Effects of carbon nanotubes grafted on a carbon fiber surface on their interfacial properties with the matrix in composites

377

CARBON 55 (2013) 375– 378

Effect of high temperature treatment on the topological micro-

Tongji University, Shanghai Key Laboratory of Special Artificial Micro-

structure of micro-coil carbon fibers

structure Materials and Technology, Shanghai 20092, China

Fa-yu Wua, Yan-wen Zhoua, Jun-wei Zhanga, Jin-hong Dub, Feng Lib a

Carbon aerogels were synthesized at room temperature by a

School of Materials Science and Engineering, University of Science and

Technology Liao Ning, 185 Qianshan Road, Anshan 114051, China b

Shenyang National Laboratory for Materials Science, Institute of Metal

Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China The topological microstructure of micro-coiled carbon fibers (MCFs) before and after high temperature treatment (HTT) was explored and characterized. Results suggested that as-grown MCFs had an annular ring-like structure in the cross section and a herringbone-like structure in the longitudinal section, but the orientation range of graphitic domains was wide. After HTT, the coiled fibers consisted of stacked pyramidal prisms of ordered graphitic domains. The apparent morphology of the coiled fibers

sol–gel polymerization route using resorcinol and formaldehyde as precursors, acetonitrile as solvent and hydrochloric acid as catalyst, followed by CO2 supercritical drying and carbonization. FT-IR, SEM, XRD and nitrogen adsorption were used to characterize the microstructure of the aerogels. Results showed that the carbon aerogels are graphite-like amorphous materials with nano-skeleton networks formed by nanoparticles around 40– 70 nm in diameter, whose specific surface area is up to 1300 m2 g

1

and lowest density about 0.050 g/cm3. The heat of

condensation and the catalytic action of hydrochloric acid made it possible to form gels at room temperature. The high surface area and low density of the as-prepared carbon aerogels were ascribed to a strong interaction between acetonitrile and –OH groups by hydrogen bonding. [New Carbon Materials 2012, 27(6): 462–468]

is a uniform spiral prism. The evolvement of the microstructure of MCFs after HTT was also confirmed by X-ray diffraction and Raman spectroscopy. The topological microstructure provides a reliable reference for the prediction of properties and projected

Synthesis and characterization of condensed poly-nuclear aro-

applications of the MCFs.

matic resin using heavy distillate from ethylene tar

[New Carbon Materials 2012, 27(6): 448–454]

Ming-bo

Wua,

Yang-yang

Shia,

Shi-bin

Lia,

Ning

Guoa,

Yu-wei Wanga, Jing-tang Zhenga, Jie-shan Qiub a

State Key Laboratory of Heavy Oil Processing, China University of

Effects of carbon nanotubes grafted on a carbon fiber surface on

Petroleum, Qingdao 266555, China

their interfacial properties with the matrix in composites

b

Xiu-ying Liu, Ying Song, Cun-mei Li, Fu-ping Wang

Chemical Engineering, Dalian University of Technology, Dalian 116024,

School of Chemical Engineering and Technology, Harbin 150001, China

Carbon Research Laboratory, State Key Lab of Fine Chemicals, School of

China Heat-resistant condensed poly-nuclear aromatic resin (COPNAR) was prepared using heavy distillate (>250 °C, named DO)

Carbon fibers (CFs) were oxidized by concentrated HNO3 and

from distilled ethylene tar (ET). The basic properties of ET, DO

then reacted with polyamidoamine dendrimers (PAMAM) with

and COPNAR were investigated by FT-IR, 1H NMR, TGA and ele-

an average molecular weight of 157 to form CF–PAMAM. The CF–

mental analysis. The structural parameters of DO and ET were

PAMAM was further reacted with oxidized carbon nanotubes

obtained by the improved Brown–Ladner method and the forma-

(CNTs) to form CF–PAMAM–CNTs that were used as the reinforce-

tion mechanism of the COPNAR from DO was deduced. Results

ment for epoxy resin-based composites. The functional groups

show that a superior heat-resistant COPNAR can be obtained

and structure of the CF–PAMAM–CNTs were examined by XPS,

from DO. The distillation of ET increases the heat resistance of

SEM and AFM, and their wettability and the tensile strength were

the COPNAR, and the reaction mechanism is confirmed to be an

investigated by contact angle measurements and single strand

acid-catalyzed positive ion-type polymerization.

extension respectively. The interfacial shear strength of the com-

[New Carbon Materials 2012, 27(6): 469–475]

posites was measured by a micro-debonding method. Results showed that, compared with CFs, the surface roughness, surface energy and tensile strength of the CF–PAMAM–CNTs were increased by 180%, 300% and 22%, respectively when the CNT content was 15 mass%. The interfacial shear strength of the composite reinforced with CF–PAMAM–CNTs was increased by 178% for

Purification of natural graphite by microwave assisted acid leaching Yu-feng Lia,b, Shi-fu Zhua, Lei Wangb

the same CNT content, which showed that the grafted nanotubes

a

improved the interfacial properties of the filler with the matrix.

China

[New Carbon Materials 2012, 27(6): 455–461]

b

Department of Materials Science, Sichuan University, Chengdu 610064, Deep-processing Laboratory of Graphite, Panzhihua University,

Panzhihua 617000, China

Preparation of carbon aerogels at room temperature using ace-

Natural graphite was leached under microwave irradiation by

tonitrile as solvent

acid mixtures containing HCl (12 M) and HNO3 (16 M). It was

Pei-di Wu, Bin Zhou, Ai Du, Zhi-hua Zhang, Guang-ming Wu, Jun

found that the purification efficiency was affected by microwave

Shen

power, reaction pressure, reaction time and the acid ratio. The