Defining the Conformation of Water-Soluble Poly(vinyl alcohol) in Solution: A SAXS, DLS, and AFM Study
Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide This study examines the conformation of soluble poly(vinyl alcohol) (PVA) in aqueous solution using small angle X-ray scattering (SAXS), dynamic light scattering (DLS), and atomic force microscopy (AFM). The focus is on PVA grades used in industrial water-soluble detergent films, comparing their behavior to nanometer-sized polystyrene (PS) beads. SAXS analysis indicates that soluble PVA chains adopt a single molecule random Gaussian coil conformation with a radius of gyration ( R g ) of approximately 14 nm, consistent across various grades, dissolution temperatures, and water hardness. DLS corroborates this single-molecule behavior, and AFM imaging confirms separated PVA chains. SAXS, DLS, and AFM collectively enhance understanding of PVA’s behavior in solution. They provide distinguishing features (e.g., SAXS form factors, q –4 decay, q –2 decay; SAXS- and DLS-derived R g / R h ratio, AFM images) to aid in visualizing and differentiating between water-soluble polymers and micro- or nanoplastic polymers, which exhibit a hard interface. The study concludes that soluble PVA grades used in the detergent films maintain a stable single molecular chain conformation in water with a nonsolid interface, hence very different from known microplastics. This study also provides a basis for a methodology to differentiate the behavior of water-soluble polymers from microplastics.
Source: ACS Omega
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,935
OpenAlex ID: W4409907895