石墨及功能化碳纤维改性双马来酰亚胺树脂复合材料的制备方法

正本发明涉及一种石墨及功能化碳纤维改性双马来酰亚胺树脂复合材料的制备方法。本发明将碳纳米管经过羧基化后,在碳纳米管上引入二元胺或多元胺,得到胺基化的碳纳米管。将胺基化的碳纳米管与经羧基化的碳纤维反应,得到胺基化的碳纤维表面接枝有碳纳米管,在碳纤维表面引入二元胺或多元胺,使碳纤维表面未完全与胺基化的碳纳米     

长链醚胺修饰碳纳米管衍生物及其制备方法

通过氧化后多壁碳纳米管上所引入的羧基和十八叔胺聚氧乙烯醚之间的酸碱反应,制备了长链醚胺修饰的碳纳米管衍生物,并利用红外光谱表征了醚胺功能化前后的碳纳米管上的功能基团,验证了酸碱反应形成的羧基盐的存在。通过热失重分析得出该衍生物中醚胺的质量分数高达76.8%,为改善碳纳米管在极性聚合物中的分散性及与聚合物基质间界面相互作用提供了途径。     

石墨及功能化碳纤维改性环氧树脂复合材料的制备方法

本发明涉及一种石墨及功能化碳纤维改性环氧树脂复合材料的制备方法。本发明将碳纳米管经羧基化功能化后,在碳纳米管上引入二元胺或多元胺,得到表面胺基化的碳纳米管;将胺基化的碳纳米管与表面经过羧基化的碳纤维反应,得到胺基化的碳纤维表面接枝有碳纳米管,在碳纤维表面引入二元胺或多元胺,使碳纤维表面未完全与胺基化的碳纳米管反应的羧基充分胺基化,将碳纤维与环氧树脂预聚合反应,得到功能化的碳纤维表面接枝有     

石墨及功能化碳纤维增强聚酰亚胺复合材料的制备方法

正本发明涉及一种石墨及功能化碳纤维增强聚酰亚胺复合材料的制备方法。本发明将碳纳米管经过羧基化功能化,在碳纳米管上引入二元胺或多元胺,得到的表面氨基化的碳纳米管与表面经过羧基化的碳纤维反应,得到表面接枝有碳纳米管的碳纤维,再将表面接枝有碳纳米管的碳纤维进行后氨化处理,引入二元胺或多元胺,得到氨基化的碳纤维表面接枝有碳纳米管的增强体;将     

碳纳米管及功能化碳纤维增强环氧树脂复合材料的制备方法

正本发明涉及一种碳纳米管及功能化碳纤维增强环氧树脂复合材料的制备方法。本发明将碳纳米管经过羧基化功能化后,在碳纳米管上引入二元胺或多元胺,得到表面胺基化的碳纳米管;将胺基化的碳纳米管与表面经过羧基化的碳纤维反应,得到胺基化的碳纤维表面接枝有碳纳米管,在碳纤维表面引入二元胺或多元胺,使碳纤维表面未完全与     

碳纳米管及功能化碳纤维增强聚酰亚胺复合材料的制备方法

正本发明涉及一种碳纳米管及功能化碳纤维增强聚酰亚胺复合材料的制备方法。本发明将碳纳米管经过羧基功能化后,在碳纳米管上引入二元胺或多元胺,将得到的氨基化的碳纳米管与羧基化的碳纤维反应,得到表面接枝有碳纳米管的碳纤维,再将表面接枝有碳纳米管的碳纤维进行后胺化处理,引入二元胺或多元胺,得到氨基化碳     

碳纳米管及功能化碳纤维增强双马来酰亚胺树脂复合材料的制备方法

正本发明涉及一种碳纳米管及功能化碳纤维增强双马来酰亚胺树脂复合材料的制备方法。本发明将碳纳米管经过羧基化功能化后,在碳纳米管上引入二元胺或多元胺,得到表面胺基化的碳纳米管;将胺基化的碳纳米管与表面经过羧基化的碳纤维反应,得到胺基化的碳纤维表面接枝有碳纳米管,在碳纤维表面引入二元胺或多元胺,使碳纤维表面未完全与胺基化的碳纳米管反应的羧基充分胺基化,     

聚四氟乙烯及功能化碳纤维改性聚酰亚胺树脂复合材料的制备方法

本发明涉及一种聚四氟乙烯及功能化碳纤维改性聚酰亚胺树脂复合材料的制备方法。本发明将碳纳米管经过羧基化功能化后,在碳纳米管上引入二元胺或多元胺,再将氨基化的碳纳米管与表面经过羧基化的碳纤维反应,得到表面接枝有碳纳米管的碳纤维,将表面接枝有碳纳米管的碳纤维进行后氨化处理,引入二元胺或多元胺,得到氨基化的碳纤维表面接枝有碳纳米管的增强体;将聚四氟乙烯与聚酰亚胺树脂混合搅拌均     

热塑性聚氨酯复合材料薄膜的制备及其性能研究

利用纵向氧化切割多层碳纳米管（MWCNTs）制得氧化石墨烯纳米带碳纳米管（GONRs-CNTs）2种维度纳米杂化材料,用异氰酸苯酯对GONRs(67 %)-CNTs纳米杂化体进行表面化学修饰制得功能化GONRs(67 %)-CNTs（pGONRs-CNTs,GONRs质量分数为67 %）,探究了pGONRs-CNTs对热塑性聚氨酯（TPU）薄膜阻隔、力学和降解性能的影响。结果表明,改性后所得pGONRs-CNTs杂化体表面变得模糊而粗糙,亲油性得到明显提高,有利于其在聚合物基体中实现均匀稳固分布。当pGONRs-CNTs含量为0.5 %（质量分数,下同）时,TPU/pGONRs-CNTs材料相比纯TPU材料的氧气透过率（OTR）低63.08 %,拉伸强度高46.55 %,其对应的阻透性能与力学性能均有较大程度提高;而且,由于pGONRs-CNTs物质的使用,使TPU材料的使用寿命延长。     

羟基化多壁碳纳米管/R141b纳米流体核沸腾

向多壁碳纳米管引入羟基基团,改善了其在制冷剂R141b中的分散性和稳定性。同时研究了不同质量分数纳米流体热导率、表面颗粒沉积、接触角变化对核沸腾传热性能的影响。结果表明:羟基化碳纳米流体强化沸腾传热,强化率随质量分数的增加而增加,沸腾后期有所下降。在测试浓度范围内,质量分数为0.05%,热通量为87.4 kW·m^-2时,强化率达到最大168%。流体的热导率随着质量分数的增加而增大,质量分数为0.10%时其热导率是纯R141b的1.18倍。分析认为:纳米流体热导率的增加、表面沉积颗粒及纳米颗粒扰动是强化传热的主要影响因素,接触角变化的影响可忽略不计。结论由质量分数为0.03%纳米流体沸腾过程高速成像得到验证。     

Synthesis and characterization of functionalized carbon nanotubes with different wetting behaviors and their influence on the wetting properties of carbon nanotubes/polymethylmethacrylate coatings

The synthesis and characterization of hydrophobic functionalized multi-wall carbon nanotubes (MWCNTs) were investigated and their influence on the wetting properties of organic coatings and composites was studied. Functionalization was performed using oxidation, 1,3-dipolar cycloaddition, and silanization. Silanization was conducted using three hydrophobic silane precursors: 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, 1H,1H,2H,2H-perfluorooctyltrimethoxysilane, and triethoxyoctylsilane. Functionalization was directly confirmed and characterized by Fourier transform infrared spectroscopy, thermal gravimetric analysis, and scanning electron microscopy. The water contact angle of the functionalized MWCNTs was 40–142° for different surface functionalities and the functionalized MWCNTs were incorporated into an acidic solution of polymethylmethacrylate. The effect of surface functionality and the concentration of the functionalized MWCNTs on the wetting properties of these composites were studied by measuring the water contact angle. Under optimum conditions, composite surfaces with water contact angles greater than 110° were obtained. Atomic force microscopy was used to determine the topography of the surface and energy dispersion spectroscopy was used to determine the distribution of the functionalized MWCNTs in the composite film. It was shown that the hydrophobic functionalized MWCNTs migrated to the surface; this was more pronounced for the more hydrophobic MWCNTs.     

Effects of multi‐walled carbon nanotube functionalization on the morphological and mechanical properties of nanocomposite foams based on poly(vinyl chloride)/(wood flour)/ (multi‐walled carbon nanotubes)

Experimental results are presented for nanocomposite foams based on unplasticized poly(vinyl chloride)/(wood flour)/(multi‐wall carbon nanotubes) (PVC/WF/MWCNTs). The nanocomposite samples were prepared in an internal mixer and foamed via a batch processing method using compression molding. Nanoparticles were functionalized by sodium hypochlorite solution, and the functionalization process was monitored by Fourier‐transform infrared spectroscopy. The effects of MWCNTs (both neat and functionalized) and blowing agent concentration on the morphological properties (cell size and cell density) and mechanical properties (tensile and flexural strength) of the foam samples were studied. The results revealed that foam cell sizes decreased and cell densities increased with addition of MWCNTs. The dispersion of nanoparticles in the PVC medium was increased by functionalization, and the morphological properties of the foams containing functionalized nanoparticles were improved. Density of nanocomposite foams decreased more with functionalized MWCNTs as compared to other samples. Chemical blowing agent concentration had no significant effect on sample density. Mechanical properties of the samples were improved by using functionalized MWCNTs in comparison with those of foams without this component. J. VINYL ADDIT. TECHNOL., 18:161–167, 2012. © 2012 Society of Plastics Engineers     

Effect of radical grafting of tetramethylpentadecane and polypropylene on carbon nanotubes' dispersibility in various solvents and polypropylene matrix

Multiwalled carbon nanotubes (MWCNTs) have been functionalized by tetramethylpentadecane (TMP), 1-dodecanethiol (DT) and polypropylene (PP) through radical addition onto MWCNTs' surface using dicumyl peroxide as hydrogen abstractor. Surface functionalized MWCNTs were characterized by Raman, IR spectroscopy, elementary analysis (EA) and thermogravimetric analysis (TGA). We studied the effect of temperature, peroxide concentration and solvent on TMP grafting densities and it was found that this surface treatment lead to a fair solubility in various solvents. TMP-functionalized MWCNTs were also imaged by transmission electronic microscopy showing single long functionalized MWCNTs distinct from the starting pristine bundles. For the first time, PP was then grafted onto MWCNTs through a radical grafting reaction. However, scanning electronic microscopy images of PP-functionalized MWCNTs/PP composites did not show a significant improvement in MWCNTs dispersion within the PP matrix.     

Effect of amino‐functionalization of multi‐walled carbon nanotubes on the dispersion with epoxy resin matrix

Amino‐functionalization of multiwalled carbon nanotubes (MWCNTs) was carried out by grafting triethylenetetramine (TETA) on the surfaces of MWCNTs through the acid–thionyl chloride way. The amino‐functionalized MWCNTs show improved compatibility with epoxy resin and, as a result, more homogenous dispersion in the matrix. The mechanical, optical, and thermal properties of the amino‐functionalized MWCNT/epoxy composites were also investigated. It was found that introducing the amino‐functionalized MWCNTs into epoxy resin greatly increased the charpy impact strength, glass transition temperature, and initial decomposing temperature of cured epoxy resin. In addition, introducing unfunctionalized MWCNTs into epoxy resin was found greatly depressing the light transmission properties, which would affirmatively confine the application of the MWCNTs/epoxy composites in the future, while much higher light transmittance than that of unfunctionalized MWCNTs/epoxy composites was found for amino‐functionalized MWCNTs/epoxy composites. SEM of the impact cross section and TEM of ultrathin film of the amino‐functionalized MWCNTs/epoxy composites showed that the amino‐functionalized MWCNTs were wetted well by epoxy matrix. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 97–104, 2006     

Cross-Linking of Multi-Walled Carbon Nanotubes with Polyethylene Glycol

In this paper a new approach to cross-link two individual multi-walled carbon nanotubes (MWCNTs) by a nucleophilic substitution of brominated MWCNTs using polyethylene glycol anion was introduced. The functionalized MWCNTs were characterized using thermogravimetric analysis (TGA), energy-dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) spectroscopy. It is found that polyethylene glycol act as cross-linking agents to interconnect or cross-link the MWCNTs within and among the bundles, as demonstrated by TEM analysis, and few defects will be induced to the nanotube sidewalls. After cross-linking of PEG, the functionalized MWCNTs are still insoluble in any solvent; however, the morphologies of the cross-linked MWCNTs were largely intact, undoubtedly which will provide a useful way to construct nanoscale devices with MWCNTs in the future.     

Fast and clean functionalization of carbon nanotubes by dielectric barrier discharge plasma in air compared to acid treatment

Multi-walled carbon nanotubes (MWCNTs) have been functionalized by a dielectric barrier discharge plasma in air and compared to those functionalized in HNO₃. The MWCNTs were prepared by chemical vapor deposition of xylene using ferrocene as a catalyst at 850 °C. Air oxidation followed by acid treatment was used to purify the MWCNTs, which were then annealed in helium. The MWCNTs were functionalized in air in a plasma reactor at room temperature. Quantitative analyses of gases evolved during the temperature programmed desorption of the functionalized nanotubes were carried out using Fourier transform infrared spectroscopy and gas chromatography. The influence of plasma parameters, including power in the range of 8-90 W and treatment time in the range of 1-9 min, on the number of the functional groups was investigated. It is shown that the extent of functionalization increases with increasing discharge power, provided that the exposure time of the MWCNTs in the plasma atmosphere does not exceed a certain period of time. Compared to acid treatment, plasma functionalization offers the advantages of much shorter treatment time, and produces less damage.     

Influence of modified multi-walled carbon nanotubes on the mechanical behavior and toughening mechanism of an environmentally friendly granulated blast furnace slag-based geopolymer matrix

This study aimed to investigate the mechanical behavior of an environmentally friendly granulated blast furnace slag-based geopolymer matrix reinforced with modified multi-walled carbon nanotubes (MWCNTs). The modified MWCNTs were obtained using a modification method combining nitric acid and sulfuric acid and were then dispersed using sodium dodecylsulfate (SDS) as a dispersant. Two types and three concentrations of MWCNTs were mixed directly into the aqueous solution, sonicated, and then mechanically mixed with waste granulated blast furnace slag to form the geopolymer matrix. Raman and Fourier transform infrared (FT-IR) spectroscopy were used to evaluate the ordered structure and crystallization degree of the modified MWCNTs. Then, the dispersity of the modified MWCNTs was characterized using transmission electron microscopy (TEM). The compressive and bending strengths were measured to evaluate the mechanical behavior of specimens. Moreover, the polycondensation products, polycondensation degree, pore structure, and microscopic morphology of the geopolymer matrix were analyzed using X-ray diffraction (XRD), FT-IR spectroscopy, nuclear magnetic resonance (NMR), mercury intrusion porosimetry (MIP), and field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDS). The experimental results showed that the incorporation of 0.1% functionalized MWCNTs had an optimal influence on the fluidity and mechanical behavior. The slump diameters of geopolymers with 0.1% functionalized MWCNTs with and without SDS were increased by 16.3% and 23.5%, respectively, compared with the reference geopolymer matrix. For geopolymer matrix samples at a curing age of 28 d, the compressive strength of geopolymers with 0.1% functionalized MWCNTs with and without SDS were increased by 16.3% and 17.6%, respectively. For the bending strength, the corresponding increases were 17.6% and 18.7%, respectively. It was found that functionalized MWCNTs could increase the degree of polycondensation, leading to a more traditional amorphous N-A-S-H phase, a finer C–S–H phase, more Q⁴ (2Al) and Q⁴ (3Al), and lower porosity. In addition, the propagation of micro-cracks in the geopolymers was inhibited by the incorporation of functionalized MWCNTs.     

Cure reaction of multi‐walled carbon nanotubes/diglycidyl ether of bisphenol A/2‐ethyl‐4‐methylimidazole (MWCNTs/DGEBA/EMI‐2,4) nanocomposites: effect of carboxylic functionalization of MWCNTs

BACKGROUND: The aim of this work was to study, using differential scanning calorimetry, the effect of carboxylic functionalization of multi‐walled carbon nanotubes (MWCNTs) on the cure reaction of MWCNTs/diglycidyl ether of bisphenol A/2‐ethyl‐4‐methylimidazole (MWCNTs/DGEBA/EMI‐2,4) nanocomposites. This is important for the practical design, analysis and optimization of novel materials processing. RESULTS: Comparing the influence of non‐functionalized MWCNTs and carboxyl‐functionalized MWCNTs, it was found that, at the initial curing stage, both MWCNTs act as catalyst and COOH functionalization of MWCNTs has a catalytic effect on the curing process. Then, at the later curing stage, non‐functionalized MWCNTs prevent the occurrence of vitrification, whereas COOH functionalization of MWCNTs promotes vitrification. Non‐functionalized MWCNTs decrease the degree of curing, as evidenced by lower total heat of reaction and lower glass transition temperatures of nanocomposites compared to neat epoxy; however, COOH functionalization of MWCNTs increases the degree of curing. CONCLUSION: For the development of composites, COOH functionalization of MWCNTs could bring a positive influence to the composite process. Its acceleration of cure could help shorten pre‐cure time or lower pre‐treatment temperature, and its effect of promoting vitrification could help shorten post‐cure time or lower post‐treatment temperature. Copyright © 2009 Society of Chemical Industry     

Rheological and thermal properties of epoxy nanocomposites reinforced with alkylated multi‐walled carbon nanotubes

The effects of functionalized multi‐walled carbon nanotubes (MWCNTs) on thermal and chemorheological behaviors of an epoxy‐based nanocomposite system were investigated. Chemical functionalization of MWCNTs by acid modification (A‐MWCNTs) and chemical amidation (D‐MWCNTs) was confirmed using Fourier transform infrared spectroscopy and thermogravimetric analysis. It was found that the D‐MWCNTs had a significant effect on the chemorheological behaviors of the epoxy‐based nanocomposite. Compared to the epoxy/A‐MWCNT nanocomposite, the epoxy/D‐MWCNTs nanocomposite showed a significant increase in gel time, as obtained from isothermal rheology measurements. Also, the storage modulus of the diglycidylether of bisphenol F (DGEBF)/D‐MWCNTs nanocomposite was higher than that of the DGEBF/D‐MWCNTs nanocomposite and gradually increased with an increase of frequency. This could be interpreted by the relatively strongly interconnected structure of the D‐MWCNTs in the DGEBF epoxy resin, which arises from the functionalized alkyl groups of the D‐MWCNTs in dispersion phases with the DGEBF epoxy resin. Copyright © 2012 Society of Chemical Industry     

Combination of Plasma Functionalization and Phase Inversion Process Techniques for Efficient Dispersion of MWCNTs in Polyamide 6: Assessment through Morphological,Electrical, Rheological and Thermal Properties

Different contents of multiwalled carbon nanotube (MWCNTs) functionalized by He-dielectric barrier discharge (DBD) plasma followed by an exposure to NH₃ were incorporated into PA6 matrix via a phase inversion based solution method. Optical and electron microscopic results were indicative of the excellent dispersion state of the MWCNTs. The differential scanning calorimetry and thermogravimetric analysis measurements revealed that even addition of a slight amount of the MWCNTs significantly increased the thermal stability and crystallization temperature. Moreover, the low electrical percolation threshold of the PA 6/functionalized MWCNTs nanocomposites was another confirmation for achieving a good dispersion state of MWCNTs using this approach.