Complex interplay between formation routes and natural organic matter modification controls capabilities of C_(60)nanoparticles(nC_(60)) to accumulate organic contaminants

Accumulation of organic contaminants on fullerene nanoparticles（nC（60）） may significantly affect the risks of C（60） in the environment.The objective of this study was to further understand how the interplay of nC（60） formation routes and humic acid modification affects contaminant adsorption of nC（60）.Specifically,adsorption of 1,2,4,5-tetrachlorobenzene（a model nonionic,hydrophobic organic contaminant） on nC（60） was greatly affected by nC（60）formation route- the formation route significantly affected the aggregation properties of nC（60）,thus affecting the available surface area and the extent of adsorption via the pore-filling mechanism.Depending on whether nC（60） was formed via the ＂top-down＂ route（i.e.,sonicating C（60） powder in aqueous solution） or ＂bottom-up＂ route（i.e.,phase transfer from an organic solvent） and the type of solvent involved（toluene versus tetrahydrofuran）,modification of nC（60） with Suwannee River humic acid（SRHA） could either enhance or inhibit the adsorption affinity of nC（60）.The net effect depended on the specific way in which SRHA interacted with C（60） monomers and/or C（60） aggregates of different sizes and morphology,which determined the relative importance of enhanced adsorption from SRHA modification via preventing C（60） aggregation and inhibited adsorption through blocking available adsorption sites.The findings further demonstrate the complex mechanisms controlling interactions between nC（60） and organic contaminants,and may have significant implications for the life-cycle analysis and risk assessment of C（60）.

(Super)paramagnetic nanoparticles as platform materials for environmental applications: From synthesis to demonstration

Over the past few decades,engineered,(super)paramagnetic nanoparticles have drawn extensive research attention for a broad range of applications based on their tunable size and shape,surface chemistries,and magnetic properties.This review summaries our recent work on the synthesis,surface modification,and environmental application of(super)paramagnetic nanoparticles.By utilizing high-temperature thermo-decomposition methods,first,we have broadly demonstrated the synthesis of highly monodispersed,(super)paramagnetic nanoparticles,via the pyrolysis of metal carboxylate salts in an organic phase.Highly uniform magnetic nanoparticles with various size,composition,and shape can be precisely tuned by controlled reaction parameters,such as the initial precursors,heating rate,final reaction temperature,reaction time,and the additives.These materials can be further rendered water stable via functionalization with surface mono/bi-layer coating structure using a series of tunable ionic/non-ionic surfactants.Finally,we have demonstrated platform potential of these materials for heavy metal ions sensing,sorption,and separation from the aqueous phase.