{
    "protocol": "To synthesize hydrophilic polymers with functional groups, prepare tannic acid by utilizing its hydroxyl groups. For functionalization, create complexes with proteins or zwitterionic polymers like poly(sulfobetaine methacrylate) (PSBMA). For surface modifications, apply tannic acid onto substrates such as metal oxides or hydrophobic polymers to achieve a thickness of approximately 20 nm. Generate metal−phenolic networks (MPNs) by coordinating metal ions with tannic acid, resulting in thin adherent films suitable for various substrates. For functionalizing surfaces, use techniques such as vacuum filtration to create superoleophobicity. Explore complexes by lyophilizing catechin with poly(ethylene glycol) (PEG) to enhance water solubility for therapeutic uses. Consider using laccase for oxidative cross-linking in urushiol-based coatings to develop protective layers on surfaces."
}