Controlled Crosslink Of Silver Nanoparticles With Diels-Alder Reaction And Its Application On Antibacterial Property

Nanomaterials are widely used in real life and play an important role in the past,modern society and even future life.Compared with the traditional materials,silver nanoparticles have their unique properties,such as quantum size effect,surface effect,macroscopic quantum tunneling effect and small size effect.In this paper,silver nanoparticles(AgNPs)were synthesized,then furan groups were modified on the surface by mercaptan and carbene,and then Diels-Alderimide(DA)reacted with bismaleimide to control the size of the nanoparticles.Finally,nanometer silver antibacterial materials with different antibacterial activities were obtained.The main content of this research are as follows:1.Furfuryl thiol route.The furfuryl mercaptan with furan group is coordinated with silver nanoparticles to form silver nanoparticles with furan groups.The optimum synthesis conditions were obtained by studying the ratio of materials,solvent,temperature and reaction time.The products were characterized by scanning electron microscope.The Diels-Alder reaction occurs between furan and maleimide by the addition of bismaleimide(BMI),the temperature and reaction time were adjusted to synthesize silver nanoparticles of different sizes.The products were characterized by UV spectroscopy,scanning electron microscopy(SEM),nanometer particle size analyzer and XPS.The characterization results show that the cross-linking reaction between furan group and bismaleimide has a great influence on the size of AgNPs,which varied from 40 nm to 800 nm.The size of the AgNPs could be controlled by the temperature of DA/r-DA equilibrium.Finally,the silver nanoparticles were introduced into a medium containing E.coli,Listeria and Staphylococcus aureus,and the inhibitory loop diameter was used to evaluate the antibacterial activity.It was found that these particles were effective bactericides.Moreover,as the particle size increases,the antibacterial activity of the nanoparticles gradually decreases.2.Furcate carbene route.The 4-chloro-4'-hydroxybenzophenone and furfuryl alcohol were subjected to a series of reactions to produce furyldiazomethane,and the structure and purity of each compound were tested by nuclear magnetic and infrared lamps.The furanyl diazomethane is added to the synthesized silver nanoparticles and heated to 120~oC.The carbene compound and the hydroxyl group on the surface of the silver nanoparticles are combined in the form of a covalent bond to form silver nanoparticles with furan groups.The optimum synthesis conditions were obtained by investigating the material ratio,reaction time,reaction temperature and reaction solvent.The products characterized by transmission electron microscopy.The Diels-Alder reaction occurs between furan and maleimide by the addition of bismaleimide,the temperature and reaction time were adjusted to synthesize silver nanoparticles of different sizes.The products were characterized by UV spectroscopy,scanning electron microscopy,nanometer particle size analyzer and XPS.The test results show that the size of AgNPs can be controlled by the equilibrium temperature of the DA/r-DA reaction.Finally,the antibacterial activity of AgNPs was studied using penicillin as a reference.