Manal El-Sheikh

5 Questions 24 Answers 0 Followers

Questions related from Manal El-Sheikh

Are polyphenols, naturally present in plant extract, electrically conductive?

Extracts of fruits, herbs, vegetables, cereals, and other plant materials are rich in polyphenols. Polyphenols are rich in conjugated benzene rings with high electron density. Can the...

05 May 2016 9,691 10 View

Why I can not find a UV-Vis band for polyaniline?

I am preparing AgNPs/PANI nanocomposite. I can see the brown yellow color of AgNPs during synthesis and the green-violet color of PANI (emeraldine) after precipitation with ethanol. I can also see...

04 April 2015 5,071 17 View

Why are silver salts easily converted to AgNPs while for other metal salts they are converted to the corresponding metal oxide nanoparticles?

In presence of sodium hydroxide, reducing and stabilizing agents (eg. modified starch, cellulose or chitosan), the salts of copper, iron or aluminum are converted to the corresponding copper, iron...

05 May 2014 6,863 11 View

Why does the deep brown color of the silver nanoparticles plasmon is turned black upon drying?

I was able to prepare high concentrated silver nanoparticles. I also succeeded to precipitate it easily using ethanol and filter it easily using normal filtration tools. Upon drying, the deep...

03 March 2014 9,524 25 View

Can we calculate the concentration of Ag NPs (silver nanoparticles) using the absorbance of UV-Vis spectrum of the Ag NPs colloidal solution?

Ag NPs colloidal solution have a characteristic peak at about 390-420 nm using UV-Vis spectrophotometer. The intensity of the peak is proportional to the concentration of the Ag NPs of the...

02 February 2013 3,225 35 View