Crystal growth of calcium carbonate in biological simulation was investigated via egg white protein with different volume fractions,during which calcium carbonate was synthesized by calcium chloride and sodium carbona...Crystal growth of calcium carbonate in biological simulation was investigated via egg white protein with different volume fractions,during which calcium carbonate was synthesized by calcium chloride and sodium carbonate.The morphology,thermal properties and microstructure of the calcium carbonate micro-to-nanoscale crystals were characterized by scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,Fourier transform infrared spectroscopy（FTIR）,thermogravimetric analysis（TG） and X-ray diffraction（XRD） analysis.The results show that the volume fraction of egg white protein has great influence on the shape,size and morphology of calcium carbonate crystals.The calcium carbonate crystals were the mixtures of calcite-vaterite-like crystals including spherical and rough surface,which are different from that formed in pure water.With the increase of egg white protein concentration,the diameter of calcium carbonate crystals changed,the amount of formed spherical calcium carbonate particles decreased and that of vaterite increased.These results indicate that the coordination and electrostatic interaction between egg white protein and Ca2＋ significantly affect the calcium carbonate crystalization.展开更多
An efficient reflux extraction of polyethylene wax(PEW) in soil is presented, followed by molecular structure characterization methods to explore its degradation mechanism. To more realistically simulate the actual de...An efficient reflux extraction of polyethylene wax(PEW) in soil is presented, followed by molecular structure characterization methods to explore its degradation mechanism. To more realistically simulate the actual degradation of PE film powders in soil, low density PE(M=5 000) powders, being used as simulated PEW residue sample, were uniformly mixed with soil and then recovered by reflux extraction with decahydronaphthalen(decalin) at 90 ?C for 60 min. The average recovery of PEW from fortified soils was 96.5% with the developed reflux extraction procedure. The recovered PEW residue samples were characterized by infrared spectroscopy(IR), element analysis(EA), X-ray fluorescence(XFR), and high-temperature gel permeation chromatography(GPC). The results from spectra analysis show that there were no significant changes in molecular structures and molecular mass distribution of PEW samples after the reflux extraction, which demonstrate the reliability of this method. These results also indicate that the reflux extraction procedure and analytical methods of characterization could serve as a novel measurement technique to evaluate the degradation of low-density PE powders in soil over time.展开更多
基金Supported by the Key Projects in the National Science & Technology Pillar Program During the Eleventh Five-year Plan Period,China(No.2007BAB18B08)
文摘Crystal growth of calcium carbonate in biological simulation was investigated via egg white protein with different volume fractions,during which calcium carbonate was synthesized by calcium chloride and sodium carbonate.The morphology,thermal properties and microstructure of the calcium carbonate micro-to-nanoscale crystals were characterized by scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,Fourier transform infrared spectroscopy（FTIR）,thermogravimetric analysis（TG） and X-ray diffraction（XRD） analysis.The results show that the volume fraction of egg white protein has great influence on the shape,size and morphology of calcium carbonate crystals.The calcium carbonate crystals were the mixtures of calcite-vaterite-like crystals including spherical and rough surface,which are different from that formed in pure water.With the increase of egg white protein concentration,the diameter of calcium carbonate crystals changed,the amount of formed spherical calcium carbonate particles decreased and that of vaterite increased.These results indicate that the coordination and electrostatic interaction between egg white protein and Ca2＋ significantly affect the calcium carbonate crystalization.
基金Funded by National Eleventh Five-Year Plan Technology Support Program of China(2007BAE42B04)the Open Project of State Key Laboratory Cultivation Base for Nonmetal Composites,Functional Materials of Sichuan Province(10zxfk23)+1 种基金Scientific Research Project of Sichuan Normal University(11KYL06)Key Fund Project of Sichuan Provincial Department of Education(14ZA0027)
文摘An efficient reflux extraction of polyethylene wax(PEW) in soil is presented, followed by molecular structure characterization methods to explore its degradation mechanism. To more realistically simulate the actual degradation of PE film powders in soil, low density PE(M=5 000) powders, being used as simulated PEW residue sample, were uniformly mixed with soil and then recovered by reflux extraction with decahydronaphthalen(decalin) at 90 ?C for 60 min. The average recovery of PEW from fortified soils was 96.5% with the developed reflux extraction procedure. The recovered PEW residue samples were characterized by infrared spectroscopy(IR), element analysis(EA), X-ray fluorescence(XFR), and high-temperature gel permeation chromatography(GPC). The results from spectra analysis show that there were no significant changes in molecular structures and molecular mass distribution of PEW samples after the reflux extraction, which demonstrate the reliability of this method. These results also indicate that the reflux extraction procedure and analytical methods of characterization could serve as a novel measurement technique to evaluate the degradation of low-density PE powders in soil over time.
