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1.
In this work, different poly (lactic acid) (PLA)-based nanocomposite electrospun fibers, reinforced with both organic and inorganic nanoparticles, were obtained. As organic fibers, cellulose nanocrystals, CNC, both neat and functionalized by “grafting from” reaction, chitosan and graphene were used; meanwhile, hydroxyapatite and silver nanoparticles were used as inorganic fibers. All of the nanoparticles were added at 1 wt% with respect to the PLA matrix in order to be able to compare their effect. The main aim of this work was to study the morphological, thermal and mechanical properties of the different systems, looking for differences between the effects of the addition of organic or inorganic nanoparticles. No differences were found in either the glass transition temperature or the melting temperature between the different electrospun systems. However, systems reinforced with both neat and functionalized CNC exhibited an enhanced degree of crystallinity of the electrospun fibers, by up to 12.3%. From a mechanical point of view, both organic and inorganic nanoparticles exhibited a decreased elastic modulus and tensile strength in comparison to neat electrospun PLA fibers, improving their elongation at break. Furthermore, all of the organic and inorganic reinforced systems disintegrated under composting conditions after 35 days.  相似文献   

2.
Silver-impregnated silica gels prepared by us have very good adsorption characteristics for both organic and inorganic radioiodine. Under the operating conditions applied, the adsorption capacity is up to 200 mg I g–1 and the utilization of silver on the sorbent is higher than 90%. The adsorbent can be used to remove iodine from nuclear fuel reprocessing off-gases and from air cleaning systems of nuclear reactors.  相似文献   

3.
We give a perspective on the relations between inorganic and organic cation ionic liquids (ILs), including members with melting points that overlap around the borderline 100 degrees C. We then present data on the synthesis and properties (melting, boiling, glass temperatures, etc.) of a large number of an intermediate group of liquids that cover the ground between equimolar molecular mixtures and ILs, depending on the energetics of transfer of a proton from one member of the pair to the other. These proton-transfer ILs have interesting properties, including the ability to serve as electrolytes in solvent-free fuel cell systems. We provide a basis for assessing their relation to aprotic ILs by means of a Gurney-type proton-transfer free energy level diagram, with approximate values of the energy levels based on free energy of formation and pK(a) data. The energy level scheme allows us to verify the relation between solvent-free acidic and basic electrolytes, and the familiar aqueous variety, and to identify neutral protic electrolytes that are unavailable in the case of aqueous systems.  相似文献   

4.
The current interest in ionic liquids (ILs) is motivated by some unique properties, such as negligible vapour pressure, thermal stability and non-flammability, combined with high ionic conductivity and wide electrochemical stability window. However, for material applications, there is a challenging need for immobilizing ILs in solid devices, while keeping their specific properties. In this critical review, ionogels are presented as a new class of hybrid materials, in which the properties of the IL are hybridized with those of another component, which may be organic (low molecular weight gelator, (bio)polymer), inorganic (e.g. carbon nanotubes, silica etc.) or hybrid organic-inorganic (e.g. polymer and inorganic fillers). Actually, ILs act as structuring media during the formation of inorganic ionogels, their intrinsic organization and physicochemical properties influencing the building of the solid host network. Conversely, some effects of confinement can modify some properties of the guest IL, even though liquid-like dynamics and ion mobility are preserved. Ionogels, which keep the main properties of ILs except outflow, while allowing easy shaping, considerably enlarge the array of applications of ILs. Thus, they form a promising family of solid electrolyte membranes, which gives access to all-solid devices, a topical industrial challenge in domains such as lithium batteries, fuel cells and dye-sensitized solar cells. Replacing conventional media, organic solvents in lithium batteries or water in proton-exchange-membrane fuel cells (PEMFC), by low-vapour-pressure and non flammable ILs presents major advantages such as improved safety and a higher operating temperature range. Implementation of ILs in separation techniques, where they benefit from huge advantages as well, relies again on the development of supported IL membranes such as ionogels. Moreover, functionalization of ionogels can be achieved both by incorporation of organic functions in the solid matrix, and by encapsulation of molecular species (from metal complexes to enzymes) in the immobilized IL phase, which opens new routes for designing advanced materials, especially (bio)catalytic membranes, sensors and drug release systems (194 references).  相似文献   

5.
Conventional lithium-ion batteries, with flammable organic liquid electrolytes, have serious safety problems, which greatly limit their application. All-solid-state batteries (ASSBs) have received extensive attention from large-scale energy-storage fields, such as electric vehicles (EVs) and intelligent power grids, due to their benefits in safety, energy density, and thermostability. As the key component of ASSBs, solid electrolytes determine the properties of ASSBs. In past decades, various kinds of solid electrolytes, such as polymers and inorganic electrolytes, have been explored. Among these candidates, organic–inorganic composite solid electrolytes (CSEs) that integrate the advantages of these two different electrolytes have been regarded as promising electrolytes for high-performance ASSBs, and extensive studies have been carried out. Herein, recent progress in organic–inorganic CSEs is summarized in terms of the inorganic component, electrochemical performance, effects of the inorganic ceramic nanostructure, and ionic conducting mechanism. Finally, the main challenges and perspectives of organic–inorganic CSEs are highlighted for future development.  相似文献   

6.
有机-无机纳米复合材料的研究在当前纳米科学技术的发展中占有重要地位,开创了材料与催化科学研究的新纪元。自从10年前首次合成纳米孔无机材料MCM-41至今,该领域研究不断深入,已展现出广阔的应用前景。当客体有机分子分散于纳米孔道内部时,其分子性质将产生明显变化。本文结合作者近期研究成果,力图从实验与理论两方面阐明在纳米复合体系中客体分子性质变化的原因。  相似文献   

7.
Low-dimensional (low-D) organic metal halide hybrids (OMHHs) have emerged as fascinating candidates for optoelectronics due to their integrated properties from both organic and inorganic components. However, for most of low-D OMHHs, especially the zero-D (0D) compounds, the inferior electronic coupling between organic ligands and inorganic metal halides prevents efficient charge transfer at the hybrid interfaces and thus limits their further tunability of optical and electronic properties. Here, using pressure to regulate the interfacial interactions, efficient charge transfer from organic ligands to metal halides is achieved, which leads to a near-unity photoluminescence quantum yield (PLQY) at around 6.0 GPa in a 0D OMHH, [(C6H5)4P]2SbCl5. In situ experimental characterizations and theoretical simulations reveal that the pressure-induced electronic coupling between the lone-pair electrons of Sb3+ and the π electrons of benzene ring (lp-π interaction) serves as an unexpected “bridge” for the charge transfer. Our work opens a versatile strategy for the new materials design by manipulating the lp-π interactions in organic–inorganic hybrid systems.  相似文献   

8.
Research on redox-flow batteries (RFBs) is currently experiencing a significant upturn, stimulated by the growing need to store increasing quantities of sustainably generated electrical energy. RFBs are promising candidates for the creation of smart grids, particularly when combined with photovoltaics and wind farms. To achieve the goal of “green”, safe, and cost-efficient energy storage, research has shifted from metal-based materials to organic active materials in recent years. This Review presents an overview of various flow-battery systems. Relevant studies concerning their history are discussed as well as their development over the last few years from the classical inorganic, to organic/inorganic, to RFBs with organic redox-active cathode and anode materials. Available technologies are analyzed in terms of their technical, economic, and environmental aspects; the advantages and limitations of these systems are also discussed. Further technological challenges and prospective research possibilities are highlighted.  相似文献   

9.
To meet the ever‐increasing requirements for the next generation of sustainable and versatile energy‐related devices, conjugated polymers, which have potential advantages over small molecules and inorganic materials, are among the most promising types of green candidates. The properties of conjugated polymers can be tuned through modification of the structure and incorporation of different functional moieties. In addition, superior performances can be achieved as a result of the advantages of nanostructures, such as their large surface areas and the shortened pathways for charge transfer. Therefore, nanostructured conjugated polymers with different properties can be obtained to be applied in different energy‐related organic devices. This review focuses on the application and performance of the recently reported nanostructured conjugated polymers for high‐performance devices, including rechargeable lithium batteries, microbial fuel cells (MFCs), thermoelectric generators, and photocatalytic systems. The design strategies, reaction mechanisms, advantages, and limitations of nanostructured conjugated polymers are further discussed in each section. Finally, possible routes to improve the performances of the current systems are also included in the conclusion.  相似文献   

10.
高效氧催化反应中的金属有机骨架材料(英文)   总被引:1,自引:0,他引:1  
氧电催化反应包括氧气还原反应(ORR)和氧气析出反应(OER).作为核心电极反应,这两个反应对诸多能源存储与转换技术(比如燃料电池、金属空气电池以及全水分解制氢等)的能量效率起决定性作用.然而,ORR和OER涉及多个反应步骤、多个电子转移过程以及多相界面传质过程.这些复杂的过程较大程度上限制了ORR和OER的反应速率.从理论和实践两个方面来看,ORR和OER都需要高效电催化剂的参与来促进其反应速率,从而能够最终提高上述能源存储与转换技术的能量转换或利用效率.目前,以Pt,Pd,Ir,Ru为代表的贵金属基电催化剂具有十分突出的电催化性能.但是,过高的成本和过低的储量始终制约着贵金属基电催化剂在催化ORR和OER反应方面,乃至在能源存储与转换技术领域的规模化应用.因而,开发高效非贵金属基氧电催化剂成为近年来能源存储与转换领域的研究重点之一.在众多已经报道的非贵金属基氧电催化剂中,金属有机骨架材料(MOFs)备受瞩目.MOFs是一类由有机配体和金属节点通过配位键自组装而成的晶态多孔材料.它们具备超高比表面积、超高孔隙率以及规则性纳米孔道.相比较其他传统的多孔材料(比如活性炭、分子筛、介孔炭、介孔氧化硅等),MOFs最主要的优势在于它们的结构和功能可以依据需求通过选择合适的有机配体和金属节点进行便利地设计,或通过后处理进行必要的改性和调节.基于独特的多孔特性以及结构与功能的可设计、可调节性,MOFs在气体分离与存储、异相催化、化学传感、药物输送、环境保护以及能源存储与转化等领域都具有潜在的应用价值.因而,近年来,MOFs备受基础研究领域和工业界的青睐.针对MOFs开展的基础研究和应用开发逐渐成为诸多领域的研究焦点.也正由于MOFs具有的上述优异特性,尤其是结构与功能的可设计、可调节性,使得设计制备基于单纯MOFs以及MOFs衍生材料成为开发高效非贵金属基氧电催化剂的新途径.本综述首先论述了基于单纯MOFs的氧电催化剂(包括纯MOFs、活性物种修饰的MOFs以及与导电材料构成的复合MOFs)的合成以及它们在ORR或OER催化反应中应用的研究进展.在第二部分论述中,本综述主要针对MOFs衍生的各类氧电催化剂(包括无机微米-纳米结构/多孔碳复合材料、纯多孔碳材料、纯无机微米-纳米结构材料以及单原子型电催化材料)的研究进展进行了简要介绍和讨论.最后,本综述对MOFs基氧电催化剂目前存在的挑战进行了简要分析;同时,也对这类氧电催化剂的通用设计准则以及未来发展方向进行了展望.尽管存在诸多挑战,MOFs始终被认为是极好的"平台"材料.充分利用它们将有利于开发高效且实用的非贵金属基氧电催化剂.  相似文献   

11.
The analysis of advantages and disadvantages of the main well known methods of waste processing taking into account their energy efficiency and ecological safety are presented in the article. The energy efficiency of the designed by the authors complex processing of organic waste (CPOW) is shown by calculations. Kinetic laws of main stages of the sequential processing of waste by biochemical (anaerobic digestion) and thermal chemical (pyrolysis or oxidative thermo-destruction) methods into caloric fuel gas and their beneficial mutual influence are considered. The main products of CPOW are: fuel gas, carbon dioxide, production of greenhouses, hot water, and inorganic residue of waste. The complex is thermally independent and environmentally almost friendly. No more than 20% of the potential of the internal structure of waste is used for functioning of the complex. It is shown that CPOW is the most efficient among the known method of the organic waste processing.  相似文献   

12.
Ultralong organic room-temperature phosphorescence(RTP) materials have attracted tremendous attention recently due to their diverse applications. Several ultralong organic RTP materials mimicking the host-guest architecture of inorganic systems have been exploited successfully. However, complicated synthesis and high expenditure are still inevitable in these studies. Herein, we develop a series of novel host-guest organic phosphorescence systems, in which all luminophores are electron-rich, commercially available and halogen-atom-free. The maximum phosphorescence efficiency and the longest lifetime could reach 23.6% and 362 ms, respectively. Experimental results and theoretical calculation indicate that the host molecules not only play a vital role in providing a rigid environment to suppress non-radiative decay of the guest, but also show a synergistic effect to the guest through F?rster resonance energy transfer(FRET). The commercial availability, facile preparation and unique properties also make these new host-guest materials an excellent candidate for the anti-counterfeiting application. This work will inspire researchers to develop new RTP systems with different wavelengths from commercially available luminophores.  相似文献   

13.
Silicon and carbon may be looked upon as the two fundamental antipodes with respect to the naturally occurring forms of matter and life on earth: Silicon plays the key role in the “petrification” of inanimate matter, while carbon is the representative element for the “incarnation” of living organisms. If a scientist were to search for a highly efficient method of uniting inorganic and organic matter, he would, at a very early stage of attempting to solve this problem, combine these two natural principles of matter and think of “bireactive” molecules containing a silicon functionality for bonding to inorganic material on the one hand and a carbon functionality for anchoring to an organic counterpart on the other. The title compounds and their derivatives epitomize such molecules: they are wanderers between both (chemical) worlds. Owing to their bifunctionality they are capable of binding to inorganic (especially siliceous) systems as well as to organic polymers. Whether their commercial application concerns the strengthening of polyester resins with glass fibers for use in boatbuilding or the incorporation of silica as a filler in rubber mixtures for the manufacture of wear-resistant tires or even the immobilization of enzymes on glass spheres for carrying out reactions in enzyme reactors—in all cases organofunctionalized silanes guarantee a reliable and permanent union between two otherwise “incompatible” material systems.  相似文献   

14.
This review covers recently reported polymer composites that show a thermoelectric (TE) effect and thus have potential application as thermoelectric generators and Peltier coolers. The growing need for CO2‐minimizing energy sources and thermal management systems makes the development of new TE materials a key challenge for researchers across many fields, particularly in light of the scarcity or toxicity of traditional inorganic TE materials based on Te and Pb. Recent reports of composites with inorganic and organic additives in conjugated and insulating polymer matrices are covered, as well as the techniques needed to fully characterize their TE properties.  相似文献   

15.
Clouding behaviour in surfactant systems   总被引:1,自引:0,他引:1  
A study on the phenomenon of clouding and the applications of cloud point technology has been thoroughly discussed. The phase behaviour of clouding and various methods adopted for the determination of cloud point of various surfactant systems have been elucidated. The systems containing anionic, cationic, nonionic surfactants as well as microemulsions have been reviewed with respect to their clouding phenomena and the effects of structural variation in the surfactant systems have been incorporated. Additives of various natures control the clouding of surfactants. Electrolytes, nonelectrolytes, organic substances as well as ionic surfactants, when present in the surfactant solutions, play a major role in the clouding phenomena. The review includes the morphological study of clouds and their applications in the extraction of trace inorganic, organic materials as well as pesticides and protein substrates from different sources.  相似文献   

16.
A biochemical fuel cell is a device which converts chemical energy into electrical power. The catalysts used in this process can be either inorganic or organic type giving rise to ‘inorganic fuel cells’ or ‘biochemical fuel cells’, respectively. Biochemical fuel cells use either micro-organism or enzymes as active components to carry out electrochemical reactions. The efficiency of such a device theoretically can be as high as 90%. The difficulty in attaining these values arises due to sluggishness of electron transfer from active site to conducting electrode. This can be overcome by using mediators or by immobilizing active components on conducting electrode. We have immobilizedfad-glucose oxidase on a graphite electrode using a semiconducting chain as a bridge. At the present stage of development, such a device tacks high current densities, which is essential for commercial power generation but can be used in applications such as pacemakers and glucose sensors.  相似文献   

17.
Hybrid organic–inorganic approaches are used for the synthesis of bifunctional proton exchange membrane fuel cell (PEMFC) membranes owing to their ability to combine the properties of a functionalized inorganic network and an organic thermostable polymer. We report the synthesis of both sulfonic and phosphonic acid functionalized mesostructured silica networks into a poly(vinylidenefluoride‐co‐hexafluoropropylene) (poly(VDF‐co‐HFP) copolymer. These membranes, containing different amounts of phosphonic acid and sulfonic acid groups, have been characterized using FTIR and NMR spectroscopy, SA‐XRD, SAXS, and electrochemical techniques. The proton conductivity of the bifunctional hybrid membranes depends strongly on hydration, increasing by two orders of magnitude over the relative humidity (RH) range of 20 to 100 %, up to a maximum of 0.031 S cm−1 at 60 °C and 100 % RH. This value is interesting as only half of the membrane conducts protons. This approach allows the synthesis of a porous SiO2 network with two different functions, having  SO3H and  PO3H2 embedded in a thermostable polymer matrix.  相似文献   

18.
无机材料电子迁移率高、光谱响应范围与太阳光谱匹配,而有机材料价格低廉、合成方法简单、容易制作在基底上,因此在太阳能电池中具有更广阔的应用前景。 目前,阻碍有机太阳能电池发展的主要原因是材料的载流子迁移率低、器件稳定性差、吸收光谱与太阳光谱不匹配,导致光电转换效率较低。 若能将有机、无机材料二者的优点相结合,将可提高有机太阳能电池的能量转换效率。 目前的研究已经取得了一定进展,无机材料在受体层、阴极缓冲层、阳极缓冲层中的应用均不同程度地提高了有机太阳能电池的能量转换效率。 本文综述了目前该领域的研究现状,并对今后的研究提出了展望。  相似文献   

19.
There is no doubt that the outstanding optical and electronic properties that low-dimensional carbon-based nanomaterials exhibit call for their implementation into optoelectronic devices. However, to harvest the enormous potential of these nanocarbons it is essential to probe them in multifunctional electron donor-acceptor systems, placing particular attention on the interactions between electron donors/electron acceptors and nanocarbons. This feature article outlines challenges and recent breakthroughs in the area of interfacing organic and inorganic semiconductors with low-dimensional nanocarbons that range from fullerenes (0D) and carbon nanotubes (1D) to graphene (2D). In the context of organic semiconductors, we focus on aromatic macrocycles and extended tetrathiafulvalenes, and CdTe nanocrystals/quantum dots represent the inorganic semiconductors. Particular emphasis is placed on designing and probing solar energy conversion nanohybrids.  相似文献   

20.
The deliquescence behavior of ternary inorganic (ammonium sulfate and ammonium nitrate)/organic (glutaric acid and malonic acid)/water aerosol particles has been investigated at 293 K using a novel surface aerosol microscopy (SAM) technique. The results obtained for the deliquescence relative humidities (DRH) for particles of variable inorganic/organic contents show a eutectic behavior with the mixed particles showing deliquescence at lower DRH compared to the pure inorganic and organic components, respectively. This behavior has been quantitatively modeled using the extended aerosol inorganics (E-AIM) thermodynamic model of Clegg et al. in combination with the UNIFAC group activity approach to account for organic molecular solutes. In addition, we have investigated the crystallization behavior of supersatured and formerly deliquesced ternary solution droplets using space resolved Raman spectroscopy. It is found that such droplets produce solid particles in which the inorganic and organic phases show some spatial separation with the organic component being predominantly found at the outer part of the particle. Independent measurements of the contact angles of such ternary droplets reveal that their angles are within experimental error identical to those of the purely organic/water solutions.  相似文献   

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