the composite of the present invention is about 5 to 100 nm in particle size application_number US 201113109919 A description in the present invention the materials used in examples and comparative examples include 1 polyurethane pu purchased from kuo ching chem co product name kc58238au fig1 shows the synthesis reaction from polyethylene glycol peg 1 4 butandiol and 4 4 methylenediphenyl isocyanate 2 silver nitrate agno 3 99 8 wt as the source of silver ions purchased from aldrich co other silver salts such as agi agbr agcl and silver pentafluoropropionate can also be used 3 reducing agents 1 ethanolamine the general formula hoch 2 ch 2 3 x n r x x 0 1 or 2 r u2550 h or alkyl or alkenyl having 1 to 18 carbon atoms for example methyl ethyl or cyclohexyl fig2 shows several examples the preferred examples include diethanolamine dea monoethanolamine mea diglycolamine dga and u00b1 1 amino 2 propanol mpa 2 poly oxyalkylene amine including monoamine diamine and tramine having poe poly oxyethylene or poe poly oxypropylene segments serving as monomers for reducing silver ions fig3 shows the examples those used in examples are purchased from huntsman product names ed 2003 d 2000 m 2070 t 403 and t 5000 3 epoxy capable of reacting with ethanolamine and poly oxyalkylene amine to generate an oily polymeric polymer fig4 shows the diglycidyl ether derivatives of epoxy in examples diglycidyl ether of bisphenol a be188 is used the detailed steps are described as follows and.