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2020 Volume 39 Issue 12
2020, 39(12): 2057-2067
doi: 10.14102/j.cnki.0254–5861.2011–3020
Abstract:
Solvent-free polyurethanes are synthesized under certain conditions via a rapid reaction between liquid prepolymers. During this process the molecular weight of the polymer is rapidly increased to produce polymeric materials containing a carbamate-based structure at a very fast rate. The organic solvents are completely avoided in the solvent-free polyurethane synthesis process, thus avoiding all the problems associated with the use of organic solvents. Solvent-free polyurethane synthetic leather is extruded directly without adding solvents in the production and processing process, which has the advantages of low VOC emission and environmentally friendly. This review brings together theoretical and experimental research on the application and synthesis and preparation of solvent-free polyurethanes to generate an understanding of the theory and synthesis and preparation techniques associated with solvent-free polyurethanes. The review includes (i) the application and development direction of solvent-free polyurethane, (ii) an overview of the technology of solvent-free polyurethane synthetic leather preparation, (iii) a study of the modification and synthesis of solvent-free polyurethane prepolymers, (iv) a summary of the technology of rapid foam forming of solvent-free polyurethane and its influencing factors, (v) a review of the technology of solvent-free polyurethane synthetic leather preparation. In addition to the review, a corresponding overview of the theoretical and experimental advances in solvent-free delayed foaming technology in recent years and a summary of the technology and experience in the preparation of solvent-free polyurethanes are also presented.
Solvent-free polyurethanes are synthesized under certain conditions via a rapid reaction between liquid prepolymers. During this process the molecular weight of the polymer is rapidly increased to produce polymeric materials containing a carbamate-based structure at a very fast rate. The organic solvents are completely avoided in the solvent-free polyurethane synthesis process, thus avoiding all the problems associated with the use of organic solvents. Solvent-free polyurethane synthetic leather is extruded directly without adding solvents in the production and processing process, which has the advantages of low VOC emission and environmentally friendly. This review brings together theoretical and experimental research on the application and synthesis and preparation of solvent-free polyurethanes to generate an understanding of the theory and synthesis and preparation techniques associated with solvent-free polyurethanes. The review includes (i) the application and development direction of solvent-free polyurethane, (ii) an overview of the technology of solvent-free polyurethane synthetic leather preparation, (iii) a study of the modification and synthesis of solvent-free polyurethane prepolymers, (iv) a summary of the technology of rapid foam forming of solvent-free polyurethane and its influencing factors, (v) a review of the technology of solvent-free polyurethane synthetic leather preparation. In addition to the review, a corresponding overview of the theoretical and experimental advances in solvent-free delayed foaming technology in recent years and a summary of the technology and experience in the preparation of solvent-free polyurethanes are also presented.
2020, 39(12): 2068-2076
doi: 10.14102/j.cnki.0254–5861.2011–3005
Abstract:
Defect engineering has being regarded as one of the effective ways to regulate chemical and electronic structure of semiconductors. Recently, our collaborative work has shown experimentally that carbon vacancy on polymeric carbon nitride (CV) can greatly improve the CO2 to CO conversion with a 45-fold improvement over the polymeric carbon nitride (Angew. Chem. Int. Ed., 2019, 58, 1134). In order to clarify the detailed mechanism of promotion, we have systematically studied the electronic properties of CV and hydrogenated CV (CV+H) as well as the effective CO2 reduction reaction through density functional theory calculations. We found that it is the synergistic effect for the CO2 reduction reaction in the CV systems, as the onset potentials of several CVs are much lower than that of the polymeric carbon nitride. In particular, the onset potentials of CV1, CV2, and CV2+H are around 0.9~1.5 eV with a strong chemisorbed CO2 on them. Combined with the analysis of the electronic properties, our results confirm that defect engineering increases the lifetime of photo-generated charges, improves photocatalytic activity, and promotes the CO2 reduction reaction on the defected polymeric carbon nitrides.
Defect engineering has being regarded as one of the effective ways to regulate chemical and electronic structure of semiconductors. Recently, our collaborative work has shown experimentally that carbon vacancy on polymeric carbon nitride (CV) can greatly improve the CO2 to CO conversion with a 45-fold improvement over the polymeric carbon nitride (Angew. Chem. Int. Ed., 2019, 58, 1134). In order to clarify the detailed mechanism of promotion, we have systematically studied the electronic properties of CV and hydrogenated CV (CV+H) as well as the effective CO2 reduction reaction through density functional theory calculations. We found that it is the synergistic effect for the CO2 reduction reaction in the CV systems, as the onset potentials of several CVs are much lower than that of the polymeric carbon nitride. In particular, the onset potentials of CV1, CV2, and CV2+H are around 0.9~1.5 eV with a strong chemisorbed CO2 on them. Combined with the analysis of the electronic properties, our results confirm that defect engineering increases the lifetime of photo-generated charges, improves photocatalytic activity, and promotes the CO2 reduction reaction on the defected polymeric carbon nitrides.
2020, 39(12): 2077-2084
doi: 10.14102/j.cnki.0254–5861.2011–3029
Abstract:
Sulfonylcalix[4]arenes-based coordination containers, namely metal-organic supercontainers (MOSCs), are a new class of coordination containers constructed from the self-assembly of divalent metal ions, suitable carboxylate linkers, and sulfonylcalix[4]arenes container precursor. MOSCs feature both endo cavity surrounded by carboxylate linkers and exo cavities originated from the upper rim of sulfonylcalix[4]arenes. The molecular topologies and endo cavity of MOSCs are tuneable via judicious design of carboxylate linkers, while the modulation of endo cavity are accessible by chemical modification on the para substituent group of the sulfonylcalix[4]arenes. In this paper, recent advances and typical examples of design and functionalization of MOSCs are presented.
Sulfonylcalix[4]arenes-based coordination containers, namely metal-organic supercontainers (MOSCs), are a new class of coordination containers constructed from the self-assembly of divalent metal ions, suitable carboxylate linkers, and sulfonylcalix[4]arenes container precursor. MOSCs feature both endo cavity surrounded by carboxylate linkers and exo cavities originated from the upper rim of sulfonylcalix[4]arenes. The molecular topologies and endo cavity of MOSCs are tuneable via judicious design of carboxylate linkers, while the modulation of endo cavity are accessible by chemical modification on the para substituent group of the sulfonylcalix[4]arenes. In this paper, recent advances and typical examples of design and functionalization of MOSCs are presented.
2020, 39(12): 2085-2090
doi: 10.14102/j.cnki.0254–5861.2011–3036
Abstract:
At present, the development of antineoplastic drugs has been highly concerned. Many strategies have been developed to explore the safety and effectiveness of antitumor drugs. In recent years, the progress of structural analysis of tumor-associated proteins provides a solid foundation for the design of new targeted drugs through efficient prediction and screening technology. In this review, we briefly summarize the research and development of new antitumor drugs based on structure to enhance tumor targeting property and reduce side effects.
At present, the development of antineoplastic drugs has been highly concerned. Many strategies have been developed to explore the safety and effectiveness of antitumor drugs. In recent years, the progress of structural analysis of tumor-associated proteins provides a solid foundation for the design of new targeted drugs through efficient prediction and screening technology. In this review, we briefly summarize the research and development of new antitumor drugs based on structure to enhance tumor targeting property and reduce side effects.
2020, 39(12): 2091-2101
doi: 10.14102/j.cnki.0254–5861.2011–3010
Abstract:
Copper halide clusters have become one of the most prosperous cluster-based materials. They are not only widely used in the fields of photophysics and photochemistry, but also adsorption, catalysis, biology, etc. Herein, the recent progress in copper halide based chemistry is reviewed from three aspects. In the first place, we summarize the new synthesis strategies promoting the crystallization of copper halide cluster-based materials. Then, the structural diversity of the compounds is introduced according to the dimension of copper halogen clusters. Finally, we discuss the functionality of copper halide cluster-based materials including optical, catalytic and adsorption properties. In addition, perspectives on their potential applications are presented.
Copper halide clusters have become one of the most prosperous cluster-based materials. They are not only widely used in the fields of photophysics and photochemistry, but also adsorption, catalysis, biology, etc. Herein, the recent progress in copper halide based chemistry is reviewed from three aspects. In the first place, we summarize the new synthesis strategies promoting the crystallization of copper halide cluster-based materials. Then, the structural diversity of the compounds is introduced according to the dimension of copper halogen clusters. Finally, we discuss the functionality of copper halide cluster-based materials including optical, catalytic and adsorption properties. In addition, perspectives on their potential applications are presented.
2020, 39(12): 2102-2114
doi: 10.14102/j.cnki.0254–5861.2011–3022
Abstract:
As one important member of main group metals, magnesium (Mg) takes great parts in fields involving biology, medicine, industry, and some others. Because of the unique characteristics including but not limited to low-cost, non-toxic and light-weight, Mg-based coordination polymers (CPs) with good performances such as gas storage and separation, catalysis and fluorescence have received certain attention in recent years. However, compared with the well-studied transition metal and rare earth metal based CPs, the report on Mg-CPs is relatively scarce. In this review we briefly summarize the synthesis, structural features, and fluorescent (FL) properties of Mg-CPs on the basis of recent related advances made in our lab. The chemical sensing, white emitting, and mechanoresponsive photoluminescence of selected FL-Mg-CPs are emphasized.
As one important member of main group metals, magnesium (Mg) takes great parts in fields involving biology, medicine, industry, and some others. Because of the unique characteristics including but not limited to low-cost, non-toxic and light-weight, Mg-based coordination polymers (CPs) with good performances such as gas storage and separation, catalysis and fluorescence have received certain attention in recent years. However, compared with the well-studied transition metal and rare earth metal based CPs, the report on Mg-CPs is relatively scarce. In this review we briefly summarize the synthesis, structural features, and fluorescent (FL) properties of Mg-CPs on the basis of recent related advances made in our lab. The chemical sensing, white emitting, and mechanoresponsive photoluminescence of selected FL-Mg-CPs are emphasized.
2020, 39(12): 2115-2122
doi: 10.14102/j.cnki.0254–5861.2011–3025
Abstract:
Oxidative coupling of methane to ethylene is of high importance to the future of light olefin industry. However, the carbon atom efficiency is normally below 50% in gas phase reaction which is limited to the overoxidation of methane to carbon dioxide with oxidants. Here we present an alternative approach of electrochemical oxidation of methane in an oxygen permeation membrane reactor and show the highest conversion of methane and C2 selectivity of 28% and 40.2% at 1150 ℃, respectively. We prepare the 100-μm-thick perovskite (La0.8Sr0.2)1-xCr0.5Fe0.5O3-δ (LSCrF) dense membrane supported on the 500-μm-thick porous (La0.8Sr0.2)1-xCr0.5Fe0.5O3-δ (LSCrF–Fe) (x = 0, 0.02, 0.05 and 0.10) scaffolds while the excess of Fe would be exsolved on porous skeleton to create metal-oxide interfaces toward methane oxidation. The metal-oxide interfaces not only facilitate the activation of C–H bond in methane but also enhance the coking resistance.
Oxidative coupling of methane to ethylene is of high importance to the future of light olefin industry. However, the carbon atom efficiency is normally below 50% in gas phase reaction which is limited to the overoxidation of methane to carbon dioxide with oxidants. Here we present an alternative approach of electrochemical oxidation of methane in an oxygen permeation membrane reactor and show the highest conversion of methane and C2 selectivity of 28% and 40.2% at 1150 ℃, respectively. We prepare the 100-μm-thick perovskite (La0.8Sr0.2)1-xCr0.5Fe0.5O3-δ (LSCrF) dense membrane supported on the 500-μm-thick porous (La0.8Sr0.2)1-xCr0.5Fe0.5O3-δ (LSCrF–Fe) (x = 0, 0.02, 0.05 and 0.10) scaffolds while the excess of Fe would be exsolved on porous skeleton to create metal-oxide interfaces toward methane oxidation. The metal-oxide interfaces not only facilitate the activation of C–H bond in methane but also enhance the coking resistance.
2020, 39(12): 2123-2130
doi: 10.14102/j.cnki.0254-5861.2011-3017
Abstract:
After millions of years of evolution, species in nature have structures and complex elements that are difficult to synthesize artificially. Moreover, these fine structures and compositions are often beneficial to improve the photocatalytic performance. Therefore, various materials with special morphology, pore structure and element composition derived from biomass have emerged and are widely used. This mini review focuses on the preparation of bio-inspired materials and their current status in photocatalytic hydrogen production. Hopefully, this will bring new perspectives to researchers and make them learn more about the advantages of "learning from nature" and pay more attention to the green design of material structures.
After millions of years of evolution, species in nature have structures and complex elements that are difficult to synthesize artificially. Moreover, these fine structures and compositions are often beneficial to improve the photocatalytic performance. Therefore, various materials with special morphology, pore structure and element composition derived from biomass have emerged and are widely used. This mini review focuses on the preparation of bio-inspired materials and their current status in photocatalytic hydrogen production. Hopefully, this will bring new perspectives to researchers and make them learn more about the advantages of "learning from nature" and pay more attention to the green design of material structures.
2020, 39(12): 2131-2138
doi: 10.14102/j.cnki.0254-5861.2011-3023
Abstract:
Inorganic two-dimensional (2D) materials have attracted tremendous interests recently. Controlled functionalization of 2D materials can achieve additional functions and properties, but usually suffers from less modification ratio, poor controllability, defects and so on. 2D organic metal chalcogenide (OMC) materials with periodically arranged organic functional group between the inorganic analogues layers offer opportunities to develop adjustable electrical properties and extended applications. In this mini-review, we will provide an overview of the composition and preparation, band gap engineering, and conductivity modulation of the serial OMC materials and illustrate the application investigation such as biomimetic catalysis, photodetecting and chemiresistive gas sensing.
Inorganic two-dimensional (2D) materials have attracted tremendous interests recently. Controlled functionalization of 2D materials can achieve additional functions and properties, but usually suffers from less modification ratio, poor controllability, defects and so on. 2D organic metal chalcogenide (OMC) materials with periodically arranged organic functional group between the inorganic analogues layers offer opportunities to develop adjustable electrical properties and extended applications. In this mini-review, we will provide an overview of the composition and preparation, band gap engineering, and conductivity modulation of the serial OMC materials and illustrate the application investigation such as biomimetic catalysis, photodetecting and chemiresistive gas sensing.
2020, 39(12): 2139-2147
doi: 10.14102/j.cnki.0254-5861.2011-3026
Abstract:
In this paper, we briefly reviewed the new non-phosphorous extraction systems proposed according to the different applicational ends. These systems were established by choosing the suitably modified chemical group and the corresponding substrate with unique chemical/physical properties. The guiding principle for the foundation of these new systems was to combine the advantages of the substrate and functions of the modified chemical group, majorly the diglycolamide-acid. The induced physical/chemical properties of the substrate and the functions of modified moieties had the potential to import unique traits to the as-founded adsorbent, establishing a task-tailored bi-/multi-functional system. We believe the new systems had the potential to create new adsorption/desorption extraction/bask-extraction paradigms to improve the selectivity and capacity of the extraction/adsorption process, as well as to be more time-efficient and environmentally friendly.
In this paper, we briefly reviewed the new non-phosphorous extraction systems proposed according to the different applicational ends. These systems were established by choosing the suitably modified chemical group and the corresponding substrate with unique chemical/physical properties. The guiding principle for the foundation of these new systems was to combine the advantages of the substrate and functions of the modified chemical group, majorly the diglycolamide-acid. The induced physical/chemical properties of the substrate and the functions of modified moieties had the potential to import unique traits to the as-founded adsorbent, establishing a task-tailored bi-/multi-functional system. We believe the new systems had the potential to create new adsorption/desorption extraction/bask-extraction paradigms to improve the selectivity and capacity of the extraction/adsorption process, as well as to be more time-efficient and environmentally friendly.
2020, 39(12): 2148-2156
doi: 10.14102/j.cnki.0254-5861.2011-3028
Abstract:
UV nonlinear optical (NLO) crystals are essential materials for UV solid state laser output. To date, frequency conversion in UV region is mainly dependent on borates with planar BO3 or B3O6 units. Since the practical applications require more and more high comprehensive properties of crystals, it is urgent to develop new UV NLO crystals. However, it is more and more difficult to find new borate NLO crystals because borate NLO crystals have been studied for several decades. Therefore, it is important to search new systems for the exploration of UV NLO crystals. Based on the relationship between the microstructure and properties of the groups, we proposed that inorganic (CO3)2- and (NO3)- groups can be as new NLO active units for UV NLO crystals because they have π-conjugated configuration. Accordingly, our group have performed related work in carbonate and nitrate systems in recent years, which resulted in finding some excellent carbonates and nitrates NLO crystals. In addition, we have recently expanded the research field from inorganic to organic π-conjugated systems, such as isocyanurates. This mini review will introduce the research results of our team in the field of UV NLO crystals including carbonates, nitrates and cyanurates in recent years.
UV nonlinear optical (NLO) crystals are essential materials for UV solid state laser output. To date, frequency conversion in UV region is mainly dependent on borates with planar BO3 or B3O6 units. Since the practical applications require more and more high comprehensive properties of crystals, it is urgent to develop new UV NLO crystals. However, it is more and more difficult to find new borate NLO crystals because borate NLO crystals have been studied for several decades. Therefore, it is important to search new systems for the exploration of UV NLO crystals. Based on the relationship between the microstructure and properties of the groups, we proposed that inorganic (CO3)2- and (NO3)- groups can be as new NLO active units for UV NLO crystals because they have π-conjugated configuration. Accordingly, our group have performed related work in carbonate and nitrate systems in recent years, which resulted in finding some excellent carbonates and nitrates NLO crystals. In addition, we have recently expanded the research field from inorganic to organic π-conjugated systems, such as isocyanurates. This mini review will introduce the research results of our team in the field of UV NLO crystals including carbonates, nitrates and cyanurates in recent years.
Recent Progress in Developing Crystalline Ion Exchange Materials for the Removal of Radioactive Ions
2020, 39(12): 2157-2171
doi: 10.14102/j.cnki.0254-5861.2011-3018
Abstract:
The nuclear fuel cycle inevitably generates a large amount of radioactive waste liquid, which will pose a serious threat to the ecological environment and human health. Ion exchange method has received wide attention for its easy operation, low cost and no secondary pollution. However, the effective removal of radioactive ions from complex solutions still remains a serious challenge due to their environmental mobility and radiotoxicity. We have developed an efficient strategy to construct crystalline ion-exchange materials by inducing layered or three-dimensional microporous anionic frameworks by organic cations that can be effectively exchanged by radioactive metal ions. This type of materials can be applied effectively to the removal of radioactive ions from complex solutions and the removal mechanism has been deeply clarified by means of single crystal structure analyses, theoretical calculations, etc. This review summarizes our recent progress in the study of synthesis, structures and properties of radioactive ion removals for such type of crystalline ion-exchange materials.
The nuclear fuel cycle inevitably generates a large amount of radioactive waste liquid, which will pose a serious threat to the ecological environment and human health. Ion exchange method has received wide attention for its easy operation, low cost and no secondary pollution. However, the effective removal of radioactive ions from complex solutions still remains a serious challenge due to their environmental mobility and radiotoxicity. We have developed an efficient strategy to construct crystalline ion-exchange materials by inducing layered or three-dimensional microporous anionic frameworks by organic cations that can be effectively exchanged by radioactive metal ions. This type of materials can be applied effectively to the removal of radioactive ions from complex solutions and the removal mechanism has been deeply clarified by means of single crystal structure analyses, theoretical calculations, etc. This review summarizes our recent progress in the study of synthesis, structures and properties of radioactive ion removals for such type of crystalline ion-exchange materials.
2020, 39(12): 2172-2181
doi: 10.14102/j.cnki.0254-5861.2011-3019
Abstract:
Second-order nonlinear optical (NLO) crystalline materials are fundamentally and technologically important for their ability to double or triple the frequency of lasers. This article provides a brief review of the atom response theory (ART) of NLO responses recently developed on the basis of the partial response functional method. The ART analysis enables one to quantitatively evaluate the contributions of individual constituent atoms to the second harmonic generation (SHG) response of a NLO crystal material on the basis of first principles DFT calculations. The general partitioning principles developed in our recent work provide the conceptual foundation for determining the functional motifs of SHG responses. In this mini review we will focus on the concepts and principles as well as on applications with examples. Some practically important empirical rules resulting from the ART studies will also be reviewed.
Second-order nonlinear optical (NLO) crystalline materials are fundamentally and technologically important for their ability to double or triple the frequency of lasers. This article provides a brief review of the atom response theory (ART) of NLO responses recently developed on the basis of the partial response functional method. The ART analysis enables one to quantitatively evaluate the contributions of individual constituent atoms to the second harmonic generation (SHG) response of a NLO crystal material on the basis of first principles DFT calculations. The general partitioning principles developed in our recent work provide the conceptual foundation for determining the functional motifs of SHG responses. In this mini review we will focus on the concepts and principles as well as on applications with examples. Some practically important empirical rules resulting from the ART studies will also be reviewed.
