The adsorption of 2,4-dinitrophenol and 2.6-dinitrophenol on non-polar and polar adsorbents was studied. The results showed that the equilibrium adsorption did not comply with the Langmuir equation and was not mono-la...The adsorption of 2,4-dinitrophenol and 2.6-dinitrophenol on non-polar and polar adsorbents was studied. The results showed that the equilibrium adsorption did not comply with the Langmuir equation and was not mono-layer absorption. It is of interest to notice that the effect of pH on the adsorption of 2.4-or 2,6-dinitrophenol onto ADS-7 and ADS-21 was very small. The result is explained by hydrogen bonding interaction between 2, 4- or 2. 6-dinitrophenol and the adsorbent ADS21. The large adsorption capacity of dinitrophenol onto ADS-21, which was about 500 mg/g at an equilibrium concentration of 400 mg/L. and the small dinitrophenol leakage in the effluent from ADS- 21 column presented a good prospect for treatment of wastewater containing dinitrophenol with absorbent ADS-21.展开更多
A strongly hydrophilic hydrogen-bonding adsorbent-macroporous crosslinked poly(N- vinyl-acetamide). which contain both hydrogen bond acceptor and donator, was synthesized. Adsorption mechanism and dynamic adsorption o...A strongly hydrophilic hydrogen-bonding adsorbent-macroporous crosslinked poly(N- vinyl-acetamide). which contain both hydrogen bond acceptor and donator, was synthesized. Adsorption mechanism and dynamic adsorption of tannin from aqueous solution onto the adsorbent were investigated. Most of the differential adsorption heats for various adsorption capacities calculated from the adsorption isotherms according to Clapeyron-Clausius equation lay in the range of hydrogen bond energy (8-50kJ/mol). Adsorption properties of the adsorbent were studied in detail. These results revealed a hydrogen bonding mechanism of the adsorption of tannin from aqueous solution onto the adsorbent. The result of the dynamic adsorption of tanning with the initial concentration under 600 mg/L showed that the adsorption rate of tannin exceeded 90% when the flow rate was 3BV/h and the effluent volume reached 100 BV. Therefore, the developed hydrogen-bonding adsorbent--macroporous crosslinked poly(N-vinyl-acetamide)—is an excellent adsorbent to remove tannin from extract of natural products. and has great value in application.展开更多
After a concise introduction of hydrogen bonding effects in solute-solute and solutesolvent bonding, the design of polymeric adsorbents based on hydrogen bonding, selectivity in adsorption through hydrogen bonding. an...After a concise introduction of hydrogen bonding effects in solute-solute and solutesolvent bonding, the design of polymeric adsorbents based on hydrogen bonding, selectivity in adsorption through hydrogen bonding. and characterization of hydrogen bonding in adsorption and separation were reviewed with 28 references.展开更多
Two hydrogen-bonding adsorbents-macroporous crosslinked poly(p-nitrostyrene) and poly(p-vinylbenzyl amide)--were synthesized, and the absorption property of phenol from cyclohexane solution onto the adsorbents was stu...Two hydrogen-bonding adsorbents-macroporous crosslinked poly(p-nitrostyrene) and poly(p-vinylbenzyl amide)--were synthesized, and the absorption property of phenol from cyclohexane solution onto the adsorbents was studied. The differential adsorption heats for varied adsorption capacities calculated from the adsorption isotherms according to the Clapeyron-Clausius equation lay in the range of hydrogen bond energy (8-50kJ/mol). The adsorption capacity of o-nitrophenol in cyclohexane was much less than that of phenol under the same condition. The adsorption capacity of phenol from cyclohexane onto polyacrylonitile was much less than that onto poly(p-nitrostyrene) or poly(p-vinylbenzyl amide). All these results revealed that adsorption of phenol from cyclohexane by poly(p-nitrostyrene) or poly(p-vinylbenzyl amide) is based on hydrogen-bonding.展开更多
Spherical macroporous copolymers of methyl acrylate and trimethylolpropane triacrylate with different surface and pore structure were synthesized via suspension polymerization. and their surface and pore structure wer...Spherical macroporous copolymers of methyl acrylate and trimethylolpropane triacrylate with different surface and pore structure were synthesized via suspension polymerization. and their surface and pore structure were characterized by measurements of surface area, apparent density and skeleton density and calculation of average pore diameter The results revealed that crosslinking degree and porogent determined the physical structure of these copolymers. Some of the copolymers were applied to adsorptive purification of ginkgo leaves extract to enhance the content of flavonoids, the results showed that most of the copolymers could be used to increase the flavonoids content.展开更多
The adsorption isotherms of caffeine from aqueous solution onto three hydrogen donating adsorbents - hydroxypolystyrene. polystyrene-azo-pyrogallol, and D72 resin-were measured. The adsorption enthalpies calculated fr...The adsorption isotherms of caffeine from aqueous solution onto three hydrogen donating adsorbents - hydroxypolystyrene. polystyrene-azo-pyrogallol, and D72 resin-were measured. The adsorption enthalpies calculated from the isotherms according to the Clausius-Clapeyron equation were-24~ -36kJ/mol, -32~ -37kJ/mol. and -19~ -24kJ/mol respectively These values implied that the absorption processes were based on hydrogen bonding. Furthermore, the mechanism of the adsorption of caffeine onto D72 resin was studied by IR spectra and the small molecular model experiments. and the results showed that the adsorption of caffeine onto hydrogen donating adsorbents was based on hydrogen bonding.展开更多
Possibilities for enhancement of catalytic reaction rate by combining phase transfer catalysis and hydrogen bonding of the catalyst with the substrate and reagent were studied. A phase transfer catalyst library with s...Possibilities for enhancement of catalytic reaction rate by combining phase transfer catalysis and hydrogen bonding of the catalyst with the substrate and reagent were studied. A phase transfer catalyst library with sixty polystyrene-supported quaternary ammonium salt catalysts was synthesized. The reduction of acetophenone by NaBH, was used as the probing reaction to select out the most active catalyst in the library by using iterative method, which was the gel-type triethanolamine aminating strongly basic anion exchange resin with the crosslinking degree of 2% A hydrogen bonding assisted catalytic mechanism was proposed to explain the high catalytic activity of the catalyst.展开更多
Spherical crosslinked polystyrene-isocyanuric acid resin was synthesized by reaction of chloromethylated polystyrene with isocyanuric acid. The sorption isotherms of phenol from aqueous solution and cyclohexane soluti...Spherical crosslinked polystyrene-isocyanuric acid resin was synthesized by reaction of chloromethylated polystyrene with isocyanuric acid. The sorption isotherms of phenol from aqueous solution and cyclohexane solution onto the resin were measured. It is of interest to notice that the resin sorbed phenol efficiently though its specific surface area was 0 and did not swell in water, and the sorption capacity.from aqueous solution was close to that of phenol onto XAD-4 at the same equilibrium concentration. Sorption enthalpies calculated from the isotherms according to the Clausius-Clapeyron equation were -2I~ -25lJ/mol and -39~ -41kJ/mol respectively. These values implied that the sorption processes were based on hydrogen bonding. In addition the details of the hydrogen bonding between the active sites of the resin and phenol were suggested.展开更多
Molecular imprinted polymers (MIPs) are novel functional polymer materials and known as specific adsorbents for the template molecules. These novel functional polymers have promised potential applications in racemic r...Molecular imprinted polymers (MIPs) are novel functional polymer materials and known as specific adsorbents for the template molecules. These novel functional polymers have promised potential applications in racemic resolution, sensor, chromatography, adsorptive separation and other fields. This review exhibits the approach for preparing MIPs, the features of MIPs obtained by different routes and the characteristics of adsorptive separations with MIPs. The molecular recognition mechanism and the idea of the present possibilities and limitations of molecular imprinting polymerization are discussed as well.展开更多
基金Supported by the National Natural Science Foundation of China !(Grant No. 29574164)
文摘The adsorption of 2,4-dinitrophenol and 2.6-dinitrophenol on non-polar and polar adsorbents was studied. The results showed that the equilibrium adsorption did not comply with the Langmuir equation and was not mono-layer absorption. It is of interest to notice that the effect of pH on the adsorption of 2.4-or 2,6-dinitrophenol onto ADS-7 and ADS-21 was very small. The result is explained by hydrogen bonding interaction between 2, 4- or 2. 6-dinitrophenol and the adsorbent ADS21. The large adsorption capacity of dinitrophenol onto ADS-21, which was about 500 mg/g at an equilibrium concentration of 400 mg/L. and the small dinitrophenol leakage in the effluent from ADS- 21 column presented a good prospect for treatment of wastewater containing dinitrophenol with absorbent ADS-21.
基金Supported by the National Natural Science Foundation of China! (Grant No. 29574164)
文摘A strongly hydrophilic hydrogen-bonding adsorbent-macroporous crosslinked poly(N- vinyl-acetamide). which contain both hydrogen bond acceptor and donator, was synthesized. Adsorption mechanism and dynamic adsorption of tannin from aqueous solution onto the adsorbent were investigated. Most of the differential adsorption heats for various adsorption capacities calculated from the adsorption isotherms according to Clapeyron-Clausius equation lay in the range of hydrogen bond energy (8-50kJ/mol). Adsorption properties of the adsorbent were studied in detail. These results revealed a hydrogen bonding mechanism of the adsorption of tannin from aqueous solution onto the adsorbent. The result of the dynamic adsorption of tanning with the initial concentration under 600 mg/L showed that the adsorption rate of tannin exceeded 90% when the flow rate was 3BV/h and the effluent volume reached 100 BV. Therefore, the developed hydrogen-bonding adsorbent--macroporous crosslinked poly(N-vinyl-acetamide)—is an excellent adsorbent to remove tannin from extract of natural products. and has great value in application.
基金Supported by the National Natural Science Foundation of China! (Grant No. 29574164 and 29974015)
文摘After a concise introduction of hydrogen bonding effects in solute-solute and solutesolvent bonding, the design of polymeric adsorbents based on hydrogen bonding, selectivity in adsorption through hydrogen bonding. and characterization of hydrogen bonding in adsorption and separation were reviewed with 28 references.
基金Supported by the National Natural Science Foundation of China !(Grant No. 29574164 and 29974015)
文摘Two hydrogen-bonding adsorbents-macroporous crosslinked poly(p-nitrostyrene) and poly(p-vinylbenzyl amide)--were synthesized, and the absorption property of phenol from cyclohexane solution onto the adsorbents was studied. The differential adsorption heats for varied adsorption capacities calculated from the adsorption isotherms according to the Clapeyron-Clausius equation lay in the range of hydrogen bond energy (8-50kJ/mol). The adsorption capacity of o-nitrophenol in cyclohexane was much less than that of phenol under the same condition. The adsorption capacity of phenol from cyclohexane onto polyacrylonitile was much less than that onto poly(p-nitrostyrene) or poly(p-vinylbenzyl amide). All these results revealed that adsorption of phenol from cyclohexane by poly(p-nitrostyrene) or poly(p-vinylbenzyl amide) is based on hydrogen-bonding.
基金Supported by the National Natural Science Foundation of China !(Grant No. 29574164)
文摘Spherical macroporous copolymers of methyl acrylate and trimethylolpropane triacrylate with different surface and pore structure were synthesized via suspension polymerization. and their surface and pore structure were characterized by measurements of surface area, apparent density and skeleton density and calculation of average pore diameter The results revealed that crosslinking degree and porogent determined the physical structure of these copolymers. Some of the copolymers were applied to adsorptive purification of ginkgo leaves extract to enhance the content of flavonoids, the results showed that most of the copolymers could be used to increase the flavonoids content.
基金Supported by the National Natural Science Fsundation of China !(Grant No. 29574164)
文摘The adsorption isotherms of caffeine from aqueous solution onto three hydrogen donating adsorbents - hydroxypolystyrene. polystyrene-azo-pyrogallol, and D72 resin-were measured. The adsorption enthalpies calculated from the isotherms according to the Clausius-Clapeyron equation were-24~ -36kJ/mol, -32~ -37kJ/mol. and -19~ -24kJ/mol respectively These values implied that the absorption processes were based on hydrogen bonding. Furthermore, the mechanism of the adsorption of caffeine onto D72 resin was studied by IR spectra and the small molecular model experiments. and the results showed that the adsorption of caffeine onto hydrogen donating adsorbents was based on hydrogen bonding.
基金Supported by the National Natural Science Foundation of China !(Grant No. 29574164 and 29974015)
文摘Possibilities for enhancement of catalytic reaction rate by combining phase transfer catalysis and hydrogen bonding of the catalyst with the substrate and reagent were studied. A phase transfer catalyst library with sixty polystyrene-supported quaternary ammonium salt catalysts was synthesized. The reduction of acetophenone by NaBH, was used as the probing reaction to select out the most active catalyst in the library by using iterative method, which was the gel-type triethanolamine aminating strongly basic anion exchange resin with the crosslinking degree of 2% A hydrogen bonding assisted catalytic mechanism was proposed to explain the high catalytic activity of the catalyst.
基金Supported by the National Natural Science Foundation of China !(Grant No. 29574164 and 29974015)
文摘Spherical crosslinked polystyrene-isocyanuric acid resin was synthesized by reaction of chloromethylated polystyrene with isocyanuric acid. The sorption isotherms of phenol from aqueous solution and cyclohexane solution onto the resin were measured. It is of interest to notice that the resin sorbed phenol efficiently though its specific surface area was 0 and did not swell in water, and the sorption capacity.from aqueous solution was close to that of phenol onto XAD-4 at the same equilibrium concentration. Sorption enthalpies calculated from the isotherms according to the Clausius-Clapeyron equation were -2I~ -25lJ/mol and -39~ -41kJ/mol respectively. These values implied that the sorption processes were based on hydrogen bonding. In addition the details of the hydrogen bonding between the active sites of the resin and phenol were suggested.
文摘Molecular imprinted polymers (MIPs) are novel functional polymer materials and known as specific adsorbents for the template molecules. These novel functional polymers have promised potential applications in racemic resolution, sensor, chromatography, adsorptive separation and other fields. This review exhibits the approach for preparing MIPs, the features of MIPs obtained by different routes and the characteristics of adsorptive separations with MIPs. The molecular recognition mechanism and the idea of the present possibilities and limitations of molecular imprinting polymerization are discussed as well.
