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Application of Carbamates in the C—H Bond Activation

Chuqiang Que, Ning Chen*, Jiaxi Xu*

Progress in Chemistry. 2018, 30(2/3): 139-155. https://doi.org/10.7536/PC170919

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Chuqiang Que, Ning Chen*, Jiaxi Xu*. Application of Carbamates in the C—H Bond Activation[J]. Progress in Chemistry, 2018, 30(2/3): 139-155.

Carbamates widely exist in natural products, drugs and pesticides, and have also been utilized as directing groups in the C-H bond activation. Generally, in the presence of transition metals, the carbamate group can selectively direct the ortho C-H bond activation of substrates to realize the coupling approaches with various coupling reagents through metal-bearing six-membered ring intermediates. The application of carbamates in the C-H bond activation reactions has been systematically summarized, including:(1) sp² C-H bond activation and functionalization of N-aryl carbamates, and aryl carbamates under the catalysis of Pd, Rh, Ru, or Ir to afford the corresponding halogenation, arylation, cyclization, and alkenylation products;(2) sp² C-H bond activation and functionalization of alkenyl carbamates in the presence of Rh to afford the corresponding alkenylation and allylation products;(3) sp³ C-H bond activation and functionalization of N-dialkyl carbamates in the presence of Pd, Cu, Fe or even the transition-metal-free conditions to afford the acetoxylation, alkylation or arylation products. During the aromatic sp² C-H bond activation approaches, both electronic and steric effects control the reaction yields and regioselectivities. In most cases, substrates bearing electron donating and less steric hindrance groups show better reactivity. Moreover, owing to the high activity of vicinal position of amines, the C-H functionalization of benzylamine, tetrahydroisoquinolines or 1,2-dihydroquinoline, bearing N-alkoxycarbonyl, can be carried out under the catalysis of copper, iron, or even the transition-metal-free conditions, some of which can also show high enantioselectivity through the asymmetric induction. The review can provide some guidance to promote the further development and application of carbamates in C-H bond activation reactions.
Contents
1 Introduction
2 Ortho-directed sp² C-H bond activation reactions of N-aryl carbamates
2.1 Pd-catalyzed reactions
2.2 Rh-catalyzed reactions
2.3 Ru-catalyzed reactions
2.4 Ir-catalyzed reactions
3 Ortho-directed sp² C-H bond activation reactions of aryl carbamates
3.1 Pd-catalyzed reactions
3.2 Rh-catalyzed reactions
3.3 Ru-catalyzed reactions
3.4 Ir-catalyzed reactions
4 Ortho-directed sp² C-H bond activation reactions of N-alkenyl carbamates and alkenyl carbamates
5 Directing sp³ C-H bond activation reactions of N-dialkyl carbamates
6 Non-directing sp³ C-H bond activation reactions of N-dialkyl carbamates
7 Conclusion
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Research in the Preparation and Application of Nanobowl Arrays

Li Li, Jian Dong, Weiping Qian*

Progress in Chemistry. 2018, 30(2/3): 156-165. https://doi.org/10.7536/PC170901

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Li Li, Jian Dong, Weiping Qian*. Research in the Preparation and Application of Nanobowl Arrays[J]. Progress in Chemistry, 2018, 30(2/3): 156-165.

Nanobowl arrays, such as gold nanobowl arrays, silver nanobowl arrays, ZnO nanobowl arrays and TiO₂ nanobowl arrays, all have ordered periodic holes, large surface area and reduced symmetry. These unique nanobowls not only provide nano-porous structures, but also bring many special physical and chemical properties. In recent years, these nanobowl arrays have attracted a great deal of attention because of their novel and/or enhanced properties arising from the porous structures. In this review, all kinds of preparation methods and fabricated processes of various nanobowl arrays are introduced. The details are as follows. Firstly, colloidal crystal template(generally silica spheres or polystyrene microspheres) is prepared via self-assembly. Secondly, different kinds of materials as required are deposited on the colloidal crystal template by physical vapor deposition, chemical deposition or electrochemical deposition. Finally, colloidal crystal template is removed via dissolving or high temperature treatment to obtain nanobowl arrays. Meanwhile, the diverse applications of the nanobowl arrays are also summarized, for example, SERS substrates, nanosensor, catalysis, optics application. What's more, the advantages and disadvantages of different fabrication methods are discussed, as well as the prospects of the nanobowl arrays and the existing problems.
Contents
1 Introduction
2 Preparation of nanobowl arrays
2.1 Preparation of colloidal crystal template
2.2 Preparation of inorganic and organic nanoshell
2.3 Removal of template
2.4 Fabrication of various nanobowl arrays
3 Applications of nanobowl arrays
3.1 Application in surface-enhanced Raman spectroscopy
3.2 Application in sensor
3.3 Application in catalysis
3.4 Application in optics
4 Conclusion
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Confined Self-Assembly of Block Copolymers within the Three-Dimensional Soft Space

Yan Zhang, Xuejie Liu, Nan Yan, Yuexin Hu, Haiying Li, Yutian Zhu

Progress in Chemistry. 2018, 30(2/3): 166-178. https://doi.org/10.7536/PC170910

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Yan Zhang, Xuejie Liu, Nan Yan, Yuexin Hu, Haiying Li, Yutian Zhu. Confined Self-Assembly of Block Copolymers within the Three-Dimensional Soft Space[J]. Progress in Chemistry, 2018, 30(2/3): 166-178.

Under the three-dimensional(3D) confinement, block copolymers(BCPs) can self-assemble into various well-ordered nanostructures, which have versatile applications in the fields of catalyst carrier, electronics, optical sensor, and so on. It is known that the nature of the BCPs as well as the internal nanostructures and the external shapes of the self-assembled materials significantly influence their properties and applications. This review introduces the recent progress in the self-assembly methods for the 3D confined self-assembly of block copolymers. The internal and external factors that affect the self-assembled structures of BCPs are also summarized. The internal factors mainly refer to the nature of BCPs, including the block type, molecular weight and block volume fraction of different blocks. The external factors include the size of confined space, the oil/water interfacial interaction, thermal or solvent annealing treatment, and so on. Moreover, the co-assembly of BCPs and inorganic nanoparticles(NPs) under 3D soft confinement is also reviewed. The morphological transition after incorporating NPs and the controllable distribution and localization of NPs within BCP matrix, as well as the potential applications of the resulting hybrid structures are discussed. Finally, open questions on this issue are discussed and prospects of this field are described.
Contents
1 Introduction
2 Self-assembly of BCPs under 3D soft confinement
2.1 Overview of the methods of the 3D soft confined self-assembly
2.2 Factors affecting the self-assembly structures
2.3 Other methods for tuning the self-assembly structures
3 Co-assembly of BCPs and NPs under 3D soft confinement
3.1 Morphological transition induced by NPs
3.2 Controllable distribution and localization of NPs in BCP matrix
4 Applications of the 3D soft confined assembly of BCPs
5 Conclusion
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Controlled Synthesis of New Polymethylene-Based Copolymers

Hao Zhang, Fang Xu, Heying Wang, Tao Jiang, Zhi Ma

Progress in Chemistry. 2018, 30(2/3): 179-189. https://doi.org/10.7536/PC170825

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Hao Zhang, Fang Xu, Heying Wang, Tao Jiang, Zhi Ma. Controlled Synthesis of New Polymethylene-Based Copolymers[J]. Progress in Chemistry, 2018, 30(2/3): 179-189.

Novel property and application of polyolefin stem from precise control of its structure and composition. Polymethylene(polyethylene's analogue) and its copolymers have become one of hot topics of current research in the polyolefin functionalization field in recent years. In this review, firstly, the polyhomologation of ylide leading to linear polymethylenes with controllable molecular weight and narrow molecular weight distribution is introduced briefly. Then, various borane initiators and ylide monomers used for polyhomologation are described in detail. In addition, the controllable syntheses of new polymethylene-based copolymers by combining polyhomologation with ring-opening polymerization, atom transfer radical polymerization, reversible addition-fragmentation chain transfer polymerization, nitroxide mediated polymerization, ionic polymerization, ring-opening metathesis polymerization and coupling reactions, are reviewed. Finally, the future development of the controllable synthesis strategies and practical application of new polymethylene-based copolymers are prospected.
Contents
1 Introduction
2 Initiators of polyhomologation
2.1 Trifunctional organoboranes
2.2 Bifunctional organoboranes
2.3 Monofunctional organoboranes
3 Monomers of polyhomologation
3.1 Sulfur ylides
3.2 Arsenic ylides
4 Combination with other methodologies to prepare polymethylene-based copolymers
4.1 Combination with ring-opening polymerization
4.2 Combination with atom transfer radical polymerization
4.3 Combination with reversible addition-fragmentation chain transfer polymerization
4.4 Combination with nitroxide-mediated radical polymerization
4.5 Combination with ionic polymerization
4.6 Combination with ring-opening metathesis polymerization
4.7 Combination with coupling reaction
5 Conclusion and outlook
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Shear-Responsive Drug Delivery Systems

Zhirui Dong, Weijun Tong*

Progress in Chemistry. 2018, 30(2/3): 190-197. https://doi.org/10.7536/PC170817

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Zhirui Dong, Weijun Tong*. Shear-Responsive Drug Delivery Systems[J]. Progress in Chemistry, 2018, 30(2/3): 190-197.

One major symptom of atherosclerosis and vascular thrombosis is vascular stenosis caused by vascular lesion. Atherosclerosis has become one of the major threats to human health since it can result in severe diseases such as myocardial infarction and cerebral infarction. Therefore,it is of great significance to develop more effective ways to treat vascular stenosis diseases. The wall shear stress at severely stenosed arteries is at least one order of magnitude higher than that in healthy vessels. The significantly increased mechanical force could be used as a trigger signal for effective targeted drug delivery. Shear-responsive drug delivery systems can release their payloads under increased shear stress at the stenosed sites and have minimal side effects on the normal tissues and organs. Therefore, this natural physical trigger is an important and promising approach for targeted drug delivery to cure some cardiovascular diseases, especially vascular stenosis diseases such as atherosclerosis. Shear-responsive drug delivery systems have attracted great interests of researchers. The recent advances on shear-responsive drug delivery systems are reviewed. Various shear-responsive drug delivery systems classified on the basis of design ideas and responsive mechanisms are discussed. At last, the urgent needs, challenges and some personal perspectives of the shear-responsive drug carriers are also presented.
Contents
1 Introduction
2 Mechanism of shear-responsive drug delivery
3 Shear-responsive drug delivery systems
3.1 Aggregates of nanoparticles
3.2 Microcapsules and vesicles
3.3 RBCs-nanoparticles composite carriers
3.4 Supramolecular self-assembly hydrogels
4 Conclusion
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Applications of Halloysite Nanotubes in Separation and Enrichment

Huadong Zhang, Gongke Li*, Yufei Hu*

Progress in Chemistry. 2018, 30(2/3): 198-205. https://doi.org/10.7536/PC170712

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Huadong Zhang, Gongke Li*, Yufei Hu*. Applications of Halloysite Nanotubes in Separation and Enrichment[J]. Progress in Chemistry, 2018, 30(2/3): 198-205.

Halloysite nanotubes(HNTs), as a natural nano-tubular material, with a variety of advantages, such as environmental friendliness, biocompatibility, low cytotoxicity and so on, have been widely used in recent years. As a kind of biocompatible "green" material, because of their low cost and abundant natural resources, HNTs can be used as excellent additives for biomaterials. Besides, nano-tubular structure, surface charge and adsorption properties provide favorable conditions for separation and enrichment of metal ions, dyes, organic compounds and so on. Even better, HNTs and HNTs-derived biomaterials have been used as absorbents to capture circulating tumor cells in recent studies. For better understanding and utilize the nanotube, we introduce the structure and properties of HNTs in detail, and review their application in separation, loading and controlled release of active molecules, etc. in this paper. Finally, we give a conclusion that HNTs own a splendid perspectives on future opportunities and promising applications.
Contents
1 Introduction
2 Structure and properties of halloysite nanotubes
2.1 General Structure
2.2 Main Properties
3 Application of halloysite nanotubes in detection
3.1 Application in detection of heavy metal ions
3.2 Application in detection of compounds
4 Application of halloysite nanotubes in enrichment
4.1 Enrichment of dyes
4.2 Enrichment of functional compounds
4.3 Enrichment of tumor cells
5 Conclusion
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Application of Signal Amplification Technology in the Area of Food Safety Detection

Yangyang Zhou, Jian Zhong, Xiaojun Bian, Gang Liu, Liang Li, Juan Yan

Progress in Chemistry. 2018, 30(2/3): 206-224. https://doi.org/10.7536/PC170708

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Yangyang Zhou, Jian Zhong, Xiaojun Bian, Gang Liu, Liang Li, Juan Yan. Application of Signal Amplification Technology in the Area of Food Safety Detection[J]. Progress in Chemistry, 2018, 30(2/3): 206-224.

Food safety is the foundation of safeguarding human health and improving the quality of human life. At the same time, because of the phased development of our economy and society, food safety issues are increasingly exposed in China. At present, there are many problems in the area of food safety detection, including few detection methods, immature rapid detection methods, especially the absence of ultratrace analytical techniques leading to low detection sensitivity. Signal amplification technology provides a possible way to solve those problems. The combination of signal amplification technology and traditional detection methods is gradually attracting more attention because of its applications in the trace detection of heavy metal, biotoxin/chemical toxins, microorganism and illegal additives in foodstuffs. This review introduces four kinds of signal amplification technology and the applications and development tendency in the area of food safety detection. The emphasis and prospect of the development of signal amplification technology in this area are put forward.
Contents
1 Introduction
2 Signal amplification technology
2.1 Signal amplification technology of biotin-avidin system
2.2 Signal amplification technology of enzymatic catalysis
2.3 Signal amplification technology based on nanomaterials
2.4 Nucleic acid amplification
3 The application of signal amplification technology in the area of food safety detection
3.1 Heavy metals detection
3.2 Biotoxins/chemical toxins detection
3.3 Microorganism detection
3.4 Illegal additives detection
3.5 Detection of genetically modified food
4 Conclusion and outlook
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Synthesis of Fe₃O₄-Based Nanomaterials and Their Application in the Removal of Radionuclides and Heavy Metal Ions

Shanye Yang, Xiangxue Wang, Zhongshan Chen, Qian Li, Benben Wei, Xiangke Wang

Progress in Chemistry. 2018, 30(2/3): 225-242. https://doi.org/10.7536/PC170829

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Shanye Yang, Xiangxue Wang, Zhongshan Chen, Qian Li, Benben Wei, Xiangke Wang. Synthesis of Fe₃O₄-Based Nanomaterials and Their Application in the Removal of Radionuclides and Heavy Metal Ions[J]. Progress in Chemistry, 2018, 30(2/3): 225-242.

Nowadays, Fe₃O₄-based magnetic nanomaterials have shown broad prospects in multidisciplinary areas, especially in the efficient elimination of radionuclides and heavy metal ions from large volumes of aqueous solutions as they have special physicochemical properties, such as large specific surface area, large amounts of oxygen-containing functional groups and active sites, and easy magnetic separation from wastewater. However, the magnetic nanomaterials have some weak points like easy coagulation, and poor dispersibility and chemical stability in the meantime. To overcome these shortcomings, the surface functionalization of Fe₃O₄ nanomaterials with different oxygen-containing functional groups is an efficient method. In this review, the types and properties of Fe₃O₄-based magnetic nanocomposites synthesized by variety surface modification methods are reviewed, and the merits and demerits of these synthetic methods are discussed as well. The types of the Fe₃O₄-based magnetic nanocomposites for the removal of radionuclides or heavy metal ions are classified. And then, their removal ability, advantages and disadvantages in the removal of radionuclides or heavy metal ions on each kind of functionalized magnetic nanomaterials are compared and summarized, and the interaction mechanism of the radionuclides or heavy metal ions with the Fe₃O₄-based magnetic nanocomposites are discussed in detail. The possible application of functionalized magnetic nanocomposites in the efficient removal of radionuclides and heavy metal ions are prospected.
Contents
1 Introduction
2 Synthesis of Fe₃O₄-based nanomaterials
2.1 Solvothermal method
2.2 Coprecipitation method
2.3 Plasma-induced grafting technique
2.4 Other methods
3 Classification of Fe₃O₄-based nanomaterials
3.1 Organics modified magnetic nanomaterials
3.2 Inorganics modified magnetic nanomaterials
4 The applications and mechanisms of Fe₃O₄-based nanomaterials
4.1 Removal of radionuclides
4.2 Removal of heavy metal ions
5 Conclusion
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High Performance and High Power Density Membrane Electrode Assembly for Proton Exchange Membrane Fuel Cells

Bin Chi, Sanying Hou, Guangzhi Liu, Shijun Liao*

Progress in Chemistry. 2018, 30(2/3): 243-251. https://doi.org/10.7536/PC170818

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Bin Chi, Sanying Hou, Guangzhi Liu, Shijun Liao*. High Performance and High Power Density Membrane Electrode Assembly for Proton Exchange Membrane Fuel Cells[J]. Progress in Chemistry, 2018, 30(2/3): 243-251.

Membrane electrode assembly(MEA) is the most important component of proton exchange membrance(PEM) fuel cell and it plays a crucial role for the performance of the fuel cell. High performance and high power density MEA is urgently desired for the commercialization of the fuel cell on a large scale. The conventional MEA is consist of proton exchange membrane, cathode/anode catalyst layer, cathode/anode gas diffusion layer(usually called five in one MEA), and the gas diffusion layer includes gas diffusion material and microporous layer. The performance of MEA depends on two aspects of materials and preparation technology. The preparation technology, the key component material of MEA and the platinum loading have an important influence on the performance and power density of MEA. In recent years, the performance of MEA has been greatly improved with the improvement of the key material(such as catalyst, proton exchange membrane) and the progress of preparation technology, and the volume power density of the Toyota Corporation can achieve as high as 3.2 kW/L. In this paper, the research progress of MEAs with high performance and high power density in recent years are introduced from the main views of MEA's preparation technology, involving the preparation technology of catalyst layer and gas diffusion layer. Meanwhile, the research progress are introduced in two aspects:reducing platinum loading and developing self-humidifying MEAs.
Contents
1 Introduction
2 Research and development of electrode preparation and assembly technology
3 Construction and research of proton exchange membrane and functional layers
3.1 The influence of proton exchange membrane on the performance of membrane electrode
3.2 Construction of catalyst layer
3.3 Construction of gas diffusion layer and microporous layer
4 Low platinum supported membrane electrode assembly with high performance
5 Self-humidifying membrane electrode assembly with high performance
6 Conclusion
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Poly(3, 4-Ethylenedioxythiophene) Based Electrode Materials: Preparation, Modification and Application in Electronic Devices

Di Xu, Hujiang Shen*, Huihui Yuan, Wei Wang, Junjie Xie

Progress in Chemistry. 2018, 30(2/3): 252-271. https://doi.org/10.7536/PC170813

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Di Xu, Hujiang Shen*, Huihui Yuan, Wei Wang, Junjie Xie. Poly(3, 4-Ethylenedioxythiophene) Based Electrode Materials: Preparation, Modification and Application in Electronic Devices[J]. Progress in Chemistry, 2018, 30(2/3): 252-271.

As a kind of low-cost transparent conductive material with good film-forming properties, high thermal stability and tunable conductivity, poly(3,4-ethylenedioxythiophene)(PEDOT) has exhibited attractive applications in various energy conversion and storage devices. However, the performances of these devices are restricted by some drawbacks of PEDOT, mainly its low conductivity. In this review, firstly the basic properties, commonly adopted chemical and physical approaches for synthesizing PEDOT films and several ways to improve their conductivity are briefly introduced. Then the latest research progresses of devices including solar cells, light-emitting diodes, electrochromic devices and supercapacitors assembled by PEDOT and PEDOT-based composited materials are reviewed. In addition to elucidating the roles of PEDOT-based materials played in the aforementioned devices, the design ideas of PEDOT-based materials proposed by researchers for fulfilling the requirements of different devices are introduced in detail. The ideas include designing PEDOT films with specific microstructures, modulating the conductivity, work function, optical transparency and other properties of PEDOT, and coupling PEDOT with other active materials such as carbon materials, metal nanoparticles and metal oxides. Finally, the challenges nowadays in the studying of PEDOT-based electrode materials are pointed out, and the prospect of these materials is proposed.
Contents
1 Introduction
2 Preparation and modification of PEDOT based electrode materials
2.1 Preparation of PEDOT based electrode materials
2.2 Modification of PEDOT based electrode materials
3 Applications of PEDOT based electrode materials
3.1 Solar cells
3.2 Light-emitting diodes
3.3 Electrochromic devices
3.4 Supercapacitors
3.5 Other devices
3.6 Working mechanisms of PEDOT based electrode materials
4 Conclusion
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Nano/Micro Structured Silicon-Based Negative Materials

Shuaijin Wu, Juanyu Yang, Bing Yu, Sheng Fang, Zhaohui Wu, Bimeng Shi

Progress in Chemistry. 2018, 30(2/3): 272-285. https://doi.org/10.7536/PC170740

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Shuaijin Wu, Juanyu Yang, Bing Yu, Sheng Fang, Zhaohui Wu, Bimeng Shi. Nano/Micro Structured Silicon-Based Negative Materials[J]. Progress in Chemistry, 2018, 30(2/3): 272-285.

Due to high theoretical specific capacity(4200 mAh/g), silicon is considered as one of the most promising materials for lithium-ion battery negative electrodes. Nano-silicon negative materials can effectively avoid the pulverization of the particles during cycling and have shorter Li⁺ and electron transport paths. The electrochemical performance of the corresponding electrodes is significantly improved compared to that of the micro-sized silicon based electrodes. However, the specific surface area of nano-materials is too large while the tap density is low, that limits the application of nano-silicon negative materials in practical production. In recent years, the strategy of using nano-structured silicon materials as building units to construct nano/micro structured silicon-based negative materials has been widely studied. The development of nano/micro structured silicon-based materials for lithium-ion batteries is reviewed. The selection and structural design elements of nano-sized primary particles as well as micro-sized secondary particles are summarized. The physical and electrochemical properties of representative nano/micro structured silicon-based materials are also introduced. Moreover, an optimized design of the nano/micro structured silicon-based material structure and electrode structure is proposed. Finally, challenges and problems existing in nano/micro structured silicon-based negative materials are briefly analyzed and prospects of them as negative materials for lithium-ion batteries are discussed.
Contents
1 Introduction
2 Structure of primary particles in nano/micro structured silicon-based negative materials
2.1 Primary particles of nano-silicon
2.2 Void space in primary particles
3 Design elements of secondary particles in nano/micro structured silicon-based negative materials
3.1 Void space in secondary particles
3.2 Surface coating of secondary particles
3.3 Size optimization of secondary particles
4 Conclusion and outlook
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The Classification of Electrofluorochromism Materials and Color Change Mechanisms

Jin Du, Rui Liao, Xinglin Zhang, Huibin Sun, Wei Huang

Progress in Chemistry. 2018, 30(2/3): 286-294. https://doi.org/10.7536/PC170729

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Jin Du, Rui Liao, Xinglin Zhang, Huibin Sun, Wei Huang. The Classification of Electrofluorochromism Materials and Color Change Mechanisms[J]. Progress in Chemistry, 2018, 30(2/3): 286-294.

Electrofluorochromism(EFC) refers to a phenomenon that luminescence color of materials can be tuned by the application of an extra electric field, of which the fluorescence is generally switched between ON/OFF or different colors under an electrical stimulus. These materials have received increasing attention because of their extensive applications in ion sensing, information display, bioanalysis, optical imaging, information storage and so on. It is rather remarkable that EFC materials are considered to be prospective smart materials because they can convert electrical signals to more intuitive visual signals. Herein recent research progress in electrofluorochromism field are reviewed, which mainly elaborates the main EFC materials including dyads, fluorophores and polymers(including conjugated polymers) and their emission-color changing mechanism. Structure features of those EFC materials and their functional realization principles in specific applications are highlighted. Those materials have high luminescence contrast, fast response rate, long term stability and exhibit multicolor emissions switching of fluorescence and a number of advantages and have found applications in organic optoelectronic devices field. At the end of the paper, a brief overview of the future directions of this research field is also presented.
Contents
1 Introduction
2 Electrofluorochromism mechanism
3 Classification of electrofluorochromism materials
3.1 Dyads
3.2 Electroswitchable fluorophores
3.3 Fluorescent conjugated polymers
4 Conclusion
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Layered Double Hydroxides/Polymer Nanocomposites

Lu Jia, Jianzhong Ma, Dangge Gao, Bin Lv

Progress in Chemistry. 2018, 30(2/3): 295-303. https://doi.org/10.7536/PC170738

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Lu Jia, Jianzhong Ma, Dangge Gao, Bin Lv. Layered Double Hydroxides/Polymer Nanocomposites[J]. Progress in Chemistry, 2018, 30(2/3): 295-303.

Layered double hydroxides(LDH) are a class of ionic lamellar compounds made up of positively charged layered hydroxides with an interlayer region containing charge compensating anions. LDH can be introduced as precursor into polymer matrix to prepare LDH/polymer nanocomposites. The properties of the polymer matrix can be strengthened as the addition of LDH, and nanocomposites have shown excellent performances and development potentials in many fields. In this paper, the preparation methods of LDH/polymer nanocomposites are reviewed, such as blending, intercalation, in-situ, exfoliation/adsorption, layer-by-layer(LBL) assembly. Then the applications of the LDH/polymer nanocomposites are also summarized, such as flame retardant, gas barrier, infrared absorption, controlled release, adsorption. Finally, development trends of research direction and research field of the LDH/polymer nanocomposites are prospected.
Contents
1 Introduction
2 Structure and properties of LDH
2.1 Structure of LDH
2.2 Properties of LDH
3 Preparation methods of LDH/polymer nanocomposite
3.1 Blending method
3.2 Intercalation method
3.3 In-situ method
3.4 Exfoliation/adsorption method
3.5 Reconstruction method
3.6 Layer-by-layer(LbL) assembly
3.7 Spin-coating method
4 The applications of LDH/polymer nanocomposite
4.1 Flame retardant material
4.2 Ultraviolet and infrared absorption material
4.3 Biomedical material
4.4 Water treatment material
4.5 Gas barrier material
4.6 Luminescent material
4.7 Energy storage materials
5 Conclusion
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Solvent Effects on Reaction-Controlled Phase-Transfer Catalysis

Jinshuai Zhang, Fengli Yu, Bing Yuan, Congxia Xie, Shitao Yu

Progress in Chemistry. 2018, 30(2/3): 304-313. https://doi.org/10.7536/PC170903

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Jinshuai Zhang, Fengli Yu, Bing Yuan, Congxia Xie, Shitao Yu. Solvent Effects on Reaction-Controlled Phase-Transfer Catalysis[J]. Progress in Chemistry, 2018, 30(2/3): 304-313.

The paper mainly discusses the effects of solvents on reaction-controlled phase-transfer catalysis which possesses the advantages of both homogeneous and heterogeneous catalysis. The reaction-controlled phase-transfer catalysis system not only realizes the catalyst recovery from the product over homogeneous catalysis but also avoids the low reaction rate, long reaction time, leaching of the active species and low selectivity in heterogeneous catalysis. For a reaction-controlled phase-transfer catalyt,its characteristic is affected not only by its composition including anion and cation but also by the used solvent during the reaction. A suitable solvent can increase the conversion rate of the substrate and the yield of product, and benefits the recovery of the catalyst. The effects of solvents on reaction-controlled phase-transfer catalysis systems including epoxidation of olefins, oxidation of alcohols to prepare aldehydes or ketones, esterification, oxidative cleavage of olefins or alcohols to prepare dicarboxylic acid, acetalation, oxidative desulfurization, hydroxylation reaction and catalytic reduction by Se, are presented in this paper. Finally, some possible measures to overcome the shortcomings in the present catalytic system are put forward and the future research prospects are discussed.
Contents
1 Introduction
2 Principle of the reaction-controlled phase-transfer catalysis
3 Effects of solvents on reaction-controlled phase-transfer catalysis
3.1 Epoxidation of olefins
3.2 Oxidation of alcohols to prepare aldehydes or ketones
3.3 Esterification
3.4 Oxidative cleavage of olefins or alcohols to prepare dicarboxylic acid
3.5 Acetalation
3.6 Oxidative desulfurization
3.7 Hydroxylation reaction
3.8 Catalytic reduction by Se
4 Conclusion and outlook
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Preparation of 5-Hydroxymethylfurfural from Glucose

Yunchao Feng, Miao Zuo, Xianhai Zeng*, Yong Sun, Xing Tang, Lu Lin*

Progress in Chemistry. 2018, 30(2/3): 314-324. https://doi.org/10.7536/PC171007

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Yunchao Feng, Miao Zuo, Xianhai Zeng*, Yong Sun, Xing Tang, Lu Lin*. Preparation of 5-Hydroxymethylfurfural from Glucose[J]. Progress in Chemistry, 2018, 30(2/3): 314-324.

Biomass derived 5-hydroxymethylfurfural(HMF) has emerged as an important and versatile platform compound containing furan, hydroxymethyl and aldehyde groups to realize the goal for production of several high value added products, such as levulinic acid, 2,5-dimethylfuran, 2,5-furan dicarboxylic acid, 2,5-furan dimethanol, γ-valerolalactone, 5-aminolevulinic acid, which could be served as biofuels, fuel additives, bulk polymer monomers, chemicals and pharmaceuticals. Moreover, glucose is a bulk six-carbon monosaccharide from cellulose by hydrolyzation, and the preparation of HMF from glucose is one of the most effective and promising routes to maximize the utilization of sustainable biomass resources. In this review, focus is primarily put on the recent advances of systematically characterization on catalysts of HMF production from glucose for its activity, stability and application prospect. Then, the various solvent systems used in HMF production in recent years, such as single-phase solvents, biphasic solvents, ionic liquids and deep eutectic solvents, are reviewed and discussed. Finally, the future research directions such as an innovative catalyst, deep eutectic sol-vents are proposed, which might be helpful for researchers.
Contents
1 Introduction
2 Catalysts
2.1 Homogeneous catalysts
2.2 Heterogeneous catalysts
3 Reaction solvents
3.1 Single-phase solvents
3.2 Biphasic solvents
3.3 Ionic liquids
3.4 Deep eutectic solvents
4 Conclusion

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