聚乳酸／功能化石墨烯纳米复合薄膜的制备与性能

以十八烷基胺修饰氧化石墨烯(GO–ODA)为纳米填料,通过溶液铸膜法制备了聚乳酸(PLA)／GO–ODA纳米复合薄膜。用傅立叶变换红外光谱和扫描电子显微镜对GO–ODA及纳米复合薄膜的化学结构及形貌进行了表征,并对纳米复合薄膜的拉伸性能、热稳定性和透氧率进行了测试。结果表明,GO–ODA与PLA具有良好的相容性,可均匀分散于PLA基体中,对PLA膜起到增韧增强的效果,同时GO–ODA的加入使PLA的热稳定性和氧气阻隔性均有所提高。     

Nanocomposites of Poly(Vinyl Alcohol)/Functionalized-Multiwall Carbon Nanotubes Conjugated With Glucose Oxidase for Potential Application as Scaffolds in Skin Wound Healing

A novel nanocomposite scaffold based on poly(vinyl alcohol) (PVA) and multiwalled carbon nanotubes (MWNT) were synthesized and characterized regarding to morphological, physical, and mechanical properties and also the preliminary biocompatibility was assessed by MTT assay. Additionally, the concept of developing hybrid systems was tested by bioconjugating functionalized MWNT to glucose oxidase and dispersed in the PVA matrix. The nanocomposites have presented mechanical properties, degree of swelling, and cytocompatibility comparable to the skin tissues. Moreover, the bionanocomposite with enzyme showed bioactivity toward injecting glucose with simultaneous antimicrobial behavior against bacterial pathogens due to the generation hydrogen peroxide.     

MWNTs/PUR复合材料的制备与气敏响应性研究

将端羧基丁二烯丙烯腈橡胶(CTBN)改性为多端羟基橡胶(f-CTBN)后,掺杂功能化多壁碳纳米管(MWNTs),与4,4′-二环己基甲烷二异氰酸酯(H12MDI)反应得到预聚物,再加入聚乙二醇(PEG6000)共聚合,得到一系列聚氨酯复合材料MWNTs/PUR;采用扫描电镜(SEM)、热失重(TG)等手段进行表征;考察了MWNTs含量、固化温度等因素对聚氨酯复合材料气敏响应能力的影响。结果表明,掺杂纳米管不仅提高了聚氨酯复合材料的力学和热学性能,更增强了其对有机溶剂饱和蒸汽的气敏响应能力;当固化温度为80℃时,聚氨酯复合材料的气敏响应能力最强。     

磺化聚醚醚酮/接枝多壁碳纳米管复合膜的制备与表征

以浓硫酸为磺化剂,室温下制备了磺化聚醚醚酮(SPEEK)。以N,N-二环己基碳酰亚胺(DCC)为催化剂,将对氨基苯磺酸接枝到多壁碳纳米管(MWCNTs)的表面。采用溶液共混法制备了SPEEK/g-MWCNTs复合膜。采用傅里叶变换红外光谱仪(FT-IR)分析了复合膜的化学结构,采用光学显微镜以及扫描电子显微镜(FESEM)观察了膜的表面和断面结构,并采用交流阻抗法考察了膜的质子传导性能。结果表明:碳纳米管在复合膜中分散均匀,树脂基体包覆在碳管表面,复合膜的质子传导性和拉伸强度均优于磺化聚醚醚酮纯膜。     

POM/MWNTs-PEG复合材料的制备和结晶性能研究

采用原子转移自由基聚合的方法将聚乙二醇（PEG）接枝到多壁碳纳米管（MWNTs）上,然后利用平板硫化机制备出聚甲醛（POM）/MWNTs-PEG复合材料。利用扫描电子显微镜、透射电子显微镜、红外光谱和热重分析对MWNTs-PEG进行表征。通过差式扫描量热仪研究了该复合材料结晶行为的变化,用Jeziorny法和Mo法对其进行非等温结晶动力学分析。结果表明,PEG均匀接枝到MWNTs上;MWNTs-PEG的加入具有异相成核的作用,使POM结晶温度向高温区移动,结晶速率提高,半结晶时间缩短;结晶速率常数值增加,F(T)值降低;有效结晶活化能降低;MWNTs-PEG最终起到促进POM结晶的作用。     

Optical Properties of Composites Based on Poly(o-phenylenediamine), Poly(vinylenefluoride) and Double-Wall Carbon Nanotubes

In this work, synthesis and optical properties of a new composite based on poly(o-phenylenediamine) (POPD) fiber like structures, poly(vinylidene fluoride) (PVDF) spheres and double-walled carbon nanotubes (DWNTs) are reported. As increasing the PVDF weight in the mixture of the chemical polymerization reaction of o-phenylenediamine, the presence of the PVDF spheres onto the POPD fibers surface is highlighted by scanning electron microscopy (SEM). The down-shift of the Raman line from 1421 cm⁻¹ to 1415 cm⁻¹ proves the covalent functionalization of DWNTs with the POPD-PVDF blends. The changes in the absorbance of the IR bands peaked around 840, 881, 1240 and 1402 cm⁻¹ indicate hindrance steric effects induced of DWNTs to the POPD fiber like structures and the PVDF spheres, as a consequence of the functionalization process of carbon nanotubes with macromolecular compounds. The presence of the PVDF spheres onto the POPD fiber like structures surface induces a POPD photoluminescence (PL) quenching process. An additional PL quenching process of the POPD-PVDF blends is reported to be induced in the presence of DWNTs. The studies of anisotropic PL highlight a change of the angle of the binding of the PVDF spheres onto the POPD fiber like structures surface from 50.2° to 38° when the carbon nanotubes concentration increases in the POPD-PVDF/DWNTs composites mass up to 2 wt.%.     

Cellulose Nanocrystals/ZnO as a Bifunctional Reinforcing Nanocomposite for Poly(vinyl alcohol)/Chitosan Blend Films: Fabrication,Characterization and Properties

In this study, cellulose nanocrystals/zinc oxide (CNCs/ZnO) nanocomposites were dispersed as bifunctional nano-sized fillers into poly(vinyl alcohol) (PVA) and chitosan (Cs) blend by a solvent casting method to prepare PVA/Cs/CNCs/ZnO bio-nanocomposites films. The morphology, thermal, mechanical and UV-vis absorption properties, as well antimicrobial effects of the bio-nanocomposite films were investigated. It demonstrated that CNCs/ZnO were compatible with PVA/Cs and dispersed homogeneously in the polymer blend matrix. CNCs/ZnO improved tensile strength and modulus of PVA/Cs significantly. Tensile strength and modulus of bio-nanocomposite films increased from 55.0 to 153.2 MPa and from 395 to 932 MPa, respectively with increasing nano-sized filler amount from 0 to 5.0 wt %. The thermal stability of PVA/Cs was also enhanced at 1.0 wt % CNCs/ZnO loading. UV light can be efficiently absorbed by incorporating ZnO nanoparticles into a PVA/Cs matrix, signifying that these bio-nanocomposite films show good UV-shielding effects. Moreover, the biocomposites films showed antibacterial activity toward the bacterial species Salmonella choleraesuis and Staphylococcus aureus. The improved physical properties obtained by incorporating CNCs/ZnO can be useful in variety uses.     

A Novel Approach for Preparation of Nano-gold Particles/Carbon Nanotube Composites from Gold Film,Poly(ferrocenylsilane) and Acetylene

A novel approach for preparing nano-gold particles/carbon nanotube composites from gold film, poly(ferrocenylsilane) and acetylene has been developed. The morphologies of resultant nano-gold particles/carbon nanotube composites were examined. This paper is submitted to Journal of Inorganic and Organometallic Polymers and Materials to honor Professor Dr. Ian Manners.     

l-Phenylalanine amino acid functionalized multi walled carbon nanotube (MWCNT) as a reinforced filler for improving mechanical and morphological properties of poly(vinyl alcohol)/MWCNT composite

Carbon nanotube dispersion in polymer matrix is one of the most crucially important aspects in carbon nanotube/polymer composites. This paper is aimed to discuss the considerable improvement in dispersion of multi walled carbon nanotubes (MWNTs) in poly(vinyl alcohol) (PVA) matrix that was attained through bio-functionalization of MWCNTs. Initially, for getting better dispersion in water, pure MWCNTs have been functionalized by l-phenylalanine amino acid. The functionalized MWCNTs (f-MWCNTs) show much enhanced solubility in water. So, effects of modified MWCNT on dispersion in PVA matrix and certain properties of the resulting composites, like; mechanical, thermal and morphological properties were studied. The prepared composites were examined by Fourier transform infrared spectroscopy, X-ray diffraction and transmission electron microscopy. Also, the mechanical and thermal properties of composite films have been investigated and revealed that incorporation of just a few percent of f-MWCNTs can improve the PVA mechanical and thermal properties significantly.     

Organic-inorganic nanocomposite polymer electrolyte membranes for fuel cell applications

Organic-inorganic nanocomposite polymer electrolyte membrane (PEM) contains nano-sized inorganic building blocks in organic polymer by molecular level of hybridization. This architecture has opened the possibility to combine in a single solid both the attractive properties of a mechanically and thermally stable inorganic backbone and the specific chemical reactivity, dielectric, ductility, flexibility, and processability of the organic polymer. The state-of-the-art of polymer electrolyte membrane fuel cell technology is based on perfluoro sulfonic acid membranes, which have some key issues and shortcomings such as: water management, CO poisoning, hydrogen reformate and fuel crossover. Organic-inorganic nanocomposite PEM show excellent potential for solving these problems and have attracted a lot of attention during the last ten years. Disparate characteristics (e.g., solubility and thermal stability) of the two components, provide potential barriers towards convenient membrane preparation strategies, but recent research demonstrates relatively simple processes for developing highly efficient nanocomposite PEMs. Objectives for the development of organic-inorganic nanocomposite PEM reported in the literature include several modifications: (1) improving the self-humidification of the membrane; (2) reducing the electro-osmotic drag and fuel crossover; (3) improving the mechanical and thermal strengths without deteriorating proton conductivity; (4) enhancing the proton conductivity by introducing solid inorganic proton conductors; and (5) achieving slow drying PEMs with high water retention capability. Research carried out during the last decade on this topic can be divided into four categories: (i) doping inorganic proton conductors in PEMs; (ii) nanocomposites by sol-gel method; (iii) covalently bonded inorganic segments with organic polymer chains; and (iv) acid-base PEM nanocomposites. The purpose here is to summarize the state-of-the-art in the development of organic-inorganic nanocomposite PEMs for fuel cell applications.     

Functionalization of carbon nanomaterials for advanced polymer nanocomposites: A comparison study between CNT and graphene

The allotropes of carbon nanomaterials (carbon nanotubes, graphene) are the most unique and promising substances of the last decade. Due to their nanoscale diameter and high aspect ratio, a small amount of these nanomaterials can produce a dramatic improvement in the properties of their composite materials. Although carbon nanotubes (CNTs) and graphene exhibit numerous extraordinary properties, their reported commercialization is still limited due to their bundle and layer forming behavior. Functionalization of CNTs and graphene is essential for achieving their outstanding mechanical, electrical and biological functions and enhancing their dispersion in polymer matrices. A considerable portion of the recent publications on CNTs and graphene have focused on enhancing their dispersion and solubilization using covalent and non-covalent functionalization methods. This review article collectively introduces a variety of reactions (e.g. click chemistry, radical polymerization, electrochemical polymerization, dendritic polymers, block copolymers, etc.) for functionalization of CNTs and graphene and fabrication of their polymer nanocomposites. A critical comparison between CNTs and graphene has focused on the significance of different functionalization approaches on their composite properties. In particular, the mechanical, electrical, and thermal behaviors of functionalized nanomaterials as well as their importance in the preparation of advanced hybrid materials for structures, solar cells, fuel cells, supercapacitors, drug delivery, etc. have been discussed thoroughly.