纳米材料改性聚氨酯的研究进展

简述了纳米材料改性聚氨酯的研究进展,重点介绍了纳米SiO2、纳米CaCO3和纳米蒙脱土对聚氨酯改性的研究现状.并简要介绍了新型纳米材料多面体低聚倍半硅氧烷(POSS)改性聚氨酯的研究状况,指出了聚氨酯/纳米复合材料的研究方向.     

纳米材料改性树脂基耐烧蚀材料研究新进展

综述了近年来纳米材料改性树脂基耐烧蚀材料的研究进展。介绍了碳纳米管、石墨烯、蒙脱土、纳米SiO2、纳米碳粉等纳米材料在改性烧蚀材料中的研究近况,详细探讨和比较了改性材料的热稳定性、成炭率、力学性能等,同时分析了纳米材料改性树脂材料中存在的问题,并预测了纳米材料改性耐烧蚀树脂的发展趋势。提出纳米材料,特别是新型的纳米碳材料改性树脂基耐烧蚀材料的研究将是很有发展前景的研究领域,并会进一步得到人们的重视。     

纳米材料改性纸张包装性能的研究进展

目的综述国内外纳米材料改性纸张性能的研究进展,为进一步开发纳米材料在包装工业中的应用提供科学的研究基础。方法概括纳米材料改性纸张性能的方法,分析纳米纤维素、壳聚糖纳米粒子、纳米黏土、纳米氧化物和金属纳米粒子分别对纸张包装性能的影响,及国内外相关的研究进展,并进一步总结纳米材料改性包装纸的应用领域和发展展望。结论大量研究结果表明,在造纸时加入或在纸表面涂覆纳米材料是改善纸张表面特性、光学特性、力学特性、印刷适性和阻隔性能等的有效途径。     

聚氨酯/纳米复合材料的研究进展

本文简述了纳米材料在聚氨酯中的应用,重点介绍纳米CaCO3、纳米SiO2、纳米碳材料及粘土对聚氨酯的改性研究,并指出了聚氨酯/纳米复合材料未来的研究方向.     

饲喂法制备碳纳米材料改性蚕丝的导热性能

将纳米石墨烯、单壁碳纳米管和纳米石墨粒子这三种碳纳米材料均匀涂覆在桑叶上饲喂四龄蚕,采用简易且绿色经济的饲喂法制备改性蚕丝.利用瞬态电热技术(TET)对蚕丝的导热性能进行研究结果表明:饲喂添加碳纳米材料的桑叶所得到的改性蚕丝的导热性能均有所降低,并且碳纳米材料的添加量越大,改性蚕丝的导热性能越低.导致改性蚕丝导热性能下...     

纳米材料改性纸张包装性能的研究进展

目的 -国内外纳米材料改性纸张性能的研究进展,为进一步开发纳米材料在包装工业中的应用提供科学的研究基础。方法 -概括纳米材料改性纸张性能的方法,分析纳米纤维素、壳聚糖纳米粒子、纳米黏土、纳米氧化物和金属纳米粒子分别对纸张包装性能的影响,及国内外相关的研究进展,并进一步总结纳米材料改性包装纸的应用领域和展望。结论 -大量研究结果表明,在造纸时加入或在纸表面涂覆纳米材料是改善纸张表面特性、光学特性、力学特性、印刷适性和阻隔性能等的有效途径。     

改性碳纳米材料在低温燃料电池中的应用

碳纳米材料(如炭黑、介孔碳、碳纳米管、石墨烯、碳纳米纤维、碳纳米角等)因其优异的电学性能和结构特性(良好的导电性能和超大的比表面积),被研究者广泛用作低温燃料电池贵金属催化剂的载体.然而,作为催化剂载体的这类碳纳米材料通常都存在电化学腐蚀的问题,碳载体的腐蚀通常会导致贵金属纳米催化剂的聚集,这将使催化剂的性能降低.为了改善碳载体的抗腐蚀性能,提高金属纳米粒子的活性和稳定性,许多研究工作致力于制备特殊结构的碳纳米材料,或对碳纳米材料进行表面修饰、掺杂等.与此同时,为了取代价格昂贵的贵金属催化剂,非贵金属催化剂的研究也成为一大热点,掺杂碳纳米材料就是研究热点之一.对近几年来围绕碳纳米材料制备、改性,以及这些改性碳纳米材料作为金属纳米粒子载体等的研究工作做了较为详细的综述,同时介绍了掺杂碳纳米材料作为氧还原催化剂的研究进展.     

纳米材料改性酚醛树脂及其在耐火材料中的应用

利用纳米材料改性的酚醛树脂具有较高的力学强度和优良的耐热性能,被广泛应用于耐火材料等领域.主要介绍了添加纳米二氧化硅、纳米碳素材料以及蒙脱土对酚醛树脂性能以及耐火制品理化指标的影响,同时介绍了二氧化钛、累托石、蛭石对酚醛树脂的改性作用,指出纳米改性酚醛树脂技术是一个颇具前景的研究方向.     

纳米材料对塑料改性的研究

讨论了纳米无机粒子在塑料改性中的功能及作用,综述了纳米材料改性塑料的制备方法及在塑料性能改善方面的研究进展。总结了纳米材料改性塑料的表征方法,最后展望了纳米塑料的发展前景。     

纳米材料改性聚磷酸铵在聚合物阻燃中的应用研究进展

综述了纳米材料改性聚磷酸铵(APP)的方法及其在聚合物材料中的协同阻燃作用。重点讨论了纳米二氧化硅(SiO2)、纳米碳酸钙(CaCO3)、海泡石、碳纳米管、纳米纤维素、纳米蒙脱土和可膨胀石墨改性APP协同阻燃聚合物材料方面取得的研究成果。提出了纳米材料改性APP在阻燃应用中存在的一些问题。     

Modification of nanostructured materials for biomedical applications

Adaptation (or incorporation) of nanostructured materials into biomedical devices and systems has been of great interest in recent years. Through the modification of existing nanostructured materials one can control and tailor the properties of such materials in a predictable manner, and impart them with biological properties and functionalities to better suit their integration with biomedical systems. These modified nanostructured materials can bring new and unique capabilities to a variety of biomedical applications ranging from implant engineering and modulated drug delivery, to clinical biosensors and diagnostics. This review describes recent advances of nanostructured materials for biomedical applications. The methods and technologies used to modify nanostructured materials are summarized briefly, while several current interests in biomedical applications for modified and functionalized nanostructured materials are emphasized.     

Doping Induced Tailoring in the Morphology,Band-Gap and Ferromagnetic Properties of Biocompatible ZnO Nanowires,Nanorods and Nanoparticles

Nano-Micro Letters - The modification of nanostructured materials is of great interest due to controllable and unusual inherent properties in such materials. Single phase Fe doped ZnO...     

Nanostructured materials for microwave receptors

Microwave heating promises numerous benefits over conventional heating including rapid thermal ramps, energy transfer rather than heat transfer, material selectivity, and improved automation and safety. This set of advantages has led to growing application in industrial processes. Currently, use of microwave heating is restricted because many materials of interest have poor dielectric loss properties and therefore respond poorly to microwave radiation. For this reason, nanostructured materials with high dielectric loss constants that can absorb microwave energy and convert it to heat are desired. Combination of the nanoscale receptors with base materials offers the opportunity to create composites with a high dielectric loss factor. This review covers the development of nanostructured microwave receptors and their applications. The structure of microwave receptors and their compatibility with the base material have a significant effect on the final dielectric properties. Therefore, various nanostructured microwave receptors, their surface modification, and the effect of the interface between the nanostructured receptors and the base materials are reviewed. Fundamental aspects of dielectric materials and their role in dielectric performance are discussed. Finally, key challenges, directions for further studies, and some promising nanostructured microwave receptors are suggested.     

Functional properties of silicon nanocrystals in oxygen-rich amorphous matrices formed by laser irradiation of substoichiometric silicon oxides

Silicon-based nanostructured thin films have been obtained through laser irradiation of amorphous silicon oxides. The optoelectronic properties of nanostructured films largely differ from their amorphous counterpart, exhibiting optical gap narrowing, wavelength-dependent spectral modification of the photoluminescence (PL) and conduction mechanism variations. In particular, following the hydrogen effusion and related defect density increase, a spectral red shift and PL intensity quenching is detected for λ_exc=514.5 nm, whereas PL enhancement and spectral blue shift is observed at λ_exc=632.8 nm. Different thermal activation regimes of conductivity are also detected by conductivity measurements.Such results are discussed in terms of microstructural changes from an hydrogenated amorphous network to a nanostructured two-phase material where wavelength-selective excitation of radiative recombination channels and temperature-dependent conductivity paths occurs.     

亲/疏水纳米结构表面微通道内流体的流动行为

在毛细管微通道内壁沉积二氧化硅微球并加以亲/疏水改性,以此来构建亲/疏水纳米结构表面微通道,考察了一定粘度的羧甲基纤维素钠水溶液在光滑亲/疏水微通道和粗糙亲/疏水微通道中的流动行为。结果表明,保持压力恒定,光滑毛细管(基材)中的液体流量随着粘度和管长的增加而减小;粘度一定,压力增加,无论壁面光滑或粗糙,疏水管中的流量均大于亲水管,且粗糙管中疏水/亲水流量斜率比大于光滑管;在低压时亲水管流量大于疏水管,而高压时恰好相反。采用滑移理论和牛顿运动定律对上述现象进行了解释,本研究以期为合理地操控微通道内的流体流动提供有价值的指导。     

Liquid crystal alignment in electro-responsive nanostructured thermosetting materials based on block copolymer dispersed liquid crystal

Novel well-defined nanostructured thermosetting systems were prepared by modification of a diglicydylether of bisphenol-A epoxy resin (DGEBA) with 10 or 15?wt% amphiphilic poly(styrene-b-ethylene oxide) block copolymer (PSEO) and 30 or 40?wt% low molecular weight liquid crystal 4'-(hexyl)-4-biphenyl-carbonitrile (HBC) using m-xylylenediamine (MXDA) as a curing agent. The competition between well-defined nanostructured materials and the ability for alignment of the liquid crystal phase in the materials obtained has been studied by atomic and electrostatic force microscopy, AFM and EFM, respectively. Based on our knowledge, this is the first time that addition of an adequate amount (10?wt%) of a block copolymer to 40?wt% HBC-(DGEBA/MXDA) leads to a well-organized nanostructured thermosetting system (between a hexagonal and worm-like ordered structure), which is also electro-responsive with high rate contrast. This behavior was confirmed using electrostatic force microscopy (EFM), by means of the response of the HBC liquid crystal phase to the voltage applied to the EFM tip. In contrast, though materials containing 15?wt% PSEO and 30?wt% HBC also form a well-defined nanostructured thermosetting system, they do not show such a high contrast between the uncharged and charged surface.     

Nanocatalysis for detoxification technologies

Transition metal based nanomaterials have been used in concurrence with Atmospheric Pressure Non Equilibrium Plasma (APNEP) generated using microwaves to detoxify volatile organic compound (VOC) polluted gas streams. Sol-gel synthesized titania nanostructured surfaces using reverse micelles alone or with further surface modification on alumina and cordierite substrate geometries, have been developed. By the construction of a pilot reactor which contains the heterogeneous catalyst after the plasma generation chamber, it was shown that the nanostructured titania greatly enhanced the destruction of the model VOC compounds (Toluene and 1,2 dichlorobenzene) as opposed to the plasma stream alone. Experiments presented show the effect of microwave power, gas stream composition (N2, N2/O2 and N2/H2O) and temperature on the effectiveness of the catalyst. These experimental variables cause a change in the Fermi electron (e-) and electron hole density (h+) of the nanostructured material, therefore, causing enhanced redox VOC destruction to occur on the surface of the nanoparticles. It was observed that the catalyst is greatly enhanced at low microwave plasma power by doping the surface of the nanoparticles with noble metals at low concentrations by chemical vapour deposition (CVD). These results demonstrate that APNEP microwave technology performance is greatly enhanced with the use of nanostructured heterogeneous catalysis for detoxification of VOC polluted gas streams.     

Carbon nitride film deposition by active screen plasma nitriding

Deposition of CN-based films by a novel version of active screen plasma nitriding, aiming at surface modification of polymers, is reported. The approach relies on the use of pure graphite as the grid material, which was found to act both as an active screen and as a dry source of carbon atoms for the synthesis of thin films consisting mainly of a stoichiometric CN layer with columnar-type structure and dome-like nanostructured morphology.     

Construct hierarchical superhydrophobic silicon surfaces by chemical etching

We present a simple approach for preparing hydrophobic silicon surfaces by constructing silicon nanowire arrays using Ag-assisted chemical etching without low-surface-energy material modification. The static and dynamic wetting properties of the nanostructured surfaces and their dependence on etching conditions were studied. It was revealed that the surface topologies of silicon nanowire arrays and their corresponding wetting properties could be tuned by varying the etching time. Under optimized etching conditions, superhydrophobic surfaces with an apparent contact angle larger than 150 degrees and a sliding angle smaller than 10 degrees were achieved due to the formation of a hierarchical structure. The origin of hydrophobic behavior was discussed based on Wenzel and Cassie models. In addition, the effects of surface modification of Si surface nanostructures on their hydrophobic characteristics were also investigated.