Application of hollow fiber flow field-flow fractionation with UV-Vis detection in the rapid characterization and preparation of poly(vinyl acetate) nanoemulsions

Poly(vinyl acetate) (PVAc) nanoemulsions have wide applications in the construction and adhesives industries, with their unique properties being closely dependent on the PVAc nanoparticle (NP) size. Effective and robust analytical methods are needed to accurately characterize the NP size according to the specific requirements to satisfy quality controls and scale production demands. Herein, hollow fiber flow field-flow fractionation (HF5) with UV-Vis detection, which features instrumental simplicity, convenient operation, and low running costs, was proposed for the real-time size characterization of PVAc NPs. The results obtained by the proposed method were in good agreement with the size values obtained by TEM, thereby demonstrating the applicability and reliability of the HF5-based method for PVAc NP size characterization without tedious sample preparation requirements. In order to assess the parameters dominating PVAc NP size, the variables of emulsifier concentration, composite emulsifier ratio, reaction temperature, and stirring rate were investigated in detail. The results proved that the emulsifier component and string rates were the key parameters controlling particle size. Furthermore, NP growth processes were tracked by HF5 over 8 h, clearly indicating a gradual increase in PVAc NP size with time. The results firmly confirmed that HF5 has great potential in NP size control applications during the production and product quality evaluation of PVAc NPs.