A novel Ni(Ⅱ) ion-imprinted silica gel polymer was prepared via the surface imprinting technique combined with aqueous solution polymerization by using 2-acrylamido-2-methyl-1-propanesulfonic acid(AMPS) as a func...A novel Ni(Ⅱ) ion-imprinted silica gel polymer was prepared via the surface imprinting technique combined with aqueous solution polymerization by using 2-acrylamido-2-methyl-1-propanesulfonic acid(AMPS) as a functional monomer for the selective separation of Ni(Ⅱ) from aqueous solution. The sorbent showed good chemical and thermal stability. Kinetics studies indicated that the equilibrium adsorption was achieved within 10 min and the adsorption kinetics fitted well with the pseudo-second-order kinetic model. The maximum adsorption capacity of the ion-imprinted polymer towards Ni(Ⅱ) at the optimal p H of 7.0 was 66.22 mg·g^(-1). The relative selectivity coefficients of the sorbent were 9.23, 15.71, 14.72 and 20.15 for Ni(Ⅱ)/Co(Ⅱ), Ni(Ⅱ)/Cu(Ⅱ), Ni(Ⅱ)/Zn(Ⅱ) and Ni(Ⅱ)/Pb(Ⅱ), respectively. The adsorption isotherm fitted well with Langmuir isotherm model. The thermodynamic results indicated that the adsorption of Ni(Ⅱ) was a spontaneous and endothermic process. The sorbent showed good reusability evidenced by six cycles of adsorption/desorption experiments. The precision of this method is satisfactory. Thus, the prepared sorbent can be considered as a promising sorbent for selective separation of Ni(Ⅱ) in real water samples.展开更多
In order to better understand linear polymer aqueous solutions in soft lubrication from boundary to mixed lubrication,poly(ethylene glycol) and sodium hyaluronateare used as model polymers were investigated by using U...In order to better understand linear polymer aqueous solutions in soft lubrication from boundary to mixed lubrication,poly(ethylene glycol) and sodium hyaluronateare used as model polymers were investigated by using UMT-2 tribometer with the ball-on-disk mode. The relationship between the master Stribeck curves of the polymer aqueous solutions and the influence factors were investigated. Experimental results indicated that soft lubrication is determined by lubricant rheological properties and surface-lubricant interactions, e.g., wetting behavior of polymer aqueous solution on tribological surfaces.展开更多
Based on the principle and calibration of vapor pressure os-mometer and itsapplication in the thermodynamics of the aqueous solutions, the results on aqueous solutions ofmonomer glycol, PEG_(200), PEG_(400), PEG_(1500...Based on the principle and calibration of vapor pressure os-mometer and itsapplication in the thermodynamics of the aqueous solutions, the results on aqueous solutions ofmonomer glycol, PEG_(200), PEG_(400), PEG_(1500) and PEG_(2000) over the different concentrationrange at various temperatures were reported. Using a linear least-square fitting routing, theosmotic coefficients were fitted by a simple polynomial equation. It was found that the relationshipbetween the molar osmotic coefficients (Φ) and the molar concentration (c) of the solutions are ina quite good agreement with the fitted polynomial equation at various temperatures over thedifferent concentration range. The experimental results also show that over the studiedconcentration range and at various temperatures, the concentration dependence of the molar osmoticcoefficients of the aqueous solution systems with the solutes of PEG_(200), PEG_(400), PEG_(1500)and PEG_(2000) are totally presented in a rising trend, and their temperature dependence of theosmotic coefficients of the aqueous solution systems of the molar concentration exhibits their ownregularities, respectively. The aqueous glycol solution system exhibits the properties of the dilutesolution.展开更多
Sodium polyacrylate was synthesized with acrylic acid as the monomer, and sodium bisulfate and ammonium persulfate as the initiator, by means of aqueous solution polymerization. The factors influencing the properties ...Sodium polyacrylate was synthesized with acrylic acid as the monomer, and sodium bisulfate and ammonium persulfate as the initiator, by means of aqueous solution polymerization. The factors influencing the properties of moisture absorption, such as monomer concentration, dosage of initiator, and reaction temperature were systematically investigated. The experimental results indicate that the moisture-absorbing property of this polymer was better than other traditional material, such as silica gel, and molecular sieve. The best reaction condition and formula are based on the orthogonal experiment design. The optimum moisture absorbency of sodium polyacrylate reaches 1.01 g/g. The mathematical correlation of this polymer with various factors and moisture absorbency is obtained based on the multiple regression analysis. The moisture content intuitive analysis table shows that neutralization degree has the most significant influence on moisture absorbency, followed by monomer concentration and reaction temperature, while other factors have less influence.展开更多
文摘A novel Ni(Ⅱ) ion-imprinted silica gel polymer was prepared via the surface imprinting technique combined with aqueous solution polymerization by using 2-acrylamido-2-methyl-1-propanesulfonic acid(AMPS) as a functional monomer for the selective separation of Ni(Ⅱ) from aqueous solution. The sorbent showed good chemical and thermal stability. Kinetics studies indicated that the equilibrium adsorption was achieved within 10 min and the adsorption kinetics fitted well with the pseudo-second-order kinetic model. The maximum adsorption capacity of the ion-imprinted polymer towards Ni(Ⅱ) at the optimal p H of 7.0 was 66.22 mg·g^(-1). The relative selectivity coefficients of the sorbent were 9.23, 15.71, 14.72 and 20.15 for Ni(Ⅱ)/Co(Ⅱ), Ni(Ⅱ)/Cu(Ⅱ), Ni(Ⅱ)/Zn(Ⅱ) and Ni(Ⅱ)/Pb(Ⅱ), respectively. The adsorption isotherm fitted well with Langmuir isotherm model. The thermodynamic results indicated that the adsorption of Ni(Ⅱ) was a spontaneous and endothermic process. The sorbent showed good reusability evidenced by six cycles of adsorption/desorption experiments. The precision of this method is satisfactory. Thus, the prepared sorbent can be considered as a promising sorbent for selective separation of Ni(Ⅱ) in real water samples.
基金supported by the National Natural Science Foundation of China(Grant No.51175514)the Ph.D.Programs Foundation of Ministry of Education of China(Grant No.20100007120010)+1 种基金the Tribology Science Fund of State Key Laboratory of Tribology(Grant No.SKLTKF11A05)the Science Foundation of China University of Petroleum,Beijing(Grant No.KYJJ2012-04-17)
文摘In order to better understand linear polymer aqueous solutions in soft lubrication from boundary to mixed lubrication,poly(ethylene glycol) and sodium hyaluronateare used as model polymers were investigated by using UMT-2 tribometer with the ball-on-disk mode. The relationship between the master Stribeck curves of the polymer aqueous solutions and the influence factors were investigated. Experimental results indicated that soft lubrication is determined by lubricant rheological properties and surface-lubricant interactions, e.g., wetting behavior of polymer aqueous solution on tribological surfaces.
文摘Based on the principle and calibration of vapor pressure os-mometer and itsapplication in the thermodynamics of the aqueous solutions, the results on aqueous solutions ofmonomer glycol, PEG_(200), PEG_(400), PEG_(1500) and PEG_(2000) over the different concentrationrange at various temperatures were reported. Using a linear least-square fitting routing, theosmotic coefficients were fitted by a simple polynomial equation. It was found that the relationshipbetween the molar osmotic coefficients (Φ) and the molar concentration (c) of the solutions are ina quite good agreement with the fitted polynomial equation at various temperatures over thedifferent concentration range. The experimental results also show that over the studiedconcentration range and at various temperatures, the concentration dependence of the molar osmoticcoefficients of the aqueous solution systems with the solutes of PEG_(200), PEG_(400), PEG_(1500)and PEG_(2000) are totally presented in a rising trend, and their temperature dependence of theosmotic coefficients of the aqueous solution systems of the molar concentration exhibits their ownregularities, respectively. The aqueous glycol solution system exhibits the properties of the dilutesolution.
基金Supported by the 863 Project (Grant No. 2005AA001650)
文摘Sodium polyacrylate was synthesized with acrylic acid as the monomer, and sodium bisulfate and ammonium persulfate as the initiator, by means of aqueous solution polymerization. The factors influencing the properties of moisture absorption, such as monomer concentration, dosage of initiator, and reaction temperature were systematically investigated. The experimental results indicate that the moisture-absorbing property of this polymer was better than other traditional material, such as silica gel, and molecular sieve. The best reaction condition and formula are based on the orthogonal experiment design. The optimum moisture absorbency of sodium polyacrylate reaches 1.01 g/g. The mathematical correlation of this polymer with various factors and moisture absorbency is obtained based on the multiple regression analysis. The moisture content intuitive analysis table shows that neutralization degree has the most significant influence on moisture absorbency, followed by monomer concentration and reaction temperature, while other factors have less influence.