Nitroaromatic explosives are major pollutants produced during wars that cause serious environmental and health problems. The removal of a typical nitroaromatic explosive, 2,4,6-trinitrotoluene(TNT), from aqueous solut...Nitroaromatic explosives are major pollutants produced during wars that cause serious environmental and health problems. The removal of a typical nitroaromatic explosive, 2,4,6-trinitrotoluene(TNT), from aqueous solution, was conducted using a new recyclable magnetic nano-adsorbent(Fe@SiO_(2) –NH_(2)). This adsorbent was prepared by grafting amino groups onto Fe@SiO_(2) particles with a well-defined core-shell structure and demonstrated monodispersity in solution. The removal performance of the nano-adsorbent towards TNT was found to be 2.57 and 4.92 times higher than that towards two analogous explosives, 2,4-dinitrotoluene(2,4-DNT) and 2-nitrotoluene(2-NT), respectively, under neutral conditions. The difference in the removal performance among the three compounds was further compared in terms of the effects of different conditions(pH value, ionic strength, humic acid concentration, adsorbent modification degree and dosage, etc.) and the electrostatic potential distributions of the three compounds. The most significant elevation is owing to modification of amino on Fe@SiO_(2) which made a 20.7% increase in adsorption efficiency of TNT. The experimental data were well fit by the pseudo-second-order kinetic model and the Freundlich adsorption isotherm model, indicating multilayer adsorption on a heterogeneous surface. The experimental results and theoretical considerations show that the interactions between Fe@SiO_(2) –NH_(2) NPs and TNT correspond to dipole-dipole and hydrophobic interactions. These interactions should be considered in the design of an adsorbent. Furthermore, the adaptability to aqueous environment and excellent regeneration capacity of Fe@SiO_(2) –NH_(2) NPs makes these remediation materials promising for applications.展开更多
2,4,6-trinitrotoluene(TNT)is a commonly used explosive.It is not only a threat to public safety but also causes environmental pollution,affecting human health.However,at this stage of TNT detection,technology cannot m...2,4,6-trinitrotoluene(TNT)is a commonly used explosive.It is not only a threat to public safety but also causes environmental pollution,affecting human health.However,at this stage of TNT detection,technology cannot meet the demands of the current situation.To acquire a new method devoted to the study of fast and quantitative detection of TNT.It combines the molecular imprinting technique(MIT)with surface plasmon resonance(SPR)technology for high sensitivity.In this study,a molecularly imprinted polymer(MIP)film for the detection of TNT was synthesized by heat in acetonitrile at 60°C,using the TNT imprinting molecule and azobisisobutyronitrile(AEBN)as initiators.In the present work,there are many factors that can influence the elution efficiency,such as raw material ratios,fore-reaction time,reaction time,etc.The polymers have the highest elution efficiency when raw material mole ratios[n(TNT):n methacrylic acid(MAA):n ethylene glycol dimethylacrylate(EGDMA)]were 1:4:8;the MIP sensor could detect a TNT concentration as low as 1x10-10 M.Compared to the blank polymer with the same chemical composition,the imprinted polymer had higher binding efficiency and higher selectivity.展开更多
In this work,metal oxide nanoparticle ZnO was employed for the reinforcement of TNT.Scanning electronic microscopy(SEM)was used to study the microstructure on the fractured surface of TNT/nano-ZnO,and ultraviolet-visi...In this work,metal oxide nanoparticle ZnO was employed for the reinforcement of TNT.Scanning electronic microscopy(SEM)was used to study the microstructure on the fractured surface of TNT/nano-ZnO,and ultraviolet-visible(UV-Vis)spectroscopy was utilized for structure characterization.Moreover,to understand the reinforcing mechanism between ZnO and TNT,quantum chemistry and molecular dynamics simulation were undertaken to investigate the intermolecular interaction and mechanical properties.It is concluded that with 2.85 wt%ZnO nanoparticle addition,the amount of voids and defects decreases with the increase in bulk and shear modulus.The modified TNT/ZnO composite has high heat of formation,negative oxygen balance,and good detonation properties,which is expected to be a candidate for high-energy blended explosives.展开更多
基金supported by the National Natural Science Foundation of China(No.21677177)the Science Foundation of China University of Petroleum-Beijing(No.2462020XKJS04)+1 种基金the Beijing Municipal Science&Technology Commission(No.Z181100005318002)the China Postdoctoral Science Foundation(No.2018M631491)。
文摘Nitroaromatic explosives are major pollutants produced during wars that cause serious environmental and health problems. The removal of a typical nitroaromatic explosive, 2,4,6-trinitrotoluene(TNT), from aqueous solution, was conducted using a new recyclable magnetic nano-adsorbent(Fe@SiO_(2) –NH_(2)). This adsorbent was prepared by grafting amino groups onto Fe@SiO_(2) particles with a well-defined core-shell structure and demonstrated monodispersity in solution. The removal performance of the nano-adsorbent towards TNT was found to be 2.57 and 4.92 times higher than that towards two analogous explosives, 2,4-dinitrotoluene(2,4-DNT) and 2-nitrotoluene(2-NT), respectively, under neutral conditions. The difference in the removal performance among the three compounds was further compared in terms of the effects of different conditions(pH value, ionic strength, humic acid concentration, adsorbent modification degree and dosage, etc.) and the electrostatic potential distributions of the three compounds. The most significant elevation is owing to modification of amino on Fe@SiO_(2) which made a 20.7% increase in adsorption efficiency of TNT. The experimental data were well fit by the pseudo-second-order kinetic model and the Freundlich adsorption isotherm model, indicating multilayer adsorption on a heterogeneous surface. The experimental results and theoretical considerations show that the interactions between Fe@SiO_(2) –NH_(2) NPs and TNT correspond to dipole-dipole and hydrophobic interactions. These interactions should be considered in the design of an adsorbent. Furthermore, the adaptability to aqueous environment and excellent regeneration capacity of Fe@SiO_(2) –NH_(2) NPs makes these remediation materials promising for applications.
基金This work is one part of research on drug and development of explosive detection technique,and was supported by the Opening Project of Key Laboratory of Evidence Science(China University of Political Science and Law)Ministry of Education(2012KFKT07)+1 种基金the Program for Young Innovative Research Team in China University of Political Science and Law(1000-10814344)Academician Foundation of the Ministry of Public Security of the People's Republic of China(No.2011-23210044,2011-23211119,23212052).
文摘2,4,6-trinitrotoluene(TNT)is a commonly used explosive.It is not only a threat to public safety but also causes environmental pollution,affecting human health.However,at this stage of TNT detection,technology cannot meet the demands of the current situation.To acquire a new method devoted to the study of fast and quantitative detection of TNT.It combines the molecular imprinting technique(MIT)with surface plasmon resonance(SPR)technology for high sensitivity.In this study,a molecularly imprinted polymer(MIP)film for the detection of TNT was synthesized by heat in acetonitrile at 60°C,using the TNT imprinting molecule and azobisisobutyronitrile(AEBN)as initiators.In the present work,there are many factors that can influence the elution efficiency,such as raw material ratios,fore-reaction time,reaction time,etc.The polymers have the highest elution efficiency when raw material mole ratios[n(TNT):n methacrylic acid(MAA):n ethylene glycol dimethylacrylate(EGDMA)]were 1:4:8;the MIP sensor could detect a TNT concentration as low as 1x10-10 M.Compared to the blank polymer with the same chemical composition,the imprinted polymer had higher binding efficiency and higher selectivity.
基金financially supported by Joint Fund of the National Natural Science Foundation of China and China Academy of Engineering Physics(No.11076002)the National Natural Science Foundation of China(Nos.51373159 and 11402237)the Science and Technology Fund of China Academy of Engineering Physics(No.2015B0302055)。
文摘In this work,metal oxide nanoparticle ZnO was employed for the reinforcement of TNT.Scanning electronic microscopy(SEM)was used to study the microstructure on the fractured surface of TNT/nano-ZnO,and ultraviolet-visible(UV-Vis)spectroscopy was utilized for structure characterization.Moreover,to understand the reinforcing mechanism between ZnO and TNT,quantum chemistry and molecular dynamics simulation were undertaken to investigate the intermolecular interaction and mechanical properties.It is concluded that with 2.85 wt%ZnO nanoparticle addition,the amount of voids and defects decreases with the increase in bulk and shear modulus.The modified TNT/ZnO composite has high heat of formation,negative oxygen balance,and good detonation properties,which is expected to be a candidate for high-energy blended explosives.
