The invention discloses a
lignin / silver composite
antibacterial agent, and a preparation method and application thereof, belonging to the technical field of preparation of antibacterial agents. The method comprises the following steps: reacting alkali
lignin with a
carboxylation reaction to introduce an anionic functional group, and then adding a cationization
reagent to introduce a cationic functional groups so as to obtain an anionic-cationic amphoteric
lignin solution; then adjusting a
system to allow the
system to be negatively charged, adding a silver salt and carrying out light-tight absorption so as to obtain a lignin / silver
mixed solution; and then adjusting the
system to allow the system to be positively charged, and successively carrying out aging, separation and
drying so as to obtain the lignin / silver composite
antibacterial agent. According to the method, lignin is subjected to
chemical modification, and pH value regulation is carried out so as to allow the lignin to have properties like an anionic-cationic amphoteric
polymer, so the prepared lignin / silver composite
antibacterial agent has a positively-charged surface, substantially enhanced bactericidal ability, long-lasting bactericidal
efficacy and high compatibility with high polymers; and when the lignin / silver composite antibacterial agent is applied to preparation of antibacterial materials, the problems of poor stability,
short duration of bactericidal
efficacy and high cost of conventional silver-series antibacterial agents are overcome.