The in situ spectroelectrochemical experiment shows that an absorption peak at 580.5 nm attributable to poly(methylene blue) grows slowly at the beginning of the electrolysis of methylene blue, and then this peak grow...The in situ spectroelectrochemical experiment shows that an absorption peak at 580.5 nm attributable to poly(methylene blue) grows slowly at the beginning of the electrolysis of methylene blue, and then this peak grows more quickly. The visible spectra prove that there are two absorption peaks at 580.5 and 690.2 nm respectively for the mixture solution after electrolysis. The former one indicates that poly(methylene blue)polymerized on the ITO electrode is partly soluble; the latter one is attributed to a water-soluble polymer since it completely dissolves in the aqueous solution. The result from the rotating ring-disk electrode identifies that an intermediate is produced at the disk electrode, which is collected at the ring electrode. The ring current increases with decreasing the ring potential and with increasing the rotation rate. Thus, the intermediate is a species carrying a positive charge and not too stable.The result from the XPS experiment shows that the anions can be doped into poly(methylene blue) film and dedoped from it during oxidation and reduction processes. The results from the impedance experiment indicate that the charge transfer impedance of poly(methylene blue) decreases with decreasing potential.展开更多
Hydrogels have attracted large attention in wastewater treatment fields due to their low-cost and good interaction with pollutants,among which novel double network hydrogel is an outstanding class.To expand the applic...Hydrogels have attracted large attention in wastewater treatment fields due to their low-cost and good interaction with pollutants,among which novel double network hydrogel is an outstanding class.To expand the application of double network hydrogel in water treatment,in this study,eco-friendly physically cross-linked double network polymer hydrogel beads(DAP)are prepared and studied in depth on the mechanism of Methylene Blue(MB)adsorption;and then the polymer hydrogels are further functionalized by inorganic materials.MB adsorption on DAP favors alkaline condition which is due to the increase of electrostatic attraction and adsorption site,and it reaches equilibrium within 10 hr,which is faster than that of the single network hydrogel beads(SAP).Through thermodynamics study,the process shows to be an exothermic and spontaneous process.The adsorption isotherms are well fitted by Langmuir model,with a maximum monolayer adsorption capacity of 1437.48 mg/g,which is larger than SAP(1255.75 mg/g).After being functionalized with common inorganic materials including activated carbon,Fe_3O_4and graphene oxide(GO),the composites show to have larger pore sizes and have obvious increases in adsorption capacity especially the one contains GO.Then the composites contains Fe_3O_4are used as heterogeneous Fenton catalyst which shows to have excellent performance in MB degradation.The results indicate the potential of polymer double network to be functionalized in environmental areas.展开更多
文摘The in situ spectroelectrochemical experiment shows that an absorption peak at 580.5 nm attributable to poly(methylene blue) grows slowly at the beginning of the electrolysis of methylene blue, and then this peak grows more quickly. The visible spectra prove that there are two absorption peaks at 580.5 and 690.2 nm respectively for the mixture solution after electrolysis. The former one indicates that poly(methylene blue)polymerized on the ITO electrode is partly soluble; the latter one is attributed to a water-soluble polymer since it completely dissolves in the aqueous solution. The result from the rotating ring-disk electrode identifies that an intermediate is produced at the disk electrode, which is collected at the ring electrode. The ring current increases with decreasing the ring potential and with increasing the rotation rate. Thus, the intermediate is a species carrying a positive charge and not too stable.The result from the XPS experiment shows that the anions can be doped into poly(methylene blue) film and dedoped from it during oxidation and reduction processes. The results from the impedance experiment indicate that the charge transfer impedance of poly(methylene blue) decreases with decreasing potential.
基金supported by the National Key R & D Program of China (No.2016YFA0203204)
文摘Hydrogels have attracted large attention in wastewater treatment fields due to their low-cost and good interaction with pollutants,among which novel double network hydrogel is an outstanding class.To expand the application of double network hydrogel in water treatment,in this study,eco-friendly physically cross-linked double network polymer hydrogel beads(DAP)are prepared and studied in depth on the mechanism of Methylene Blue(MB)adsorption;and then the polymer hydrogels are further functionalized by inorganic materials.MB adsorption on DAP favors alkaline condition which is due to the increase of electrostatic attraction and adsorption site,and it reaches equilibrium within 10 hr,which is faster than that of the single network hydrogel beads(SAP).Through thermodynamics study,the process shows to be an exothermic and spontaneous process.The adsorption isotherms are well fitted by Langmuir model,with a maximum monolayer adsorption capacity of 1437.48 mg/g,which is larger than SAP(1255.75 mg/g).After being functionalized with common inorganic materials including activated carbon,Fe_3O_4and graphene oxide(GO),the composites show to have larger pore sizes and have obvious increases in adsorption capacity especially the one contains GO.Then the composites contains Fe_3O_4are used as heterogeneous Fenton catalyst which shows to have excellent performance in MB degradation.The results indicate the potential of polymer double network to be functionalized in environmental areas.
