Formation of self-healing ferrogels modified with Au/Fe3O4 and Ag/Fe3O4 core-shell structures

摘要

Recently, great attention is devoted towards formation of hydrogels with the ability to repair themselves after damage that could extend the applications of such materials. The healing is reversible and can be switched on and off via changes in pH, temperature and exposure to light. So far, self healing has been demonstrated in linear polymers, host-guest polymers, supramolecular networks, dendrimers, metal-ion polymer systems and multi-component systems. Mere we describe formation of self-healing hydrogels based on N-acryloylaminocaproic acid (A6ACA) monomers. Notably, hydrogels without A6ACA lose their self healing capacity. Subsequently, the received monomers of A6ACA will be modified by addition of either Ag@Fe_3O_4 or Au@Fe_3O_4 in order to enhance their antimicrobial activity. Initial stage of this study is based on synthesis of magnetic nanoparticles developed by Massart in 1981. This method involves addition of FeCl_2×4H_2O and FeCl_3×6H_2O with the Fe~(+3)/Fe~(+2) molar ratio equal 2:1 to previously boiled solution of 1.5M NaOH. The black precipitate forms immediately. The formation of magnetic nanoparticles proceeds according to following reaction: Subsequently, the appropriate amounts of either HAuCl_4×H_2O or AgNO_3 and hydroxylamine are added in order to form shell layers of either reduced Au or Ag that surround and stabilize previously attained magnetic nanostructures. The received core-shell structures can be analyzed by means of UV-Vis, XRD, DLS and visualized by TEM. Fig.1. UV-Vis spectra of obtained Au/Fe_3O_4. Fig. 2 XRD diffractogram of obtained Au/Fe_3O_4. Future prospects of this study will involve preparation of polymeric matrices based on formation of mixtures of core-shell magnetic nanostructures with variable amounts of A6ACA monomers exposed to UV-light in order to form ferrogels. The received materials will be physicochemically analyzed to determine their swelling ability.