臭氧处理对碳纤维表面及其复合材料性能的影响

利用X射线光电子能谱(XPS)研究了碳纤维经臭氧(O3)氧化处理后表面元素组成及表面官能团的变化，结果发现，O3表面处理主要增加了碳纤维表面上的羟基或醚基官能团；研究了表面O3氧化处理对复合材料力学性能的影响，结果表明，碳纤维经O3氧化处理后明显改善了碳纤维与环氧树脂间的界面粘结，其复合材料的层间剪切强度明显提高。     

碳纤维表面氨化处理对环氧树脂在其表面浸润性的影响

分别用氧化方法和氨化方法对碳纤维进行表面处理,采用XPS研究不同处理方法对碳纤维表面元素组成以及官能团的影响。结果表明经过氧化处理后,碳纤维表面的氧含量明显增加,表面有较高的m(O+N)/m(C)比;氨化处理后,碳纤维表面的氮元素明显增加,氧含量减少,并且增加的氮元素主要以氨基的形式存在。采用接触角测试中的插入法和液滴法分别研究碳纤维处理后在水和环氧树脂中的接触角变化。结果表明,经过氧化和氨化方法处理后碳纤维与环氧树脂的接触角降低。氧化与氨化相比,氨化处理后碳纤维与环氧树脂之间有较低的接触角,表明在碳纤维表面增加氨基官能团能显著改善碳纤维和环氧树脂之间的浸润性能。     

XPS对瞬时高温空气氧化法和气液双效法表面处理炭纤维的分析

利用XPS研究了瞬时高温空气氧化法和气液双效法表面处理炭纤维的表面氧含量和含氧官能团的变化。表明,经表面处理后,炭纤维表明氧含量增加。羧基减少,但羰基或羟基的增加增强了CFRP界面的粘结情况,提高了CFRP的层间剪切强度。并对上述两种方法进行了比较。发现羟基是增强CFRP界面粘结强度的主要基因;羰基可能是增强CFRP断裂韧性的基因。     

化学滴定法分析PAN基HM炭纤维表面酸性官能团

利用化学滴定法分析阳极氧化PAN基HM炭纤维表面酸性官能团，结果发现：炭纤维表面酸性官能团随电流密度增大而明显增加，最终达到“饱和”。这将有利于进一步研究PAN基高模炭纤维氧化机理和粘结机理。     

改性炭黑的表面性质与微观结构

通过氮气氛围下高温处理和双氧水H_2O_2,硝酸HNO_3氧化炭黑N234,利用氮吸附比表面积(BET),红外光谱(IR)和X射线光电子能谱(XPS)表征了上述改性炭黑的比表面积,表面的官能团和元素组成。高温处理炭黑表面氧元素含量降低,含氧官能团部分被除去,而双氧水和硝酸氧化炭黑表面氧元素含量增加,生成了很多C=O和C-O官能团。高分辨透射电镜(HR-TEM)结果显示,双氧水和硝酸改性的炭黑表面形成了很多结构上的缺陷,比表面积显著增加。     

氨气处理碳纤维 第I报 表面组成和反应机理

采用原位漫反射红外光谱(FT-IR)在线分析碳纤维表面谱图变化。结果发现,当温度升至500℃后,3260cm-1处吸收峰减弱,在3157cm-1、3048cm-1、2829cm-1和1405cm-1处新增吸收峰。用X-射线光电子能谱(XPS)对未处理与在氨气气氛中600℃处理30s后碳纤维的表面官能团组成进行分析对比发现,处理后的碳纤维表面氮元素显著增加,而氧含量降低。由FT-IR和XPS的谱图变化推测出在高温时,碳纤维表面的羟基和羧基与氨气发生反应,形成了氨基官能团。     

含氮沥青基活性炭纤维的制备

用不同比例的浓氨水与水的混合物使乙烯渣油沥青基炭纤维活化,得到不同氮含量的活性炭纤维PACF（NH3）。元素分析及XPS均表明通过该活化方法可在活性炭纤维表面引入含氮官能团。含氮官能团以两种类型存在于PACF（NHa）的表面,即类吡啶和／或类腈官能团和类酰胺和／或类胺官能团。其N2吸附等温线均为I型,表明了PACF（NH3）的微孔性。     

氨气处理碳纤维第Ⅰ报表面组成和反应机理

采用原位漫反射红外光谱(FT-IR)在线分析碳纤维表面谱图变化.结暴发现,当温度升至500℃后,3260 cm-1处吸收峰减弱,在3157 cm-1、3048cm-1、2829cm-1和1405cm-1处新增吸收峰.用X-射线光电子能谱(XPS)对未处理与在氨气气氛中600%处理30s后碳纤维的表面官能团组成进行分析对比发现,处理后的碳纤维表面氮元素显著增加,而氧含量降低.由FT-IR和XPS的谱图变化推测出在高温时,碳纤维表面的羟基和羧基与氨气发生反应,形成了氨基官能团.     

炭纤维表面处理综述

综述了炭纤维的表面结构与性能,介绍了两种通用的炭纤维表面处理方法：电化学氧化法和等离子氧化法;同时也总结了炭纤维表面处理对提高炭纤维／树脂复合材料界面的粘接机理。     

活性炭表面含氧官能团对水中卤乙酸吸附去除的影响

为了改善极性、亲水性卤乙酸(HAAs)分子在非极性、疏水性活性炭上的吸附性能,利用N₂等温吸附实验、X射线光电子能谱实验（XPS）、HAAs等温吸附实验等方法,对几种不同产地的活性炭孔隙结构、表面元素形态结构组成,以及HAAs吸附性能进行了研究,考察了活性炭孔结构及含氧官能团对HAAs吸附性能的影响.活性炭表面含氧官能团对HAAs的吸附性能影响显著,当活性炭表面含氧官能团组成较小时,其HAAs吸附能力较强.     

碳纤维的硝酸氧化及表面化学分析

采用 X光电子能谱 (XPS)及化学衍生法探讨了硝酸氧化前后的碳纤维表面化学的变化。研究表明 ,高模量碳纤维的表面化学基团含量要比低模量碳纤维的低。硝酸氧化对低模量碳纤维的表面改性远比高模量碳纤维的大。硝酸氧化减少了碳纤维表面的羟基含量 ,同时增加了碳纤维表面的羧基含量。     

活性炭纤维表面结构及其吸附银机理研究

用Ｘ射线光电子能谱（ＸＰＳ）等分析方法对剑麻基碳化纤维、磷酸化学活化纤维及其热处理纤维吸附Ａｇ＋前后的表面结构进行了研究,结果表明：活性炭纤维的氧化还原吸附性能不与其比表面积成正比,而受表面官能团影响很大,且还原吸附的纳米银与纤维的界面间除相互的物理作用外,还有Ａｇ－Ｏ－Ｃ配位键合存在;纤维还原能力强,但负载的纳米银与载体纤维之间的相互作用力并不一定大,而活化作用使纤维表面的Ｏ物种利于Ａｇ的成核和成键,促进Ａｇ－Ｏ－Ｃ的形成,使负载上的纳米银较稳定。     

ESCA characterization of polyacrylonitrile-based carbon fiber precursors during its stabilization process

Oxidation process control plays a key role in influencing the development of carbon fiber properties. The characterization of oxidized fibers is difficult because of their poor solubility in organic solvents and strong absorbance. X-ray photoelectron spectroscopy (XPS) has been used in the surface characterization of carbon fiber precursors during the oxidation or stabilization process. The changes in surface elemental composition and functionalities of carbon and oxygen have been identified. Quantitative changes have been noticed in surface functional groups as the oxidation process proceeds. © 1994 John Wiley & Sons, Inc.     

Effects of treatment on the surface composition and energy of carbon fibers

The surface composition and energy of carbon fiber has been carefully analyzed and quantified. Untreated, AU, surface-treated, AS, and heat-treated AHT fibers were all studied. AS fiber was surface-treated by an electrolytic oxidation process. AHT fiber was heat-treated at elevated high temperatures under vacuum. X-ray photoelectron spectroscopy (XPS or ESCA) was used to investigate the surface elemental concentration of carbon fibers. The corresponding surface free energies of these fibers were calculated from the contact angles measured by a dynamic contact angle analyzer. Results showed a strong correlation between the surface treatment and heat-treatment history and the surface chemistry of carbon fibers. After oxidation treatment, the surface free energy was increased by adding functional group elements (oxygen and nitrogen). However, these added elements could be removed by high temperature treatment under vacuum. The diffusion of O, N, and Na was discussed. The correlation between oxygen and nitrogen concentration and carbon fiber surface free energy has been plotted. These fibers would be used to quantify the relationship between carbon fiber surface free energy and the interfacial shear strength of the fiber-polymer interface.     

碳纤维的表面处理对其力学性能和结构的影响

通过X射线衍射、扫描电镜、拉曼光谱、X射线电子能谱及电子拉力等分析表明,硝酸、空气中氧化、烧灼等处理可使中强碳纤维的力学性能得到改善.硝酸处理使碳纤维表面产生氧化形成一些活性基团和表面粗化.而空气中氧化、灼烧等处理未能改变碳纤维的表面化学结构.     

Sizing removal and functionalization of the carbon fiber surface studied by combined TOF SIMS and XPS

Time-of-flight secondary ion mass spectrometry (TOF SIMS) and X-ray photoelectron spectroscopy (XPS) have been jointly used to study a two-step surface processing of AS4 carbon fiber: extraction of sizing in CH₂Cl₂ and functionalization with trimellitic anhydride. The combined information on molecular specificity obtained with TOF SIMS and quantification obtained with XPS allows us to follow qualitatively and quantitatively the changes in functional groups on the carbon surface. The results show that the sizing on AS4 contains at least four different compounds. These compounds can be extracted in CH₂Cl₂ and the elimination is almost complete for silicone. The functionalization of AS4 with trimellitic anhydride has been realized. The reaction takes place between the amine groups on the carbon fiber and the two types of functional groups in trimellitic anhydride.     

等离子体改性对活性炭纤维表面化学结构的影响

采用放电等离子体对活性炭纤维表面进行改性,通过改变活性炭纤维的化学官能团来强化活性炭纤维对SO2和NOx的吸附和催化作用。利用XPS、FTIR等方法对改性活性炭纤维的化学性质进行表征,研究了活性炭纤维表面官能团在等离子体改性过程中的转化规律和机理。试验结果表明放电改性过程可以有效的向活性炭纤维表面引入有利于脱硫脱氮的含氧、含氮官能团;当电压为8kV,放电时间为5分钟时,放电改性活性炭纤维的效果最佳。     

THE INFLUENCE OF OXIDATION OF THE FIBERS ON THE TRIBOLOGICAL PROPERTIES OF CARBON FIBER-REINFORCED NYLON COMPOSITES

Three-dimensional braided carbon fiber-reinforced nylon composites (C_3D/MCN) were prepared in order to investigate the influence of oxidation of carbon fibers on the tribological properties of the C_3D/MCN composites. Friction and wear tests of the C_3D/MCN composites with untreated and treated carbon fabric were conducted. The characteristics of the carbon fiber, the interface strength, the hardness, and the worn surface morphologies of the C_3D/MCN composites were analyzed. The results show that the specific surface area of treated carbon fiber was far higher than that of untreated carbon fiber and there formed a functional group of -C=O on the carbon fiber surface after air oxidation. The oxidation of the carbon fibers improved the interface strength between the carbon fibers and the matrix and had little effect on the hardness of the composites. The friction coefficient and wear rate of C_3D/MCN composites with oxidized carbon fibers were apparently lower than those with untreated carbon fibers. In conclusion, the oxidation of the fibers showed good effects on the improvement of the interface strength and the tribological properties of the composites.     

XPS studies by use of the digital difference spectrum technique of functional groups on the surface of carbon fiber

The digital difference spectrum technique in X-ray photoelectron spectroscopy has proved to be effective for the analysis of the functional groups introduced by surface oxidation treatment of carbon fibers. The major functional groups introduced to the carbon fiber surface by surface oxidation are hydroxyl and carboxyl groups. Disordering of the crystal lattice is also observed together with generation of carboxyl groups in the case of surface oxidation of graphite fibers.