Preparations And Research Of Sulfide Ions Responsive Materials

Microbial corrosion is an important factor causing accelerated damage to Marine environmental engineering facilities,and sulfate reducing bacteria(SRB)is one of the typical corrosion microorganisms.Traditional chemical control methods using fungicides can destroy the ecological environment and enhance bacterial resistance.To solve this problem,this study constructed three different types of sulfide-ion responsive release materials by means of physical drug loading and chemical drug loading,verified the release situation of the drug loading system under different concentration of sulfideion,and revealed the release mechanism of the drug loading material under the condition of sulfide-ion.The results are as follows:(1)Based on the principle that Cu-BTA can form a complex film layer,it was modified as a blocking layer to the end of the halloysite nanotube filled with bactericide molecules(metronidazole)by vacuum loading.The blocking effect of copper ion solution with different concentration and the release of sulfide ions solution with different concentration were studied.The results showed that the best copper ions concentration was 10.24 g /L,and the drug loading system could realize the response release of sulfide ion,and the corresponding minimum sulfide ions concentration was 3.2mg /L.(2)Following the principle of the previous chapter,the port sealing method is replaced by the integral sealing method.The gelatin solution doped with Cu-BTA complex is used to coat the nanotubes loaded with bactericide(metronidazole).The results showed that the mass concentration of the pure gelatin solution which be able to take drug-loading nanotubes effectively blocked is 10 g/L;the optimal doping ratio of gelatin and Cu-BTA mixed complex coating for drug-loading halloysite is 1:1;the results also proved that drug-loading halloysite nanotubes can achieve the dual responsiveness under the condition of sulfide ions and acid ions,the minimum concentration of sulfide ions which realize the responsive release is 32 mg/L.(3)Taking sulfide ions as the damage player for the coordination bond formed by the participation of metal ions,changing the way of physical loading before.Using the SBA-15 molecular sieve as the carrier material,the coordination bond was built by grafting different metal ions and different fungicides step-by-step after the amino modified.Then the “amino-metal ion-microbicides" system was built.The results showed that the release of the bactericide is associated with sulfides precipitation coefficient formed by metal ions and sulfide ions,the easier precipitation formed,the easier original coordinate bond damaged,then fungicide was easier to release.With copper ions as metal ions,the lowest concentration of sulfide ions that caused the responsive release of drug-loading system is 3.2 mg/L,the quantity to vancomycin was up to 200 mg/L,it best fits the research needs.In addition,experiments had verified that the more coordination structure the fungicide molecule have,the more stable coordination bond they get.