The separation of ultrafine oil droplets from wasted nanoemulsions stabilized with high concentration of surfactants is precondition for oil reuse and the safe discharge of effluent.However,the double barriers of the interfacial film and network structures formed by sur-factants in nanoemulsions significantly impede the oil-water separation.To destroy these surfactant protective layers,we proposed a newly-developed polyethyleneimine micelle template approach to achieve simultaneous surface charge manipulation and morphology transformation of magnetic nanospheres to magnetic nanorods.The results revealed that positively charged magnetic nanospheres exhibited limited separation performance of na-noemulsions,with a maximum chemical oxygen demand(COD)removal of 50％,whereas magnetic nanorods achieved more than 95％COD removal in less than 30 s.The magnetic nanorods were also applicable to wasted nanoemulsions from different sources and exhib-ited excellent resistance to wide pH changes.Owing to their unique one-dimensional struc-ture,the interfacial dispersion of magnetic nanorods was significantly promoted,leading to the efficient capture of surfactants and widespread destruction of both the interfacial film and network structure,which facilitated droplet merging into the oil phase.The easy-to-prepare and easy-to-tune strategy in this study paves a feasible avenue to simultaneously tailor surface charge and morphology of magnetic nanoparticles,and reveals the huge po-tential of morphology manipulation for producing high-performance nanomaterials to be applied in complex interfacial interaction process.We believe that the newly-developed magnetic-nanorods significantly contribute to hazardous oily waste remediation and ad-vances technology evolution toward problematic oil-pollution control.

Yongjiao Xiong;Xiangfeng Huang;Lexue Li;Wanqi Liu;Jialu Zhang;Mengfan He;Jia Liu;Lijun Lu;Kaiming Peng

College of Environmental Science and Engineering,State Key Laboratory of Pollution Control and Resource Reuse,Ministry of Education Key Laboratory of Yangtze River Water Environment,Tongji University,Shanghai 200092,China

环境科学学报（英文版）

[1]Yongjiao Xiong;Xiangfeng Huang;Lexue Li;Wanqi Liu;Jialu Zhang;Mengfan He;Jia Liu;Lijun Lu;Kaiming Peng-.Destructing surfactant network in nanoemulsions by positively charged magnetic nanorods to enhance oil-water separation)[J].环境科学学报（英文版）,2022(08):112-121

Destructing,factants,noemulsions

network,nanoemulsions,by,positively,charged,magnetic,nanorods,enhance,water,separation,ultrafine,droplets,from,wasted,stabilized,high,concentration,surfactants,precondition,reuse,safe,discharge,effluent,However,double,barriers,interfacial,film,structures,formed,significantly,impede,To,destroy,these,protective,layers,proposed,newly,developed,polyethyleneimine,micelle,template,approach,surface,manipulation,morphology,transformation,nanospheres,results,revealed,that,exhibited,limited,performance,maximum,chemical,oxygen,demand,COD,removal,whereas,achieved,more,than,less,were,also,applicable,different,sources,excellent,resistance,changes,Owing,their,unique,one,dimensional,dispersion,promoted,leading,efficient,capture,widespread,destruction,both,which,facilitated,merging,into,phase,easy,prepare,tune,strategy,this,study,paves,feasible,avenue,simultaneously,tailor,nanoparticles,reveals,huge,tential,producing,nanomaterials,applied,complex,interaction,process,We,believe,contribute,hazardous,oily,remediation,vances,technology,evolution,toward,problematic,pollution,control

0.538215