Biomimetic silver-containing colloids of poly(2-methacryloyloxyethyl phosphorylcholine) and their film-formation properties.

The synthesis of stable dispersions of hybrid colloids comprising copolymers of biocompatible 2-hydroxyethyl methacrylate (HEMA) and zwitterionic, biomimetic 2-methacryloyloxyethyl phosphorylcholine (MPC) incorporating antibacterial AgBF(4) by inverse miniemulsion is described. The prepared hybrid colloids were designed to provide both antibacterial and antifouling properties for the formation of interesting, multifunctional films. The obtained particles had sizes in the range of 130-160 nm with two different weight ratios of MPC to HEMA (1:10 and 2:5) and AgBF(4) contents between 0% and 15%. The silver salt takes on the role of the lipophobe in stabilizing the miniemulsion droplets against Ostwald ripening and is reduced after polymerization to Ag nanoparticles by gaseous hydrazine. Subsequently, the hybrid particles are transformed into smooth and stable films with thicknesses between 145 and 225 nm by simple drop casting and solvent annealing. The dispersions and films were thoroughly characterized by DLS, TEM, SEM, EDX, TGA, UV-vis spectroscopy, ICP-OES, XRD, AFM, and contact angle measurements. After immersion into water, the films did not show detectable leakage of silver, so they could be employed as dual-functional antifouling and antibacterial coatings.

Synthesis of silver/poly(2-hydroxyethyl methacrylate) particles via a combination of inverse miniemulsion and silver ion reduction in a "nanoreactor".

Silver salt/poly(2-hydroxyethyl methacrylate) (poly(HEMA)) hybrid particles were first prepared by inverse miniemulsion polymerization of 2-hydroxyethyl methacrylate (HEMA) with silver tetrafluoroborate (AgBF(4)) as a lipophobe. High silver salt loads of up to 13% with respect to the disperse phase were achieved. The silver/poly(HEMA) hybrid particles were subsequently formed via a gas-phase in situ reduction of AgBF(4) by hydrazine on the surfaces of silver salt/poly(HEMA) particles. The formation of silver nanoparticles was confirmed by UV-vis spectroscopy and X-ray diffraction. The morphology of the hybrid particles of silver salt/poly(HEMA) and silver/poly(HEMA) was fully characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), and dynamic light scattering (DLS). The influence of the reaction parameters including the type and amount of cosolvent, salt content, and type of surfactant on the particle properties and colloidal stability during the reduction process was thoroughly investigated.