最新刊期
卷 29 ， 期 9 ， 2016
- 摘要：This article briefly introduces my 30 years research carrier on conjugated polymers in Institute of Chemistry, Chinese Academy of Sciences (ICCAS). The achievements mentioned here mainly focus on the fields of conjugated polymers,including the electrochemistry of conducting polypyrrole (PPy),polymer light-emitting electrochemical cells (LECs) and conjugated polymer donor materials for polymer solar cells (PSCs). In the field of electrochemistry of conducting PPy,I and my group systematically studied the electrochemical preparation and electrochemical properties of conducting PPy. We elucidated the effects of various electropolymerization conditions on conductivity and mechanical properties of the as-prepared PPy films. We found that donor number of the electrolyte solvents greatly influences the conductivity of the as-prepared PPy films : the smaller the donor number of the electrolyte solvent,the greater the electric conductivity of the as-prepared PPy films. Very smooth conducting PPy films with high mechanical strength were prepared by using non-ionic surfactant additive in the aquesous electrolyte solution. For the reaction mechanism of pyrrole electropolymerization, I proposed and confirmed the solution-participated cation-radical electropolymerization mechanism, and deduced a kinetic equation for the pyrrole electropolymerization reaction. We also found that there are two doping structures (main chain oxidized with counter-anions doping structure and the proton-acid doping structure) in the conducting PPy films prepared from NaNO3 aqueous solution. We studied and elucidated mechanisms of the reduction and re-oxidation of conducting PPy films in aqueous solutions, and the mechanisms of the first reduction and re-oxidation of conducting PPy films in organic electrolyte solutions. In the studies of LECs, I confirmed the electrochemical doping mechanism and the formation of p-i-n structure of the LECs after applying voltage higher than Eg/e of the luminescent conjugated polymers by ac impedance measurements. We synthesized a series of luminescent and ionic conductive conjugated polymers with main chian containing ionic-conducting units, and the phase separation problem in the LECs was avoided by using the bi-functional polymers as the luminescent polymers in the LECs. We fabricated quasi-frozen junction LECs by using ionic liquid as electrolyte salt in the active layers of LECs which improved the electroluminescent properties of the LECs significantly. In the studies of conjugated polymer donor materials for PSCs,we proposed a molecular design strategy of two-dimension (2D)-conjugated polymers with conjugated side chains to broaden the absorption and enhance the hole mobility of the conjugated polymers for improving its photovoltaic performance. We synthesized a series of 2D-conjugated polythiophenes with conjugated side chains which show broader absorption, higher hole mobility and improved photovoltaic performance. Then the 2D-conjugation strategy was further extended to the narrow bandgap 2D-conjugated PBDTTTs by attaching thiophene conjugated side chains on benzodithiophene (BDT) units. We introduced alkylthio substituents on the thiophene conjugated side chains of the 2D-conjugated PBDTTTs and further improved their photovoltaic properties. Finally, I introduced our recent research progress on non-fullerene PSCs based on our 2D-conjugated polymers as donor and narrow bandgap n-type organic semiconductor as acceptor.关键词：Conjugated polymers;Conducting polypyrrole;Electrochemical polymerization;Polymer light-emitting electrochemical cells;Conjugated polymer photovoltaic materials
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发布时间：2022-09-12 - 摘要：With the rapid development of electronic industry, more heat is accumulated during the operating of the electric device or equipment. The heat should be removed timely to ensure the normal operation of the equipment. Polymer-based thermally conductive composites are widely used due to their easy processability and low cost. Hexagonal boron nitride (h-BN) possesses both outstanding thermal conductivity and electrical insulativity,and has attracted increasing attention in fabrication of thermally conductive and electrically insulating composites in recent years. The research progress of h-BN/polymer thermally conductive composites is reviewed in this article from the aspects of size,surface modification, orientation structure of h-BN and hybrid fillers.关键词：Boron nitride;Thermal conductive;Composites
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发布时间：2022-09-12 - 摘要：Gel,as a kind of semi-solid soft matter, plays a very important role as functional materials. Both polymers and low molecular weight gel (LMWGs) are possible to form gels. However,they exhibit different macroscopic mechanical properties and responsiveness on external stimuli. By mixing the polymers, even though some of them are non-gelator,into LMWGs, the mechanical properties can be increased while keeping the responsiveness of LMWGs. In this review,we summarized the recent research progress in the mixed gels composed of LWMGs/polymers (either gelative or non-gelative) to show the merit of such mixed gels.关键词：Polymer gel;Low molecular weight gel;Mixed gel;Self-assembly
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发布时间：2022-09-12 - 摘要：Janus composites possess two different compositions thus functions distinctly compartmentalized onto the same objects. It is key to precisely tune their morphology, microstructure, and composition thus performance. Our recent progress in synthesis of Janus composites is summarized. Some challenging issues remain unsolved. A huge of practical applications ask for commercial availability of Janus functional composites.关键词：Janus;Amphiphilic;Functional;Composites;Interfacial engineering
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发布时间：2022-09-12 - 摘要：Polyolefin is the most important product of petrochemical industry, and majorly related to polyethylene, meanwhile α-olefins are not only co-monomer in co-polymerization but also basic substance for fine-chemical industry. Therefore the national ethylene industry represents the technical development of petrochemical industry. Regarding the newly developing process in ethylene industry, late-transition metal precatalysts achieve highly activities in oligomerization and polymerization, in which the resultant polyethylenes potentially become new plastic materials of polyethylenes. It is still a hot topic of developing new precatalysts through modifying coordination ligands to enhance the activities and thermal-stabilities of late-transtion metal complexes ; the finely controlled microstructures of resultant polyethylenes resulted the better properties and provided essentials toward industrial process. Relied on variations of ligands' classifications, the complex precatalysts of iron, cobalt and nickel have been compared in their performances in ethylene oligomerization and polymerization. The new progress has been reviewed, specially focusing on our researches.关键词：Late-transition metal precatalyst;Ethylene oligomerization;Ethylene polymerization;Iron complex;Cobalt complex;Nickel complex
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发布时间：2022-09-12 - 摘要：Recently, due to its good environmental stability,low toxicity and adjustable electrical conductivity, polypyrrole (PPy) as thermoelectric (TE) material has received increasing attention. Controlled fabrication of PPy nanostructures or compounding with high electrically conductive carbon nanoparticles to prepare polymer/carbon nanoparticle composites can effectively improve the TE performance. In this review,the recent developments of PPy and its TE composites are discussed in detail. In addition, the preparation of one-dimensional PPy nanostructures was introduced as well.关键词：Polypyrrole;Carbon nanoparticle;Composites;Thermoelectric performance
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发布时间：2022-09-12 - 摘要：Organic solar cells (OSCs) have attracted considerable interests from both academic and industrial community over the past decade due to the potentials such as low cost, tunable flexibility and high specific weight. The design of novel organic donors and optimization of device structures have helped to boost the power conversion efficiency to over 10 %. From the aspect of the material design, a wide variety of donor and acceptor units were developed to build the organic conjugated donors. Among which, benzothiadiazole (BT) unit is widely used in constructing high-efficiency OSCs materials due to its large conjugate plane and strong electron-withdrawing properties. In this review,we present an overview the recent progress of the BT-based organic photovoltaic materials and their application in OSCs.关键词：Benzothiadiazole;Organic solar cells;Photovoltaic properties
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发布时间：2022-09-12 - 摘要：Cellulose is an abundant biomass resource with low cost and biodegradable properties, which is one of the most promising green materials. Cellulose, containing a lot of hydroxyl groups on the molecular chain to form strong inter-and intramolecular hydrogen bonding network, is difficult to dissolve in ordinary solvents, and is not easy to process, which greatly limits its wide applications. This paper introduces the research progress of cellulose functional materials from the preparations of cellulose derivatives, graft copolymers and gels. Cellulose-based functional materials, containing various structures and functions, have been prepared through weaken inter- and intramolecular hydrogen bonding in cellulose by chemical modifications, which broadens the application field of cellulose.关键词：Cellulose;Functional materials;Derivative;Graft copolymer;Gel
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发布时间：2022-09-12 - 摘要：The environmental stability, including ageing behaviors and anti-ageing, of polymers is an important basic science topic and has become a research hotspot in recent years. This paper introduced the processes and mechanisms of thermal oxidation ageing and photo-oxidation ageing of polymers. The characterization methods and the anti-ageing additives were introduced too. Nanoparticles,such as nano-silica, nano-titanium dioxide and nano-zinc oxide, are today considered new-generation anti-ageing agents with enhanced performance. Some achievements obtained by us in the field were reviewed here.关键词：Thermal oxidation ageing;Photo-oxidation ageing;Nano-silica;Nano-titanium dioxide;Nano-zinc oxide;Composite
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发布时间：2022-09-12 - 摘要：Poly(butylene succinate) (PBS) is one of the most promising members of biodegradable materials because of its good physical property and processability. In this review,progress on synthesis, copolymerization and functionalization of PBS has been summarized. The material's mechanical properties, biodegrability, thermal properties and crystallization behavior can be tuned by random copolymerization and block copolymerization. Sulfonate, carboxylate, amino have been introduced to improve the hydrophilicity and biocompatibility via the high-efficient reaction of the double bonds on poly (butylene fumarate) based random or block polymers. Micelles with pH-triggered reversible surface charges has been prepared. It has great potential to be used as intelligent drug delivery system for cancer therapy.关键词：Poly(butylene succinate);Copolymerization;Mechanical properties;Biodegradation;Functionalization
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发布时间：2022-09-12 - 摘要：As an important component of Ziegler-Natta catalysts, support materials show profound influences on catalyst properties as well as polyolefin particle morphology and structure and properties. Advancement in support technology is thus contributing greatly to the innovations of Ziegler-Natta catalysts and the development of high-performance polyolefin materials. This paper reviewed the recent research progress in Ziegler-Natta catalyst support technology, including those on magnesium-alcohol support, inorganic salt-doped MgCl2 support, hybrid MgCl2 support and nano particle support. Researches in our group relevant to this subject are also referenced.关键词：Ziegler-Natta catalyst;Polyolefins;Support technology;Progress
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发布时间：2022-09-12 - 摘要：Cellulose-based aerogel is a new kind of functional biomass material, which combines the advantages of typical inorganic aerogels with ultralight weight, very high porosity and specific surface area and renewable biopolymers with abundance in nature, biocompatibility and biodegradability. This review first briefly introduced cellulose-based aerogels. Then the preparation of cellulose-based aerogels by using ionic liquids as solvents are discussed in detail, followed by their structure and properties. Finally, a perspective on this promising family of materials and the research that needs to be done in the future are briefly discussed.关键词：Cellulose;Ionic liquid;Aerogel;Dissolution-regeneration
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发布时间：2022-09-12 - 摘要：In this paper, dicumyl peroxide(DCP)and azobisisobutyronitrile(AIBN)were used to initiate polymerization of liquid vinylpolycarbosilane( VHPCS). The curing reaction kinetics of VHPCS/AIBN,VHPCS/DCP systems were studied by non-isothermal differential scanning calorimetry (DSC). The related kinetic parameters were analyzed by Kissinger equation and Crane equation, and the nth-order curing models of both systems were obtained based on these curing kinetic parameters. The curing process temperatures of two systems were determined by the β-T extrapolation method. In addition, the cross-linking mechanism of VHPCS and the thermal property of cross-linked products were also studied. The results showed that the activation energy E of VHPCS/AIBN,VHPCS/DCP systems were 72. 17 KJ/mol, 94. 11 KJ/mol, and the reaction order n were 0. 92,0. 93,respectively. The characteristic temperatures of VHPCS/AIBN, VHPCS/DCP systems were approximate gelling temperature of 55℃,peak temperature of 110℃, 107℃, termination temperature of 129. 5℃,134℃, respectively. FTIR result indicated that the cross-linking of VHPCS mainly by self-polymerization of vinyl group. The mass residue of cross-linked products were higher than that of VHPCS.关键词：VHPCS;Initiator;DSC;Reaction kinetics
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发布时间：2022-09-12 - 摘要：The effect of poly(acrylic acid) (PAA),poly (allylamine) (PEI) and poly (vinyl alcohol) (PVA) on the ice recrystallization (IR) were studied. The results showed that the IR inhibition activity gradually increased with the increase of polymer solution concentration. Compared with the weak IR inhibition activity of PAA and PEI, PVA was a very effective inhibitor of IR. PVA with higher alcoholysis degree could inhibit IR much more effectively. The water mobility was detected by 1H-NMR, namely, water proton spin-spin relaxation times (T2). As the proportion of hydroxyl groups increased, the IR inhibition activity of PVA increased due to the reduced mobility of water molecules.关键词：Hydrophilic polymers;Ice recrystallisation inhibition;Water molecular dynamics
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发布时间：2022-09-12 - 摘要：Carbon fiber is a very important material that can reinforce other materials like polymers, and it is widely used in military weapons and high-end products. Since the structure of the original PAN fiber will propagate to that of final carbon fiber, the quality and performance of carbon fibers are largely depended on the preparation of PAN fiber. The phase separation and gelation processes during the solidification of PAN fiber decide its ultimate structure. Therefore, clarification of the mechanism of these two processes would benefit the control of the PAN fiber structure. In this feature article, we report the newly discovered results in PAN/DMSO/ H2O blends by using rheology and optical method. We find the second self-similar structure in PAN concentrated system and the underlying mechanism is also discussed. We also analyze the coupling of the phase separation and gelation in semi-dilute PAN concentration system, besides we also predict and explain the non-uniform structure of the resulted gel. Validity of the Chambon-Winter model is also confirmed in such phase separated system. At last, we forecast the future work on the PAN/DMSO/H2O blends.关键词：Polyacrylonitrile;Gelation;Phase separation;Rheology;Optical microscopy
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发布时间：2022-09-12 - 摘要：Long carbon chain polyamide based thermoplastic elastomer (LCPAE) represents a category of high-performance thermoplastic elastomer, consisting of long carbon chain polyamide (LCPA) as hard segments ( HS) and polyether as soft segments (SS). A series of copolymers can be synthesized by adjusting the molecular weight of HS, SS and their relative ratio, covering the Shore hardness from 25D to 70D. Incompatibility of HS and SS renders LCPAE micro-phase separation aggregation state, which leads to a combination of merits of LCPA as anti-abrasion, high mechanical strength, thermal stability, good processability, and that of polyether as flexibility under low temperatures, high resilience. This paper generally reviews the development roadmap, current market situation, domestic and overseas research, related patents of LCPAE since 1970s, briefly summarizes the aggregation structural evolution of LCPAE under uniaxial deformation, investigated by in site X-ray diffraction, which revealed the structure-property relationship of LCPAE,can be referred as instructions for macromolecular design of LCPAE. The achievement of our own lab is also introduced on designing and synthesizing LCPAE by employing indigenous-patented even-even LCPA1012. In the end, outlook and proposal are made on the issues that what scientific problems should be settled for LCPAE and how the collaboration among research institute and domestic enterprise should be streamlined to commercialize LCPAE with independent intellectual property.关键词：Long carbon chain polyamide;Thermoplastic elastomer;in-situ X-ray diffraction;Micro-phase separation
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发布时间：2022-09-12 - 摘要：Dental resin composites have been widely used in clinical due to their esthetics. However, the marginal gap is still a major problem for resin composite restorative materials,which then lead to the occurrence of secondary caries. In recent years, remineralizing resin composites have been developed to prevent or decrease dental secondary caries,which can release remineralizing agents,such as calcium and phosphate ions. This review summarizes the effects of the kinds, content,particle size and surface treatment of bioactive filler on the physical and mechanical properties of resin composites, focusing on the remineralization behavior of the remineralizing dental composites. It was found that a variety of bioactive dental resin composites are able to promote remineralization. This suggests that remineralizing rein composites have the potential to slow the development and propagation of secondary caries at restoration margins.关键词：Composites;Bioactive fillers;Remineralization;Mechanical strength
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发布时间：2022-09-12 - 摘要：Dendrimers are a kind of nanomaterials with precise three dimensional structures. Recently, an emerging attention is received from synthesis and characterization of dendrimers towards their functions and applications. Currently, most of traditional fluorescence imaging probes developed are small molecules, but the weak specificity, poor stability, short duration time, and high toxicity greatly limit their applications. Dendrimers with many designable terminal functional groups and large intramolecular cavities are promising for applications in fluorescent biological imaging due to theirs diversity and unique molecular structures. Herein, we mainly introduce the recent progress of dendritic organic fluorescent probes and quantum dots probes for bioimaging.关键词：Dendrimers;Fluorescent probes;Bioimaging
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发布时间：2022-09-12 - 摘要：The health of patients is threatened by nosocomial infections, it may finally resulted in high hospitalization costs and fatalities. Firstly, bacteria adhere onto biomedical polymer materials or medical device surface, and ultimately biofilms develop. To decrease the incidence of device-associated infections,the surface of biomedical polymer materials or medical devices should resist or prevent bacterial attachment,establishment, and proliferation. So far, most antibacterial methods for preventing the infection of medical device are antifouling (bacteria-repelling) strategy or bactericidal strategy, their combination of antifouling and bactericidal strategy and switching strategy from bactericidal to antifouling. ( 1 ) Antifouling (bacteria-repelling) strategy usually involves modification of the hydrophobic surface of the medical device to reduce the bacterial attachment by coating with antifouling polymers (polyethylene glycol, zwitterionic polymers, poly (Nvinyl pyrrolidone), 2-methacryloyloxyethyl phosphorylcholine, etc), superhydrophobic surface or lubricant-infused surface. However, antifouling strategy hardly kills the adherent bacteria, which will lead to the subsequent bacterial proliferation and biofilm formation. (2) The bactericidal strategy incorporates the active biocides such as cationic polymers, antimicrobial peptides,antibiotics or bactericidal nanoparticles onto/into the surface or bulk polymer, while it suffers from the high cytotoxicity of biocides or antibiotic resistance. However, the preparation procedures of above methods are usually tedious with complicated chemical reactions or bactericidal nanoparticles could easily release from the medical device. (3) The combination of antifouling and bactericidal strategy could avoid the disadvantages of above two approaches. The antifouling and bactericidal components were incorporated through copolymerizaion, blend, etc. However, the contents and functions of above two components could be easily disturbed. (4) Switching strategy from bactericidal to antifouling could release the dead bacteria after switching. Before switching bactericidal components firstly kill the live bacteria. However, the preparation of this method is tedious and the switching is under certain condition. Although the research on antibacterial polymer and medical device has made progress, the antibacterial strategy still exist some deficiencies. The following three aspects need to be broken through: (1) The establishment of novel method to modify the biomaterials and medical device; (2) Antibacterial surface with excellent antibacterial and biocompatible properties; (3) Development of multifunctional biomaterial and medical device, such as antibacterial, anticoagulant and lubricant properties.关键词：Biomedical polymer materials;Medical device;Antibacterial property;Biocompatibility
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发布时间：2022-09-12 - 摘要：Hydrosilylation is one of the most important reactions in organosilicon chemistry, by which Si-X bond can be constructed. Using favorable monomers and catalysts, polymers with different structures and unique functions can be prepared through hydrosiltlation polymerization, which is a frontier in polymer chemistry. In this paper, hydrosilylation polymerization of olefins, alkynes,aldehydes and ketones, as well as nonlinear hydrosilylation polymerization are mainly introduced. We focus on the molecular weight and properties of polymers obtained from diverse systems. By summarizing the previous works of hydrosilylation polymerization,it is hoped to give some ideas and inspirations for related researchers.关键词：Hydrosilylation polymerization;Polycarbosilane;Polycarbosiloxane;Poly ( silyl ether);Hyperbranched silicon-containing polymer
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发布时间：2022-09-12 - 摘要：The methods of organic modification of clay for polymer/clay nanocomposites and the thermal stability of organoclay and their effect on the properties of nanocomposites are reviewed. The possibility of the change of gallery space of clay in intercalated nanocomposites resulting from the varied configuration of intercalants at high temperatures and the discrepancy between the thermal stability characterized by TGA and the oxidation induced time are stressed.关键词：Clay;Nanocomposite;Organic modification;Thermal stability
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发布时间：2022-09-12 - 摘要：Polymer grafted nanoparticles (PGNPs) are very useful fillers for polymer nanocomposites. The so-called "completely miscible" polymer composites will be obtained by well dispersing the PGNPs with the controlled grafted length and density in the polymer matrix that is same to the grafted chains. This will provide a good model system for the studies on the structure-property relationships of nanocomposites with PGNPs. In this review,we summarize the recent progresses in preparation of PGNPs and the structure-property relationships of nanocomposites with PGNPs. We focus on preparation of PGNPs, dispersion state of PGNPs in polymer matrix, and rheological behaviors and mechanical properties of nanocomposites with PGNPs. We conclude this review with a brief outlook on some future directions.关键词：Polymer grafted nanoparticles;Nanocomposites;Dispersion state;Rheological behavior;Mechanical property
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发布时间：2022-09-12 - 摘要：Oil/water separation is a challenging task for industrial water treatment. Although progress had been made in many ways, the costs and effects are still far from satisfactory. Recently with the development of novel water/oil materials, new types of oil/water separation technologies with lower cost and better efficiencies have become possible. According to the needs from various waste oil/water treatment porcesses,this paper reviewed the properties of recently developed oil/ water separation materials, including inorganic membranes, polymer membranes, and modified polyurethane foams, and the progress made in treating oil bearing waste waters. The future trends in treating oil bearing waste water are also prospected.关键词：Oil-water separation;Materials;Membrane;Polyurethane foam;Research progress
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发布时间：2022-09-12 - 摘要：Aerogels are lightweight open-celled mesoporous materials. Due to their special characteristics, such as low density (0. 003~0. 5g/cm3 ),high porosity (70~99. 8 % ), low dielectric constant (~1. 1), low thermal conductivity (the lowest reported was 0. 012W/(m• K) ) and high surface area (100~1600m /g), They have drawn great interest in a wide range of applications, including heat insulator, sound attenuator, support for catalysts,drug carrier, low dielectric constant material,adsorbent, etc. Polyimide is an important high-performance material, and polyimide aerogel has received a lot of attentions in recent years. In this paper, the preparation methods of polyimide aerogel and their merits and shortcomings were reviewed. In addition,the further works in research are prospected.关键词：Aerogel;Polyimide;Preparation method
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发布时间：2022-09-12
Special Issue for Celebrating 60th Anniversary of ICCAS
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