关于尼龙-6/炭纳米管复合材料的研究

在原位复合尼龙－６／炭纳米管（ＰＡ６／ＣＮＴ）过程中,炭纳米管将以其外壁上连接的羧基官能团（－ＣＯＯＨ）参与尼龙－６（ＰＡ６）的加成聚合反应,并阻碍ＰＡ６分子的长大。这在很大程度上削弱了基体强度。采用改进原位复合法复合ＰＡ６／ＣＮＴ,可大大提高ＰＡ６分子的平均分子量,减轻炭纳米管对基体ＰＡ６强度的削弱,大幅度提高ＰＡ６／ＣＮＴ复合材料的强度。     

原位复合法复合PA6/巴基管复合材料的试验研究

经过硝酸处理的利用ＣＶＤ法生产的巴基管与ＰＡ６采用原位复合法进行复合时，将以其外壁上联结的羟基－ＯＨ和羧基－ＣＯＯＨ参与己内酰胺合成ＰＡ６的缩水聚合反应，从而结合到ＰＡ６的网状大分子结构中，同时也阻止ＰＡ６分子长大，并产生较大应力。     

紫外线辐照HDPE／PA6共混物界面相互作用的研究

采用ＥＳＣＡ、Ｍｏｌａｕ实验、ＳＥＭ、ＤＳＣ、ＤＭＡ、抽滤分析、ＦＴ－ＩＲ和拉抻应力－应弯曲线，研究了紫外线辐照ＨＤＰＥ／ＰＡ６共混物的界面相互作用机理。结果表明，紫外线辐照下，ＨＤＰＥ分子链上引入Ｃ＝Ｏ、ＣＯＯＨ、－ＯＨ、－ＯＯＨ、－Ｃ－Ｏ－等极性基因；在与ＰＡ６熔融共混过程中， 的Ｃ＝Ｏ、ＣＯＯＨ等基团与ＰＡ６分子我寂的酰胺基或端胺基发生化学反应，生成ＨＤＰＥ－ＰＡ６共聚物。共聚物的形成增强了     

紫外线辐照HDPE与尼龙－6相容性的研究

采用ＩＲ、ＳＥＭ、ＤＳＣ和拉伸应力－应变曲线研究了紫外线辐照ＨＤＰＥ／ＰＡ６的相容性，结果表明，随紫外线辐照时间的增长，ＨＤＰＥ分子链上引入Ｃ＝Ｏ－Ｃ－Ｏ－等极性基团明显增加；ＰＡ６的粒径减小，与基体间界面作用加强；两组分玻璃化温度差（Ｔ_（ｇ，ＰＡ６）－Ｔ_（ｇ，ＨＤＰＥ））减小；共混物拉伸应力－应变曲线上出现屈服点及拉伸冷流塑性形变。当辐照时间达１４４ｈ后，由于ＨＤＰＥ热稳定性明显变差，共混物韧性突降，拉伸应力－应变曲线上未出现屈服点。     

紫外线辐照HDPE与尼龙—6相容性的研究

采用ＩＲ，ＳＥＭ，ＤＳＣ和拉伸应力－应变曲线研究了紫外线辐照ＨＤＰＥ／ＰＡ６的相容性，结果表明，随紫外线辐照时间的增长，ＨＤＰＥ分子链上引入〉Ｃ＝Ｏ－Ｃ－Ｏ－等极基团明显增加；ＰＡ６的粒径减小，与基体间界面作用加强；两组分玻璃化温度差减小；共混物拉伸应力－应变曲线上出现屈服点及拉伸冷流塑性形变。     

Al2O3和Y2O3包覆的SiC复合粒子制备

本文利用非均匀成核法,将Ａｌ（ＯＨ）３和Ｙ（ＯＨ）３均匀地包覆在ＳｉＣ粒子表面,制备出被覆Ａｌ２Ｏ３和Ｙ２Ｏ的ＳｉＣ复合粒子,包覆Ａｌ（ＯＨ）３的ＳｉＣ粒子,其等电点ＩＥＰ的ｐＨ＝３．４移至ｐＨ＝７．３,再用Ｙ（ＯＨ）３包覆表面被覆Ａｌ（ＯＨ）３的ＳｉＣ复合粒子后,其等电点ＩＥＰ又从ｐＨ＝７．３移至ｐＨ＝８．６ｄａｄｋ。     

乙酰乙基纤维素的热致液晶性能及其与PA6原位复合的研究

将乙基纤维素乙酰化制备乙酰乙基纤维素。用ＮＭＲ，ＩＲ测定了ＡＥＣ的乙酰取代度，用ＤＳＣ，ＨＳＰＬＭ研究了ＡＥＣ的热致液晶性能，织构与Ａ－ＤＳ的关系。在此基础上研究了ＰＡ６／ＡＥＣ原位复合单丝的形态结构和力学性能，证明一定条件下ＡＥＣ对ＰＡ６有明显增强作用，总取代度增大是主要作用机制。     

等离子喷涂HA/Ti复合涂层研究 I.结构、组成和力学性能

采用等离子喷涂方法,在Ｔｉ－６Ａｌ－４Ｖ基体上成功地制备了ＨＡ／Ｔｉ复合涂层,并对复合涂层的微观结构,相组成和力学性能进行了研究。结果表明,ＨＡ和Ｔｉ两相均匀地分布于复合涂层中。ＨＡ／Ｔｉ复合涂层的结合强度明显高于纯ＨＡ涂层,这主要是由于ＨＡ／Ｔｉ的复合和了涂层与基体之间的热膨胀系数失配,ＨＡ／Ｔｉ复合涂层在模拟体液中浸泡一段时间后,结合强度没有明显降低,ＨＡ／Ｔｉ复合涂层的断裂韧性和硬度均高于Ｈ     

等离子喷涂制备HA/ZrO2复合涂层

采用等离子喷涂技术,在Ｔｉ－６Ａｌ－４Ｖ基体上成功地制备了羟基磷灰石／氧化锆（ＨＡ／ＺｒＯ２）复合涂层,对涂层的微观结构,相组成和结合强度进行了研究,并以模拟体液试验评估涂层的生物活性,结果表明,复合涂层较有较为微观结构,ＨＡ／ＺｒＯ２复合涂层的结合强度明显高于ＨＡ涂层,ＨＡ／６０ｗｔ％ＺｒＯ２涂层的结合强度高达２８．５ＭＰａ,为ＨＡ涂层的２．２倍,复合涂层在模拟体液中浸泡一段时间后,表面覆盖一层     

Naβ/β″-Al2O3膜的制备与电学性能研究

通过ＭｇＡｌ２Ｏ４－α－Ａｌ２Ｏ３复合相陶瓷基体与Ｌｉ２Ｏ，Ｎａ２Ｏ气氛的反应制备了Ｌｉ２Ｏ和ＭｇＯ共同稳定的Ｎａβ／β″－Ａｌ２Ｏ３膜，相分析的结果表明，反应温度是决定膜中β／β″Ａｌ２Ｏ３相形成速率的主要因素，当温度低于１１００℃时，α－Ａｌ２Ｏ３基体不能转化为β／β″－Ａｌ２Ｏ３基体中的ＭｇＡｌ２Ｏ４可以促进膜的形成，并降低膜的形成温度，交流复阻抗谱和四极法测量的结果表明，复合基体表面形成的     

原位聚合制备尼龙6/多壁碳纳米管复合材料及性能表征

用原位聚合法制备了尼龙6/多壁碳纳米管(MWCNTs)复合材料。先对多壁碳纳米管进行胺基功能化处理,再研究了多壁碳纳米管添加量对复合材料电性能和力学性能的影响,结果显示,复合材料体积电阻率和表面电阻率相对于不加碳纳米管制得的尼龙6基体降低了3个数量级,复合材料的介电常数显著增加,相对于不加碳纳米管的增加了71%;复合材料的弹性模量、弯曲模量、弯曲强度随碳纳米管加入量的增加大幅提高。     

碳纳米管增强PA6复合材料的机理

在探讨碳纳米管的加入对PA6复合材料力学性能影响的基础上，用扫描电镜(SEM)、拉曼光谱和特性粘数法对碳纳米管增强PA6复合材料的机理进行了初步探讨。结果表明，碳纳米管的加入提高了PA6的强度，此时碳纳米管能以纳米状态均匀地分布在基体中，且碳纳米管与PA6之间在界面存在一定的相互作用，同时碳纳米管在原位复合过程中未对高分子链段的增长带来负面影响，反而使PA6的聚合程度略有增大。     

碳纳米管的加入对PMMA强度和导电性能的影响

本文研究了ＰＭＭＡ与碳纳米管的原位复合过程、复合体强度及电学性能，结果表明，碳纳米管与ＰＭＭＡ原位复合时，将参与ＭＭＡ的链式聚合反应，这不仅影响了ＭＭＡ的聚合过程和复合体的强度，而且影响了碳纳米管在基体ＰＭＭＡ中的分散度。适当推迟碳纳米管的加入时间，将提高ＰＭＭＡ的强度，碳纳米管的加入也将提高ＰＭＭＡ的导电性能。     

Consideration of critical axial properties of pristine and defected carbon nanotubes under compression

Carbon nanotubes are hexagonally configured carbon atoms in cylindrical structures. Exceptionally high mechanical strength, electrical conductivity, surface area, thermal stability and optical transparency of carbon nanotubes outperformed other known materials in numerous advanced applications. However, their mechanical behaviors under practical loading conditions remain to be demonstrated. This study investigates the critical axial properties of pristine and defected single- and multi-walled carbon nanotubes under axial compression. Molecular dynamics simulation method has been employed to consider the destructive effects of Stone-Wales and atom vacancy defects on mechanical properties of armchair and zigzag carbon nanotubes under compressive loading condition. Armchair carbon nanotube shows higher axial stability than zigzag type. Increase in wall number leads to less susceptibility of multi-walled carbon nanotubes to defects and higher stability of them under axial compression. Atom vacancy defect reveals higher destructive effect than Stone-Wales defect on mechanical properties of carbon nanotubes. Critical axial strain of single-walled carbon nanotube declines by 67% and 26% due to atom vacancy and Stone-Wales defects.     

Mechanical Reinforcement of Polymers Using Carbon Nanotubes

Owing to their unique mechanical properties, carbon nanotubes are considered to be ideal candidates for polymer reinforcement. However, a large amount of work must be done in order to realize their full potential. Effective processing of nanotubes and polymers to fabricate new ultra‐strong composite materials is still a great challenge. This Review explores the progress that has already been made in the area of mechanical reinforcement of polymers using carbon nanotubes. First, the mechanical properties of carbon nanotubes and the system requirements to maximize reinforcement are discussed. Then, main methods described in the literature to produce and process polymer–nanotube composites are considered and analyzed. After that, mechanical properties of various nanotube–polymer composites prepared by different techniques are critically analyzed and compared. Finally, remaining problems, the achievements so far, and the research that needs to be done in the future are discussed.     

碳纳米管/聚乙烯复合物分子动力学模拟研究

采用分子动力学方法模拟了碳纳米管/聚乙烯复合物的结构、热力学和力学特性,分析其随模拟温度和碳纳米管填充率的变化。模拟结果表明,碳纳米管/聚乙烯复合物为各向同性的无定形结构,聚乙烯和碳纳米管通过较强的范德华作用结合在一起,在聚乙烯基体作用下,碳纳米管壁上的碳原子排列的周期性下降,出现弯曲和褶皱。从能量上看,填充率较高的复合物更加稳定。碳纳米管/聚乙烯复合物具有比聚乙烯体系更高的等容热容和与聚乙烯体系相反的负值热压力系数,热容随碳纳米管填充率的变化较小,但随温度的升高而明显减小,具有显著的温度效应;热压力系数随温度的变化较小,温度稳定性比聚乙烯更好,但随填充率增加而减小。碳纳米管/聚乙烯复合物的力学特性表现出各向同性材料的弹性常数张量,弹性模量和泊松比比纯聚乙烯体系高得多,并且都随温度的升高和碳纳米管含量的降低而减小,说明加入碳纳米管可显著改善聚乙烯的力学性质。     

The impact of fluorinated MWCNT additives on the enhanced dynamic mechanical properties of e-beam-cured epoxy

Multi-walled carbon nanotubes were embedded into e-beam-cured epoxy resin to improve the mechanical properties of epoxy resin. The surfaces of these carbon nanotubes were modified using a fluorination treatment to improve their dispersion and adhesion in epoxy resin. The dynamic mechanical properties of epoxy/carbon nanotube composites were investigated at various heating rates and frequencies. As an effect of fluorination treatment, the semi-ionic bond of C–F on the surface of multi-walled carbon nanotubes played an important role in the improved dispersion and adhesion of carbon nanotubes into the epoxy resin. The storage modulus and loss modulus of the composites increased with higher applied frequency. The activation energy of the composites was increased by the effects of a higher heating rate due to the slow heat transfer in the epoxy/carbon nanotube composites. Eventually, the dynamic mechanical properties of the investigated epoxy were significantly improved by the carbon nanotubes dispersed therein via the fluorination treatment.     

Carbon nanotube dispersion in nematic liquid crystals: An overview

The aim of present review article is to present a comprehensive and current overview of scientific advancement in liquid crystal and carbon nanotube suspension. Particular attention has been paid to the recent developments and fundamental understanding of carbon nanotube dispersion in nematic liquid crystals. The dispersion and interaction of carbon nanotube in liquid crystal matrices and more elaborately the effect of dispersion on the properties of liquid crystalline materials has been extensively discussed. Recent progress has shown that even a very minute concentration of carbon nanotube in liquid crystals can have a reflective impact on the electrical and optical properties of liquid crystals. Liquid crystals provide a distinctive environment for controlling the alignment of carbon nanotubes whereas carbon nanotubes are important for the enhancement and fine-tuning of liquid crystalline properties. Potential applications of liquid crystal and carbon nanotube suspension are briefly discussed. Conclusion and future perspectives of this rapidly emerging field is provided at the end.