| Title of Invention | POLYURETHANE FOAM COATED WITH SILVER NANOPARTICLES |
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| Abstract | A process for the manufacture of polyurethane foam coated with silver nanoparticles comprising the steps of soaking the said foam in a solution of nanoparticles of silver, the solution being of 10<sup>-3</sup> molar concentration of silver and the said nanoparticles being in the size range 1-10 nano metres; and coated foam being washed and dried thereafter. |
| Full Text | This invention relates to polynretliaae foam coated with silver nanoparticles to result in stable and nnifonn nanopaiticle covered foam for antibacterial applications. Bacterial contamination is a major issue concemmg environment. The World Health Organization (WHO) standards for drinking water are that any 100ml water sample collected should not contain a smgle bacterial strain. This invention proposes a simple and direct method of coating polyurethaoe foams (PU) with silver nanopartictes and the coated foams can be used for different antibacterial purposes. According to this invention, the process for the manufacture of polyurethane foam coated with silver nanoparticles comprises the steps of soaking the said foam ia asofaition of nanoparticles of silver, the sohition being of 10'^ molar concentration of silver and the said nanoparticles being in the size range 1 -100 nano metres; the coated foam being washed and dried thereafter. EXAMPLE Cleaned PU foam of 2-20 mm thiekness comm ercially available were soaked with nanoparticle sobtions of silver in the size range of 60-80 nm prepared by the standard citrate reduction method. This method involves heating 1 litre of silver nitrate sohitiott (10*^ molar) in w^er to refhix and adding 40 ml (1% by weight) of sodium citrate sohition in water and continuing the boiling for five minutes after which the sohition colour changes to golden yellow. The nanoparticle sohition thus formed is cooled to room temperature by leaving it outside the heater, tlie PU foams were exposed to the sohition of nanoparticles for 6 hours. The foams were repeatedly washed with water to remove any adsorbed ions and were then air dried. These treated foams were found to be efTective as aatibaterial water filters as no bacterial strain was detected in water samples having a load of lO' CFU^l (colony forming units^il) ofE.coU strains such as ATCC 25922 and MTCC 1302, when exposed to the said coated foams. The amount of silver coated iiuist be more than 0.001 % and less than 0T% (by \veight). The nanopartkles are retained on the surface of the foam for several months. Preferably, the PU foam used must be hydrophilic and of food grade quality if they are to be used for drinkins water fihers. Apart from the above mentioned application, the coated foam can be used for antibacterial and antiseptic purposes in products such as footwear, textiles, clinical, medicinal packaging, as a part or whole of products. The terms and expressions herein are of description and not of hmitation having regard to the scope and ambit of this invention. We Claim: 1. A process for the manufacture of polyurethane foam coated with silver nanoparticles comprising the steps of soaking the said foam in a solution of nanoparticles of silver, the solution being of 10' molar concentration of silver and the said nanoparticles being in the size range of 1-10 nano metres; the coated foam being washed and dried thereafter. 2. The process for the manufacture of polyurethane foam as claimed in Claim 1 wherein the foam is soaked in the said solution for 2-8 hours, 3. The process as claimed in Claim 1 or Claim 2 wherein the silver coating concentration must be more than 0.001 % and less than 0,1% (by weight). 4. The process for the manufacture of polyurethane foam coated with silver nanoparticles substantial!)^ as herein described and illustrated with reference to the Example. 5. Polyurethane foam coated with silver nanoparticles whenever manufactured by a process as claimed in any one of the preceding Claims. |
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0891-che-2004-correspondnece-others.pdf
0891-che-2004-correspondnece-po.pdf
0891-che-2004-description(complete).pdf
| Patent Number | 219111 | |||||||||
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| Indian Patent Application Number | 891/CHE/2004 | |||||||||
| PG Journal Number | 23/2008 | |||||||||
| Publication Date | 06-Jun-2008 | |||||||||
| Grant Date | 25-Apr-2008 | |||||||||
| Date of Filing | 03-Sep-2004 | |||||||||
| Name of Patentee | INDIAN INSTITUTE OF TECHNOLOGY | |||||||||
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| PCT International Classification Number | C08 J 07/12 | |||||||||
| PCT International Application Number | N/A | |||||||||
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