PMID- 26461459
OWN - NLM
STAT- MEDLINE
DCOM- 20160621
LR  - 20181202
IS  - 1520-5851 (Electronic)
IS  - 0013-936X (Linking)
VI  - 49
IP  - 22
DP  - 2015 Nov 17
TI  - Heteroaggregation of Cerium Oxide Nanoparticles and Nanoparticles of Pyrolyzed 
      Biomass.
PG  - 13294-303
LID - 10.1021/acs.est.5b03541 [doi]
AB  - Heteroaggregation with indigenous particles is critical to the environmental 
      mobility of engineered nanomaterials (ENM). We studied heteroaggregation of ceria 
      nanoparticles (n-CeO2), as a model for metal oxide ENM, with nanoparticles of 
      pyrogenic carbonaceous material (n-PCM) derived from pecan shell biochar, a model 
      for natural chars and human-made chars used in soil remediation and agriculture. 
      The TEM and STEM images of n-PCM identify both hard and soft particles, both 
      C-rich and C,O,Ca-containing particles (with CaCO3 crystals), both amorphous and 
      "onion-skin" C-rich particles, and traces of nanotubes. Heteroaggregation was 
      evaluated at constant n-CeO2, variable n-PCM concentration by monitoring 
      hydrodynamic diameter by dynamic light scattering and zeta-potential under 
      conditions where n-PCM is "invisible". At pH 5.3, where n-CeO2 and n-PCM are 
      positively and negatively charged, respectively, and each stable to 
      homoaggregation, heteroaggregation is favorable and occurs by a charge 
      neutralization-charge reversal mechanism (CNCR): in this mechanism, primary 
      heteroaggregates that form in the initial stage are stable at low or high n-PCM 
      concentration due to electrostatic repulsion, but unstable at intermediate n-PCM 
      concentration, leading to secondary heteroaggregation. The greatest instability 
      coincides with full charge neutralization. At pH 7.1, where n-CeO2 is neutral and 
      unstable alone, and n-PCM is negative and stable alone, heteroaggregation occurs 
      by a charge-accumulation, core-shell stabilization (CACS) mechanism: n-PCM binds 
      to and forms a negatively charged shell on the neutral surface of the nascent 
      n-CeO2 core, stabilizing the core-shell heteraggregate at a size that decreases 
      with n-PCM concentration. The CNCR and CACS mechanisms give fundamental insight 
      into heteroaggregation between oppositely charged, and between neutral and 
      charged nanoparticles.
FAU - Yi, Peng
AU  - Yi P
AD  - Department of Environmental Sciences, The Connecticut Agricultural Experiment 
      Station , New Haven, Connecticut 06511, United States.
AD  - Department of Civil, Environmental and Geomatics Engineering, Florida Atlantic 
      University , Boca Raton, Florida 33431, United States.
FAU - Pignatello, Joseph J
AU  - Pignatello JJ
AD  - Department of Environmental Sciences, The Connecticut Agricultural Experiment 
      Station , New Haven, Connecticut 06511, United States.
FAU - Uchimiya, Minori
AU  - Uchimiya M
AD  - Agricultural Research Service, United States Department of Agriculture , 1100 
      Robert E. Lee Boulevard, New Orleans, Louisiana 70124, United States.
FAU - White, Jason C
AU  - White JC
AD  - Department of Analytical Chemistry, The Connecticut Agricultural Experiment 
      Station , New Haven, Connecticut 06511, United States.
LA  - eng
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20151027
PL  - United States
TA  - Environ Sci Technol
JT  - Environmental science & technology
JID - 0213155
RN  - 0 (biochar)
RN  - 16291-96-6 (Charcoal)
RN  - 30K4522N6T (Cerium)
RN  - 619G5K328Y (ceric oxide)
RN  - H0G9379FGK (Calcium Carbonate)
SB  - IM
MH  - Biomass
MH  - Calcium Carbonate/chemistry
MH  - Carya/chemistry
MH  - Cerium/*chemistry
MH  - Charcoal/chemistry
MH  - Hydrogen-Ion Concentration
MH  - Microscopy, Electron, Transmission
MH  - Nanoparticles/*chemistry
MH  - Nanostructures/chemistry
MH  - Static Electricity
EDAT- 2015/10/16 06:00
MHDA- 2016/06/22 06:00
CRDT- 2015/10/14 06:00
PHST- 2015/10/14 06:00 [entrez]
PHST- 2015/10/16 06:00 [pubmed]
PHST- 2016/06/22 06:00 [medline]
AID - 10.1021/acs.est.5b03541 [doi]
PST - ppublish
SO  - Environ Sci Technol. 2015 Nov 17;49(22):13294-303. doi: 10.1021/acs.est.5b03541. 
      Epub 2015 Oct 27.