DOI: 10.5061/dryad.2z34tmpws
title: Data from: Particle dynamics of nanoplastics suspended in water with soil microparticles: Insights from small angle neutron scattering (SANS) and ultra-SANS

description: Small-angle neutron scattering (SANS) and Ultra-SANS (USANS) were employed
 to understand the agglomeration behavior of nanoplastics (NPs) formed from
 a biodegradable mulch film, and microparticles of vermiculite (V), an
 artificial soil, suspended in water in the presence of low convective
 shear (ex-situ stirring) prior to measurements. Neutron contrast matching
 was employed to minimize the signal of V (by 100-fold) and thereby isolate
 the signal due to NPs in the neutron beam, as the contrast match point
 (CMP) for V (67 vol% deuteration in water) differed from that of NPs by
 more than 20%. The original NPs’ size distribution was bimodal: &lt;
 200 nm and 500-1200 nm, referred to as small and large NPs, i.e., SNPs and
 LNPs, respectively. In the absence of V, SNPs formed agglomerates at
 higher concentrations, with size decreasing slightly with stirring time to
 40-50 nm, while the size of LNPs remained unchanged. The presence of V at
 2-fold lower concentration than NPs did not change the size of SNPs but
 reduced the size of LNPs by nearly 2-fold as stirring time increased.
 Because the size of SNPs and LNPs did not differ substantially between
 solvents, both at CMP and 100% D2O, even with nanosized V particles
 contributing toward scattered intensity for the latter solvent, it is
 evident that SNPs and LNPs are mainly composed of NPs and not V. The
 results suggest that LNPs are susceptible to size reduction through
 collisions with soil microparticles via convection, yielding SNPs near
 soil-water interfaces within vadose zones.
description: Data for Fig 1 (nanoplastic recovery suspended in water and
 settling out) was collected in the laboratory and the results were
 recorded in a Microsoft Excel file. Other data was collected on the
 small-angle neutron scattering (SANS) and ultra-SANS instruments at Oak
 Ridge National Laboratory, specifically, the Bio-SANS (high-flux isotope
 reactor) and Beamline 1A (spallation neutron source), respectively
 (downloaded into Microsoft Excel files and displayed in Figs 2 and S1-S5).
 Data for Figs 3 and S6 include form factor-structure factor modeling of
 merged SANS and USANS data, after subtraction of a power law
 relationship.  Modeling was done using Igor Pro-based software written by
 National Institute of Standards scientists and the model fits to the data
 and resultant parameters were downloaded to Microsoft Excel files. The
 models' parameters allowed for determination of box plots and
 histograms of nanoplastic size and size distribution under several
 different conditions, Figs 4 and S7, respectively. The latter two figures
 were generated using JMP software, and were subsequently downloaded to
 Microsoft Excel files.
description: # Data from: Particle dynamics of nanoplastics suspended in water with
 soil microparticles: Insights from small angle neutron scattering (SANS)
 and ultra-SANS
 [https://doi.org/10.5061/dryad.2z34tmpws](https://doi.org/10.5061/dryad.2z34tmpws) ## Description of the data and file structure ### Files and variables #### File: Fig\_1.xlsx **Description:**  **Fig. 1** Recovery yield (%) of vermiculite (V_only), nanoplastics (NPs_only), and their mixture in metastable suspensions (1% and 5% NP+V) after centrifugation for **(A)** CMP and **(B)** 100% D2O solvents at various *ex-situ stirring* times (0, 24, 168 hours). Error bars represent the standard error of the measurements. ##### Variables * Nanoplastic concentration (0, 1 wt% or 5%), vermiculite concentration (0 or 5 wt%), stirring time (0 h, 24 h, 168 h), solvent type (Contrast Match Point [CMP], D2O], % Recovery (average), % Recovery (error) #### File: Fig\_3.xlsx **Description:**  \**Fig 3. **Model fitting of oscillations for SANS and USANS scattering data after subtraction of the power law **(Eq. 2) **from *I(Q)*** (Fig. 2) **for suspensions of **(A, B) **NPs (1 %); **(C, D)** NPs (1%) + V (0.5%), and **(E, F)** NPs (5%) + V (0.5%) in contrast matching solvent for V (67% D2O / 33% H2O) at 22oC. (**A, C, E)** USANS data fitted by a Schulz polydisperse sphere form factor model (**Eq. 4)** for large NPs (LNPs) and **(B, D, F)** SANS data fitted by a lognormal form factor model (**Eq. 3)** for small NPs (SNPs). Blue font represents data derived from model fits to the SANS and USANS data, while black font represents the SANS and USANS data that was collected. ##### Variables * Nanoplastic concentration (0, 1 wt% or 5%), vermiculite concentration (0 or 5 wt%), stirring time (0 h, 24 h, 168 h), SANS data: scattering angle (Q), scattered intensity after subtraction of power law [I(Q)], error for I(Q), Model fits to SANS data at low- and high-Q: Q, I(Q), error for I(Q) #### File: SANS\_USANS\_data.xlsx **Description:** Merged SANS and USANS data used in **Figures 2 and S1-S5**.·**Figs S1-S3** contain plots of the raw data given below. **Figs 2, S4, and S5** contain plots of the same raw data, but with I(Q) multiplied by a constant (as given in the figure captions) in several cases to improve visualization.  Data were fit by power law models, Eq. 2, with the equation parameters given in **Table S1**. If an entry for *Error in I(Q)* is blank, the value is zero. Blue and black font represent data derived from SANS and USANS, respectively, representing Small NPs and Large NPs, respectively. ##### Variables * Nanoplastic concentration (0, 1 wt% or 5%), vermiculite concentration (0 or 5 wt%), stirring time (0 h, 24 h, 168 h), solvent type (Contrast Match Point [CMP], D2O], SANS data: scattering angle (Q), scattered intensity [I(Q)], error for I(Q) #### File: Fig\_4.xlsx **Description:** **Fig. 4.** Box plots for size of NPs or their agglomerates suspended in aqueous suspensions at the CMP of V (67 vol% D2O/33% H2O): **(A)** SNPs and **(B)** LNPs vs. *ex-situ *stirring time and NP and V concentrations and NPs or their agglomerates suspended in 100% D2O: **(C)** SNPs and **(D)** LNPs vs. *ex-situ *stirring time and NP and V concentration. ##### Variables * Nanoplastic concentration (0, 1 wt% or 5%), vermiculite concentration (0 or 5 wt%), stirring time (0 h, 24 h, 168 h), solvent type (Contrast Match Point [CMP], D2O], Nanoplastic size: median, top and bottom of box, top and bottom of whiskers. #### File: Fig\_S6.xlsx **Description:** **Fig S6. **Model fitting of oscillations for SANS and USANS scattering data after subtraction of the power law **(Eq. 2) **from *I(Q)*** (Fig. 2) **for suspensions of **(A, B) **NPs (1 %); **(C, D)** NPs (1%) + V (0.5%), and **(E, F)** NPs (5%) + V (0.5%) in 100% D2O at 22C. (**A, C, E)** USANS data fitted by a Schulz polydisperse sphere form factor model (**Eq. 4)** for large NPs (LNPs) and **(B, D, F)** SANS data fitted by a lognormal form factor model (**Eq. 3)** for small NPs (SNPs). Blue font represents data derived from model fits to the SANS and USANS data, while black font represents the SANS and USANS data that was collected. ##### Variables * Nanoplastic concentration (0, 1 wt% or 5%), vermiculite concentration (0 or 5 wt%), stirring time (0 h, 24 h, 168 h), SANS data: scattering angle (Q), scattered intensity after subtraction of power law [I(Q)], error for I(Q), Model fits to SANS data at low- and high-Q: Q, I(Q), error for I(Q) #### File: Fig\_S7.xlsx **Description:** **Fig. S7. **Histograms of particle size** **distributions for NPs derived from the curve fitting of SANS and USANS data, after subtraction of Eq. 2, provided by Igor and Irena software, which represents average particle size reduction because of *ex-situ* stirring. Smaller-sized NPs (SNP) represent the lognormal fit and larger-sized NPs (LNPs) by polydisperse spheres (Schulz distribution). Blue and black font represent data derived from SANS and USANS, respectively, representing Small NPs and Large NPs, respectively. ##### Variables * * Nanoplastic concentration (0, 1 wt% or 5%), vermiculite concentration (0 or 5 wt%), stirring time (0 h, 24 h, 168 h), solvent type (Contrast Match Point [CMP], D2O], particle diameter (nm), volume distribution ## Code/software Microsoft Excel (*filename.xlsx*); version 2010 or later. ## Access information Other publicly accessible locations of the data: * Not applicable Data was derived from the following sources: * Not applicable