{
    "protocol": "1) Deposit a sticky polydopamine/ $\\mathsf{\\Pi}_{\\mathsf{F e}^{3+}}$ coating on the surface of the substrates to create a sticky initiation layer (SIL). 2) Reduce $\\mathsf{F e}^{3+}$ ions to $\\mathsf{F e}^{2+}$ ions as active catalysts by UV illumination with the assistance of citric acid. 3) Conduct surface catalytically initiated radical polymerization (SCIRP) in a monomer solution at room temperature to grow hydrogel coatings.The synthesis of hydrophilic polymers involves several key steps: First, graft coupling molecules with specific functional groups onto the substrate. Depending on the method chosen, such as the hydrogel painting method, a polymer layer is grafted using silane before the curing process. In the SCIRP method, an iron catalyst is doped into the substrates beforehand. For the UV-SCIRP method, a sticky initiation layer (SIL) is formed, providing an anchoring site for radical initiation. Following this, radical initiators are introduced and a monomer solution is applied. The photoinitiation or thermal initiation is then conducted, facilitating the radical polymerization process under UV or heat for a duration of 30-90 minutes."
}