Study On Preparation Of P-type Molecular Sieve Antibacterial Agents And Antibacterial Properties

Escherichia coli caused by diarrhea disease has brought huge losses to farmers,using the zeolite molecular sieve to adsorption grafted the novel antibacterial organic acid-potassium diformate is expected to solve this problem.The natural stilbite contain amount of impurities,and the adsorption capacity ability is weak,pores is irregular.So it can not be used as a carrier for antibacterial agents,but can be used as the raw material by modifying natural stilbite.Potassium diformate is a new type of organic acid promoter agent that can inhibit the growth of bacteria such as E.coli in the intestinal tract of animals and do not produce drug resistance,but it decomposes rapidly in the stomach and intestines,resules that it can not reach the terminal of the intestine.To solve this problem,we use zeolite molecular sieve adsorb the potassium diformate to achieve sustained-release of potassium diformate.Taking into account the chitosan and agarose has high surface activity and their biodegradation,biocompatibility and biological activity have great advantages,this preparation process forms"chitosan-potassium diformate"ligand and"Agarose-potassium diformate"ligand.In this paper,P-type zeolite molecular sieves were prepared by the modified stilbite,and used chitosan and agarose as intermediates adsorbed potassium diformate to prepared P-type zeolite molecular sieve antibacterial agents to achieve the effect of sustained-release of potassium diformate.The mechanism of the adsorption of potassium diformate on the P-type zeolite molecular sieve using chitosan?agarose?as an intermediate was analyzed by material characterization method.The experimental results are as follows:?1?The 50 mesh natural stilbite mixed with concentration of 15%hydrochloric acid by the ratio of solid-liquid ratio of 1:3,for 2 h at 90?.Acidification treatment of natural stilbite broken its structure and made it amorphous,and removed some impurities.?2?Reaction the acidified zeolite precursor and NaOH solution by the mass ratio of 5:1,for 15 minute at 80?,and the product was centrifuged for 15 minute.Alkali-dissolving treatment of the zeolite precursor can activate the zeolite precursor,effectively increasing SiO₂ activity in the zeolite precursor and eliminating other impurities of the zeolite precursor.?3?Using the method of hydrothermal preparation of P-type zeolite molecular sieves,the optimal process conditions is following:The molar ratio of SiO₂/Al₂O₃ is 3,for 6.5 h at 90?.It is tetragonal system of gather spherical crystal shape,and the volume average particle size is 1?m.The P-type zeolite molecular sieves characteristic peaks of IR at 3 459,1 641,1 008,746,682,607,and 443 cm^-1.The moisture absorption rate of P-type zeolite molecular sieves is significantly greater than the natural stilbite.The closer to neutral conditions,the better P-type zeolite molecular sieves adsorption and grafting properties are;the pore size of P-type zeolite molecular sieves is around 4 nm at most concentrated.?4?Using P-type zeolite molecular sieve as carrier and chitosan as intermediate,adsorbed potassium diformate to prepared to P-type zeolite molecular sieve antibacterial agent,the optimal process conditions is following:P-type zeolite molecular sieve and chitosan and potassium diformate by the mass ratio of 3:1:2,for 3h at 90?.Under this condition,the K⁺of the antibacterial agent measured by the atomic absorption spectrophotometer was the highest.The antibacterial agent surface is irregularity.The particle size is relatively uniform and the average particle size is about 1 um.After P-type zeolite molecular sieve adsorption grafted,its surface chemical environment has a certain change.P-type zeolite molecular sieve surface oxygen,silicon,aluminum element has the tendency of gaining electrons.?5?Using P-type zeolite molecular sieve as carrier and agarose as intermediate,adsorbed potassium diformate to prepared to P-type zeolite molecular sieve antibacterial agent,the optimal process conditions is following:P-type zeolite molecular sieve and agarose and potassium diformate by the mass ratio of 3:1:2,for 3h at 90?.Under this condition,the K⁺of the antibacterial agent measured by the atomic absorption spectrophotometer was the highest.The antibacterial agent surface is irregularity.The particle size is relatively uniform and the average particle size is about 1 um.There was a layer of adhesive on the surface of the antibacterial agent at50?.After P-type zeolite molecular sieve adsorption grafted,its surface chemical environment has a certain change.P-type zeolite molecular sieve surface oxygen,silicon,aluminum element content has been reduced.?6?The antibacterial performance of the P-type zeolite molecular sieve antibacterial agent?taking the chitosan as intermediate as an example?analyzes that the P-type zeolite molecular sieve antibacterial agent had the antibacterial effect against Escherichia coli,Bacillus subtilis,and Staphylococcus aureus,and with the higher concentration of antibacterial agent,antibacterial effect was more obvious.P-type zeolite antibacterial agent has the best inhibitory effect on Staphylococcus aureus,and the antibacterial rate is as high as 89%,followed by Escherichia coli.