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2019 Volume 36 Issue 10
2019, 36(10): 1099-1108
doi: 10.11944/j.issn.1000-0518.2019.10.190057
Abstract:
Pheromones as a class of chemicals that are released from insects in vitro to regulate or induce the behavior and response of other individuals. In recent years, usage of pheromones as a replacement for pesticides against harmful insects has become a new technology for integrated pest management. Compared with traditional pesticide control methods, pheromones have some important ecological advantages such as high specificity, non-resistance, low toxicity and harmless to beneficial organisms. Furthermore, pheromones are generally susceptible to degradation accompanied with high volatility. Therefore, pheromone-based controlled release technology has attracted extensive interests of scientific community and is a new interdisciplinary subject covering chemistry, materials and agriculture. Controlled or sustained release of insect pheromones through a specific method or technology can effectively control pests, reduce the use of pesticides and improve the level of environmental ecology. At the same time, the controlled release technology can also reduce the total amount of regional chemicals and save costs. This paper reviews the latest research progress of sustained release technology for insect pheromone and the future development is prospected.
Pheromones as a class of chemicals that are released from insects in vitro to regulate or induce the behavior and response of other individuals. In recent years, usage of pheromones as a replacement for pesticides against harmful insects has become a new technology for integrated pest management. Compared with traditional pesticide control methods, pheromones have some important ecological advantages such as high specificity, non-resistance, low toxicity and harmless to beneficial organisms. Furthermore, pheromones are generally susceptible to degradation accompanied with high volatility. Therefore, pheromone-based controlled release technology has attracted extensive interests of scientific community and is a new interdisciplinary subject covering chemistry, materials and agriculture. Controlled or sustained release of insect pheromones through a specific method or technology can effectively control pests, reduce the use of pesticides and improve the level of environmental ecology. At the same time, the controlled release technology can also reduce the total amount of regional chemicals and save costs. This paper reviews the latest research progress of sustained release technology for insect pheromone and the future development is prospected.
2019, 36(10): 1109-1117
doi: 10.11944/j.issn.1000-0518.2019.10.190112
Abstract:
Glycidol(GLY) and doxorubicin(DOX) were coupled to ACAylated nanodiamond(ND) carrier to obtain nanodiamond-aminocaproic acid-glycidol-doxorubicin (ND-ACA-GLY-DOX, NAGD) drug delivery system through ester bond. The amounts of ACA and DOX coupled to the surface of the ND were (185±10.0) μg/mg and (115±5.2) μg/mg, respectively, as determined by fluorescence spectroscopy. The results showed that the amount of NAGD released was very low in the physiological environment(pH=7.4), while the ester bond was hydrolytically cleaved and a large amount of DOX was released in the presence of lysozyme in the lysosome environment of the tumor cells. Using liver cancer cells as the model, the cell morphology test showed that NAGD could effectively kill tumor cells. The above results indicate that NAGD can be used as a good drug delivery system.
Glycidol(GLY) and doxorubicin(DOX) were coupled to ACAylated nanodiamond(ND) carrier to obtain nanodiamond-aminocaproic acid-glycidol-doxorubicin (ND-ACA-GLY-DOX, NAGD) drug delivery system through ester bond. The amounts of ACA and DOX coupled to the surface of the ND were (185±10.0) μg/mg and (115±5.2) μg/mg, respectively, as determined by fluorescence spectroscopy. The results showed that the amount of NAGD released was very low in the physiological environment(pH=7.4), while the ester bond was hydrolytically cleaved and a large amount of DOX was released in the presence of lysozyme in the lysosome environment of the tumor cells. Using liver cancer cells as the model, the cell morphology test showed that NAGD could effectively kill tumor cells. The above results indicate that NAGD can be used as a good drug delivery system.
2019, 36(10): 1118-1127
doi: 10.11944/j.issn.1000-0518.2019.10.190031
Abstract:
Aluminum porphyrin is a soil-tolerant metal porphyrin complex. Although its catalytic activity on the copolymerization of CO2 and propylene oxide has been disclosed by Inoue in 1978, the catalytic activity is still very low, and the synthesized poly(propylene carbonate) has low relative molecular mass. It is a big challenge to make progress on the catalytic performance of aluminum porphyrin. In this work, the electronic environment of central aluminum was adjusted by delicate design of porphyrin ligand using meso-tetrasubstituted porphyrin derivatives that were employed to catalyze the copolymerization of CO2 and propylene oxide with bis-(triphenyl phosphine) iminium chloride(PPNCl) as the co-catalyst. It was found that the electronic environment of the central aluminum ion had great effect on the catalytic performance of aluminum porphyrin catalysts, the turnover frequency(TOF) value of Cl substituted aluminum porphyrin catalyst 6a reached 2672 h-1 at 90℃ and 3 MPa, while poly(propylene carbonate) with relative molecular mass of 1.84×104 was afforded using catalyst 4b bearing toluene sulfonic group(OTs-) as axial group of good leaving ability. Our work indicates that delicate designed aluminum porphyrin can become a possible candidate as high performance catalyst in the copolymerization of CO2 and propylene oxide, under optimized copolymerization conditions.
Aluminum porphyrin is a soil-tolerant metal porphyrin complex. Although its catalytic activity on the copolymerization of CO2 and propylene oxide has been disclosed by Inoue in 1978, the catalytic activity is still very low, and the synthesized poly(propylene carbonate) has low relative molecular mass. It is a big challenge to make progress on the catalytic performance of aluminum porphyrin. In this work, the electronic environment of central aluminum was adjusted by delicate design of porphyrin ligand using meso-tetrasubstituted porphyrin derivatives that were employed to catalyze the copolymerization of CO2 and propylene oxide with bis-(triphenyl phosphine) iminium chloride(PPNCl) as the co-catalyst. It was found that the electronic environment of the central aluminum ion had great effect on the catalytic performance of aluminum porphyrin catalysts, the turnover frequency(TOF) value of Cl substituted aluminum porphyrin catalyst 6a reached 2672 h-1 at 90℃ and 3 MPa, while poly(propylene carbonate) with relative molecular mass of 1.84×104 was afforded using catalyst 4b bearing toluene sulfonic group(OTs-) as axial group of good leaving ability. Our work indicates that delicate designed aluminum porphyrin can become a possible candidate as high performance catalyst in the copolymerization of CO2 and propylene oxide, under optimized copolymerization conditions.
2019, 36(10): 1128-1134
doi: 10.11944/j.issn.1000-0518.2019.10.190171
Abstract:
A series of alkenyl-functionalized bis(imidate)pyridine vanadium V(Ⅲ) complexes was synthesized and used for olefin polymerization in a self-immobilization mode. All the complexes were well-characterized by Fourier transform infrared spectrometer(FTIR), elemental analysis and nuclear magnetic resonance spectroscopy(NMR). Being activated by ethylaluminum sesquichloride(EASC), the V(Ⅲ) complexes displayeded high activity in ethylene polymerization(7.2~12.1 g/(mol·h·Pa)). Additionally, the length of self-immobilized alkenyl chains showed a little influence on the catalytic activity of the precatalysts. These V(Ⅲ) complexes also exhibited high activity in initiating ethylene/1-hexene copolymerization, affordiong copolymer products with high molecular weight(up to 68.1×103). Scanning electron microscope(SEM) studies showed that the polymer products formed platelet clusters.
A series of alkenyl-functionalized bis(imidate)pyridine vanadium V(Ⅲ) complexes was synthesized and used for olefin polymerization in a self-immobilization mode. All the complexes were well-characterized by Fourier transform infrared spectrometer(FTIR), elemental analysis and nuclear magnetic resonance spectroscopy(NMR). Being activated by ethylaluminum sesquichloride(EASC), the V(Ⅲ) complexes displayeded high activity in ethylene polymerization(7.2~12.1 g/(mol·h·Pa)). Additionally, the length of self-immobilized alkenyl chains showed a little influence on the catalytic activity of the precatalysts. These V(Ⅲ) complexes also exhibited high activity in initiating ethylene/1-hexene copolymerization, affordiong copolymer products with high molecular weight(up to 68.1×103). Scanning electron microscope(SEM) studies showed that the polymer products formed platelet clusters.
2019, 36(10): 1135-1146
doi: 10.11944/j.issn.1000-0518.2019.10.190068
Abstract:
Hydrogenated star-shaped poly(styrene-b-butadiene-b-styrene) copolymer(HSBS) was synthesized by catalytic hydrogenation at atmospheric pressure. The product was treated by sequential chloromethylation, quaternization and alkalization to fabricate two kinds of alkaline anion exchange membranes(AEMs) with good comprehensive properties. And they were HSBS4303-OH and HSBS4402-OH(the mass fraction of styrene in the raw materials were 30% and 40%, respectively). The structures and preparation process of AEMs were characterized by Fourier transform infrared(FTIR) spectroscopy. The ionic conductivity, water absorption, swelling, mechanical properties, microphase structure and alkaline resistance of the membranes were systematically studied. The results show that the characteristic melting peak corresponding to the crystalline structure of the HSBS occured at about 90℃ and its mechanical properties and size stability were significantly improved compared with parent SBS. In particular, HSBS4402-OH has superior performance. Its ion exchange capacity(IEC), water absorption and swelling degree at 30℃ were 1.99 mmol/g, 27.65% and 5.12%, respectively. Its ionic conductivity achieved 86.8 mS/cm at 80℃. And the loss of its ionic conductivity was only 8.3% even as the membrane was immersed in 2 mol/L NaOH solution for 432 h at 60℃. Apparently, this method can produce promising AEMs for anion exchange membrane fuel cells.
Hydrogenated star-shaped poly(styrene-b-butadiene-b-styrene) copolymer(HSBS) was synthesized by catalytic hydrogenation at atmospheric pressure. The product was treated by sequential chloromethylation, quaternization and alkalization to fabricate two kinds of alkaline anion exchange membranes(AEMs) with good comprehensive properties. And they were HSBS4303-OH and HSBS4402-OH(the mass fraction of styrene in the raw materials were 30% and 40%, respectively). The structures and preparation process of AEMs were characterized by Fourier transform infrared(FTIR) spectroscopy. The ionic conductivity, water absorption, swelling, mechanical properties, microphase structure and alkaline resistance of the membranes were systematically studied. The results show that the characteristic melting peak corresponding to the crystalline structure of the HSBS occured at about 90℃ and its mechanical properties and size stability were significantly improved compared with parent SBS. In particular, HSBS4402-OH has superior performance. Its ion exchange capacity(IEC), water absorption and swelling degree at 30℃ were 1.99 mmol/g, 27.65% and 5.12%, respectively. Its ionic conductivity achieved 86.8 mS/cm at 80℃. And the loss of its ionic conductivity was only 8.3% even as the membrane was immersed in 2 mol/L NaOH solution for 432 h at 60℃. Apparently, this method can produce promising AEMs for anion exchange membrane fuel cells.
2019, 36(10): 1147-1154
doi: 10.11944/j.issn.1000-0518.2019.10.190070
Abstract:
A porous organic polymer containing pillar[5]arene and 1, 3, 5-trirthynylbenze(TEB), namely, P[5]-TEB, was synthesized by Sonogashira cross-coupling reaction, then a novel polyhydroxyl polymer P[5]OH-TEB was obtained by demethylation reaction from the former polymer. The physical and chemical properties as well as adsorption properties of the two porous organic polymers were studied. Nitrogen adsorption test showed that the specific surface area of P[5]OH-TEB increased with the introduction of hydroxyl group, and the microporous structure was also introduced. It was indicated by dye adsorption that the adsorption process of the two polymers for methylene blue was consistent with the Langmuir adsorption equation, from which P[5]OH-TEB had a greater adsorption capacity for methylene blue. The adsorption kinetics test indicated that the adsorption process was more suitable for the pseudo-secondary kinetics model and belonged to the chemical adsorption process and P[5]OH-TEB got a faster adsorption rate after modification. It was showed by selectivity adsorption that the polymer can absorb more cationic dyes and the adsorption was decreased to anionic dye after the introduction of hydroxyl group into the polymer.
A porous organic polymer containing pillar[5]arene and 1, 3, 5-trirthynylbenze(TEB), namely, P[5]-TEB, was synthesized by Sonogashira cross-coupling reaction, then a novel polyhydroxyl polymer P[5]OH-TEB was obtained by demethylation reaction from the former polymer. The physical and chemical properties as well as adsorption properties of the two porous organic polymers were studied. Nitrogen adsorption test showed that the specific surface area of P[5]OH-TEB increased with the introduction of hydroxyl group, and the microporous structure was also introduced. It was indicated by dye adsorption that the adsorption process of the two polymers for methylene blue was consistent with the Langmuir adsorption equation, from which P[5]OH-TEB had a greater adsorption capacity for methylene blue. The adsorption kinetics test indicated that the adsorption process was more suitable for the pseudo-secondary kinetics model and belonged to the chemical adsorption process and P[5]OH-TEB got a faster adsorption rate after modification. It was showed by selectivity adsorption that the polymer can absorb more cationic dyes and the adsorption was decreased to anionic dye after the introduction of hydroxyl group into the polymer.
2019, 36(10): 1155-1164
doi: 10.11944/j.issn.1000-0518.2019.10.190026
Abstract:
Hydroxyl-terminated dimethylmethylvinyl(siloxane and polysiloxane) (C＝C－PDMS－OH) was used as the graft branched chain to form a flexible main chain (Brush PDMS-OH) with bottle brushes by hydrogenation of H-PDMS with the caster catalyst. Brush impact hardening polymer (B-IHP) with branched chains was prepared by dynamic cross-linking of trimethoxyboroxyhexacyclic (TMOB) and stable chemical cross-linking by isophorone diisocyanate extender (IPDI). The structure and properties of the material were characterized by nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectrometer (FTIR) and rheometer. The results show that B-IHP has good mechanical properties and impact hardening properties. Its tensile strength can reach 9.8 MPa and impact hardening value can reach more than 3500. B-IHP has good self-healing performance, the healing efficiency can reach more than 95%, and the healing time is only 6 hours. The results show that the branched structure of flexible main chain can significantly reduce the relative molecular mass threshold of chain entanglement and improve the impact hardening and self-repairing ability of materials.
Hydroxyl-terminated dimethylmethylvinyl(siloxane and polysiloxane) (C＝C－PDMS－OH) was used as the graft branched chain to form a flexible main chain (Brush PDMS-OH) with bottle brushes by hydrogenation of H-PDMS with the caster catalyst. Brush impact hardening polymer (B-IHP) with branched chains was prepared by dynamic cross-linking of trimethoxyboroxyhexacyclic (TMOB) and stable chemical cross-linking by isophorone diisocyanate extender (IPDI). The structure and properties of the material were characterized by nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectrometer (FTIR) and rheometer. The results show that B-IHP has good mechanical properties and impact hardening properties. Its tensile strength can reach 9.8 MPa and impact hardening value can reach more than 3500. B-IHP has good self-healing performance, the healing efficiency can reach more than 95%, and the healing time is only 6 hours. The results show that the branched structure of flexible main chain can significantly reduce the relative molecular mass threshold of chain entanglement and improve the impact hardening and self-repairing ability of materials.
2019, 36(10): 1165-1171
doi: 10.11944/j.issn.1000-0518.2019.10.190184
Abstract:
In this paper, the synergistic flame retardant system with ammonium polyphosphate (APP) as the main flame retardant, aluminum hypophosphite (AHP) and melamine cyanurate (MCA) as auxiliary flame retardants was investigated for the flame retardant performance of polypropylene (PP). The flame retardant properties of the prepared flame retardant samples were analyzed by vertical burning test, limiting oxygen index (LOI) test, thermogravimetric analysis, cone calorimeter test and scanning electron microscopy. The results show that the addition of 30% mass fraction of any flame retardant alone can not achieve good flame retardant properties of PP. When the total mass fraction of additives is kept at 30%, mass ratio APP:AHP:MCA=4:1:1, the ideal flame retardancy is obtained, LOI of the flame retardant PP is 33%, the vertical burning test reaches Ⅴ-0 level, and the peak heat release rate (PHRR) is reduced from 765.7 kW/m2 to 122.7 kW/m2.
In this paper, the synergistic flame retardant system with ammonium polyphosphate (APP) as the main flame retardant, aluminum hypophosphite (AHP) and melamine cyanurate (MCA) as auxiliary flame retardants was investigated for the flame retardant performance of polypropylene (PP). The flame retardant properties of the prepared flame retardant samples were analyzed by vertical burning test, limiting oxygen index (LOI) test, thermogravimetric analysis, cone calorimeter test and scanning electron microscopy. The results show that the addition of 30% mass fraction of any flame retardant alone can not achieve good flame retardant properties of PP. When the total mass fraction of additives is kept at 30%, mass ratio APP:AHP:MCA=4:1:1, the ideal flame retardancy is obtained, LOI of the flame retardant PP is 33%, the vertical burning test reaches Ⅴ-0 level, and the peak heat release rate (PHRR) is reduced from 765.7 kW/m2 to 122.7 kW/m2.
2019, 36(10): 1172-1178
doi: 10.11944/j.issn.1000-0518.2019.10.190035
Abstract:
A new donor-acceptor(D-A) pyrene-containing naphthalene derivative 2-(pyrene-1-yl)-1, 8-naphthyl was synthesized and characterized by nuclear magnetic resonance spectrometry(1H NMR, 13C NMR), Fourier transform infrared spectrometry(FTIR) and liquid chromatography-mass spectrometry(LC-MS). The linear optical properties and third-order nonlinear optical absorption of 2-(pyrene-1-yl)-1, 8-naphthyridine(PN) were studied by means of the electron spectroscopy and Z-scan technique, respectively. The thermal stability of PN was determined by thermogravimetry and differential scanning calorimetry. The experimental results show that the nonlinear absorption coefficient of PN at 532 nm and 180 fs is β=9.0×10-14 m/W, exhibiting ultrafast third-order nonlinear optical response. The molecular orbital energy, polarizability and hyperpolarizability were calculated by density functional theory, and the results show that electron transfer can take place within the molecule. There is no absorbance at more than 450 nm in ultraviolet spectrum of PN. So it is a candidate material for the next in nonlinear optical absorption, laser protection, absorption optical switch or bistable devices.
A new donor-acceptor(D-A) pyrene-containing naphthalene derivative 2-(pyrene-1-yl)-1, 8-naphthyl was synthesized and characterized by nuclear magnetic resonance spectrometry(1H NMR, 13C NMR), Fourier transform infrared spectrometry(FTIR) and liquid chromatography-mass spectrometry(LC-MS). The linear optical properties and third-order nonlinear optical absorption of 2-(pyrene-1-yl)-1, 8-naphthyridine(PN) were studied by means of the electron spectroscopy and Z-scan technique, respectively. The thermal stability of PN was determined by thermogravimetry and differential scanning calorimetry. The experimental results show that the nonlinear absorption coefficient of PN at 532 nm and 180 fs is β=9.0×10-14 m/W, exhibiting ultrafast third-order nonlinear optical response. The molecular orbital energy, polarizability and hyperpolarizability were calculated by density functional theory, and the results show that electron transfer can take place within the molecule. There is no absorbance at more than 450 nm in ultraviolet spectrum of PN. So it is a candidate material for the next in nonlinear optical absorption, laser protection, absorption optical switch or bistable devices.
2019, 36(10): 1179-1185
doi: 10.11944/j.issn.1000-0518.2019.10.190050
Abstract:
Three silicon compounds were synthesized by reaction of dimethyldichlorosilane with 1, 1, 3, 3-tetramethylguanidine substituent and lithium amide. The structures of the compounds were verified by 1H nuclear magnetic resonance (NMR), 13C NMR, electron ionization-mass spectrometry (EI-MS), and elemental analysis. The thermal stability and vapor pressures of these compounds were evaluated by thermo gravimetric analysis(TGA). The results show a nearly pure volatilization with low decomposition process and residual(< 1%). The highest vapor pressure ranges from 3600 Pa to 5300 Pa, which is suitable for chemical vapor deposition (CVD) precursors. Silicon films were prepared by using dimethyl-guanidinato-ethylmethylamide silane as the precursor in Helicon wave plasma CVD (HWP-CVD). The properties of the films were studied by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The films are composed of Si, N, and C. Guanidinate-based silicon compounds as CVD precursors have potential applications in fabrication of semiconductor devices.
Three silicon compounds were synthesized by reaction of dimethyldichlorosilane with 1, 1, 3, 3-tetramethylguanidine substituent and lithium amide. The structures of the compounds were verified by 1H nuclear magnetic resonance (NMR), 13C NMR, electron ionization-mass spectrometry (EI-MS), and elemental analysis. The thermal stability and vapor pressures of these compounds were evaluated by thermo gravimetric analysis(TGA). The results show a nearly pure volatilization with low decomposition process and residual(< 1%). The highest vapor pressure ranges from 3600 Pa to 5300 Pa, which is suitable for chemical vapor deposition (CVD) precursors. Silicon films were prepared by using dimethyl-guanidinato-ethylmethylamide silane as the precursor in Helicon wave plasma CVD (HWP-CVD). The properties of the films were studied by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The films are composed of Si, N, and C. Guanidinate-based silicon compounds as CVD precursors have potential applications in fabrication of semiconductor devices.
2019, 36(10): 1186-1193
doi: 10.11944/j.issn.1000-0518.2019.10.190163
Abstract:
Three novel boron-containing ionic liquids(ILs), 1-alkyl-3-methylimidazolium benzyoltrifluoroborates([Cnmim], n=4, 6, 8), were successfully synthesized and some of their physico-chemical properties were characterized by nuclear magnetic resonance(NMR), differential scanning calorimeter(DSC), and thermogravimetric analysis(TGA). It was found that their decomposition temperatures were around 200℃. With the increase of the length of carbon chain on the imidazolium ring, the melting temperature, viscosity and hydrophobicity gradually increased.[C4mim] was hydrophilic, while[C6mim] and[C8mim] were hydrophobic. In particular, the later two were more stable when they mixed with water for a long time. In other words, the shortcoming of tetrafluoroborate ILs(i.e., strong hydrophilicity, especially the easy hydrolysis of BF4-) was overcome to great extent. Thus, it is hopeful for the two ILs to be used in the field of spent fuel reprocessing, which will effectively impove the critical safety.
Three novel boron-containing ionic liquids(ILs), 1-alkyl-3-methylimidazolium benzyoltrifluoroborates([Cnmim], n=4, 6, 8), were successfully synthesized and some of their physico-chemical properties were characterized by nuclear magnetic resonance(NMR), differential scanning calorimeter(DSC), and thermogravimetric analysis(TGA). It was found that their decomposition temperatures were around 200℃. With the increase of the length of carbon chain on the imidazolium ring, the melting temperature, viscosity and hydrophobicity gradually increased.[C4mim] was hydrophilic, while[C6mim] and[C8mim] were hydrophobic. In particular, the later two were more stable when they mixed with water for a long time. In other words, the shortcoming of tetrafluoroborate ILs(i.e., strong hydrophilicity, especially the easy hydrolysis of BF4-) was overcome to great extent. Thus, it is hopeful for the two ILs to be used in the field of spent fuel reprocessing, which will effectively impove the critical safety.
2019, 36(10): 1194-1201
doi: 10.11944/j.issn.1000-0518.2019.10.190007
Abstract:
H2S is a component with sulfur in coal gas and it is worth studying whether activated carbon can catalyze the H2S in coal gas to form active sulfur, so as to promote the synergistic removal of H2S and Hg0. In this paper, the mechanism of H2S influence on the removal of Hg0 from activated carbon was analyzed by temperature programmed desorption method and thermodynamics. H2S significantly weakened the adsorption of activated carbon on Hg0 in low temperature, which may be caused by the consumption of adsorbed oxygen on the surface of activated carbon and the substitution of oxygen in oxygen containing functional groups by H2S. Then the feasibility of H2S in coal gas to remove Hg0 and H2S in high temperature was discussed. High temperature sulfuration cannot effectively sulfurize activated carbon with active sulfur. Therefore, mercury removal in the form of HgS with H2S as a sulfur source is not a feasible method by activated carbon. The mechanism revealed here in on the influence of H2S on Hg0 removal from pure activated carbon provides the guidance for designing activated carbon for gas mercury removal.
H2S is a component with sulfur in coal gas and it is worth studying whether activated carbon can catalyze the H2S in coal gas to form active sulfur, so as to promote the synergistic removal of H2S and Hg0. In this paper, the mechanism of H2S influence on the removal of Hg0 from activated carbon was analyzed by temperature programmed desorption method and thermodynamics. H2S significantly weakened the adsorption of activated carbon on Hg0 in low temperature, which may be caused by the consumption of adsorbed oxygen on the surface of activated carbon and the substitution of oxygen in oxygen containing functional groups by H2S. Then the feasibility of H2S in coal gas to remove Hg0 and H2S in high temperature was discussed. High temperature sulfuration cannot effectively sulfurize activated carbon with active sulfur. Therefore, mercury removal in the form of HgS with H2S as a sulfur source is not a feasible method by activated carbon. The mechanism revealed here in on the influence of H2S on Hg0 removal from pure activated carbon provides the guidance for designing activated carbon for gas mercury removal.
2019, 36(10): 1202-1210
doi: 10.11944/j.issn.1000-0518.2019.10.190039
Abstract:
The preparation of three dimensional(3D) graphene hydrogels is mostly concentrated on the centimeter scale and solid symmetrical structures while the contradiction between small size and low density exists. The graphene mini-motor constructed by the combination of shear-driven aggregation and capillary force induced drying followed by high temperature reduction using graphene oxide suspension as the precursor and aniline as the crosslinking agent. The graphene mini-motor shows ethanol-driven motion and oil adsorption performance because of its small size(about 2~5 mm in diameter), low density(about 0.2~0.7 g/cm3), hollow structure and hydrophobic oleophilicity. It is found that the fastest speed of ethanol-driven rotation can reach 3 r/s, and the saturated adsorption capacity is 794.9 mg/g.
The preparation of three dimensional(3D) graphene hydrogels is mostly concentrated on the centimeter scale and solid symmetrical structures while the contradiction between small size and low density exists. The graphene mini-motor constructed by the combination of shear-driven aggregation and capillary force induced drying followed by high temperature reduction using graphene oxide suspension as the precursor and aniline as the crosslinking agent. The graphene mini-motor shows ethanol-driven motion and oil adsorption performance because of its small size(about 2~5 mm in diameter), low density(about 0.2~0.7 g/cm3), hollow structure and hydrophobic oleophilicity. It is found that the fastest speed of ethanol-driven rotation can reach 3 r/s, and the saturated adsorption capacity is 794.9 mg/g.
2019, 36(10): 1211-1220
doi: 10.11944/j.issn.1000-0518.2019.10.190052
Abstract:
The methanol concentration plays an important role in the performance of direct methanol fuel cells(DMFCs). This work aims to establish an effective controlling strategy of methanol concentration for DMFC power system. We combined the methanol conservation equation and the thermal conservation equation to analyze the mass transport process inside DMFC. The concentration strategy was established based on the two parameters, i.e., charge and temperature. The strategy was effective clarified by the relationship of temperature and concentration. By applying the strategy, the DMFC power system realizes stable operation over 420 min. The appropriate methanol concentration of power system range from 0.70 to 0.87 mol/L. This strategy achieves the goal of methanol concentration control and will play a vital role in the DMFC power systems.
The methanol concentration plays an important role in the performance of direct methanol fuel cells(DMFCs). This work aims to establish an effective controlling strategy of methanol concentration for DMFC power system. We combined the methanol conservation equation and the thermal conservation equation to analyze the mass transport process inside DMFC. The concentration strategy was established based on the two parameters, i.e., charge and temperature. The strategy was effective clarified by the relationship of temperature and concentration. By applying the strategy, the DMFC power system realizes stable operation over 420 min. The appropriate methanol concentration of power system range from 0.70 to 0.87 mol/L. This strategy achieves the goal of methanol concentration control and will play a vital role in the DMFC power systems.
