Nanoscale Phase Separation in Lithium Niobium Silicate Glass by Femtosecond Laser Irradiation

Understanding the phase transformation in glass and the morphology of related nanostructure after femtosecond laser irradiation is of great importance for fabricating functional optics, in which glass crystallization is involved to obtain nonlinear optical properties. We report on the crystallization inside lithium niobium silicate glass induced by fs laser irradiation. Energy‐dispersive X‐ray spectroscopy coupled to scanning transmission electron microscopy (STEM/EDS) and transmission electron microscopy confirm a nanoscale phase separation whereby LiNbO₃ crystals are embedded in lamella‐shaped frames of amorphous SiO₂. The obtained nanostructure may have applications in fabricating second‐order nonlinear optical devices.     

All Solution‐Based Fabrication of Copper Oxide Thin Film/Cobalt‐Doped Zinc Oxide Nanowire Heterojunctions

Versatile and intriguing solution‐based processes are utilized to synthesize nanostructured materials for device applications to reduce material production and device fabrication costs. This study presents results on the fabrication and characterization of copper oxide (CuO) coated cobalt‐doped zinc oxide nanowires (Co‐doped ZnO NWs)‐based heterojunction diodes prepared by a two‐step synthesis route through combined hydrothermal growth and sol–gel spin coating. Highly dense, well‐ordered, undoped, and Co‐doped ZnO NWs were successfully grown by hydrothermal method. Complementary CuO thin films were synthesized by sol–gel method and subsequently coated onto both undoped and Co‐doped ZnO NWs through spin‐coating technique. Enhanced diode properties with a rectification ratio of 10³ at ±2 V and an ideality factor of n = 2.4 (in dark) were obtained for Co‐doped ZnO NWs‐based heterojunction diodes. The obtained results demonstrated that the investigated heterojunction diode structure fabricated by facile and cost‐effective solution‐based processes can be a promising candidate for the next generation optoelectronic devices.     

Applications of nanotechnology in oil and gas industry: Progress and perspective

Nanotechnology has been successfully implemented in many applications, such as nanoelectronics, nanobiomedicine, and nanodevices. However, this technology has rarely been applied to the oil and gas industry, especially in upstream exploration and production. The oil and gas industry needs to improve oil recovery and exploit unconventional resources. The cost of research and oil production is under immense pressure, and it is becoming more difficult to justify such investment when the crude oil price is weak and depressed. There is a widespread belief that nanotechnology may be exploited to develop novel nanomaterials with enhanced performance to combat these technological barriers. Increasing funding resources from governmental and global oil industry have been allocated to exploration, drilling, production, refining, and wastewater treatment. For example, nanosensors allow for precise measurement of reservoir conditions. Nanofluids prepared using functional nanomaterials may exhibit better performance in oil production processes, and nanocatalysts have improved the efficiency in oil refining and petrochemical processes. Nanomembranes enhance oil, water and gas separation, oil and gas purification, and the removal of impurities from wastewater. Functional nanomaterials can play an important role in the production of smart, reliable, and more durable equipment. In this review paper, we summarize the research progress and prospective applications of nanotechnology and nanomaterials in the oil and gas industry.     

基于德温特专利数据的低维纳米碳材料发展态势文献分析

富勒烯、碳纳米管和石墨烯等低维纳米碳材料为近年来纳米材料和纳米技术领域的研究热点。本文以3种典型的低维纳米碳材料为研究对象,通过对德温特（Derwent）专利数据库收录的从2005—2015年专利受理数量、国家分布、专利权人名称、学科类别及国际专利分类代码等相关信息进行分析,发现近年来研发人员更加关注石墨烯,对碳纳米管和富勒烯的关注度在逐渐下降。经过对全球低维纳米碳材料技术创新现状与发展趋势的分析,指出我国低维纳米碳材料在进一步发展中还存着研发领域发展不均衡、缺乏全方位发展战略的整体布局研究、技术成果不能顺利转化、经费投入偏低等问题,并针对以上问题提出了建设性意见,以期为我国低维纳米碳材料相关领域的技术创新和决策提供参考。     

纳米硫化铁在环境保护中的应用研究进展

总结了近二十年来纳米硫化铁在环境中的应用报道,综述了纳米硫化铁的合成方法、污染物去除效果和机理以及溶液组分对材料本身和污染物去除的影响。介绍了纳米硫化铁目前在环境中主要用于重金属离子去除(如镉、汞、铀、锝等)、氯代有机物的脱氯和难降解有机物的高级氧化等过程,其对污染物的去除机理主要包括吸附、(共)沉淀、还原、催化氧化。指出虽然纳米硫化铁在污染物处理方面取得了良好的效果,但是依然存在问题,如溶液中共存的阴阳离子和腐植酸会对材料的团聚、腐蚀以及污染物的吸附行为和处理效果产生不同的影响。提出目前国内外对于纳米硫化铁材料自身性能研究尚未深入,材料在反应过程中及实际环境中的迁移、转化及其对污染物去除的影响值得深入。     

Functionalized nanostructures with application in regenerative medicine

In the last decade, both regenerative medicine and nanotechnology have been broadly developed leading important advances in biomedical research as well as in clinical practice. The manipulation on the molecular level and the use of several functionalized nanoscaled materials has application in various fields of regenerative medicine including tissue engineering, cell therapy, diagnosis and drug and gene delivery. The themes covered in this review include nanoparticle systems for tracking transplanted stem cells, self-assembling peptides, nanoparticles for gene delivery into stem cells and biomimetic scaffolds useful for 2D and 3D tissue cell cultures, transplantation and clinical application.     

超临界干燥法制备TiO2/凹凸棒复合光催化剂

以凹凸棒为载体,四氯化钛为钛源,通过溶胶-凝胶法结合超临界干燥法制备TiO₂/凹凸棒复合光催化材料。采用XRD、SEM、TEM、BET、XPS等方法对材料的结构、形貌及催化性能进行表征。研究结果表明：超临界干燥可增大复合材料的比表面积,抑制TiO₂发生晶型转变。凹凸棒吸附特性良好,增加了材料表面的活性位点,显著提高催化剂的光催化活性。不同煅烧温度下的TiO₂均为锐钛矿型,粒径约为20 nm,呈不规则短棒状,成功负载于凹凸棒上。在400℃煅烧2 h条件下,催化剂3 h后对亚甲基蓝的降解率可达98.4%。     

纳米材料/十四酸混合相变蓄热材料的制备与特性

选用纳米金属Cu和碳素材料石墨烯纳米片（GnPs）为改性剂分别添加至十四酸（MA）中,制备出Cu质量分数为1%、2%、3%和4%的Cu/MA混合相变蓄热材料及GnPs质量分数为1%、2%和3%的GnPs/MA混合相变蓄热材料,并对混合相变材料性能进行表征。结果表明：Cu/MA固态和液态热导率随Cu质量分数增加呈线性提高,1%（质量）GnPs/MA固态热导率较纯MA显著提高101.51%,随GnPs质量分数增加,热导率增幅减缓;FT-IR谱图表明Cu与MA及GnPs与MA间的混合均为物理作用;DSC结果显示添加Cu或GnPs可降低MA的过冷度和相变潜热,且随质量分数增加,相变潜热逐渐降低;4%（质量）Cu/MA和3%（质量）GnPs/MA放热时间相比于纯MA分别减少了23.4%和38.7%;4%（质量）Cu/MA和3%（质量）GnPs/MA在经历300次快速热循环试验后,晶体结构和相变温度基本保持不变,相变潜热分别降至168 J·g^-1和181 J·g^-1左右,仍满足蓄放热要求,两种材料均具有良好的热循环稳定性。     

PH sensitive structural uniformity of rice husk ash‐derived MCM‐41 silica

In this study, highly uniform MCM‐41 mesoporous silica was synthesised from rice husk ash‐derived sodium silicate using cetyltrimethyl ammonium chloride (CTAC) as a template. The chemical composition of the gel mixture was based on a SiO₂:CTAC:H₂O molar ratio of 1:0.5:75. When the pH value was initially controlled at ranges of 5.0–10.5 for 5 h and then immediately adjusted to 11.25 for the next 1 h, the structural uniformity of MCM‐41 was abruptly increased by 3.3–7.5 times of the single pH value at 11.25, respectively. Moreover, thermal and hydrothermal stabilities at 900 and 250°C were clearly observed. © 2012 Canadian Society for Chemical Engineering