首页 > 最新文献

纳米科学与工程(英文)最新文献

英文 中文
Synthesis and Properties of Fumed Silicas Modified with Mixtures of Poly(methylphenylsiloxane) and Dimethyl Carbonate 聚甲基苯基硅氧烷与碳酸二甲酯混合改性气相二氧化硅的合成及性能研究
Pub Date : 2015-11-13 DOI: 10.4236/WJNSE.2015.54017
I. Protsak, V. Tertykh, Y. Bolbukh, D. Sternik, A. Deryło-Marczewska
Effect of the concentration ratios of organosiloxane/initiator and treatment temperature on the characteristics of hydrophobic products obtained by modification of surface of fumed silica with poly(methylphenylsiloxane) (PMPS) in the presence of dimethyl carbonate has been studied. Morphology, particle size, surface area and coating microstructure of modified silicas were analyzed by methods of transmission electron and atomic force microscopies, nitrogen adsorption-desorption data. Carbon contents in the grafted modifying layer of organosilicas were determined using IR spectroscopy and elemental analysis. Hydrophilic-hydrophobic properties of surface of the obtained modified silicas were estimated by measurements of contact angles of wetting. It was shown that modification of pyrogenic silicas with mixtures of poly(methylphenylsiloxane) and dimethyl carbonate allows to obtain the homogeneous hydrophobic products and serve their nanodispersity.
研究了有机硅氧烷/引发剂的浓度比和处理温度对在碳酸二甲酯存在下用聚甲基苯基硅氧烷(PMPS)对气相二氧化硅表面进行改性所得疏水产物特性的影响。采用透射电子显微镜、原子力显微镜、氮吸附-脱附数据分析了改性二氧化硅的形貌、粒径、比表面积和涂层微观结构。采用红外光谱和元素分析方法测定了有机硅接枝改性层中的碳含量。通过润湿接触角的测定,评价了改性二氧化硅表面的亲疏水性。结果表明,用聚甲基苯基硅氧烷和碳酸二甲酯的混合物对热原二氧化硅进行改性,可以得到均匀的疏水产物,并有利于其纳米分散性。
{"title":"Synthesis and Properties of Fumed Silicas Modified with Mixtures of Poly(methylphenylsiloxane) and Dimethyl Carbonate","authors":"I. Protsak, V. Tertykh, Y. Bolbukh, D. Sternik, A. Deryło-Marczewska","doi":"10.4236/WJNSE.2015.54017","DOIUrl":"https://doi.org/10.4236/WJNSE.2015.54017","url":null,"abstract":"Effect of the concentration ratios of organosiloxane/initiator and treatment temperature on the characteristics of hydrophobic products obtained by modification of surface of fumed silica with poly(methylphenylsiloxane) (PMPS) in the presence of dimethyl carbonate has been studied. Morphology, particle size, surface area and coating microstructure of modified silicas were analyzed by methods of transmission electron and atomic force microscopies, nitrogen adsorption-desorption data. Carbon contents in the grafted modifying layer of organosilicas were determined using IR spectroscopy and elemental analysis. Hydrophilic-hydrophobic properties of surface of the obtained modified silicas were estimated by measurements of contact angles of wetting. It was shown that modification of pyrogenic silicas with mixtures of poly(methylphenylsiloxane) and dimethyl carbonate allows to obtain the homogeneous hydrophobic products and serve their nanodispersity.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70879625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Energy Efficient Manufacturing of Nanocellulose by Chemo- and Bio-Mechanical Processes: A Review 利用化学和生物机械方法高效制造纳米纤维素的研究进展
Pub Date : 2015-11-13 DOI: 10.4236/WJNSE.2015.54021
A. Bharimalla, S. Deshmukh, P. G. Patil, N. Vigneshwaran
Nanocellulose is a new-age material derived from cellulosic biomass and has large specific surface area, high modulus and highly hydrophilic in nature. It comprises of two structural forms viz., nanofibrillated cellulose (NFC) and nanocrystalline cellulose (NCC). This review provides a critical overview of the recent methods of bio- and chemo-mechanical processes for production of nanocellulose, their energy requirements and their functional properties. More than a dozen of pilot plants/commercial plants are under operation mostly in the developed countries, trying to exploit the potential of nanocellulose as reinforcing agent in paper, films, concrete, rubber, polymer films and so on. The utilization of nanocellulose is restricted mainly due to initial investment involved, high production cost and lack of toxicological information. This review focuses on the current trend and exploration of energy efficient and environment-friendly mechanical methods using pretreatments (both chemical and biological), their feasibility in scaling up and the future scope for expansion of nanocellulose application in diverse fields without impacting the environment. In addition, a nanocellulose quality index is derived to act as a guide for application based screening of nanocellulose production protocols.
纳米纤维素是一种从纤维素生物质中提取的新型材料,具有比表面积大、模量高、亲水性强等特点。它包括两种结构形式,即纳米纤维化纤维素(NFC)和纳米晶体纤维素(NCC)。本文综述了近年来生产纳米纤维素的生物和化学机械工艺方法,它们的能量需求和功能特性。十几个试验工厂/商业工厂大多在发达国家运作,试图开发纳米纤维素作为纸张、薄膜、混凝土、橡胶、聚合物薄膜等增强剂的潜力。纳米纤维素的利用主要受到初期投资、生产成本高和缺乏毒理学信息的限制。本文综述了利用化学和生物两种方法进行预处理的节能环保机械方法的发展趋势和探索,其规模化的可行性以及纳米纤维素在不影响环境的情况下在各个领域的应用前景。此外,还推导了纳米纤维素质量指标,作为基于应用筛选纳米纤维素生产方案的指南。
{"title":"Energy Efficient Manufacturing of Nanocellulose by Chemo- and Bio-Mechanical Processes: A Review","authors":"A. Bharimalla, S. Deshmukh, P. G. Patil, N. Vigneshwaran","doi":"10.4236/WJNSE.2015.54021","DOIUrl":"https://doi.org/10.4236/WJNSE.2015.54021","url":null,"abstract":"Nanocellulose is a new-age material derived from cellulosic biomass and has large specific surface area, high modulus and highly hydrophilic in nature. It comprises of two structural forms viz., nanofibrillated cellulose (NFC) and nanocrystalline cellulose (NCC). This review provides a critical overview of the recent methods of bio- and chemo-mechanical processes for production of nanocellulose, their energy requirements and their functional properties. More than a dozen of pilot plants/commercial plants are under operation mostly in the developed countries, trying to exploit the potential of nanocellulose as reinforcing agent in paper, films, concrete, rubber, polymer films and so on. The utilization of nanocellulose is restricted mainly due to initial investment involved, high production cost and lack of toxicological information. This review focuses on the current trend and exploration of energy efficient and environment-friendly mechanical methods using pretreatments (both chemical and biological), their feasibility in scaling up and the future scope for expansion of nanocellulose application in diverse fields without impacting the environment. In addition, a nanocellulose quality index is derived to act as a guide for application based screening of nanocellulose production protocols.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70879876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 55
Method of Formation of Waveguides on the Basis of Any Polymeric Materials 基于任何聚合物材料的波导形成方法
Pub Date : 2015-11-13 DOI: 10.4236/WJNSE.2015.54022
V. Tsvetkov, S. Pasechnik, A. Dronov, J. Ho, V. Chigrinov, H. Kwok
This paper describes a new type of polymeric waveguides which has the core, cladding medium and active nodes made from the same material. Part of the polymer is removed in cladding medium by formation of nanopores. The pores can be filled with liquid crystals (LC) in order to create an active composite medium needed for electrically controlled nodes formation.
本文介绍了一种芯、包层介质和有源节点采用同一材料制成的新型聚合物波导。通过形成纳米孔,部分聚合物在包层介质中被去除。孔隙可以用液晶(LC)填充,以创建电控节点形成所需的活性复合介质。
{"title":"Method of Formation of Waveguides on the Basis of Any Polymeric Materials","authors":"V. Tsvetkov, S. Pasechnik, A. Dronov, J. Ho, V. Chigrinov, H. Kwok","doi":"10.4236/WJNSE.2015.54022","DOIUrl":"https://doi.org/10.4236/WJNSE.2015.54022","url":null,"abstract":"This paper describes a new type of polymeric waveguides which has the core, cladding medium and active nodes made from the same material. Part of the polymer is removed in cladding medium by formation of nanopores. The pores can be filled with liquid crystals (LC) in order to create an active composite medium needed for electrically controlled nodes formation.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70879948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
In the Heart of Femtosecond Laser Induced Nanogratings: From Porous Nanoplanes to Form Birefringence 飞秒激光诱导纳米光栅的核心:从多孔纳米平面到形成双折射
Pub Date : 2015-11-13 DOI: 10.4236/WJNSE.2015.54014
R. Desmarchelier, B. Poumellec, F. Brisset, S. Mazérat, M. Lancry
It is demonstrated that the form birefringence related to the so-called nanogratings is quantitatively correlated to the porosity-filling factor of these nanostructures. We reveal that matters surrounding the nanopores exhibit significant refractive index decrease which is likely due to the fictive temperature increase and/or the presence of a significant amount of interstitial O2. The control of the porosity was achieved by adjusting the laser pulse energy and the number of pulses/micron i.e. the overlapping rate. Applications can be numerous in fast material processing by the production of nanoporous matter, and photonics by changing the optical properties.
结果表明,与所谓的纳米光栅相关的形式双折射与这些纳米结构的孔隙填充因子定量相关。我们发现,纳米孔周围的物质表现出明显的折射率下降,这可能是由于有效温度升高和/或存在大量的间隙O2。孔隙度的控制是通过调节激光脉冲能量和脉冲数/微米即重叠率来实现的。通过生产纳米多孔物质,在快速材料加工和通过改变光学性质的光子学方面可以有许多应用。
{"title":"In the Heart of Femtosecond Laser Induced Nanogratings: From Porous Nanoplanes to Form Birefringence","authors":"R. Desmarchelier, B. Poumellec, F. Brisset, S. Mazérat, M. Lancry","doi":"10.4236/WJNSE.2015.54014","DOIUrl":"https://doi.org/10.4236/WJNSE.2015.54014","url":null,"abstract":"It is demonstrated that the form birefringence related to the so-called nanogratings is quantitatively correlated to the porosity-filling factor of these nanostructures. We reveal that matters surrounding the nanopores exhibit significant refractive index decrease which is likely due to the fictive temperature increase and/or the presence of a significant amount of interstitial O2. The control of the porosity was achieved by adjusting the laser pulse energy and the number of pulses/micron i.e. the overlapping rate. Applications can be numerous in fast material processing by the production of nanoporous matter, and photonics by changing the optical properties.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70879416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 31
Silica-Based Nanocoating Doped by Layered Double Hydroxides to Enhance the Paperboard Barrier Properties 层状双氢氧化物掺杂二氧化硅基纳米涂层增强纸板阻隔性能
Pub Date : 2015-11-13 DOI: 10.4236/WJNSE.2015.54015
Vânia M. Dias, A. Kuznetsova, J. Tedim, A. Yaremchenko, M. Zheludkevich, Inês Portugal, D. Evtuguin
Paperboard is an environment-friendly multi-layer material widely used for packaging applications. However, for food packaging paperboard lacks essential barrier properties towards oxygen and water vapor. Conventional solutions to enhance these barrier properties (e.g. paperboard film coating with synthetic polymers) require special manufacturing facilities and difficult the end-of-life disposal and recycling of the paperboard. Paperboard coating with silica-based formulations is an eco-friendly alternative hereby disclosed. Silica-nanocoatings were prepared by sol-gel synthesis, with or without the addition of Zn(2)-Al-NO3 layered double hydroxides (LDHs), and applied on the surface (ca 2 g/m2) of industrial paperboard samples by a roll-to-roll technique. The physicochemical features of silica-nanocoatings were studied by FTIR-ATR, SEM/EDS, XRD analysis and surface energy measurements. The barrier properties of uncoated and silica-coated paperboard were accessed by water vapor transmission rate (WVTR) and oxygen permeability (Jo2) measurements. The best barrier results were obtained for paperboard coated with a mixture of tetraethoxysilane (TEOS) and 3-aminopropyltriethoxysilane (APTES), with and without the incorporation of LDHs.
纸板是一种广泛用于包装的环保多层材料。然而,用于食品包装的纸板缺乏对氧气和水蒸气的基本阻隔性能。提高这些阻隔性能的传统解决方案(例如,用合成聚合物涂覆纸板薄膜)需要特殊的生产设施,并且纸板的报废处理和回收很困难。具有硅基配方的纸板涂料是一种生态友好的替代品。采用溶胶-凝胶法制备了二氧化硅纳米涂层,添加或不添加Zn(2)-Al-NO3层状双氢氧化物(LDHs),并通过卷对卷技术将其涂在工业纸板样品的表面(约2 g/m2)。采用FTIR-ATR、SEM/EDS、XRD分析和表面能测试等方法研究了二氧化硅纳米涂层的物理化学特征。通过测量水蒸气透过率(WVTR)和氧透性(Jo2),研究了未涂布和涂布二氧化硅纸板的阻隔性能。四乙氧基硅烷(TEOS)和3-氨基丙基三乙氧基硅烷(APTES)混合涂层纸板,无论是否掺入LDHs,其阻隔效果最好。
{"title":"Silica-Based Nanocoating Doped by Layered Double Hydroxides to Enhance the Paperboard Barrier Properties","authors":"Vânia M. Dias, A. Kuznetsova, J. Tedim, A. Yaremchenko, M. Zheludkevich, Inês Portugal, D. Evtuguin","doi":"10.4236/WJNSE.2015.54015","DOIUrl":"https://doi.org/10.4236/WJNSE.2015.54015","url":null,"abstract":"Paperboard is an environment-friendly multi-layer material widely used for packaging applications. However, for food packaging paperboard lacks essential barrier properties towards oxygen and water vapor. Conventional solutions to enhance these barrier properties (e.g. paperboard film coating with synthetic polymers) require special manufacturing facilities and difficult the end-of-life disposal and recycling of the paperboard. Paperboard coating with silica-based formulations is an eco-friendly alternative hereby disclosed. Silica-nanocoatings were prepared by sol-gel synthesis, with or without the addition of Zn(2)-Al-NO3 layered double hydroxides (LDHs), and applied on the surface (ca 2 g/m2) of industrial paperboard samples by a roll-to-roll technique. The physicochemical features of silica-nanocoatings were studied by FTIR-ATR, SEM/EDS, XRD analysis and surface energy measurements. The barrier properties of uncoated and silica-coated paperboard were accessed by water vapor transmission rate (WVTR) and oxygen permeability (Jo2) measurements. The best barrier results were obtained for paperboard coated with a mixture of tetraethoxysilane (TEOS) and 3-aminopropyltriethoxysilane (APTES), with and without the incorporation of LDHs.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70879917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 8
Vibration of Gold Nano-Beam with Variable Young's Modulus Due to Thermal Shock 变杨氏模量金纳米梁在热冲击下的振动
Pub Date : 2015-11-13 DOI: 10.4236/WJNSE.2015.54020
Eman A. N. Al-Lehaibi, H. Youssef
In this paper, we will study the most important effects in the nano-scale resonator: the coupling effect of temperature and strain rate, and the non-Fourier effect in heat conduction. A solution for the generalized thermoelastic vibration of nano-resonator induced by thermal loading has been developed. The Young’s modulus is taken as a linear function of the reference temperature. The effects of the thermal loading and the reference temperature in all the studied fields have been studied and represented in graphs with some comparisons. The Young’s modulus makes significant effects on all the studied fields where the values of the temperature, the vibration of the deflection, stress, displacement, strain, stress-strain energy increase when the Young’s modulus has taken to be variable.
在本文中,我们将研究纳米级谐振器中最重要的效应:温度和应变速率的耦合效应,以及热传导中的非傅立叶效应。研究了纳米谐振器在热载荷作用下的广义热弹性振动问题。杨氏模量作为参考温度的线性函数。研究了热负荷和参考温度对各研究领域的影响,并用图表表示,并进行了比较。当杨氏模量为变量时,温度、挠度振动、应力、位移、应变、应力-应变能的值均增加,杨氏模量对所研究的所有场均有显著影响。
{"title":"Vibration of Gold Nano-Beam with Variable Young's Modulus Due to Thermal Shock","authors":"Eman A. N. Al-Lehaibi, H. Youssef","doi":"10.4236/WJNSE.2015.54020","DOIUrl":"https://doi.org/10.4236/WJNSE.2015.54020","url":null,"abstract":"In this paper, we will study the most important effects in the nano-scale resonator: the coupling effect of temperature and strain rate, and the non-Fourier effect in heat conduction. A solution for the generalized thermoelastic vibration of nano-resonator induced by thermal loading has been developed. The Young’s modulus is taken as a linear function of the reference temperature. The effects of the thermal loading and the reference temperature in all the studied fields have been studied and represented in graphs with some comparisons. The Young’s modulus makes significant effects on all the studied fields where the values of the temperature, the vibration of the deflection, stress, displacement, strain, stress-strain energy increase when the Young’s modulus has taken to be variable.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70879815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 24
Angular Dependence of the Second Harmonic Generation Induced by Femtosecond Laser Irradiation in Silica-Based Glasses: Variation with Writing Speed and Pulse Energy 飞秒激光辐照在硅基玻璃中二次谐波产生的角依赖性:随写入速度和脉冲能量的变化
Pub Date : 2015-07-20 DOI: 10.4236/WJNSE.2015.53012
Jing Cao, B. Poumellec, F. Brisset, A. Helbert, M. Lancry
To control second harmonic generation (SHG) in silica-based glasses is crucial for fabricating photonic devices, such as frequency doubling waveguides. Here, we investigated SHG of laser induced nonlinear optical crystals in silica-based glasses, according to writing speed and pulse energy. We observed two regions with different probing laser polarization angular dependence: a) a well-defined cosine-like curve with period of 180° at low pulse energy (0.8 μJ) whatever the writing speed or at high pulse energy (1.4 μJ) with high writing speed (25 μm/s). This is accounted for by a well-defined texture for the nano crystals with their polar axis oriented perpendicular to the writing laser polarization; and b) a double cosine-like curve revealing a second texture of the crystals at high pulse energy (1.4 μJ) with low writing speed (5 μm/s) and with the polar axis oriented closer parallel to the writing laser polarization. Therefore, a SHG dependence on probing laser polarization angle may show high contrast by a correct choice of the writing speed and pulse energy. These results pave the way for elaboration of nonlinear optical devices.
控制硅基玻璃中二次谐波的产生是制造倍频波导等光子器件的关键。本文根据写入速度和脉冲能量,研究了硅基玻璃中激光诱导非线性光学晶体的SHG。在低脉冲能量(0.8 μJ)和高脉冲能量(1.4 μJ)和高写入速度(25 μm/s)下,我们观察到两个探测激光偏振角依赖性不同的区域:a)在低脉冲能量(0.8 μJ)和高脉冲能量(1.4 μJ)下,周期为180°的清晰的类余弦曲线。这是由于纳米晶体具有明确的纹理,其极轴垂直于书写激光偏振;b)在高脉冲能量(1.4 μJ)、低写入速度(5 μm/s)、极轴方向更平行于写入激光偏振的情况下,双余弦曲线揭示了晶体的第二织构。因此,通过正确选择写入速度和脉冲能量,SHG对探测激光偏振角的依赖性可以显示出高对比度。这些结果为非线性光学器件的研制铺平了道路。
{"title":"Angular Dependence of the Second Harmonic Generation Induced by Femtosecond Laser Irradiation in Silica-Based Glasses: Variation with Writing Speed and Pulse Energy","authors":"Jing Cao, B. Poumellec, F. Brisset, A. Helbert, M. Lancry","doi":"10.4236/WJNSE.2015.53012","DOIUrl":"https://doi.org/10.4236/WJNSE.2015.53012","url":null,"abstract":"To control second harmonic generation (SHG) in silica-based glasses is crucial for fabricating photonic devices, such as frequency doubling waveguides. Here, we investigated SHG of laser induced nonlinear optical crystals in silica-based glasses, according to writing speed and pulse energy. We observed two regions with different probing laser polarization angular dependence: a) a well-defined cosine-like curve with period of 180° at low pulse energy (0.8 μJ) whatever the writing speed or at high pulse energy (1.4 μJ) with high writing speed (25 μm/s). This is accounted for by a well-defined texture for the nano crystals with their polar axis oriented perpendicular to the writing laser polarization; and b) a double cosine-like curve revealing a second texture of the crystals at high pulse energy (1.4 μJ) with low writing speed (5 μm/s) and with the polar axis oriented closer parallel to the writing laser polarization. Therefore, a SHG dependence on probing laser polarization angle may show high contrast by a correct choice of the writing speed and pulse energy. These results pave the way for elaboration of nonlinear optical devices.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70879200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 13
Unusual Oxidation Behaviour of Mesoporous Silicates towards Lignin Model Phenolic Monomer 介孔硅酸盐对木质素模型酚醛单体的异常氧化行为
Pub Date : 2015-07-20 DOI: 10.4236/WJNSE.2015.53011
R. Sadual, S. K. Badamali, S. Dapurkar, R. Singh
Oxidation of the lignin model monomer apocynol, 1-(4-hydroxy-3-methoxyphenoxy)-ethanol catalysed by mesoporous silica catalysts i.e. MCM-41, MCM-48, SBA-15 using H2O2 as an oxidant has been studied. Selectively, 2-methoxybenzoquinone was obtained along with acetovanillone. Such unprecedented oxidation behaviour of these metal free siliceous catalysts is attributed to the polar internal surface, high surface area as well as the pore architecture. On the other hand, the studied reaction was found to be non-selective when a commercial grade mesoporous silica i.e. Silica-5 was used as catalyst for comparison. Among the various silica catalysts studied, MCMs gave highest conversion and selectivity towards 2-methoxybenzoquinone under very mild reaction conditions.
研究了介孔二氧化硅催化剂MCM-41、MCM-48、SBA-15以H2O2为氧化剂催化木质素模型单体apocynol、1-(4-羟基-3-甲氧基苯氧基)-乙醇的氧化反应。选择性地得到了2-甲氧基苯醌和乙香草酮。这些无金属硅质催化剂的这种前所未有的氧化行为归因于极性内表面,高表面积以及孔隙结构。另一方面,当使用工业级介孔二氧化硅(silica -5)作为催化剂进行比较时,发现所研究的反应是非选择性的。在所研究的各种二氧化硅催化剂中,mcm在非常温和的反应条件下对2-甲氧基苯醌的转化率和选择性最高。
{"title":"Unusual Oxidation Behaviour of Mesoporous Silicates towards Lignin Model Phenolic Monomer","authors":"R. Sadual, S. K. Badamali, S. Dapurkar, R. Singh","doi":"10.4236/WJNSE.2015.53011","DOIUrl":"https://doi.org/10.4236/WJNSE.2015.53011","url":null,"abstract":"Oxidation of the lignin model monomer apocynol, 1-(4-hydroxy-3-methoxyphenoxy)-ethanol catalysed by mesoporous silica catalysts i.e. MCM-41, MCM-48, SBA-15 using H2O2 as an oxidant has been studied. Selectively, 2-methoxybenzoquinone was obtained along with acetovanillone. Such unprecedented oxidation behaviour of these metal free siliceous catalysts is attributed to the polar internal surface, high surface area as well as the pore architecture. On the other hand, the studied reaction was found to be non-selective when a commercial grade mesoporous silica i.e. Silica-5 was used as catalyst for comparison. Among the various silica catalysts studied, MCMs gave highest conversion and selectivity towards 2-methoxybenzoquinone under very mild reaction conditions.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70879137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
Effect of Aluminium Doping on Structural and Magnetic Properties of Ni-Zn Ferrite Nanoparticles 铝掺杂对镍锌铁氧体纳米颗粒结构和磁性能的影响
Pub Date : 2015-07-20 DOI: 10.4236/WJNSE.2015.53009
K. Kumar, D. Paramesh, P. V. Reddy
Aluminium doped Ni-Zn ferrite nanoparticles of general formula of Ni0.5Zn0.5AlxFe2-xO4 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0) have been synthesized by sol-gel auto combustion method and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dis-persive X-ray (EDX), Fourier transform spectroscopy (FTIR) and vibrating sample magneto meter (VSM). XRD studies confirm that all compositions show single phase cubic spinel structure. The crystallite size was calculated using the Debye-Scherrer formula and found in the range of 17 - 52 nm. The lattice parameter “a” is found to decrease with increasing Al3+ content. The SEM images clearly show the crystalline structure and EDX patterns confirm the compositional formation of the synthesized compositions. The results of FTIR analysis indicated that the functional groups of Ni-Zn spinel ferrite were formed during the sol-gel synthesis process. The IR spectra showed two main absorption bands, the high frequency band ν1 around 600 cm-1 and the low frequency band ν2 around 400 cm-1 arising from tetrahedral (A) and octahedral (B) interstitial sites in the spinel lattice. As doping is increased the magnetic behavior is found to decrease and the composition x = 2.0 ferrite appears to be exhibiting superparamagnetism as the coercive field and retentivity are found near zero.
采用溶胶-凝胶自燃烧法合成了通式为Ni0.5Zn0.5AlxFe2-xO4 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0)的掺铝镍锌铁氧体纳米颗粒,并利用x射线衍射(XRD)、扫描电镜(SEM)、能量色散x射线(EDX)、傅里叶变换光谱(FTIR)和振动样品磁强计(VSM)对其进行了表征。XRD研究证实,所有成分均表现为单相立方尖晶石结构。用Debye-Scherrer公式计算了晶体尺寸,发现晶体尺寸在17 - 52 nm之间。晶格参数a随Al3+含量的增加而减小。SEM图像清晰地显示了晶体结构,EDX模式证实了合成产物的成分形成。FTIR分析结果表明,Ni-Zn尖晶石铁氧体的官能团是在溶胶-凝胶合成过程中形成的。红外光谱显示出尖晶石晶格中四面体(A)和八面体(B)间隙处600 cm-1附近的高频ν1和400 cm-1附近的低频ν2两个主要吸收带。随着掺杂量的增加,铁氧体的磁性行为降低,组成x = 2.0的铁氧体表现出超顺磁性,矫顽力场和保持率接近于零。
{"title":"Effect of Aluminium Doping on Structural and Magnetic Properties of Ni-Zn Ferrite Nanoparticles","authors":"K. Kumar, D. Paramesh, P. V. Reddy","doi":"10.4236/WJNSE.2015.53009","DOIUrl":"https://doi.org/10.4236/WJNSE.2015.53009","url":null,"abstract":"Aluminium doped Ni-Zn ferrite nanoparticles of general formula of Ni0.5Zn0.5AlxFe2-xO4 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0) have been synthesized by sol-gel auto combustion method and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dis-persive X-ray (EDX), Fourier transform spectroscopy (FTIR) and vibrating sample magneto meter (VSM). XRD studies confirm that all compositions show single phase cubic spinel structure. The crystallite size was calculated using the Debye-Scherrer formula and found in the range of 17 - 52 nm. The lattice parameter “a” is found to decrease with increasing Al3+ content. The SEM images clearly show the crystalline structure and EDX patterns confirm the compositional formation of the synthesized compositions. The results of FTIR analysis indicated that the functional groups of Ni-Zn spinel ferrite were formed during the sol-gel synthesis process. The IR spectra showed two main absorption bands, the high frequency band ν1 around 600 cm-1 and the low frequency band ν2 around 400 cm-1 arising from tetrahedral (A) and octahedral (B) interstitial sites in the spinel lattice. As doping is increased the magnetic behavior is found to decrease and the composition x = 2.0 ferrite appears to be exhibiting superparamagnetism as the coercive field and retentivity are found near zero.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70879403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 46
A Cold Fusion-Casimir Energy Nano Reactor Proposal 一种冷聚变-卡西米尔能量纳米反应堆方案
Pub Date : 2015-05-22 DOI: 10.4236/WJNSE.2015.52007
M. Naschie
Using a compact heap of Fullerene nano particle moduli of a nano matrix device we propose that by maximizing the Casimir forces between these particles as a desirable effect, we can achieve a gradual rather than a sudden implosion pressure. This we expect will result in a mini holographic universe from which energy can be extracted in a way constituting a nano energy reactor functioning effectively on a hybrid principle somewhere between a Casimir effect and a cold fusion process.
利用纳米基器件中密集的富勒烯纳米粒子模堆,我们提出通过最大化这些粒子之间的卡西米尔力作为理想效果,我们可以实现逐渐而不是突然的内爆压力。我们期望这将产生一个微型全息宇宙,在这个宇宙中,能量可以通过一种方式被提取出来,这种方式构成了一个纳米能量反应堆,在卡西米尔效应和冷聚变过程之间的混合原理上有效地运作。
{"title":"A Cold Fusion-Casimir Energy Nano Reactor Proposal","authors":"M. Naschie","doi":"10.4236/WJNSE.2015.52007","DOIUrl":"https://doi.org/10.4236/WJNSE.2015.52007","url":null,"abstract":"Using a compact heap of Fullerene nano particle moduli of a nano matrix device we propose that by maximizing the Casimir forces between these particles as a desirable effect, we can achieve a gradual rather than a sudden implosion pressure. This we expect will result in a mini holographic universe from which energy can be extracted in a way constituting a nano energy reactor functioning effectively on a hybrid principle somewhere between a Casimir effect and a cold fusion process.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70879328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 20
期刊
纳米科学与工程(英文)
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1