SUSTAINED SILVER RELEASE COMPOSITION FOR WATER PURIFICATION

• US 20140202943A1
• Filed: 03/23/2012
• Published: 07/24/2014
• Est. Priority Date: 03/25/2011
• Status: Abandoned Application

• Current Assignee: Indian Institute of Technology Delhi
• Original Assignee: Indian Institute of Technology Delhi
• Inventors: Pradeep, Thalappil, Sankar, Mohan Udhaya, Anshup, Chaudhary, Amrita, Rajarajan, Gayathri
• Application Number:
  US14/007,295
• Publication Number:
  US 20140202943A1
• Time in Patent Office: Days
• US Class Current: 210/198.1
• CPC Class Codes: B01J 20/0233 Compounds of Cu, Ag, Au
• CPC Class Codes: B01J 20/06 comprising oxides or hydroxides of metals not provided for in group B01J20/04
• CPC Class Codes: B01J 20/08 comprising aluminium oxide or hydroxide; comprising bauxite
• CPC Class Codes: B01J 20/28007 with size in the range 1-100 nanometers, e.g. nanosized particles, nanofibers, nanotubes, nanowires or the like carbon nanostructures B01J20/205
• CPC Class Codes: B01J 20/3057 Use of a templating or imprinting material molecularly imprinted polymers B01J20/268; filling pores of a substrate or matrix followed by the removal of the substrate or matrix
• CPC Class Codes: B01J 20/3204 Inorganic carriers, supports or substrates
• CPC Class Codes: B01J 20/3236 containing metal, other than zeolites, e.g. oxides, hydroxides, sulphides or salts
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C02F 1/001 Processes for the treatment of water whereby the filtration technique is of importance C02F1/44 takes precedence; construction of filters in general B01D24/00 - B01D41/00
• CPC Class Codes: C02F 1/288 using composite sorbents, e.g. coated, impregnated, multi-layered
• CPC Class Codes: C02F 1/50 by addition or application of a germicide or by oligodynamic treatment C02F1/4606, C02F1/467, C02F1/76 take precedence
• CPC Class Codes: C02F 1/505 by oligodynamic treatment

Abstract

Described herein are methods and compositions for preparing an adsorbent composition for sustained silver ion release is provided. The method comprises impregnating silver nanoparticles on an organic-templated-nanometal oxyhydroxide. Particle size of the silver nanoparticles is less than about 50 nm. The adsorbent composition is antimicrobial in water. In an aspect, the organic- templated-nanometal oxyhydroxide is organic-templated-boehmite nanoarchitecture (OTBN). The resultant adsorbent composition is used as a water filter in a water purification device.

Claims

1. A method for preparing an adsorbent composition, the method comprising:

impregnating silver nanoparticles on an organic-templated-nanometal oxyhydroxide, wherein the adsorbent composition kills microorganisms in water by sustained and continuous silver ion release.

2. The method according to claim 1, wherein the organic-templated-nanometal oxyhydroxide is organic-templated-boehmite nanoarchitecture (OTBN).

3. The method of claim 2, wherein silver ions are impregnated with OTBN in a gel state.

4. The method of claim 3, further comprising reducing the silver ions to a zerovalent state by using a reducing agent.

5. The method of claim 4, wherein the reducing agent comprises sodium borohydride, ascorbic acid, tri-sodium citrate or hydrazine hydrate or mixtures thereof

6. The method of claim 4, wherein the concentration of the reducing agent is about 0.001 M to about 1 M.

7. The method of claim 2, wherein silver ions are impregnated with OTBN in a solid state.

8. The method of claim 2, wherein externally prepared silver nanoparticles are impregnated in OTBN in at least one of a gel state and a solid state.

9. The method of claim 2, wherein impregnating the silver ions or silver nanoparticles comprises drop-wise adding silver ions or silver nanoparticles to the OTBN.

10. The method of claim 2, further comprising soaking the adsorbent composition.

11. The method of claim 1, further comprising soaking the adsorbent composition for about 30 minutes to 12 hours and preferably for a period of 1 hour.

12. The method of claim 1, wherein the organic template comprises chitosan, banana silk or cellulose, or mixtures thereof.

13. The method of claim 1 further comprising using a silver precursor for preparing the silver nanoparticles.

14. The method of claim 13, wherein the silver precursor comprises silver nitrate, silver fluoride, silver acetate, silver sulfate or silver nitrite, or mixtures thereof

15. The method of claim 1, wherein the concentration of silver is about 0.001 M to about 1 M.

16. The method of claim 1, wherein the adsorbent composition is used for sustained and continuous release of silver into water below 100 parts per billion (ppb).

17. The method of claim 1, wherein the particle size of the silver particles is about 3 nm to about 10 μ

m.

18. A water purification device comprising a water filter, wherein the water filter is made of an adsorbent composition prepared by impregnating silver nanoparticles on an organic-templated-nanometal oxyhydroxide, and wherein the adsorbent composition kills microorganisms in water by sustained and continuous silver ion release.

19. The water purification device of claim 18, wherein the water filter is one of a candle, a molded porous block, a filter bed and a column.

20. The water purification device of claim 18, wherein the organic-templated-nanometal oxyhydroxide is organic-templated-boehmite nanoarchitecture (OTBN).

21. The water purification device of claim 18, wherein silver ions are impregnated with OTBN in a gel state.

22. The water purification device of claim 21, wherein the silver ions are reduced to a zerovalent state by using a reducing agent.

23. The water purification device of claim 22, wherein the reducing agent comprises sodium borohydride, ascorbic acid, tri-sodium citrate or hydrazine hydrate, or mixtures thereof.

24. The water purification device of claim 23, wherein the concentration of the reducing agent is about 0.001 M to about 1 M.

25. The water purification device of claim 20, wherein silver ions are impregnated with OTBN in a solid state.

26. The water purification device of claim 20, wherein externally prepared silver nanoparticles are impregnated in OTBN in at least one of a gel state and a solid state.

27. The water purification device of claim 20, wherein impregnating the silver ions or silver nanoparticles comprises drop-wise adding silver ions or silver nanoparticles to the OTBN.

28. The water purification device of claim 18, wherein the adsorbent composition is soaked for about 30 minutes to 12 hours and preferably for a period of one hour.

29. The water purification device of claim 18, wherein the organic template comprises chitosan, banana silk or cellulose, or mixtures thereof

30. The water purification device of claim 18, wherein a silver precursor is used for preparing the silver nanoparticles.

31. The water purification device of claim 30, wherein the silver precursor comprises silver nitrate, silver fluoride, silver acetate, silver sulfate or silver nitrite, or mixtures thereof.

32. The water purification device of claim 18, wherein the concentration of silver is about 0.001 M to about 1 M.

33. The water purification device of claim 18, wherein the adsorbent composition continuously release silver into water below 100 parts per billion (ppb) for a prolonged period of time.

34. The water purification device of claim 18, wherein the particle size of the silver particles is about 3 nm to about 10 μ

m.