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Progress in Chemistry 2011, No.12 Previous issue Next issue

In this issue:

Mini Accounts
Au-Chin Tang and Chinese Theoretical Chemistry
Jiang Yuansheng
2011, 23 (12): 2399-2404 |
Published: 24 December 2011
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Abstract
This essay briefly reviews the scientific career of Prof. Au-Chin Tang, showing his academic ideology and teaching style. In the middle of the last century, Prof. Tang trained talents independently and started to perform scientific researches. He founded the field of theoretical chemistry for China and made it prosperous. He attached particular importance to the teaching, and considered the learning of related courses as the necessary procedure for the scientists to lay a good foundation, open intelligence, cultivate interests and finally start researches. Therefore, he always taught systematically when recruiting new graduate students or holding workshops for high-level personnel. When setting up research projects, Prof. Tang paid special attention to the development of new theories and new methodologies and he advocated “big” and “difficult” projects. As for the recruitment and training for scientific employees, Prof. Tang welcomed both the persons with solid mathematical and physical foundations and the general chemical staffs. He intended to improve their theoretical levels and enhance their consensus through the teaching courses.
The Pioneer of Coordination Chemistry in China ——Dai Anbang
Luo Qinhui
2011, 23 (12): 2405-2411 |
Published: 24 December 2011
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Abstract
Professor Anbang Dai (1901—1999) was a renowned inorganic chemist, chemical educator, and the pioneer and founder of coordination chemistry. In his 70 years of career he fostered numerous high quality scientists and chemical educators, with his influential invention of “Eight Principles of Heuristic Methode of Education”, and “The Theory of Comprehensive Education”. He was the first to open up the new field of coordination chemistry in China, established the Institute of Coordination Chemistry, and the State Key Laboratory of Coordination Chemistry of China. He advocated the international academic exchanges, promoted the academic growth of younger generation of scientists, advanced the international reputation and standing of the China’s Inorganic and Coordination Chemistry, and was renowned as the pioneer and founder of Coordination Chemistry in China.He advocated the idea that “basic research should serve the advancement of scientific development and practical problem solving, should pave the foundation for industrial applications”. “Solve practical problems, advance the science” is his academic thought.“Advocate solid work”,“uphold definitude”,“seek truth”,“blaze new trials”and “open-minded”should be moral standard of scientific researchers. He led by examples, working hard to find and solve the problems of great application potentials. He set up high moral standard and dedicated his whole life to science and teaching. His great contribution was recognized by more than 20 national awards, and was the recipient of the honor of “Model Worker” by Jiangsu Province. Contents 1 Introduction 2 Thedifficultpathofpioneering 2.1 Start up the discipline of coordination chemistry and foster coordination chemists 2.2 Establish the experimentbase 2.3 Advocate the academic exchange 3 Academic thoughts 3.1 Relationship between basic research and practical applications 3.2 Relationship between coordination chemistry and other sciences 4 Noble scientific spirit and character
Scientific Spirit and Academic Ideology of Professor Dai Anbang
Meng Qingjin
2011, 23 (12): 2412-2416 |
Published: 24 December 2011
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Abstract
Professor Dai Anbang is one of the initiators of Chinese chemical society and is the founder of the first Chemistry journal in Chinese(named HUAXUE) in China.As the Chief Editor, he was in charge of the journal for 17 years.He devoted his whole life to chemistry of China and has significant contribution to development and prosperity of Chemistry, especially inorganic chemistry of China. Professor Dai believes chemistry is the science for the benefit of mankind. So as chemists, they should have a remarkably keen insight into science and the devotion to chemists.Also they must be of good moral character and have the team-work spirit. Following the advance of science and technology, professor Dai Anbang engaged in various research areas such as colloid chemistry, heteropolyacid, polybase,chemical simulation of biological nitrogen fixation, antitumor platinum compounds,and study on new transition metal complexes. He founded the Coordination Chemistry Institute and State Key Laboratory of Coordination Chemistry which are playing important role in the progress of coordination chemistry in China. Contents 1 Introduction 2 Devotion of his whole life to people and chemistry development of our country 3 Tireless diligence in development of chemistry in China 4 A Fruitful chemist 5 Throw his heart and soul into his work of bringing up a new generation 6 A chemist of highest virtue and being persistent model
Review
Molecular Design and XAFS Characterization of Active Centers of Solid-State Catalysts
Long Jinlin, Gu Quan, Zhang Zizhong, Wang Xuxu
2011, 23 (12): 2417-2441 |
Published: 24 December 2011
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Abstract
Surface organometallic chemistry (SOMC) is an effective route to design and prepare surface metal species with well-defined composition and molecular structure. Synchrotron radiation X-ray absorption fine structure spectroscopy (XAFS) technique is currently a powerful tool to characterize geometrical structure of active sites of solid-state catalysts. Their combination provided a method to design and construct in molecular level catalytic active centres, which was established to be one of the important goals in the field of heterogeneous catalysis. This article reviews the recent advancements in construction of single-site active metallic centre in the channels and cages of zeolite molecular sieves by the SOMC method and in characterizing geometrical structure of active sites of heterogeneous catalytic materials with XAFS, the physical fundament, experimental methods, and data analysis of XAFS technique and its merits and demerits in characterization of catalytic materials, the chemical fundament of SOMC. Single-site mononuclear or polynuclear Ti, Cu, and Fe active centers were successfully constructed in molecular level in the channels and cages of zeolite molecular sieves by the SOMC method. Their micro-structures were characterized in detail with XAFS combined other spectroscopic techniques and their catalytic properties were evaluated. The catalytic nature of these metallic centers was elucidated by establishing the inherent relationship among structure, activity, and composition. The study results revealed in molecular level the pyrolysis mechanism of Cu 2 over the MCM-41 surface, and showed a novel route to prepare CuO, Cu2O and Cu(0)/MCM-41 materials with well-defined composition and micro-structure, clarifying the hydroxylation mechanism of phenol over copper active sites and the nuclearity-dependent catalytic function of iron-oxo species; based on the binuclear diiron clusters with well-defined structure and composition constructed in molecular level by SOMC, a novel selective catalytic reduction pathway for the iron-catalyzed NO-HC reaction was proposed; a novel concept of “surface photoexcited catalysis model” for Fe, Ti contained zeolite molecular sieve photocatalysts and N-doped TiO2 visible-light photocatalyst was proposed in terms of the local structure of photoactive species identified clearly by XAFS technique. Contents 1 Introduction 2 Chemical fundament of surface organometallic chemistry 3 Basic fundament of XAFS 3.1 Physical fundament of XAFS 3.2 Data analysis of XAFS 3.3 Main experimental methods of XAFS and its merits and demerits in characterization of catalytic materials 4 Chemical construction and characterization of catalytic active centers of solid-state catalysts 4.1 Molecular construction of photoactive Ti centers on the surface of MCM-41 molecular sieves 4.2 Molecular construction of highly-dispersed copper active centers on the surface of MCM-41 molecular sieves 4.3 Spectroscopic identification of photoactive centers of HZSM-5 zeolite with trace iron impurity 4.4 Molecular construction of iron active centers confined in the supercages of HY zeolite 4.5 Brief summary on the construction of active centers with surface organometallic chemistry 4.6 Identifying the photoactive N species of N-doped TiO2 visible-iight photocatalyst with NEXAFS 5 Conclusions and outlook
Application Studies of Ionic Liquid Based Microemulsions
Meng Yali, Li Zhen, Chen Jing, Xia Chungu
2011, 23 (12): 2442-2456 |
Published: 24 December 2011
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Abstract
Room temperature ionic liquids (RTILs) are being increasingly studied as environmentally benign media or catalysts for chemical reactions and new-style functional materials with promising applications in many fields, due to their unique and attractive physicochemical properties including negligible vapor pressure, nonflammability, high chemical/thermal stability, low toxicity and favorable conductivity. In recent years, great attention has been paid to ionic liquid based microemulsions due to their potential application prospects in biology, pharmaceutical, catalysis and material preparation. The recent studies in ionic liquid based microemulsions wherein ionic liquid is substituted for the oil component, for the polar or water component and for the surfactant component are reviewed in this paper. A series of influencing factors in the properties of ionic liquid based microemulsions are summarized, such as water, organic solvent, polymer, cosurfactant and temperature. The hot applications of ionic liquid based microemulsions in synthesis of nano-materials, biocatalysis, and organic reactions are also summarized. Foe enzyme in IL microemulsions, the improvement in activity is attributed to the safe environment created by IL-based reaction systems, in which enzyme molecules are entraped into aqueous microdroplets formed in W/IL microemulsions. The IL/O microemulsion systems are widely used as a medium to prepare porous or hollow nano materials. Contents 1 Introduction 2 Ionic liquid/oil/surfactant microemulsion system 2.1 Phase behavior and microstructure 2.2 Applications 3 Ionic liquid/water/surfactant microemulsion system 3.1 Phase behavior and microstructure 3.2 Applications 4 Other types of ionic liquid microemulsions 5 Conclusions and outlook
Construction and Application of Wettability Gradient Surfaces
Zhang Yong, Pi Pihui, Wen Xiufang, Zheng Dafeng, Cai Zhiqi, Cheng Jiang
2011, 23 (12): 2457-2465 |
Published: 24 December 2011
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Abstract
A gradient wettability surface is the one that displays a gradual change in its surface tension along its length. The wettability of solid surfaces is governed by both the surface chemical composition and the geometrical microstructure. In this paper, two ways to fabricate the wettability gradient surfaces, controlling the chemical composition or surface morphology along the surfaces are introduced,and the application of the functional wettability surfaces, such as droplet moving, micro-fluid flow, and biosorption has been presented. The dominant force responsible for drop movement is the unbalanced Young force that results from the difference in wettability between the front and backsides of the drop, and the contact angle hysteresis has a reduced effect on the droplet moving. Generally speaking, the higher the gradient, the faster the droplet moved. The wettability gradient surfaces are also used for control of liquids flow on submillimeter scales. In addition, surface wettability is found to play an important role in biosorption and the difference in protein adsorption behavior can be attributed mainly to the wettability gradient and the type of protein. Problems existed in this research field and prospects of wettability gradient surfaces are also discussed briefly. Contents 1 Introduction 2 Preparation of the wettability gradient surfaces 2.1 Surface-chemical gradients 2.2 Morphological gradients 3 Application of the wettability gradient surfaces 3.1 Droplet moving 3.2 Micro-fluid flow 3.3 Biosorption 4 Conclusion
Preparation Methods and Application of Heterogeneous Catalysts for Hydrosilylation
Bai Ying, Peng Jiajian, Li Jiayun, Lai Guoqiao, Li Xiaonian
2011, 23 (12): 2466-2477 |
Published: 24 December 2011
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Abstract
Hydrosilylation is one of the most important reactions in organo silicone chemistry, which can prepare functional silanes and silicon polymers. Since the first report in 1947, a lot of literatures relating to hydrosilylation reaction have been published. This review summarizes the novel progress in the synthesis methods and application of heterogeneous catalysts for hydrosilylation in the last decade. A variety of heterogeneous catalysts have been prepared by using a series of carriers such as active carbon, silica and zeolite e.g. supported platinum, rhodium and gold catalyst,etc. The synthesis methods of organic and inorganic heterozygous carrier loaded transition metals as heterogeneous catalysts and application in the hydrosilylation are introduced emphatically. The catalytic performance of these catalysts and the catalytic mechanism are summarized and discussed. Some new types of polymers with functional groups have been synthesized and used to immobilize metals, those carving polymer particle catalysts always show interesting performance for hydrosilylation processes. Ionic liquid supported rhodium or ruthenium complexes as a new type of catalysts have been synthesized and applied in the hydrosilylation of alkenes or alkynes with excellent catalytic activity and selectivity as well as recycle performance. The development trend of supported catalysts for hydrosilylation reaction is also described. Contents 1 Introduction 2 Inorganic carrier loaded metal catalysts and their applications in catalytic hydrosilylation 3 Preparation of inorganic carrier functionalized with organic group loaded metal catalysts and their catalytic properties 3.1 Inorganic carrier functionalized with natural organic polymer loaded metal catalysts 3.2 Inorganic carrier functionalized with silane loaded metal catalysts 4 Functional polymer loaded metal catalysts 5 Ionic liquid loaded metal catalysts 6 Conclusions and perspectives
Zinc Fluorescent Sensors with Receptors Derived from DPA
Ding Yubin, Zhu Weihong, Xie Yongshu
2011, 23 (12): 2478-2488 |
Published: 24 December 2011
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Abstract
Zinc ion plays important roles in many biological systems. Its analysis and detection are highly valuable in clinical diagnosis and therapeutic monitoring. Fluoresecent zinc sensors have attracted extensive interest due to their simplicity and high sensitivity. A typical fluorescent sensor contains a receptor linked to a fluorophore directly or through a spacer, which translates the recognition event into the fluorescence signal. As the action centre of the sensor, the receptor unit plays an important role in the whole recognition process. Since its first incorporation to fluorescein in 1996, di-2-picolylamine (DPA) has been used as the most popular receptor to construct Zn2+ sensors. In this review, we briefly summarized various kinds of zinc sensors with receptors derived from DPA, and discussed the synthesis and the sensing mechanisms of the sensors. In the last part of the paper, other receptors that might be incorporated into Zn2+ sensors are also briefly introduced. Contents 1 Introduction 2 Mechanism of Zn2+ sensing 3 Di-2-picolylamine (DPA) as receptor 3.1 BODIPY as fluorophore 3.2 Quinoline and its derivatives as fluorophore 3.3 Naphthalimide as fluorophore 3.4 Anthracene as fluorophore 3.5 Cyanine dyes as fluorophore 3.6 Fluorescein as fluorophore 3.7 NBD as fluorophore 3.8 Coumarin and its derivatives as fluorophore 3.9 Other fluorophores 4 Other receptors in Zn2+ sensors 5 Summary and outlook
Ordered Metal Nanoshell Materials
Rao Yanying, Qian Weiping
2011, 23 (12): 2489-2497 |
Published: 24 December 2011
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Abstract
Ordered metal nanostructures such as ordered hollow nanoshells and macroporous nanostructures have attracted great attentions because they have both metal and photonic crystal properties. In this review, we first introduce the methods and main processes of fabricating these metal structures. The fabrication processes mainly include the assembling of template, the deposition of metal shell and the removing of template. All these three processes are reviewed respectively. Furthermore, the ordered metal nanostructures possess unique properties due to their small size, low dimension, and interactions between neighboring units, which have been used as substrates of surface-enhanced Raman scattering (SERS), high efficiency catalyst, immunoassay and nanosensors, etc. Finally, the prospects of the ordered metal nanostructures along with the existed problems are presented. Contents 1 Introduction 2 Preparation of ordered metal nanoshell materials 2.1 Assembly of colloidal crystal template 2.2 Fabrication of metal nonoshells 2.3 Remove of the colloidal crystal template 3 Applications of the ordered metal nanoshell materials 3.1 Surface-enhanced Raman scattering (SERS) 3.2 Catalysis 3.3 Nanosensors 4 Conclusions
Synthesis of Hierarchical Semiconductor/Semiconductor Composite Nanostructures
Li Tao, Chen Deliang
2011, 23 (12): 2498-2509 |
Published: 24 December 2011
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Abstract
Transition-metal oxides, Ⅲ-Ⅴ and Ⅱ-Ⅵ semiconductors have been widely applied in optical, electrical, solar-transfer and catalytic fields because of their unique properties. The synthesis and property control of these semiconductor nanomaterials have been one of the hot topics in advanced materials. Multifunction and high-efficiency are the basic requirements for the design of novel semiconducting materials. Multicomponents and hierarchical structures are the efficient approach to fulfill the above requirements, not only it is helpful to modulate the optic, electrical and catalytic properties by tuning the energy band structures, but also helpful to overcome the agglomeration problem via the steric effect of “house of cards” formed by anisotropic low-dimensional semiconductor nanostructures. Firstly, this paper introduces the concept and classification of hierarchical semiconductor composite nanostructures. Secondly, it reviews the synthesis of some typical hierarchical semiconductor composite nanostructures, with emphases on synthetic methods of wet-chemical, vapor growth and electrospinning processes for the construction of hierarchical semiconductor composite nanostructures. Thirdly, the newly developed hierarchical semiconductor composite nanostructures on the basis of graphene and its functional derivatives are also reviewed. Finally, the future research trends in the fields of hierarchical composite nanostructures are discussed. Contents 1 Introduction 2 Typical classifications of hierarchical semiconductor composite nanostructures 3 Synthesis of typical hierarchical semiconductor composite nanostructures 3.1 Wet-chemical methods 3.2 Vapor growth methods 3.3 Electrospinning methods 4 Synthesis of novel hierarchical semiconductor composite nanostructures based on graphene 5 Conclusions and Outlook
Biosynthesis of Inorganic Nanoparticles
Liu Chuang, Wang Yuangui, Geng Jiaqing, Jiang Zhongyi, Yang Dong
2011, 23 (12): 2510-2521 |
Published: 24 December 2011
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Abstract
Biosynthesis of inorganic nanoparticles is to synthesize inorganic nanoparticles at ambient temperature and pressure without utilizing hazardous agents and generating poisonous by-products by using organisms such as bacteria, actinomyces, fungi or higher plants in nature. It not only is a green and environmentally friendly protocol to synthesize inorganic nanoparticles, but also contributes to understand the biomineralization mechanism, and theoretically guides the design and synthesis of advanced functional materials. Therefore, it has recently attracted widely attention from researchers in the fields of chemistry, biology and materials science. In this review, we present the current development of inorganic nanoparticles synthesized by organisms according to material types including metals, sulphides and oxides, and the biosynthesis mechanism is particularly discussed. It indicates that biosynthesized nanoparticles have many advantages, such as narrow size distribution, high stability, good biocompatibility, high productivity and low cost, etc. In order to resist to heavy metal ions with high concentration, organisms often change their toxicity and solubility via a series of biochemical processes including bioadsorption, bioreduction or precipitation, bioaccumulation or effusion, etc., generating inorganic nanoparticles simultaneously. After the formation of inorganic nanoparticles, these organisms are still able to proliferate, indicating that they can be used to produce nanoparticles as biological factories. However, the physiological process involving in the biosynthesis of inorganic nanoparticles is intricate very much, which is also different among different organisms. Therefore, it needs further research for the elucidation of biosynthesis mechanism, extension of material type and morphology, post-treatment and application of these nanoparticles. Contents 1 Introduction 2 Metal nanoparticles 3 Metal sulphide nanoparticles 4 Metal oxide nanoparticles 5 Biosynthesis mechanism 6 Conclusions and outlook
Classification, Fabrication Methods and Applications of Inorganic Hollow Spheres
Xie Fei, Qi Meizhou, Li Wenjiang, Wang Kai, Yu Zhenyun, Liu Bin
2011, 23 (12): 2522-2533 |
Published: 24 December 2011
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Abstract
Hollow sphere is an important branch of the shell structure materials. Compared with solid sphere, the hollow sphere possesses lots of unique and superior physical and chemical properties, such as lower density, higher specific surface areas, better stability and permeability. Among them, inorganic hollow spheres have unique advantages such as high temperature endurance and aging resistance compared with organic hollow spheres. Thus, inorganic hollow spheres have been attracting more attention in recent years, which have been widely applied in numerous fields such as catalysis, batteries and medicine. Based on our previous study in the field of inorganic oxide hollow spheres and the predecessors’ work, the development of fabrication of inorganic hollow spheres in the last five years is reviewed. Here, we divide the materials composing shell of hollow spherical structure into five classifications, including inorganic oxides, sulfides and selenides, metallic elementary substances, composites and other inorganic materials. Meanwhile, the fabrication methods could be grouped into four major categories involving hard template methods, soft template methods, sacrificial template methods and template-free methods, each of those major categories is further subdivided. The advantages and weaknesses of those four categories are also reviewed. Moreover, some important application fields of inorganic hollow spheres are also summarized, such as in the fields of medicine, batteries, gas sensors and photocatalysis. Furthermore, the research foreground of inorganic hollow spheres is prospected briefly. Contents 1 Introduction 2 Classifications of inorganic hollow spheres 2.1 Inorganic oxides as shell 2.2 Sulfides and selenides as shell 2.3 Metallic elementary substances as shell 2.4 Composites as shell 2.5 Other inorganic materials as shell 3 Preparation methods of inorganic hollow spheres 3.1 Hard template methods 3.2 Soft template methods 3.3 Sacrificial template methods 3.4 Template-free methods 4 Application fields of inorganic hollow spheres 4.1 Applications in the field of medicine 4.2 Applications in the field of batteries 4.3 Applications in the field of gas sensors 4.4 Applications in the field of photocatalysis 5 Prospects
Synthesis of Organometallic Coordination Polymers
Qin Wangping, Liang Guodong, Zhu Fangming, Wu Qing
2011, 23 (12): 2534-2540 |
Published: 24 December 2011
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Abstract
Organometallic coordination polymers (metallopolymers) combining the advantages of both metals and polymers attracted increasing interests recently due to their widely potential applications in engineering sectors such as clean energy, smart materials, high-performanced devices and so on. The physical properties and performance of this kind of materials are strongly dependent on their chain structures, and so determined by synthesis approaches adopted. The main progresses made in the field of metallopolymer synthesis during the last decade are reviewed. This paper is organized in terms of sequence of the formation of polymer chains and the incorporation of metal centers, including synthesis of polymer chains first and subsequent incorporation of metal complexes into the polymers, synthesis of metal-containing monomers followed by polymerization of the reactable monomers, and one-pot synthesis of metallopolymers, saying the formation of polymer and the incorporation of metal centers are fulfilled simultaneously. Synthesis approaches to metallopolymers with various topological structures such as lineal, comb (or grafting), star, dendronized and so on in each catalogue are exemplified in details. The advantages and disadvantages of each synthesis approach are discussed. We put emphasis on the correlation among synthesis approaches, topological structure and their performances of metallopolymers. Finally, the further work needed to do and development trends in the field of metallopolymer synthesis are proposed. Contents 1 Introduction 2 Incorporation methods of metal centers into polymers 3 Synthesis of metallopolymer 3.1 Synthesis of polymer and subsequent incorpora-tion of metal complexes 3.2 Synthesis of metal-containing monomers followed by polymerization 3.3 One-pot synthesis of metallopolymers 4 Conclusions and outlook
Thermoresponsive Unimolecular Polymeric Micelles
Luo Shizhong, Han Mengcheng, Cao Yuehui, Ling Congxiang
2011, 23 (12): 2541-2549 |
Published: 24 December 2011
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Abstract
Unimolecular polymeric micelles consist of a core-shell architecture that resembles conventional micellar structures but with significant thermodynamic stability in aqueous solutions. The core or shell of the micelles consisting of temperature-sensitive polymers can form the thermoresponsive unimolecular polymeric micelles which have attracted much interest recently due to their unique structures and potential applications. There are more and more papers present the synthesis and performance of the navel micelles in recent years. This review details the types, preparation as well as application of the thermorsensitve unimolecular polymeric micelles. The summary for the phase transition behavior of the micelles based on hyperbranched polymers has been represented here. Furthermore, the future development trend of thermoresponsive unimolecular polymeric micelles is also discussed. Contents 1 Introduction 2 Types of thermoresponsive unimolecular polymeric micelles 2.1 Cross-linked micelles 2.2 Multiarm star-like unimolecular polymeric micelles 3 Preparation of thermoresponsive unimolecular polymeric micelles 3.1 Self-assembly micelles 3.2 Unimolecular polymeric micelles based on hyperbranched polymers 3.3 Inorganic template method 4 Phase transition behavior of thermoresponsive unimolecular polymeric micelles 4.1 Unimolecular polymeric micelles with a hydropho-bic hyperbranched core 4.2 Unimolecular polymeric micelles with a hydro-philic hyperbranched core 5 Application of thermoresponsive unimolecular polymeric micelles 5.1 Drug delivery 5.2 Non-viral gene vectors 5.3 Thermoresponsive hybrid nanoparticles 6 Conclusion and outlook
Preparation and Applications of Ordered and Gradient Scaffolds in Regenerative Medicine
Xing Dongming, Ma Lie, Gao Changyou
2011, 23 (12): 2550-2559 |
Published: 24 December 2011
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Abstract
The tissue loss or organ failure, resulting from trauma or diseases, is a major concern in human healthcare. The recent development of regenerative medicine by combing the cells and degradable scaffolds offers a unique pathway to recreate tissues and organs with high bioactivity and biomimetic structures. This article reviews the state-of-art of the ordered and gradient scaffolds in terms of their preparation methods and biological performance. In contrast with the homogeneous counterpart, the ordered scaffolds facilitate delivery of nutrients and metabolites, and can guide cell growth, distribution and new tissue formation in vitro, leading to construction of 3D-engineered tissues with ordered cells and extracellular matrix. On the other hand, the gradient cues (e.g. physical, chemical and biological properties) incorporated into the 3D scaffolds can create a microenvironment governing the cell behaviors such as migration rate and direction as well as differentiation, and thereby guiding the tissue regeneration. The methods of phase separation, electrospinning, injection and centrifugation are usually employed to prepare the ordered and gradient 2D substrate and 3D scaffolds. The biological performance of these scaffolds is discussed. Wish such a structure mimicking the native tissue-like environment, the scaffolds are expected to show exceptional advantages in regeneration of tissues and organs of better functions and structures. Contents 1 Introduction 2 Ordered regenerative medicine materials and their preparation 2.1 Phase separation/directional freeze-drying 2.2 Electrospinning 2.3 Other methods 3 Gradient regenerative medicine materials and their preparation 3.1 Cell migration and gradient surface 3.2 Preparation of 3D gradient medical material 4 Conclusion and perspectives
Research Progresses in Self-Healing Polymer Materials
Qi Hengzhi, Zhao Yunhui, Zhu Kongying, Yuan Xiaoyan
2011, 23 (12): 2560-2567 |
Published: 24 December 2011
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Abstract
Self-healing was put forward to cope with slight damages in polymer materials which are difficult to detect. Research progress in self-healing polymer materials in recent years is summarized in this paper. According to the healing agents employing or not, self-healing methods in polymer materials or polymer composites can be classified into two categories, namely, extrinsic and intrinsic. The extrinsic self-healing polymer materials accomplish self-healing with the aid of self-healing agents incorporated in microcapsules or hollow-fibers. The self-healing agents are released when microcapsules or hollow-fibers are attacked by microcracks, and then reactions involved self-healing take place and the crack surfaces are bonded together to achieve self-healing. This method performs easily and efficiently, but the self-healing process can not be repeated and the candidates of self-healing agents are limited. On the other hand, the intrinsic self-healing polymers bring into effect with the help of Diels-Alder reactions, dynamic covalent chemistry, disulfide-bond reactions, supramolecular structure with hydrogen-bond, π-π stacking, ionomes and so on. Furthermore, the chemical reactions related to these special molecular structures are reversible. Though the preparation of intrinsic self-healing polymers is more complicated, the self-healing process is efficient in repeatable manner. So, the durability of polymer materials can be extended. This paper reviews mainly on the specialities and applications of the above self-healing methods in polymer materials. Contents 1 Introduction 2 Extrinsic self-healing 2.1 Microcapsules 2.2 Hollow-fibers 3 Intrinsic self-healing 3.1 Diels-Alder reactions 3.2 Dynamic covalent chemistry 3.3 Disulfide-bond self-healing 3.4 Hydrogen-bond self-healing 3.5 π-π stacking 3.6 Ionomers 3.7 Other methods 4 Conclusion and outlook
Preparation and Application of Fiber-Optic Sensors Based on Layer-by-Layer Self-Assembly Multilayers
Yin Mingjie, An Quanfu, Qian Jinwen, Zhang Aping
2011, 23 (12): 2568-2575 |
Published: 24 December 2011
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Abstract
During last several decades, optical fiber has been applied in many disciplines and areas. Among its kinds of applications, optical fiber sensors have become an interesting research project due to the advantages of optical fiber, such as immunity to electromagnetic interferences, capability of remote measurements, multiplexed detection, small size and low weight and so on. Optical fiber has been applied in fiber-optic sensors based on polyelectrolyte layer-by-layer (LbL) self-assembly multilayers have become into a hot research field since it was reported in 2000. It has widely application in measuring trace substances. In this paper, layer-by-layer self-assembly polyelectrolytes on the surface of optical fibers as well as test of fiber-optic sensors are introduced. The fiber-optic structures, assembly materials, detection principle and performance of different fiber-optic sensors based on multilayers nanocoating are also summarized. Particularly, the preparation, test and application of fiber-optic pH sensors, fiber-optic humidity sensors, fiber-optic gas sensors and fiber-optic biosensors in last decade are reviewed. The outlook of fiber-optic sensors based on LbL polyelectrolyte self-assembly multilayers is suggested. Contents 1 Introduction 2 Preparation and test of fiber-optic sensors based on electrostatic self-assemble multilayers 2.1 Preparation of fiber-optic sensors 2.2 Test of fiber-optic sensors 3 Application of electrostaic self-assemble multilayers on fiber-optic sensors 3.1 Fiber-optic pH sensors 3.2 Fiber-optic humidity sensors 3.3 Fiber-optic gas sensors 3.4 Fiber-optic biosensors 3.5 Other fiber-optic sensors 4 Conclusion and outlook
Towards A Molecular Scale Understanding of the Chemistry of Inorganic Ions at Environmental Interfaces: Application of Spectroscopic Techniques
Li Wei, Luo Lei, Zhang Shuzhen
2011, 23 (12): 2576-2587 |
Published: 24 December 2011
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Abstract
Environmental interfacial reactions such as adsorption-desorption and oxidation-reduction are of vital importance in controlling the transportation, transformation and fate of pollutants. Traditional macroscopic studies have well modeled and described those environmental interfacial behaviors, but can not reveal the reaction mechanisms, such that the chemical behaviors of pollutants in natural environment can not be predicted. With the application of spectroscopic techniques, especially X-ray absorption fine structure (XAFS) and Fourier transform infrared (FTIR) spectroscopy, molecular information has been provided to interpret the mechanisms, leading to a better understanding of environmental interfacial phenomenon. These studies are pushing the development of environmental chemistry from a macroscopic level to a molecular level. Modern spectroscopic techniques allow the in-situ and real-time investigation of the chemical reactions occurring at solid/water interface, providing both quantitative and structural information to elucidate the interfacial processes. Results from these studies largely improved the current understanding of the movement and transformation of pollutants among different environmental media (soil, air and water) and the prediction of their partitioning and transportation. This work starts a simple overview of interfacial reactions, and then focuses mainly on adsorption-desorption behavior as examples to introduce the applications of several spectroscopic techniques (i.e. XAFS, FTIR, NMR, Raman and Mössbauer), and finally ends with a discussion of the constraints and promise of these techniques. Contents 1 Introduction 2 Interfacial reactions in natural environment 3 Application of spectroscopic techniques in environmental interfacial chemistry 3.1 X-ray absorption fine structure spectroscopy 3.2 Fourier-transform infrared spectroscopy 3.3 Raman spectroscopy 3.4 Nuclear magnetic resonance 3.5 Mössbauer spectroscopy 4 The emerging direction of spectroscopic research in environmental interfacial chemistry 4.1 Development in methodology 4.2 Application of multiple techniques 4.3 Comination of quantum chemical calculation 5 Conclusions and perspective
Novel Materials and Approaches for Electrochemiluminescence Studies
Luo Feng, Lin Zhijie, Chen Xi
2011, 23 (12): 2588-2597 |
Published: 24 December 2011
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Abstract
Electrochemiluminescence(ECL) approaches have been received great attention due to their versatility, simplified optical setup, and good temporal and spatial control. With the extension of ECL study, ECL has been applied in a lot of fields, and got great development in recent ten years. Besides their theory studies, to meet the ECL analytical applications, there have been many reports on new materials and approaches for ECL study. In this review, we focus on the ECL applications of new materials and techniques and summary the recent development of ECL, including nano-micro and quantum dot materials for ECL studies. In addition, solid-state ECL and visible ECL approaches based on red-green-blue(RGB) tri-color system are also discussed. Finally, the prospect of ECL studies and applications using nano or quantum dot modified electrodes is presented. Contents 1 Introduction 2 New ECL materials 2.1 Metal complexes 2.2 Nano-micro materials based on Ru complexes 2.3 Quantum dot materials for ECL 3 New development of ECL techniques 3.1 Solid-state ECL 3.2 New approaches of ECL for bio-analysis 3.3 Visible ECL technique 4 Conclusions and outlook
Liposome Formation with Electroformation Method
Jing Jing, Li Yi, Liu Jian, Zhan Sihui
2011, 23 (12): 2598-2606 |
Published: 24 December 2011
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Abstract
Liposomes have bilayer structure,which is similar to that of bio-membrane.Most liposomes obtained by the electroformation method are giant unilamellar vesicles (diameter 10—100 μm), which can be observed under optical microscope easily.So they have great potential in simulation,replacement cells and other aspects. This paper reviews the influence of electric field on liposome formation and introduces the traditional and modified electroformation setup. We also elaborate the influence of process parameters on liposome formation, such as bilayer thickness, osmotic pressure, electrolyte, solid surface, voltage, frequency, temperature, pH value, etc. Contents 1 Introduction 2 Electroformation setup 2.1 Traditional electroformation setup 2.2 Modified electroformation setup 3 Effects of parameters on liposome formation 3.1 Effects of liposome materials 3.2 Effects of electricity factors 3.3 Effects of other factors 4 Conclusions
High Efficiency Low Band Gap Conjugated Polymer Materials for Solar Cells
Yang Zhenglong, Bu Yilong, Chen Qiuyun
2011, 23 (12): 2607-2616 |
Published: 24 December 2011
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Abstract
With the rising costs of fossil fuel generated energy as well as its impending defeat to scarcity, people have begun searching for new ways of generating and producing energy. Solar power is the conversion of sunlight into electricity. It is a very effective means of energy and is practical for everyday use. Polymer solar cells (PSCs) have attracted considerable attention due to their unique advantages, such as low-cost fabrication process, light weight of device, simple process of production, and potential use in flexible devices. Bulk heterojunction polymer solar cells, whose photoactive layer is composed of low band gap conjugated polymer donor materials and soluble fullerene acceptor materials, can greatly optimize the interfacial area between donor and acceptor. By far, this kind of PSCs has obtained a maximum power conversion efficiency of 8.3%. More investigations have been carried out to develop better photovoltaic polymer donor materials in order to improve the power conversion efficiency of PSCs. In this paper, we review the recent progress of low band gap conjugated polymer donor materials for high efficiency polymer solar cells. We put focus on the research progress of benzothiadiazole-, thiophene-, and pyrazine-containing low band gap conjugated polymers as well as their corresponding performance parameters of photovoltaic devices. The advantages and disadvantages of various low band gap conjugated polymers materials are also analyzed. Finally, the advances of low band gap conjugated polymers in high efficiency PSCs applications are prospected. Contents 1 Introduction 2 Benzothiadiazole-containing low band gap conjugated polymers as electron donor materials 3 Thiophene-containing low band gap conjugated polymers as electron donor materials 4 Pyrazine-containing low band gap conjugated polymers as electron donor materials 5 Other low band gap conjugated polymers as electron donor materials 6 Summary and outlook
Fabrication of Special-Type Nanoporous Anodic Alumina Templates
Ye Qiumei, Song Ye, Liu Peng, Hu Junjun
2011, 23 (12): 2617-2626 |
Published: 24 December 2011
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Porous anodic alumina (PAA) templates have been used widely and studied extensively due to their excellent mechanical and thermal stabilities, highly-ordered hexagonal nanochannel-array architecture and controllable pore structures. In recent years, significant progress has been made in the field of PAA synthesis and a variety of special type PAA templates have been prepared by precisely adjusting the anodizing conditions. By means of the special templates, many novel functional nanomaterials have been synthesized successfully via physical or chemical processing routes. After a brief introduction to the fabrication methods of conventional PAA templates, this paper presents a comprehensive review on the fabrication approaches of PAA templates with special nanopore arrays (e.g., branched, serrated, bone-shaped or inverted cone nanopores); diamond, triangle or square pore patterns; modulated pore structures with different diameters, lengths, geometries, and periodicity. Several critical factors including the applied electric field, temperature, type and concentration of the electrolyte which determine the pore modulation of PAA are emphasized. Finally, the development trend and future prospects of the special templates are given. Contents 1 Introduction 2 Fabrication of conventional type PAA templates 3 Fabrication of special type PAA templates 3.1 In-plane or cylindrical PAA 3.2 Branched or serrated PAA 3.3 Bone-shaped or inverted conical PAA 3.4 PAA with periodically modulated pore structures 3.5 PAA with diamond, triangle, square pore patterns 3.6 PAA with nanopore gradients 4 Concluding remarks and outlook
Article
Evaluation Results of National Science Fund for Distinguished Young Scholars(2011)
2011, 23 (12): 2627-2628 |
Published: 24 December 2011
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