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1. Natural organic matter composition determines the molecular nature of silver nanomaterial-NOM corona

   https://doi.org/10.1039/c8en00018b  

   Baalousha, Mohammed ; Afshinnia, Kamelia ; Guo, Laodong ( January 2018 , Environmental Science: Nano)

   Adsorption of natural organic matter (NOM) on nanomaterials (NMs) results in the formation of interfacial area between NMs and the surrounding environment (referred to as NOM-corona), giving rise to NMs' unique surface identity. This unique surface identity is determined by the ligands and their interactions with NM surfaces. Since the chemical structure and functionality is heterogeneous and polydisperse, the molecular composition of NOM-corona is the result of competitive adsorption of NOM molecules on the NM surface. Here, we investigate the molecular composition of NOM-corona formed from two different NOM samples (isolated from the Yukon River and Milwaukee River) on the surface of AgNMs using electrospray ionization-Fourier-transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS). The composition of AgNM-NOM corona varied with the composition of the original NOM. In general, AgNM-NOM corona is rich with N- and S-containing compounds. Furthermore, AgNM-NOM corona is rich with compounds with high molecular weight, high unsaturation, and high number of oxygenated groups. However, CHOS (carbon, hydrogen, oxygen and sulfur) compounds adsorbed on AgNMs from the Yukon River NOM have low molecular weight (LMW) and low saturation index, which might be due to selective adsorption via chemical complexation (Ag–S). On the other hand, NOM compounds with LMW and low unsaturation or compounds containing few oxygenated groups (mainly alcohols and ethers) are preferentially maintained in solution phase. The results here provide evidence of molecular interactions between NOM and NMs, which are critical to understanding NM behavior and toxicity in natural environments. 

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2. An ultrahigh-resolution mass spectrometry index to estimate natural organic matter lability: FTICRMS organic matter molecular lability index

   https://doi.org/10.1002/rcm.7400  

   D'Andrilli, Juliana ; Cooper, William T. ; Foreman, Christine M. ; Marshall, Alan G. ( December 2015 , Rapid Communications in Mass Spectrometry)
3. A metal organic framework-ultrafiltration hybrid system for removing selected pharmaceuticals and natural organic matter

   https://doi.org/10.1016/j.cej.2019.122920  

   Kim, Sewoon ; Muñoz-Senmache, Juan C. ; Jun, Byung-Moon ; Park, Chang Min ; Jang, Am ; Yu, Miao ; Hernández-Maldonado, Arturo J. ; Yoon, Yeomin ( February 2020 , Chemical Engineering Journal)
4. Natural organic matter flocculation behavior controls lead phosphate particle aggregation by mono- and divalent cations

   https://doi.org/10.1016/j.scitotenv.2022.161346  

   Zhao, Juntao ; Mathew, Riya A. ; Yang, David S. ; Vekilov, Peter G. ; Hu, Yandi ; Louie, Stacey M. ( March 2023 , Science of The Total Environment)
5. Interactions of emerging contaminants with model colloidal microplastics, C 60 fullerene, and natural organic matter – effect of surface functional group and adsorbate properties

   https://doi.org/10.1039/D0EM00026D  

   Williams, Tyler ; Walsh, Clare ; Murray, Keith ; Subir, Mahamud ( January 2020 , Environmental Science: Processes & Impacts)

   Surface adsorption of two commonly detected emerging contaminants, amlodipine (AMP) and carbamazepine (CBZ), onto model colloidal microplastics, natural organic matter (NOM), and fullerene nanomaterials have been investigated. It is found that AMP accumulation at these colloidal–aqueous interfaces is markedly higher than that of CBZ. Measurements of surface excess and particle zeta potential, along with pH-dependent adsorption studies, reveal a distinct influence of colloidal functional group on the adsorption properties of these pharmaceuticals. AMP shows a clear preference for a surface containing carboxylic group compared to an amine modified surface. CBZ, in contrast, exhibit a pH-dependent surface proclivity for both of these microparticles. The type of interactions and molecular differences with respect to structural rigidity and charge properties explain these observed behaviors. In this work, we also demonstrate a facile approach in fabricating uniform microspheres coated with NOM and C 60 nanoclusters. Subsequent binding studies on these surfaces show considerable adsorption on the NOM surface but a minimal uptake of CBZ by C 60 . Adsorption induced colloidal aggregation was not observed. These findings map out the extent of contaminant removal by colloids of different surface properties available in the aquatic environment. The methodology developed for the adsorption study also opens up the possibility for further investigations into colloidal–contaminant interactions. 

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