The dispersion of nanoparticles plays a key role in enhancing the mechanical performance of polymer nanocomposites.In this work,one hybrid epoxy nanocomposite reinforced by a well dispersed,zinc oxide functionalized,m...The dispersion of nanoparticles plays a key role in enhancing the mechanical performance of polymer nanocomposites.In this work,one hybrid epoxy nanocomposite reinforced by a well dispersed,zinc oxide functionalized,multi-wall carbon nanotube (Zn O-MWCNT) and core-shell rubber (CSR) was prepared,which possesses both high modulus and fracture toughness while maintaining relatively high glass transition temperature (Tg).The improved fracture toughness from 0.82 MPa mfor neat epoxy to 1.46 MPa mfor the ternary epoxy nanocomposites is resulted from a series of synergistic toughening mechanisms,including cavitation of CSR-induced matrix shear banding,along with the fracture of MWCNTs and crack deflection.The implication of the present study for the preparation of high-performance polymer nanocomposites is discussed.展开更多
Most of the monitoring data on the occurrence of antibiotics in sewage treatment plants(STPs)have been reported from Europe,North America and some countries in Northeast Asia,while very limited data can be found in So...Most of the monitoring data on the occurrence of antibiotics in sewage treatment plants(STPs)have been reported from Europe,North America and some countries in Northeast Asia,while very limited data can be found in Southeast Asian countries.As a pioneering research in Sri Lanka,we collected 24 h composite wastewater samples at the influent and effluent of two municipal STPs for consecutive 7 days to investigate occurrence,consumption and removal efficiency of seventeen antibiotics.The STP was located in Colombo and Hikkaduwa,respectively,representing two kinds of communities(i.e.local and tourists)in Sri Lanka.The targeted antibiotics were extracted by solid-phase extraction method and detected on an Agilent HPLCMSMS(1290/6470QQQ).Results illustrated that the majority of the antibiotics can be always detected from both STPs,except for chlorotetracycine(CTC),doxycycline(DOX)and florfenicol(FF).Fluoroquinolones(FQs)were detected at highest concentrations with ciprofloxacin(CIP)being the dominant compound.Concentrations of CIP in the influent samples were in the range of 433 e6010 ng/L.The consumption of antibiotics was estimated on the basis of influent mass load and catchment population data.We found difference in consumption patterns between the two served areas.Compared to local people in Colombo,tourists in Hikkaduwa appeared to take more antibiotics during the study period with the estimated daily dose of 0.25 g per 1000 persons.Moreover,macrolides accounted for a larger portion than FQs in Hikkaduwa,with azithromycin(AZM)being the most prevalent antibacterial agent.After comparison with an official report by Medical Supplies Division of Sri Lanka,we conjected that AZM was not commonly used among local people and it was mainly introduced by foreign arrivals.As for the removal efficiency,the activated sludge system of Colombo exhibited better elimination and more stable performance than the constructed wetland process of Hikkaduwa.展开更多
基金the KANEKA Corporation for their financial support。
文摘The dispersion of nanoparticles plays a key role in enhancing the mechanical performance of polymer nanocomposites.In this work,one hybrid epoxy nanocomposite reinforced by a well dispersed,zinc oxide functionalized,multi-wall carbon nanotube (Zn O-MWCNT) and core-shell rubber (CSR) was prepared,which possesses both high modulus and fracture toughness while maintaining relatively high glass transition temperature (Tg).The improved fracture toughness from 0.82 MPa mfor neat epoxy to 1.46 MPa mfor the ternary epoxy nanocomposites is resulted from a series of synergistic toughening mechanisms,including cavitation of CSR-induced matrix shear banding,along with the fracture of MWCNTs and crack deflection.The implication of the present study for the preparation of high-performance polymer nanocomposites is discussed.
基金The authors acknowledge financial support on this research from the ＂1000 talents program＂ of China （Zhi Sun）, and the National Natural Science Foundation of China （51425405）. This research was also supported by the National Science-Technology Support Program （2015 BAB02B05）.
基金This work was funded by the International Partnership Program of the Chinese Academy of Sciences,(Grant No.132744KYSB20170002)UCAS scholarship for international students.The authors want to acknowledge the generous support from the National Water Supply and Drainage Board(Sewerage division),Sri Lanka and to Mr.S.M.Samaraweera for the assistance in wastewater sampling.
文摘Most of the monitoring data on the occurrence of antibiotics in sewage treatment plants(STPs)have been reported from Europe,North America and some countries in Northeast Asia,while very limited data can be found in Southeast Asian countries.As a pioneering research in Sri Lanka,we collected 24 h composite wastewater samples at the influent and effluent of two municipal STPs for consecutive 7 days to investigate occurrence,consumption and removal efficiency of seventeen antibiotics.The STP was located in Colombo and Hikkaduwa,respectively,representing two kinds of communities(i.e.local and tourists)in Sri Lanka.The targeted antibiotics were extracted by solid-phase extraction method and detected on an Agilent HPLCMSMS(1290/6470QQQ).Results illustrated that the majority of the antibiotics can be always detected from both STPs,except for chlorotetracycine(CTC),doxycycline(DOX)and florfenicol(FF).Fluoroquinolones(FQs)were detected at highest concentrations with ciprofloxacin(CIP)being the dominant compound.Concentrations of CIP in the influent samples were in the range of 433 e6010 ng/L.The consumption of antibiotics was estimated on the basis of influent mass load and catchment population data.We found difference in consumption patterns between the two served areas.Compared to local people in Colombo,tourists in Hikkaduwa appeared to take more antibiotics during the study period with the estimated daily dose of 0.25 g per 1000 persons.Moreover,macrolides accounted for a larger portion than FQs in Hikkaduwa,with azithromycin(AZM)being the most prevalent antibacterial agent.After comparison with an official report by Medical Supplies Division of Sri Lanka,we conjected that AZM was not commonly used among local people and it was mainly introduced by foreign arrivals.As for the removal efficiency,the activated sludge system of Colombo exhibited better elimination and more stable performance than the constructed wetland process of Hikkaduwa.
