Abstract:

This dataset contains estimates made by the Savin Group of the mutual diffusion coefficient and hydrodynamic radius of polymer-modified silica nanoparticles determined via light scattering characteristics. Dynamic light scattering (DLS) analysis measured the fluctuations in the scattering intensity of the samples, analyzed by the intensity autocorrelation function. The slope of the plot of the decay rate of the autocorrelation function versus the square of the scalar magnitude of the scattering vector yields the mutual diffusion coefficient. The estimate of the diffusion is then used to calculate the hydrodynamic size using the Stokes-Einstein relation. Measurements were made on bare silica nanoparticles (bare NP), silica nanoparticles modified by poly(caprolactone) (PCL), and silica nanoparticles modified by poly(caprolactone) and hyper-branched poly(glycidol) (HPG or HBPG). Each type of nanoparticle was characterized under conditions of low, medium, and high grafting density.

Suggested Citation:

Savin, Daniel; Walley, Susan. 2020. Dynamic light scattering determination of hydrodynamic radius and mutual diffusion coefficient of polymer-modified nanoparticles with varying degrees of grafting density. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/89WF7SZW

Purpose:

Dynamic Light Scattering allows the determination of size and thereby polymer brush thickness in polymer-modified nanoparticles.

Data Parameters and Units:

The data includes three Excel worksheets, for low, medium, and high grafting density. Each worksheet contains the following data for a bare nanoparticle, PCL-modified nanoparticle, and PCL-HBPG-modified nanoparticle: Correlation function decay rate (Gamma, [1/s]), square of light scattering vector [q^2, 1/m^2]), mutual diffusion coefficient [D_m, m^2/s], hydrodynamic radius (Rh, [nm]), viscosity of water (eta, [centipoise, or mPa s])).

Methods:

All polymer-modified silica nanoparticles were analyzed at 1% by weight particle concentration. Dynamic Light Scattering (DLS) analysis was performed on an ALV-CG5-3 four-angle, compact goniometer system, which consisted of a 35 mW HeNe linear polarized laser operating at a wavelength of 632.8 nm. Fluctuations in the scattering intensity were measured via an ALV/LSE-50004 multiple tau digital correlator. Decay rates, Gamma, were obtained by fitting single-exponential functions to the intensity autocorrelation function using a second-order cumulant analysis. A plot of Gamma vs. the square of the light scattering angle vector, q, yields the mutual diffusion coefficient, D~m~.

Instruments:

ALV/CG5-3 four-angle, compact goniometer system (Langen, Germany), ALV/LSE-50004 multiple tau digital correlator.

Individual Files: