMMA,PMMA的力学性能得到很大改善。     

原子转移自由基聚合反应改性氧化石墨烯研究进展

原子转移自由基聚合(ATRP)是一种具有潜在应用价值的可控活性自由基聚合方法,通过ATRP反应对氧化石墨烯(GO)进行改性,可以有效控制各种接枝聚合物分子链的长度和接枝密度,赋予GO不同的功能性,如良好的溶剂分散性、环境敏感刺激响应性、生物相容性等。文中分别从GO表面固定引发剂直接引发ATRP反应和GO表面非共价键结合ATRP聚合物分子链2种途径,对ATRP反应改性GO进行综述,总结了ATRP改性反应的过程条件和研究方法,并指出了GO功能化复合材料的功能特性和应用前景。     

利用开环聚合和原子转移自由基聚合在纳米二氧化硅表面接枝聚合物

利用硅烷偶联剂KH-550处理纳米二氧化硅(SiO_2)表面,得到氨基化的SiO_2,再通过溴异丁酸缩水甘油酯与氨基的开环反应,在SiO_2表面同时键接了开环聚合(ROP)的引发剂-OH和原子转移自由基聚合(ATRP)的引发剂-Br(SNPs-fOH/Br)。以SNPs-f-OH/Br为引发剂,分别进行ROP和ATRP,在纳米SiO_2表面接枝了聚己内酯(PCL)和聚苯乙烯(PS)混合聚合物刷(Mixed brush)。采用红外光谱、透射电镜、热失重、凝胶渗透色谱等方法对所得到的复合粒子进行了表征和测试。研究结果表明,混合聚合物刷成功接枝到了纳米SiO_2表面,通过控制聚合时间可以控制2种接枝聚合物的相对分子质量。本方法为纳米粒子表面接枝混合聚合物刷提供了一种简便的方法。     

ATRP可控接枝制备pH敏感性微滤膜

首先利用再生纤维素膜表面的羟基与2-溴异丁酰溴进行反应,引入原子转移自由基聚合(ATRP)所需的大分子引发剂,然后在膜表面可控接枝具有批pH敏感性的聚丙烯酸。通过X光电子能谱仪(XPS)、红外光谱测试(FT-IR),扫描电子显微镜(SEM)表征了膜的表面结构与形貌,证明已成功接枝上丙烯酸。采用膜通量测试研究了接枝膜对pH值的敏感性。实验结果证明,膜表面的接枝聚合具有一定可控性,pH敏感性的功能化可通过原子转移自由基聚合(ATRP)来设计。     

两亲性嵌段共聚物改性的多壁碳纳米管的制备

通过对碳纳米管进行表面改性制得具有引发ATRP反应活性的碳纳米管(MWNT-Br),以MWNT-Br作引发剂经过两次ATRP反应将聚乙烯基吡咯烷酮(PVP)和聚甲基丙烯酸特丁酯(PtBMA)先后接枝到多壁碳纳米管表面制得两亲性嵌段共聚物接枝的碳纳米管(MWNT-PVP-b-PtBMA),用红外光谱、热失重和透射电镜对两亲性碳纳米管进行了表征.并考察了修饰前弱亲油性的纯碳纳米管、酸化后亲水性的碳纳米管和修饰后两亲性碳纳米管这3种碳纳米管在水和氯仿形成的两相体系中的分散情况,观察到所制备的两亲性碳纳米管能够均匀分散在油水两相界面上.     

原子转移自由基聚合与高分子膜亲水化/功能化构造

原子转移自由基聚合(ATRP)对膜的亲水化/功能化改性包括对膜基体材料的共聚改性和对膜的表面改性.膜基体材料的改性最多见于PVDF为主链的两亲性聚合物.ATRP对膜的表面改性尤其是膜的表面引发方法,可实现将不同功能性单体接枝到聚合物膜表面,得到了抗污染能力强,生物相容性好,开关响应迅速等多种功能性表面层.直接的表面引发改性是一种高效,灵活的表面修饰/功能化方法,也是目前应用最广泛的改性技术.     

Preparation of water-soluble multi-walled carbon nanotubes by polymer dispersant assisted exfoliation

Water-soluble multi-walled carbon nanotubes (MWNTs) with a high solubility of 29.2?mg?ml(-1) were obtained by polymer dispersant hydrolyzed poly(styrene-co-maleic anhydride) (HSMA) assisted exfoliation and centrifugation. The MWNTs were exfoliated and dispersed in aqueous solution by non-covalent modification with polymer dispersant of HSMA. Characterizations of HSMA-coated MWNTs were conducted via transmission electron microscopy (TEM), UV-vis and fluorescence spectroscopy, and thermal gravimetric analysis (TGA). The as-prepared HSMA-coated MWNTs showed good dispersibility and stability in water.     

氧化亚铜/碳纳米管超细复合球的合成及性能研究

采用溶液法原位制备了氧化亚铜/多壁碳纳米管(Cu₂O/MWNTs)超细复合球. 通过扫描隧道显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射仪(XRD)、紫外-可见分光光度计(UV-vis)和差热分析(DSC)等手段对产品进行了形貌分析和性能检测. 结果表明: 碳纳米管均匀嵌镶在Cu₂O球中; 相比于同粒径纯Cu₂O球, 复合球的特征吸收峰发生蓝移, 复合球使高氯酸铵(AP)的高温分解温度进一步降低了11.5℃. 另外, 对复合球的形貌影响因素及生长机理进行了探讨, 发现明胶是复合物成球的关键, 而聚乙二醇影响复合球粒径的均匀性.     

Study on morphology and characterization of poly(mphenylene isophtalamide)/multi-walled carbon nanotubes composite nanofibers by electrospinning

Electrospinning technique is the main method of preparing polymer nanofiber simply, directly and continuously at present. In this work, electrospinning blend solution was prepared by in-situ polymerization using acid-modified multi-walled carbon nanotubes (MWNTs), m-phenylenediamine (MPD) and isophthaloyl chloride (IPC). And then composite nanofibers were prepared by electrospinning. MWNTs played an important role in nanofiber's properties. The effects of MWNTs on the morphology and characterization of the MWNTs/PMIA composite nanofibers were investigated. Scanning electron microscopy (SEM), thermal gravimetric analyzer (TGA), and X-ray diffraction (XRD) were utilized to characterize the MWNTs/PMIA nanofibers morphology and properties. The experimental results indicated that the nanofibers diameter decreased and solution dynamic viscosity increased with increasing MWNTs contents. XRD data demonstrated that PMIA composite nanofibers had the same crystal type as the pure PMIA nanofiber, and crystallinity was improved with increasing MWNTs loading. Transmission electron microscopy (TEM) was used to confirm MWNTs aligned along the axis of composite nanofibers.     

多壁碳纳米管的处理及其在芳纶1313中的分散

为了改善多壁碳纳米管(MWNTS)在溶剂N,N-二甲基乙酰胺(DMAc)中的分散性,提高MWNTs与芳纶1313(PMIA)基体界面的结合性能,用混酸对MWNTs进行了处理,用FT-IR对处理前后的MWNTs进行了表征,发现处理后的MWNTs表面接上了羧基.通过溶液共混的方法制得了PMIA/MWNTs纳米复合薄膜,并用SEM和TEM对其进行了表征,发现处理后的MWNTs在PMIA基体中的分散更为均匀.     

聚3-戊酰基吡咯/多壁碳纳米管复合材料的制备与电导率研究

通过原位化学聚合法制备了聚3-戊酰基吡咯(PVPy)/多壁碳纳米管(MWNTs)复合材料.利用傅里叶变换红外光谱(FT-IR)、X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、热重分析(TGA)与四探针法对样品的结构和性能进行了研究.FT-IR表明,PVPy与MWNTs分子间存在相互作用力.TEM显示,3-戊酰基吡咯(VPy)单体仅在MWNTs的外表面发生聚合.XRD谱显示,PVPy/MWNTs复合材料中MWNTs的两个特征结晶峰强度随着VPy/MWNTs原料比增加而逐渐降低,主要表现出PVPy的结晶峰.电导率测试结果表明,通过MWNTs与PVPy复合,可以显著的提高PVPy/MWNTs复合材料的导电性,其电导率分别为2.37 S/cm(VPy/MWNTs=2.5/1)与0.25 S/cm(VPy/MWNTs=5/1).     

Growth of multi-amine terminated poly(amidoamine) dendrimers on the surface of carbon nanotubes

An in situ repetitive divergent polymerization strategy was employed to grow multi-amine poly(amidoamine) dendritic macromolecules on the surfaces of multiwalled carbon nanotubes (MWNTs), affording novel three-dimensional (3D) molecular nanocomposites. The crude MWNTs were oxidized using H(2)SO(4)/HNO(3) = 3:1?(v/v) and then reacted with thionyl chloride, resulting in MWNTs functionalized with chlorocarbonyl groups (MWNT-COCl). MWNT-COCl, when reacted with an excess of ethylenediamine, produced amine-functionalized MWNT supported initiators (MWNT-NH(2)). Using the MWNT-NH(2) as the growth supporter and methylacrylate/ethylenediamine as building blocks, multi-amine dendritic poly(amidoamine) macromolecules were covalently grafted onto the sidewalls and ends of MWNTs via Michael addition reaction and amidation. Thermal gravimetric analysis (TGA) measurements showed that the weight ratio of the as-grown dendritic polymers on the MWNT surfaces lay in the 10%-50% range. The products were also characterized by Fourier transform infrared (FTIR), Raman, nuclear magnetic resonance (NMR), and transmission electron microscopy (TEM) analysis. The results indicate that the dendrimers are grafted onto the surface of MWNTs. The as-prepared nanocomposites exhibit excellent dispersibility in water.     

碳纳米管类型对CNTs/Lyocell复合纤维结构与性能的影响

分别采用单壁碳纳米管（SWNTs）和多壁碳纳米管（MWNTs）这两种碳纳米管（CNTs）制备不同的CNTs/Lyocell复合纤维,探讨了碳纳米管类型对复合纤维的结构与性能的影响。结果表明,碳纳米管类型并未影响CNTs/Lyocell纤维的结晶结构,质量分数为1%的SWNTs或MWNTs在Lyocell基体中分布都比较...     

Characterization of attractive interaction-driven carbon nanotube composites with Cd-based nanoparticles

Multiwalled carbon nanotube (MWNT) composites with cadmium telluride (CdTe) or cadmium selenide (CdSe) nanoparticles were prepared via electrostatic interaction. The MWNTs were modified with carboxylic acid groups. Both the CdTe and CdSe nanoparticles were stabilized with 2-(dimethylamino) ethanethiol hydrochloride to develop positive charges on their surfaces in water. They were characterized in detail via UV-visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The energy state of the MWNTs was significantly modified by the electrostatic binding between the nanoparticles and carboxylated MWNTs, resulting in absorption at approximately 250 nm. XPS analysis also proved the electronic redistribution of the nanoparticles and the MWNTs. The binding energies of the elements Cd, Se, and Te were definitely changed by the attractive interaction between the nanoparticles and the MWNTs. The distribution of the CdTe or CdSe nanoparticles and the morphologies of the MWNT composites were deliberately investigated from TEM images and XRD.     

PVK/MWNT electrodeposited conjugated polymer network nanocomposite films

The facile preparation of poly (N-vinyl carbazole) (PVK) and multiwalled carbon nanotubes (MWNTs) solution and conjugated polymer network (CPN) nanocomposite film is described. The stable solutions of PVK/MWNT were prepared in mixed solvents by simple sonication method, which enabled successful deaggregation of the MWNTs with the polymer matrix. MWNT was most effectively dissolved in N-cyclohexyl-2-pyrrolidone (CHP) compared to other solvents like N-methyl pyrrolidone (NMP), dimethyl formamide, and dimethyl sulfoxide (DMSO). The composite solution was relatively stable for months with no observable precipitation of the MWNTs. Thermogravimmetric analysis (TGA) revealed the thermal stability of the nanocomposite while the differential scanning calorimetry (DSC) showed an increasing melting (T(m)) and glass transition (T(g)) temperatures as the fraction of the MWNTs in the nanocomposite was increased. Cyclic voltammetry (CV) allowed the electrodeposition of the nanocomposite film on indium tin oxide (ITO) substrates and subsequent cross-linking of the carbazole pendant group of the PVK to form CPN films. Ultraviolet-visible (UV-vis), fluorescence, and Fourier transform infrared (FTIR) confirmed film composition while atomic force microscopy (AFM) revealed its surface morphology. Four-point probe measurements revealed an increase in the electrical conductivity of the CPN nanocomposite film as the composition of the MWNTs was increased: 5.53 × 10(-4) (3% MWNTs), 0.53 (5%), and 1.79 S cm(-1) (7%). Finally, the interfacial charge transfer resistance and ion transport on the CPN nanocomposite film was analyzed by electrochemical impedance spectroscopy (EIS) with a measured real impedance value of ～48.10 Ω for the 97% PVK and 3% MWNT ratio of the CPN nanocomposite film.     

Fabrication and characterization of TiO2/short MWNTs with enhanced photocatalytic activity

TiO₂/short MWNTs nanocomposites were prepared by the sol–gel method using butyl titanate and short MWNTs as starting materials in the solvent of isopropyl alcohol. Their photocatalytic activity in the degradation of X-3B was studied. The effects of mass ratio of short MWNTs to butyl titanate, and heat-treatment temperature on the photoactivity of TiO₂/short MWNTs nanocomposites were discussed. For comparison purpose, other photocatalysts were also employed in the photodegradation experiment. Thermogravimetric–differential thermal analysis (TG–DTA), scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV–Vis absorption spectra were utilized to characterize the prepared photocatalysts. The results showed that the TiO₂/short MWNTs nanocomposites synthesized with 1% mass ratio of short MWNTs to butyl titanate had the best photoactivity.