Quantitative Structural Analysis of Polystyrene Nanoparticles Using Synchrotron X-ray Scattering and Dynamic Light Scattering

Abstract

A series of polystyrene nanoparticles (PS-1, PS-2, PS-3, and PS-4) in aqueous solutions were investigated in terms of morphological structure, size, and size distribution. Synchrotron small-angle X-ray scattering analysis (SAXS) was carried out, providing morphology details, size and size distribution on the particles. PS-1, PS-2, and PS-3 were confirmed to behave two-phase (core and shell) spherical shapes, whereas PS-4 exhibited a single-phase spherical shape. They all revealed very narrow unimodal size distributions. The structural parameter details including radial density profile were determined. In addition, the presence of surfactant molecules and their assemblies were detected for all particle solutions, which could originate from their surfactant-assisted emulsion polymerizations. In addition, dynamic light scattering (DLS) analysis was performed, finding only meaningful hydrodynamic size and intensity-weighted mean size information on the individual PS solutions because of the particles’ spherical nature. In contrast, the size distributions were extracted unrealistically too broad, and the volume- and number-weighted mean sizes were too small, therefore inappropriate to describe the particle systems. Furthermore, the DLS analysis could not detect completely the surfactant and their assemblies present in the particle solutions. Overall, the quantitative SAXS analysis confirmed that the individual PS particle systems were successfully prepared with spherical shape in a very narrow unimodal size distribution.

Unimodal and Well-Defined Nanomicelles Assembled by Topology-Controlled Bicyclic Block Copolymers

“…For each topological amphiphile, the corresponding X-ray scattering profiles of the micelle solutions measured at room temperature are shown in Figure a. Each scattering profile was characterized using a combination of the indirect Fourier transformation (IFT) method ,− and Guinier law ,− to retrieve various dimensional aspects of micellar structures formed in solution; the details of these analyses are further elaborated in the Supporting Information. IFT analysis, a structure-independent method, offers several dimensional parameters based on the pair distance distribution function p ( r ) derived from a scattering profile.…”

Need analysis on the usage of multimodal reading assessment among secondary school teachers

“…The survey research method was adopted to design the multimodal reading assessment rubric (Wong et al, 2020). Selected respondents were required to complete the questionnaire that contained Likert-scale items and multiple choice questions (Mansor & Ibrahim, 2012;Mardiana-Jansar & Hanafiah, 2020).…”

Seventeen-Armed Star Polystyrenes in Various Molecular Weights: Structural Details and Chain Characteristics

“…For synchrotron X-ray scattering and DLS analyses, solutions (0.25−1.00 wt% concentration) of each star polymer were prepared in CHX and THF and then filtered by using disposable syringes equipped with polytetrafluroethylene filters (0.22 μm pore size). X-ray scattering measurements were carried out at the 4C beamline [ 26 , 27 , 28 ] of the PLS-II facility (a third-generation synchrotron radiation facility being operated at 3.0 GeV and 400 mA by Pohang Accelerator Laboratory, Pohang, Korea) by using an X-ray beam with a wavelength λ of 0.07336 nm and a two-dimensional (2D) charged-coupled detector (CCD: model Rayonix 2D SX 165, Evanston, IL, USA); the sample-to-detector distances (SDD) was 1.0 and 4.0 m. Quartz capillary cells with 1.5 mm outer diameter were used as solution sample cells; for each cell, around 70 μL solution sample was used. The polymer solutions in THF (good solvent) were exposed to the X-ray beam for 20 s at 25.0 °C (± 0.1 °C); the polymer solutions in CHX (Θ solvent) were exposed to the X-ray beam for 20 s at 35.0 °C (± 0.1 °C) (Θ condition).…”