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2021 Volume 38 Issue 2
2021, 38(2): 123-135
doi: 10.19894/j.issn.1000-0518.200220
Abstract:
Ion imprinted polymer is a special kind of polymer with the ability to selectively adsorb the target ion and is prepared by the imprinting technique with imprinting the template ion. The present reports are mostly about the preparation and performance of cation imprinted polymers, but the development of anion imprinted polymers is relatively backward. The reason comes from the more complex structure of anion templates and its smaller ratio of the charge to size, which makes it very difficult to establish a clear recognition site in anion imprinted polymers. In order to guide the preparation and applications of anion imprinted polymers more effectively, the recent status is reviewed. The types of functional monomers (including amino, quaternary ammonium, nitrogen heterocyclic and carboxyl structures) that can adsorb and bind to various common anions are summarized. And the adsorption properties of anion imprinted polymers based on the above monomers are reviewed. Then the preparation methods and synthetic strategies of anion imprinted polymers and their applications in analytical chemistry containing anion electrochemical detection and fluorescence sensing are introduced. Finally, there are still some deficiencies such as unsatisfactory adsorption capacity and rare industrial applications. The future research directions about anion imprinted polymers are also discussed and prospected.
Ion imprinted polymer is a special kind of polymer with the ability to selectively adsorb the target ion and is prepared by the imprinting technique with imprinting the template ion. The present reports are mostly about the preparation and performance of cation imprinted polymers, but the development of anion imprinted polymers is relatively backward. The reason comes from the more complex structure of anion templates and its smaller ratio of the charge to size, which makes it very difficult to establish a clear recognition site in anion imprinted polymers. In order to guide the preparation and applications of anion imprinted polymers more effectively, the recent status is reviewed. The types of functional monomers (including amino, quaternary ammonium, nitrogen heterocyclic and carboxyl structures) that can adsorb and bind to various common anions are summarized. And the adsorption properties of anion imprinted polymers based on the above monomers are reviewed. Then the preparation methods and synthetic strategies of anion imprinted polymers and their applications in analytical chemistry containing anion electrochemical detection and fluorescence sensing are introduced. Finally, there are still some deficiencies such as unsatisfactory adsorption capacity and rare industrial applications. The future research directions about anion imprinted polymers are also discussed and prospected.
2021, 38(2): 136-156
doi: 10.19894/j.issn.1000-0518.200250
Abstract:
The selective oligomerization of ethylene to prepare linear α-olefins has been highly valued in both academia and industry because of its high target product selectivity, easy product separation, and significant economic benefits. Chromium-based catalysts have good overall performance in catalyzing selective oligomerization of ethylene, and are a class of catalysts with broad application prospects. Recent studies have shown that the ligand structure has an important effect on the catalyst performance; the introduction of hydrogen in the reaction system can improve the distribution of oligomerization products and inhibit the formation of polymers; development of the catalyst without methylaluminoxane as a cocatalyst can reduce the costs of the catalyst; the ethylene selective oligomerization mechanism and the oxidation state of the central metal have important guiding significance to the design of the catalyst. Recent progress in the research of phosphoamine chromium and diphosphinoamine chromium complexes in the selective oligomerization of ethylene is reviewed from the above aspects, with the problems to be solved in the industrializaion of ethylene selective tetramerization and the further development in ethylene selective oligomerization.
The selective oligomerization of ethylene to prepare linear α-olefins has been highly valued in both academia and industry because of its high target product selectivity, easy product separation, and significant economic benefits. Chromium-based catalysts have good overall performance in catalyzing selective oligomerization of ethylene, and are a class of catalysts with broad application prospects. Recent studies have shown that the ligand structure has an important effect on the catalyst performance; the introduction of hydrogen in the reaction system can improve the distribution of oligomerization products and inhibit the formation of polymers; development of the catalyst without methylaluminoxane as a cocatalyst can reduce the costs of the catalyst; the ethylene selective oligomerization mechanism and the oxidation state of the central metal have important guiding significance to the design of the catalyst. Recent progress in the research of phosphoamine chromium and diphosphinoamine chromium complexes in the selective oligomerization of ethylene is reviewed from the above aspects, with the problems to be solved in the industrializaion of ethylene selective tetramerization and the further development in ethylene selective oligomerization.
2021, 38(2): 157-169
doi: 10.19894/j.issn.1000-0518.200229
Abstract:
Energy utilization in the world is facing great challenges and it is very important to develop green and clean energy. Hydrolysis of ammonia borane is one of the effective routes to produce clean and renewable hydrogen and suitable catalysts can improve the efficiency of hydrogen production in the hydrolysis reaction. The development of efficient and safe catalysts has been the focus and hotspot in this field. This paper reviews the role of active metal components and supports in the preparation of catalysts and the catalytic hydrolysis of ammonia borane based on the key factors that affect the catalytic performance. Finally, the current problems are summarized and the future development of this field is pointed out.
Energy utilization in the world is facing great challenges and it is very important to develop green and clean energy. Hydrolysis of ammonia borane is one of the effective routes to produce clean and renewable hydrogen and suitable catalysts can improve the efficiency of hydrogen production in the hydrolysis reaction. The development of efficient and safe catalysts has been the focus and hotspot in this field. This paper reviews the role of active metal components and supports in the preparation of catalysts and the catalytic hydrolysis of ammonia borane based on the key factors that affect the catalytic performance. Finally, the current problems are summarized and the future development of this field is pointed out.
2021, 38(2): 170-180
doi: 10.19894/j.issn.1000-0518.200243
Abstract:
In recent years, with the increasing demand for energy storage devices, potassium ion batteries have attracted more and more attention. The physical and chemical properties of potassium is similar to those of lithium, and the reserve of potassium in the earth's crust is abundant, so potassium ion battery has a promising prospect in the field of energy storage. However, due to the fact that the actual capacity of electrode materials is far less than the theoretical capacity, the performance of potassium ion battery is still inadequate. Metallic antimony has a high theoretical capacity and is widely investigated as electrodes. However, too large volume change during charging-discharging process leads to the poor stability. The structural stability can be improved by controlling the morphology, alloying and introducing carbon framework. In this paper, the research progress of antimony materials as anodes for potassium ion batteries is introduced, and the application of antimony electrode is prospected.
In recent years, with the increasing demand for energy storage devices, potassium ion batteries have attracted more and more attention. The physical and chemical properties of potassium is similar to those of lithium, and the reserve of potassium in the earth's crust is abundant, so potassium ion battery has a promising prospect in the field of energy storage. However, due to the fact that the actual capacity of electrode materials is far less than the theoretical capacity, the performance of potassium ion battery is still inadequate. Metallic antimony has a high theoretical capacity and is widely investigated as electrodes. However, too large volume change during charging-discharging process leads to the poor stability. The structural stability can be improved by controlling the morphology, alloying and introducing carbon framework. In this paper, the research progress of antimony materials as anodes for potassium ion batteries is introduced, and the application of antimony electrode is prospected.
2021, 38(2): 181-187
doi: 10.19894/j.issn.1000-0518.200266
Abstract:
The complexity of the tumor microenvironment (TME) makes it difficult to completely eliminate tumors with a single treatment. Herein, ion-doped poly(2-nitro-1, 4-phenylenediamine) multifunctional nanospheres loaded with indocyanine green (ICG) are constructed for synergistic cancer therapy by photothermal therapy (PTT)/photodynamic therapy (PDT)/chemo-dynamic therapy (CDT). Under 808 nm laser irradiation, ICG as a photosensitizer could generate 1O2 and Fe-PNPD acts as a photothermal agent with a photothermal conversion efficiency of 36.65%. Once Fe-PNPD-ICG (FPIs) is internalized into the cancer cells, it triggers the Fenton reaction to produce ·OH, and clears the over-expressed glutathione (GSH) in TME, thereby reducing the antioxidant capacity in the tumor. At the same time, the generated oxygen can reduce hypoxia in TME and enhance the therapeutic effect of PDT. FPIs is an ideal candidate for synergistic PTT/PDT/CDT therapy, and has broad application prospects for tumor therapy.
The complexity of the tumor microenvironment (TME) makes it difficult to completely eliminate tumors with a single treatment. Herein, ion-doped poly(2-nitro-1, 4-phenylenediamine) multifunctional nanospheres loaded with indocyanine green (ICG) are constructed for synergistic cancer therapy by photothermal therapy (PTT)/photodynamic therapy (PDT)/chemo-dynamic therapy (CDT). Under 808 nm laser irradiation, ICG as a photosensitizer could generate 1O2 and Fe-PNPD acts as a photothermal agent with a photothermal conversion efficiency of 36.65%. Once Fe-PNPD-ICG (FPIs) is internalized into the cancer cells, it triggers the Fenton reaction to produce ·OH, and clears the over-expressed glutathione (GSH) in TME, thereby reducing the antioxidant capacity in the tumor. At the same time, the generated oxygen can reduce hypoxia in TME and enhance the therapeutic effect of PDT. FPIs is an ideal candidate for synergistic PTT/PDT/CDT therapy, and has broad application prospects for tumor therapy.
2021, 38(2): 188-194
doi: 10.19894/j.issn.1000-0518.200199
Abstract:
To explore an efficient structural modification strategy to enhance the antitumor activity of fluoroquinolones, a methane-rhodanine fragment was used as the bioisosteric replacement of the C-3 carboxylic acid group and consequently twelve new C-3 α, β-unsaturated thiazolone derivatives (6a-6l) were designed and synthesized by Claisen-Schmid condensation reaction with oxazinoquinolin-7-one-6-carbaldehyde (5) derived from levofloxacin (1) and N-substituted rhodanines (2a-2l), respectively. The in vitro antitumor activity of the synthesized compounds is more potent than that of levofloxacin along with lower cytotoxicity against Vero cells. Meanwhile, the structure-activity relationship (SAR) reveals that halophenyl, N-unsubstituted or cyclopropyl rhodaninec ompounds display a better activity than those of the control compounds, especially the IC50 values of cyclopropyl rhodanine compound (6j) against A549 cell growth is comparable to doxorubicin. Thus, an unsaturated ketone annulated rhodanine scaffold as a bioisostere of the C-3 carboxylic acid group is found to be an alternative proposal for improving the antitumor activity of fluoroquinolones. Furthermore, whether an α, β-unsaturated ketone fragment is a promising bioisostere of the C-3 carboxylic acid group is worth further developing.
To explore an efficient structural modification strategy to enhance the antitumor activity of fluoroquinolones, a methane-rhodanine fragment was used as the bioisosteric replacement of the C-3 carboxylic acid group and consequently twelve new C-3 α, β-unsaturated thiazolone derivatives (6a-6l) were designed and synthesized by Claisen-Schmid condensation reaction with oxazinoquinolin-7-one-6-carbaldehyde (5) derived from levofloxacin (1) and N-substituted rhodanines (2a-2l), respectively. The in vitro antitumor activity of the synthesized compounds is more potent than that of levofloxacin along with lower cytotoxicity against Vero cells. Meanwhile, the structure-activity relationship (SAR) reveals that halophenyl, N-unsubstituted or cyclopropyl rhodaninec ompounds display a better activity than those of the control compounds, especially the IC50 values of cyclopropyl rhodanine compound (6j) against A549 cell growth is comparable to doxorubicin. Thus, an unsaturated ketone annulated rhodanine scaffold as a bioisostere of the C-3 carboxylic acid group is found to be an alternative proposal for improving the antitumor activity of fluoroquinolones. Furthermore, whether an α, β-unsaturated ketone fragment is a promising bioisostere of the C-3 carboxylic acid group is worth further developing.
2021, 38(2): 195-201
doi: 10.19894/j.issn.1000-0518.200174
Abstract:
Silver nanoclusters have a wide range of application prospects because they have special physical and chemical properties. Since they are prone to agglomeration, it is of great significance to explore the method of preparing silver nanoclusters with strong fluorescence, high stablility and small particle sizes. A method for the rapid preparation of silver nanoclusters in alkaline environment with chromium black T as stabilizer and thiourea as coordination stabilizer was developed in this paper. Under the optimal conditions, the average particle size of the prepared silver nanoclusters is 1.67 nm, the particle size is mainly in the range of 0.74~3.33 nm, the lattice spacing is 0.2157 nm, and the lattice type is (102). The maximum excitation wavelength is 380 nm, the maximum emission wavelength is 463 nm, and the quantum yield is 1.64%.
Silver nanoclusters have a wide range of application prospects because they have special physical and chemical properties. Since they are prone to agglomeration, it is of great significance to explore the method of preparing silver nanoclusters with strong fluorescence, high stablility and small particle sizes. A method for the rapid preparation of silver nanoclusters in alkaline environment with chromium black T as stabilizer and thiourea as coordination stabilizer was developed in this paper. Under the optimal conditions, the average particle size of the prepared silver nanoclusters is 1.67 nm, the particle size is mainly in the range of 0.74~3.33 nm, the lattice spacing is 0.2157 nm, and the lattice type is (102). The maximum excitation wavelength is 380 nm, the maximum emission wavelength is 463 nm, and the quantum yield is 1.64%.
2021, 38(2): 202-211
doi: 10.19894/j.issn.1000-0518.200223
Abstract:
Green fluorescent carbon quantum dots (G-CQDs) were synthesized from corn starch and oxalic acid via an ethanol solvothermal method. The morphology, composition and structure of G-CQDs were analyzed using transmission electron microscopy (TEM), Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The results show that G-CQDs are quasi-spherical nanoparticles with the particle size of about 2~5 nm and have graphene-like structure with abundant water-soluble groups such as C-O and O-H on the surface. The fluorescence measurement assay results exhibit that the synthesized G-CQDs display strong fluorescence emission at~520 nm with the excitation wavelength of 385 nm, and the emission intensity increases first and then decreases with the decrease of the concentration of G-CQDs. The fluorescence quantum yield of the synthesized G-CQDs can reach up to 38.5%. Moreover, the fluorescence emission of G-CQDs exhibits various decay behaviors with the varied concentration of H+ and OH-. Therefore, the synthesized G-CQDs can be utilized as the reversible "off-on" switch probe for the detection of H+ and OH-.
Green fluorescent carbon quantum dots (G-CQDs) were synthesized from corn starch and oxalic acid via an ethanol solvothermal method. The morphology, composition and structure of G-CQDs were analyzed using transmission electron microscopy (TEM), Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The results show that G-CQDs are quasi-spherical nanoparticles with the particle size of about 2~5 nm and have graphene-like structure with abundant water-soluble groups such as C-O and O-H on the surface. The fluorescence measurement assay results exhibit that the synthesized G-CQDs display strong fluorescence emission at~520 nm with the excitation wavelength of 385 nm, and the emission intensity increases first and then decreases with the decrease of the concentration of G-CQDs. The fluorescence quantum yield of the synthesized G-CQDs can reach up to 38.5%. Moreover, the fluorescence emission of G-CQDs exhibits various decay behaviors with the varied concentration of H+ and OH-. Therefore, the synthesized G-CQDs can be utilized as the reversible "off-on" switch probe for the detection of H+ and OH-.
2021, 38(2): 212-219
doi: 10.19894/j.issn.1000-0518.200217
Abstract:
Gel ink is a thermodynamically unstable pigment suspension system. The choose of low-viscosity, high-stability color pastes is one of the important means to ensure the dispersion stability of the ink system. Based on this, using pigment carbon black and phthalocyanine blue as colorants, combined with hyperdispersant (EK43) and synergist (BM10), two resin-free color pastes suitable for gel ink systems were prepared. For the first time, from the perspective of the particle size of the color paste and the dispersion stability of the system, the dosage of EK43 and BM10 and the optimal grinding time were determined, and their physical and chemical properties, stability and writing performance were analyzed and tested. The results show that: adding 10.0% mass fraction of EK43 and 2.5% mass fraction of BM10 to the black paste, the grinding time is 90 min; the particle size and dispersion stability of the two color pastes reach the best when 8.0% EK43 and 2.0% BM10 are added to the blue paste and the grinding time is 120 min. The prepared resin-free color paste has high solid content, low viscosity, good storage stability, and strong tinting power. The gel ink formulated with it has good writing performance, and good centrifugal stability and heat stability.
Gel ink is a thermodynamically unstable pigment suspension system. The choose of low-viscosity, high-stability color pastes is one of the important means to ensure the dispersion stability of the ink system. Based on this, using pigment carbon black and phthalocyanine blue as colorants, combined with hyperdispersant (EK43) and synergist (BM10), two resin-free color pastes suitable for gel ink systems were prepared. For the first time, from the perspective of the particle size of the color paste and the dispersion stability of the system, the dosage of EK43 and BM10 and the optimal grinding time were determined, and their physical and chemical properties, stability and writing performance were analyzed and tested. The results show that: adding 10.0% mass fraction of EK43 and 2.5% mass fraction of BM10 to the black paste, the grinding time is 90 min; the particle size and dispersion stability of the two color pastes reach the best when 8.0% EK43 and 2.0% BM10 are added to the blue paste and the grinding time is 120 min. The prepared resin-free color paste has high solid content, low viscosity, good storage stability, and strong tinting power. The gel ink formulated with it has good writing performance, and good centrifugal stability and heat stability.
2021, 38(2): 220-227
doi: 10.19894/j.issn.1000-0518.200241
Abstract:
Oleamide quaternary ammonium Gemini surfactants GS-1, GS-2, GS-3 were synthesized by the reaction of Oleamide propyl dimethylamine and 1, 3-dichloro-2-propanol, 1, 4-dibromo-2-butene and 1, 4-dibromo-butane, respectively. The structures of GS-1, GS-2, and GS-3 were characterized by Fourier-transform infrared (FT-IR) spectrometry and proton nuclear magnetic resonance (1H NMR), and their Krafft temperature, surface activity, emulsification performance, foam performance, and wettability were measured. The results show that three kinds of Gemini surfactants GS-1, GS-2, GS-3 are successfully prepared, and their Krafft temperatures are all less than 0℃, which provides a theoretical possibility for their use in low temperature environments with maintained high surface activity. Then, the critical micelle concentration (CMC) values of GS-1, GS-2, GS-3 are 7.7×10-5, 7.08×10-5, and 2.63×10-6 mol/L, respectively, which are consistent with the expected results. The CMC value of the Gemini surfactant is 1~2 orders of magnitude lower than that of the conventional surfactant single alkyl chain. In addition, the synthesized surfactants all show good surface a ctivity, emulsifying properties, and the ability to stabilize foam.
Oleamide quaternary ammonium Gemini surfactants GS-1, GS-2, GS-3 were synthesized by the reaction of Oleamide propyl dimethylamine and 1, 3-dichloro-2-propanol, 1, 4-dibromo-2-butene and 1, 4-dibromo-butane, respectively. The structures of GS-1, GS-2, and GS-3 were characterized by Fourier-transform infrared (FT-IR) spectrometry and proton nuclear magnetic resonance (1H NMR), and their Krafft temperature, surface activity, emulsification performance, foam performance, and wettability were measured. The results show that three kinds of Gemini surfactants GS-1, GS-2, GS-3 are successfully prepared, and their Krafft temperatures are all less than 0℃, which provides a theoretical possibility for their use in low temperature environments with maintained high surface activity. Then, the critical micelle concentration (CMC) values of GS-1, GS-2, GS-3 are 7.7×10-5, 7.08×10-5, and 2.63×10-6 mol/L, respectively, which are consistent with the expected results. The CMC value of the Gemini surfactant is 1~2 orders of magnitude lower than that of the conventional surfactant single alkyl chain. In addition, the synthesized surfactants all show good surface a ctivity, emulsifying properties, and the ability to stabilize foam.
2021, 38(2): 228-235
doi: 10.19894/j.issn.1000-0518.200325
Abstract:
Rubber materials are widely used in practice because of their unique hyperelasticity. The analysis of the stress-strain relationship can provide theoretical guidance for the engineering application of rubber mechanical properties. In order to describe the mechanical properties of rubber materials more accurately, a hybrid hyperelastic constitutive model was proposed in this paper. The new model is based on the Gaussian model and 8-chain model, which are coupled by the weight function related to the stretching ratio. When the stretching ratio is small, the new model degenerates into Gaussian form; When the stretching ratio is large, the new model can improve the deficiency of 8-chain model in small deformation by regulating of the weight function. We select experiment data from three aspects to verify the applicability of the new model: Stress-strain curve of orientation hardening, stress-strain curve of non-oriented hardening, stress-strain curve of different stretch ratios. We carry on the fitting verification from uniaxial tension, biaxial tension and pure shear experiments, respectively. The results show that the new model retains the advantages of Gaussian model in small deformation range and 8-chain model in large deformation range at the same time and has no dependence on stretching ratios and stress-strain curve forms. It breaks through the limitation of Gaussian model and 8-chain model, and provides a new idea for prediction of rubber hyperelastic mechanical properties.
Rubber materials are widely used in practice because of their unique hyperelasticity. The analysis of the stress-strain relationship can provide theoretical guidance for the engineering application of rubber mechanical properties. In order to describe the mechanical properties of rubber materials more accurately, a hybrid hyperelastic constitutive model was proposed in this paper. The new model is based on the Gaussian model and 8-chain model, which are coupled by the weight function related to the stretching ratio. When the stretching ratio is small, the new model degenerates into Gaussian form; When the stretching ratio is large, the new model can improve the deficiency of 8-chain model in small deformation by regulating of the weight function. We select experiment data from three aspects to verify the applicability of the new model: Stress-strain curve of orientation hardening, stress-strain curve of non-oriented hardening, stress-strain curve of different stretch ratios. We carry on the fitting verification from uniaxial tension, biaxial tension and pure shear experiments, respectively. The results show that the new model retains the advantages of Gaussian model in small deformation range and 8-chain model in large deformation range at the same time and has no dependence on stretching ratios and stress-strain curve forms. It breaks through the limitation of Gaussian model and 8-chain model, and provides a new idea for prediction of rubber hyperelastic mechanical properties.
2021, 38(2): 236-244
doi: 10.19894/j.issn.1000-0518.200365
Abstract:
Three metal-organic frameworks (MIL-101(Cr), MIL-101(Cr)-SO3H, MIL-101(Cr)-NH2) were used as adsorbents, and the adsorption properties of sulfadiazine and sulfadiazine were compared in environment water under different pH conditions by solid phase dispersion extraction. With MIL-101(Cr) as the best adsorbent, the main factors affecting the efficiency of adsorption and desorption, such as the amount of adsorbent used, adsorption time, type and amount of desorption solvent, and desorption time were investigated. The optimized extraction conditions were as follows: 10.0 mL of sample solution (pH=9.0) was extracted with 6.0 mg of MIL-101(Cr) adsorbent for 4.0 min, the supernatant was removed by centrifugation, and the sample was resolved with 1.5 mL of 2% (volume fraction) formic acid-methanol solution for 10.0 min. The results show that the linear range of two sulfonamides are 5.0~8000 μg/L, and r>0.9990. The detection limits of the method are 0.05 μg/L to 0.08 μg/L. The recoveries of the three spiked concentrations are from 71.2% to 91.9%. The relative standard deviations (RSDs) are in the range of 3.1%~8.5%.
Three metal-organic frameworks (MIL-101(Cr), MIL-101(Cr)-SO3H, MIL-101(Cr)-NH2) were used as adsorbents, and the adsorption properties of sulfadiazine and sulfadiazine were compared in environment water under different pH conditions by solid phase dispersion extraction. With MIL-101(Cr) as the best adsorbent, the main factors affecting the efficiency of adsorption and desorption, such as the amount of adsorbent used, adsorption time, type and amount of desorption solvent, and desorption time were investigated. The optimized extraction conditions were as follows: 10.0 mL of sample solution (pH=9.0) was extracted with 6.0 mg of MIL-101(Cr) adsorbent for 4.0 min, the supernatant was removed by centrifugation, and the sample was resolved with 1.5 mL of 2% (volume fraction) formic acid-methanol solution for 10.0 min. The results show that the linear range of two sulfonamides are 5.0~8000 μg/L, and r>0.9990. The detection limits of the method are 0.05 μg/L to 0.08 μg/L. The recoveries of the three spiked concentrations are from 71.2% to 91.9%. The relative standard deviations (RSDs) are in the range of 3.1%~8.5%.
