A new method of reinforcing graphene nanoplatelets in glass/epoxy composites

This research aims to develop a method for the amalgamation of graphene nanoplatelets in glass/epoxy composites. The poor interface bonding between the fiber and matrix is critical and hinders the full performance of the composites. Glass fabric and epoxy were used as reinforcement and matrix in the composite, respectively. Graphene nanoplatelets were utilized as an additional nano-materials filler for the composites. Glass/graphene/epoxy and glass/epoxy composites were fabricated via vacuum infusion molding. The new method of applying graphene nanoplatelets as secondary reinforcement in the composite was developed based on proper functionalization in the sonication process. The physical, tensile, flexural, and short beam interlaminar properties of fabricated composites were examined to analyze the method's effectiveness. The results showed that density decreased by around 5 %; however, thickness increased by around 34 % after introducing graphene nanoplatelets into the composites. The tensile strength and modulus of the composites declined by approximately 19 %, on the other hand, flexural strength and modulus increased by around 63.3 % and 8.3 %, respectively, after the addition of graphene nanoplatelets into the composites. Moreover, interlaminar shear strength of the composite was enhanced by approximately 50 %.     

酶的固载技术及纳米电化学酶生物传感器的研究进展

该文较详细地阐述了酶的固定化方法和各自的优缺点,以及综述了近年来各种类型的纳米材料在电化学酶生物传感器中的应用,并对今后的工作进行了展望.     

钙钛矿结构锰氧化物Pr_(1-x)Ca_xMnO_3(0.4≤x≤0.5)纳米材料的磁性质研究

采用溶胶凝胶法制备了Pr1-xCaxMnO3(0.4≤x≤0.5)系列纳米样品,对其磁性质进行了研究.所有样品在M-T曲线中250K附近的电荷有序转变和170K附近的顺磁-反铁磁转变都消失,与Dong等人的理论模拟计算相符.所有样品在40K都出现了Reentrant spin glass(RSG)态.随着Ca2+掺杂浓度的增加,Mn3+/Mn4+的比例迅速变小,破坏了Mn-O-Mn导电通道,导致磁化强度M逐渐变小.     

纳米材料改性沥青的研究状况和进展

纳米材料改性沥青的研究是道路交通材料研究中的热点和前沿课题,纳米粒子与沥青的相容性以及在沥青中的分散和稳定性是决定纳米材料改善沥青各项性能的关键。文中对近年来关于纳米材料改性沥青的各类研究进展进行介绍,总结不同研究内容的优势和存在的问题。对提高纳米粒子与沥青的相容性和分散性提出方案,最后对纳米材料改性沥青的研究前景进行展望。     

燃料和基板对火焰法制备一维碳纳米材料的影响

以乙醇、甲醇及液化石油气为碳源，低碳钢及含Ni合金钢等为基板，采用火焰法成功地制备出了一维碳纳米材料，包括碳纳米管（CNTs）和一种新的“实心”碳纳米纤维（CNFs）。利用场发射枪高分辨扫描电镜（SEM）、透射电镜（TEM）和激光Raman光谱对碳纳米材料的结构进行了表征。发现基板材料决定燃烧生成物的性质，含Fe元素及其化合物的基板材料倾向于合成“实心”碳纳米纤维，而含Nj元素及其化合物的基板材料倾向于合成“空心”的碳纳米管，认为这是由于碳与Fe的亲和力比Ni大而造成的。不同碳源对一维碳纳米材料的形态也有影响，这与它们的含碳量和燃烧热等不同有关。     

纳米羟基磷灰石的制备方法与应用

介绍了羟基磷灰石的组成、性质、结构以及在生物材料和其他方面的应用,在讨论纳米羟基磷灰石的主要几种合成方法的同时,对各种方法和制备工艺的优缺点进行分析,提出了改进的方向。     

Friction on a single MoS2 nanotube

Friction was measured on a single molybdenum disulfide (MoS₂) nanotube and on a single MoS₂ nano-onion for the first time. We used atomic force microscopy (AFM) operating in ultra-high vacuum at room temperature. The average coefficient of friction between the AFM tip and MoS₂ nanotubes was found considerably below the corresponding values obtained from an air-cleaved MoS₂ single crystal or graphite. We revealed a nontrivial dependency of friction on interaction strength between the nanotube and the underlying substrate. Friction on detached or weakly supported nanotubes by the substrate was several times smaller (0.023 ± 0.005) than that on well-supported nanotubes (0.08 ± 0.02). We propose an explanation of a quarter of a century old phenomena of higher friction found for intracrystalline (0.06) than for intercrystalline slip (0.025) in MoS₂. Friction test on a single MoS₂ nano-onion revealed a combined gliding-rolling process.PACS, 62.20, 61.46.Fg, 68.37 Ps     

MnO2纳米材料的可控制备和催化性能研究

通过简单的水热法并在不使用表面活性剂的情况下成功地合成了α-MnO2纳米线,采用XRD和扫描电子显微镜研究了MnO2的晶相、成分和形貌,初步研究了反应温度对纳米结构MnO2合成的影响,对MnO2降解亚甲基蓝催化性能进行了测试。结果表明,α-MnO2纳米颗粒和纳米线的合成是可控的,α-MnO2纳米结构的尺寸和形貌对催化降解亚甲基蓝有较大的影响,其中150℃所得的α-MnO2纳米线,其直径约为20～30nm,降解效果最佳,180min可降解91%。