Novel composite of silica and graphene quantum dots and preparation thereof

Patent metadata

Field	Value
Publication number	US-2018030344-A1
Application number	US-201615548708-A
Country	US
Kind code	A1
Filing date	Feb 3, 2016
Priority date	Feb 3, 2015
Publication date	Feb 1, 2018
Grant date	—

Abstract

The present invention relates to a novel composite of graphene quantum dot and silica. The present invention further relates to a novel one step process for the synthesis of composite of GQD and silica from paper. The composite is useful for biological applications such as bioimaging, drug delivery etc.

First claim

1 . A novel composite of graphene quantum dot and silica in the weight ratio gqd and silica is in the range of 1-5: 1-2 and depend upon source of paper.

2 . The composite as claimed in claim 1 , wherein said composite is obtained from paper, wood pulp, leaves, bananas, coconut peel, coal or cotton.

3 . The composite as claimed in claim 1 , wherein said gqd is luminescent and size is in the range of 4-6 nm.

4 . The composite as claimed in claim 1 , wherein size of said silica is in the range of 40-50 nm.

5 . The composite as claimed in claim 1 , wherein the main chemical component of said paper is silicate of magnesia wherein the amount of silica is 62-70%.

6 . A novel one step process for the synthesis of said composite of gqd and silica as claimed in claim 1 comprising the steps of:
a) burning the paper to afford ash;
b) suspending the ash of step (a) in water by sonicating and adding oxidizing agent followed by heating in a microwave for 2-4 minutes and repeating the microwave heating for six to seven times at 750 watts to afford a black residue of GQDs silica composite, with green fluorescence.

7 . The process as claimed in claim 6 , wherein said oxidizing agent is selected from glycolic acid, citric acid or ascorbic acid.

8 . The process as claimed in claim 6 , wherein said paper is silicate of magnesia wherein the amount of silica is 62-70%.

9 . The process as claimed in claim 6 , wherein said water is de-ionised water.

Assignees

• Council Scient Ind Res

Inventors

• Poddar Pankaj
• Sadhu Subha

Classifications

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• Y10S977/842

  for carbon nanotubes or fullerenes · CPC title

• B82Y20/00

  Nanooptics, e.g. quantum optics or photonic crystals · CPC title

• C01B33/18

  Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof (preparation of aerogels by dehydrating gels C01B33/158; treatment to enhance the pigmenting or filling properties C09C) · CPC title

• Y10S977/774

  Exhibiting three-dimensional carrier confinement, e.g. quantum dots · CPC title