Yanrong Chen

Extremely hydrophobic fluoromonomers are highly prone to phase separation during emulsion polymerization. Overcoming macroscopic experimental limitations, this study employs all-atom molecular dynamics (AA-MD) simulations to investigate the molecular-level solubilization behavior and thermal adaptability of the novel eco-friendly zwitterionic fluorocarbon surfactant-perfluorohexyl (butyl) sulfonyl carboxy propylamino dimethyl betaine (PFSC) and the traditional hydrocarbon surfactant SDS toward the monomers tetrafluoroethylene (TFE) and perfluoromethyl vinyl ether (PMVE). Simulation results indicate that fluorinated monomers in the SDS system exhibit a more dispersed spatial distribution, with weaker local association in surfactant-enriched regions. In contrast, fluorinated monomers in the PFSC system tend to distribute within regions rich in perfluorinated segments. This spatial characteristic is consistent with thermodynamic analysis results dominated by solubility parameter matching and van der Waals interactions. Under high-temperature conditions, the perfluorohexyl sulfonyl carboxy propylamino dimethyl betaine (C6) system maintains relatively stable local spatial characteristics, with the fluorinated monomers exhibiting low migration behavior. These spatial distribution characteristics and thermal response behaviors suggest that a fluorine-rich environment may help preserve the local distribution of fluorinated monomers under high-temperature conditions. These findings provide molecular-level insights into the structure–property relationships of eco-friendly fluorinated surfactants and offer computational guidance for their rational design.

Caffeic acid phenylethyl ester (CAPE) is a natural polyphenol extracted from propolis, which is reported to have several pharmacological effects such as antibacterial, antitumor, antioxidant and anti-inflammatory activities. Hemoglobin (Hb) is closely related to the transport of drugs, and some drugs, including CAPE, can lead to a change in Hb concentration. Herein, the effects of temperature, metal ions and biosurfactants on the interaction between CAPE and Hb were studied using ultraviolet-visible spectroscopy (UV−Vis), fluorescence spectroscopy, circular dichroism (CD), dynamic light scattering (DLS) and molecular docking analysis. The results showed that the addition of CAPE led to changes in the microenvironment of Hb amino acid residues as well as the secondary structure of Hb. Hydrogen bonding and van der Waals force were found to be the main driving forces for the interaction between CAPE and Hb through fluorescence spectroscopy and thermodynamic parameter data. The results of fluorescence spectroscopy also showed that lowering the temperature, adding biosurfactants (sodium cholate (NaC) and sodium deoxycholate (NaDC)) and the presence of Cu²⁺ increased the binding force between CAPE and Hb. These results provide useful data for the targeted delivery and absorption of CAPE and other drugs.

Multispectral and molecular docking methods were used to study the interaction mode and mechanism of two important components of whey proteins, lactoferrin (LF) and β-lactoglobulin (β-LG), and of a lactone sophorolipid (LSL) mixed system. The preservation effect of the mixed system on milk was also studied and compared. The results showed that the quenching mechanism of LSL on both β-LG and LF was static, but that the non-covalent complexes formed were the result of the different interacting forces: hydrogen bonds and the van der Waals force for the LSL-β-LG system, and electrostatic force for the LSL-LF system. The binding constants of LSL-β-LG and LSL-LF were all relatively small, and the interaction of LSL with β-LG was stronger than its interaction with LF. After adding β-LG, LF, or the mixed system with LSL to the milk, the stability of milk emulsion was effectively improved in all cases, while the preservative ability was effectively enhanced only by the addition of LF or LSL-LF. These results provide supportive data and a theoretical basis for enhancing the production of dairy products and other byproducts.