Adsorption of Bisphenol A Based on Synergy between Hydrogen Bonding and Hydrophobic Interaction

The study mainly investigated the synergetic adsorption of hydrogen bonding and hydrophobic interaction. To simplify the adsorption driving forces and binding sites, the hydrophilic and hydrophobic microdomain was introduced onto polypropylene (PP) nonwoven. The amphiphilic structure was constructed for the adsorption of bisphenol A (BPA). A solvent shielding experiment was conducted to calculate the contributions of diverse interactions. Also, a specific structure without hydrophilic microdomain was constructed as comparison to determine the adsorption rate and quantify the diffusion behaviors. On the basis of double-exponential model, the adsorption process can be distinctly divided into three stages, namely film diffusion stage, intralayer diffusion stage, and dynamic equilibrium stage. The adsorption rate was dramatically improved due to the influence of hydrophilic microdomain and participation of hydrogen bonding adsorption. Discussions on adsorption priority were also proposed. The results of surface energy heterogeneity revealed that the hydrophilic microdomain or the hydrogen bonding site was occupied preferentially.