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1.
This paper is aiming to give a brief overview of recent research in the field of all‐solid‐state, internal solution free, ion‐selective electrodes and reference electrodes, employing conducting polymers or nano‐/microstructures as solid contacts beneath the polymeric, ion‐selective or reference membranes. The emphasis is on papers published in the last five years (after 2006). According to the papers published, poly(3‐octylthiophene) conducting polymer transducers offer highly reliable sensors for various applications, involving demanding analytical approaches and miniature sensors. On the other hand, the search for alternative materials continues: the sensors obtained by placing nano‐/microstructures (conducting polymers but also other materials, like, e.g., carbon nanotubes) underneath the receptor membrane are intensively tested. The recent years have also shown how useful the application of advanced instrumental methods is for the investigation of processes occurring within all‐solid‐state ion‐selective electrodes.  相似文献   

2.
This highlight discusses the recent progress aimed at maximizing the potential of biomass for commodity monomers and polymers. These efforts are no longer solely academic issues. In recent years, a variety of alkene, diene, aromatic, and condensation type monomers have utilized renewable resources, such as cellulose, lignin, plant oils, starches, and monoterpenes in commercial polymers. Generally, these multifaceted efforts involve pretreatment of biomass with thermal, chemical, or physical methods followed by a catalyst sequence that entails a combination of acid‐catalysis, bio‐catalysis, or metal‐based catalysis. In this regard, synthesis strategies for ethylene, propylene, α‐olefins, methylmethacrylate, 1,3‐butadiene, 1,3‐cyclohexadiene, isoprene, 1,3‐propanediol, 1,4‐butanediol, and terephthalic acid are discussed as well as opportunities for other renewable‐based monomers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012  相似文献   

3.
Pyrogallic acid (PG) was used as a modeling carbon source in fabricating nano‐structured hollow carbon materials (HCMs) by a chemical vapor deposition (CVD) method. We found that non‐isothermal deposition can improve the integrity of the obtained HCMs. The different pyrolyzed species from PG under varied temperatures lead to the temperature‐dependent deposition yield, graphitization degree and morphology of the HCMs. HCMs including hollow spheres of varied sizes, cubic boxes with yolk‐shell structure, nanotubes, mesoporous particles and double‐shelled fibers, were prepared by using different templates, demonstrating the universality of this strategy. The carbon source has been extended to other plant polyphenols. The abundant and renewable solid precursors for CVD method endow this strategy excellent operation safety, improved storage and transportation convenience and low cost, and would boost the production of morphology‐ and size‐controlled HCMs and their applications in the fields such as water treatment, electrode materials, adsorbent, drug delivery, and so forth.  相似文献   

4.
The development of new energy materials that can be utilized to make renewable and clean fuels from abundant and easily accessible resources is among the most challenging and demanding tasks in science today. Solar‐powered catalytic water‐splitting processes can be exploited as a source of electrons and protons to make clean renewable fuels, such as hydrogen, and in the sequestration of CO2 and its conversion into low‐carbon energy carriers. Recently, there have been tremendous efforts to build up a stand‐alone solar‐to‐fuel conversion device, the “artificial leaf”, using light and water as raw materials. An overview of the recent progress in electrochemical and photo‐electrocatalytic water splitting devices is presented, using both molecular water oxidation complexes (WOCs) and nano‐structured assemblies to develop an artificial photosynthetic system.  相似文献   

5.
This review focuses on recent developments in the self‐assembly of lead chalcogenide nanocrystals into two‐ and three‐dimensional superstructures. Self‐assembly is categorized by the shapes of building blocks, including nanospheres, nanocubes, nano‐octahedra, and nanostars. In the section on nanospheres, rapid assemblies of lead chalcogenide‐based multicomponent nanocrystals with additional components, such as semiconductors, noble metals, and magnetic nanocrystals, are further highlighted. In situ self‐assembly of lead chalcogenide nanocrystals into one‐dimensional nanostructures at elevated temperatures is also covered. Each section of this paper highlights examples extracted from recent publications. Finally, relatively novel properties and applications arising from lead chalcogenide superlattices as typical examples are also discussed.  相似文献   

6.
Surface functionalization in a nanoscopic scaffold is highly desirable to afford nano‐particles with diversified features and functions. Herein are reported the surface decoration of dispersed block copolymer nano‐objects. First, side‐chain double bond containing oleic acid based macro chain transfer agent (macroCTA), poly(2‐(methacryloyloxy)ethyl oleate) (PMAEO), was synthesized by reversible addition‐fragmentation chain transfer (RAFT) polymerization and used as a steric stabilizer during the RAFT dispersion block copolymerization of benzyl methacrylate (BzMA) in n‐heptane at 70 °C. We have found that block copolymer morphologies could evolve from spherical micelles, through worm to vesicles, and finally to large compound vesicles with the increase of solvophobic poly(BzMA) block length, keeping solvophilic chain length and total solid content constant. Finally, different thiol compounds having alkyl, carboxyl, hydroxyl, and protected amine functionalities have been ligated onto the PMAEO segment, which is prone to functionalization via its reactive double bond through thiol‐ene radical reactions. Thiol‐ene modification reactions of the as‐synthesized nano‐objects retain their morphologies as visualized by field emission‐scanning electron microscopy. Thus, the facile and modular synthetic approach presented in this study allowed in situ preparation of surface modified block copolymer nano‐objects at very high concentration, where renewable resource derived oleate surface in the nanoparticle was functionalized. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 263–273  相似文献   

7.
Tremendous development in the field of portable electronics and hybrid electric vehicles has led to urgent and increasing demand in the field of high‐energy storage devices. In recent years, many research efforts have been made for the development of more efficient energy‐storage devices such as supercapacitors, batteries, and fuel cells. In particular, supercapacitors have great potential to meet the demands of both high energy density and power density in many advanced technologies. For the last half decade, graphene has attracted intense research interest for electrical double‐layer capacitor (EDLC) applications. The unique electronic, thermal, mechanical, and chemical characteristics of graphene, along with the intrinsic benefits of a carbon material, make it a promising candidate for supercapacitor applications. This Review focuses on recent research developments in graphene‐based supercapacitors, including doped graphene, activated graphene, graphene/metal oxide composites, graphene/polymer composites, and graphene‐based asymmetric supercapacitors. The challenges and prospects of graphene‐based supercapacitors are also discussed.  相似文献   

8.
Plant metabolites are the most significant source of renewable chemical feedstocks for a sustainable future. Among various plant secondary metabolites, triterpenoids are a large and structurally diverse 30-carbons subset of the major component terpenoids. Whereas the acyclic triterpene squalene can exist in many different conformations, the cyclic triterpenoids are more rigidified and largely chiral. The tetra and pentacyclic triterpenoids are more abundant than other triterpenoids and molecules having ten chiral centers are common. We show that acyclic and mono-cyclic to fused pentacyclic triterpenes are all nano-sized molecules having varied rigid and flexible lengths. Monte-Carlo investigation of their conformational space revealed that the nanometric lengths are maintained even in the folded conformers rendering all the triterpenoids useful as renewable nanos.  相似文献   

9.
In recent years, the microwave‐assisted ionic‐liquid method has been accepted as a promising methodology for the preparation of nanomaterials and cellulose‐based nanocomposites. Applications of this method in the preparation of cellulose‐based nanocomposites comply with the major principles of green chemistry, that is, they use an environmentally friendly method in environmentally preferable solvents to make use of renewable materials. This minireview focuses on the recent development of the synthesis of nanomaterials and cellulose‐based nanocomposites by means of the microwave‐assisted ionic‐liquid method. We first discuss the preparation of nanomaterials including noble metals, metal oxides, complex metal oxides, metal sulfides, and other nanomaterials by means of this method. Then we provide an overview of the synthesis of cellulose‐based nanocomposites by using this method. The emphasis is on the synthesis, microstructure, and properties of nanostructured materials obtained through this methodology. Our recent research on nanomaterials and cellulose‐based nanocomposites by this rapid method is summarized. In addition, the formation mechanisms involved in the microwave‐assisted ionic‐liquid synthesis of nanostructured materials are discussed briefly. Finally, the future perspectives of this methodology in the synthesis of nanostructured materials are proposed.  相似文献   

10.
In recent years, fluorescent carbon dots (CDs) have been developed and showed potential applications in biomedical imaging and light‐emitting diodes (LEDs) for their excellent fluorescent properties. However, it still remains a challenge to incorporate fluorescent CDs into the host matrix in situ to overcome their serious self‐quenching. Herein, a one‐pot hydrothermal method is used to prepare nano‐zirconia with CDs (CDs@ZrO2) nanoparticles. During the reaction, CDs and nano‐zirconia are generated simultaneously and connected with silane coupling agent. The CDs@ZrO2 nanoparticles exhibit tunable emission wavelength from 450 to 535 nm emission by regulating the content of citric acid in the feed. The quantum yield of the CDs@ZrO2 is up to 23.8%. Furthermore, the CDs@ZrO2 nanoparticles with regulable fluorescence emission can be used for the fluorescent material to prepare white LEDs. The prepared LED has significant white light emission with color coordinates of (0.30, 0.37) and its color rendering index (CRI) is 67.1. In summary, we have developed the solid‐state CDs@ZrO2 nanoparticles with tunable emission by a valuable strategy, that is, one‐pot method, for white LEDs.  相似文献   

11.
Nano magnetic‐supported sulfonic acid is found to be a powerful and reusable heterogeneous catalyst for the efficient synthesis of pyrimidinones. In this study we use various ketones such as acetophenone and cyclopentanone instead of β‐keto ester in one‐pot synthesis of pyrimidinone at biginelli like reaction. Our objective is to improve conditions for the synthesis of multicomponent reactions using nano magnetic catalyst under solvent free condition. A number of excellent and significant results have been developed that lead our perspective understanding the effect of the magnetic nanoparticles when they are used as catalysts.  相似文献   

12.
The design and development of modern biosensors for sensitive and selective detection of various biomarkers is important in diversified arenas including healthcare, environment, and food industries etc. The requirement of more robust and reliant biosensors lead to the development of various sensing modules. The nanomaterials having specific optical, electrical, and mechanical strength can pave the way towards development of ultrafast, robust, and miniaturized modules for biosensors. It can provide not only the point‐of‐care applicability but also has tremendous commercial as well as industrial justification. In order to improve the performance of the sensor systems, various nanostructure materials have been readily studied and applied for development of novel biosensors. In the last few years, researchers are engaged on harnessing the unique atomic and molecular properties of advance‐engineered materials including carbon nanotubes, graphene nanosheets, metal nanoparticles, metal oxide nanoparticles, and their nano‐conjugates. In view of such recent developments in nanomaterial engineering, the current review has been formulated emphasizing the role of these materials in surface engineering, biomolecule conjugation, and signal amplification for development of various ultrasensitive and robust biosensors having commercial as well as industrial viability. Attention is given on the electrochemical biosensors incorporating various nanomaterials and their conjugates. Importance of nanomaterials in the analytical performance of the various biosensor has also been discussed. To put a perceptive insights on the importance of various nanomaterials, an extended table is incorporated, which includes probe design, analyte, LOD, and dynamic range of various electrochemical biosensors.  相似文献   

13.
In recent years, considerable efforts have been made regarding the synthesis of renewable chemicals from natural resources. 5‐hydroxymethylfurfural (HMF) is an interesting platform chemical which has been widely exploited due to its rich chemistry and potential availability. The versatility of HMF has been demonstrated in several areas such as fine chemicals, biofuel precursors, and polymers. In particular, the potential to replace petroleum‐based analogues in the preparation of polymers associated with high performance has been observed owing to the structural rigidity of furan rings. This review aims at critically discuss the current research studies related to the derivatives of HMF, alongside with the synthesis and characterization of (co‐) polymers derived from HMF and its derivatives. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 1478–1492  相似文献   

14.
A robust catalyst for the selective dehydrogenation of formic acid to liberate hydrogen gas has been designed computationally, and also successfully demonstrated experimentally. This is the first such catalyst not based on transition metals, and it exhibits very encouraging performance. It represents an important step towards the use of renewable formic acid as a hydrogen‐storage and transport vector in fuel and energy applications.  相似文献   

15.
Solar water splitting provides a clean and renewable approach to produce hydrogen energy. In recent years, single‐crystal semiconductors such as Si and InP with narrow band gaps have demonstrated excellent performance to drive the half reactions of water splitting through visible light due to their suitable band gaps and low bulk recombination. This Minireview describes recent research advances that successfully overcome the primary obstacles in using these semiconductors as photoelectrodes, including photocorrosion, sluggish reaction kinetics, low photovoltage, and unfavorable planar substrate surface. Surface modification strategies, such as surface protection, cocatalyst loading, surface energetics tuning, and surface texturization are highlighted as the solutions.  相似文献   

16.
Two unusual 18,19‐secoursane glycosides, bodiniosides A ( 1 ) and B ( 2 ), and two known triterpenoids, hypadienic acid ( 3 ) and 2,3,19‐trihydroxyurs‐12‐en‐28‐oic acid ( 4 ), were isolated from the whole plants of Elsholtzia bodinieri. The structures of 1 and 2 were determined by intensive interpretation of spectral data. This is the first report of E‐secoursane glycosides. In addition, the biogenetic relationships among these four triterpenoids are discussed.  相似文献   

17.
In the field of metabolomics, CE‐MS is now recognized as a strong analytical technique for the analysis of (highly) polar and charged metabolites in a wide range of biological samples. Over the past few years, significant attention has been paid to the design and improvement of CE‐MS approaches for (large‐scale) metabolic profiling studies and for establishing protocols in order to further expand the role of CE‐MS in metabolomics. In this paper, which is a follow‐up of a previous review paper covering the years 2014–2016 (Electrophoresis 2017, 38, 190–202), main advances in CE‐MS approaches for metabolomics studies are outlined covering the literature from July 2016 to June 2018. Aspects like developments in interfacing designs and data analysis tools for improving the performance of CE‐MS for metabolomics are discussed. Representative examples highlight the utility of CE‐MS in the fields of biomedical, clinical, microbial, and plant metabolomics. A complete overview of recent CE‐MS‐based metabolomics studies is given in a table, which provides information on sample type and pretreatment, capillary coatings and MS detection mode. Finally, some general conclusions and perspectives are given.  相似文献   

18.
In recent years, there has been an increasing interest in using alcohols as alkylating agents for C?C and C?N bond‐forming processes employing mainly TM‐catalysts. Although BH‐catalysis looks like a green atom economy process since water is the only by‐product, it often suffers from one or more drawbacks, such as the use of expensive noble metal complexes, capricious ligands, and toxic organic solvents. Therefore, straightforward, efficient, atom economy and environmentally benign alternative protocols are desirable. This review aims to summarize the current knowledge within the published literature about dehydrative processes developed without TM‐catalysts. The most recent contributions to this topic have been reviewed keeping into account the new findings reported in this area. The features, strengths, and limitations of these alcohol‐based C?C and C?N bond‐forming processes has also been taken into account.  相似文献   

19.
A facile method was developed to prepare polyamic acid (PAA) nano‐emulsion using a non‐aqueous emulsification. The resultant PAA nano‐emulsion was characterized by light‐scattering particle size analysis, transmission electron microscopy (TEM), zeta potential, and conductivity analyses. It was found that polyamic acid salt (PAS), formed by partially neutralizing PAA at the carboxylic groups using triethyl amine (TEA), was of great importance for nano‐emulsification. The effect factors on the formation of PAA nano‐emulsion were investigated. To get a stable PAA nano‐emulsion in methanol (precipitant), the following ratios are required: amine/COOH (molar ratio) = 0.6–0.7, precipitant/solvent (mass ratio) = 1.5–2.25. A PAA nano‐emulsion with droplets ranging in size from 50 to 100 nm was obtained under optimized conditions. The driving force for the formation of PAA nano‐emulsion was also discussed. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

20.
Due to the increasing public awareness of environmental issues and the shortage of resources, the focus on products made from renewable sources to fulfill the sustainable development of modern society has intensified. Natural crystalline polysaccharides have been studied for a long time and are among the most abundant renewable resources in the world. High‐performance materials have been fabricated using crystalline polysaccharides such as cellulose and chitin. For practical applications, the mechanical performance of polysaccharide‐based materials is critical. In this review, we focus on the methods for constructing high‐strength and high‐toughness crystalline polysaccharide‐based materials. This review elucidates the three approaches of aggregate structure regulation, bioinspiration and mineralization, and the use of crystalline polysaccharides as matrices for reinforcing the mechanical properties of nanocomposites.  相似文献   

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