Question

in a COLLOIDAL NANOPARTICLES experiement

What is the difference between Plasmon peak positions between the citrate and borate stabilized nanoparticles? How does that correlate to the stated size of the particles? o Based on the rate of nanoparticle formation, what can you conclude about the reducing potential of sodium citrate vs. NaBH4?

Answer 1

The preperation of nanoparticles is the choice of the capping agent used to protect or stablize the nanopartcle colloidal solution from agglomeration.

Nanoparticles stabilization is cahieved according to two basic modes :electrostatic and steric stabilzation.Electrostatic stabilization is caused by the columbic repulsion between particles caused by electrical double layer formed by ions adsorbed at particle surface (sodium citrate) and the corresponding counter ions.

Steric stabilization is achieved because of coordination of sterically demanding organic molecules and polymers that act as protective shileds on the metallic surface

we are taking in to account of silver and gold nanoparticles synthesis NaBH4 used as a reducing agent which gives protective layer of borohydrate ions..The borohydride anions are absorbed on to silver nanoparticles...Due to capacity reduction of NaBH4 lot nuclei initiaters nanoparticles are generated.Thus during citrate reduction method uniform spherical nanoparticles are produced and which shows that there is tendency of formation for smaller and uniform speherical gold nanoparticles.The citrate conecentration is the most importeenr factor is not only important function of particle size distribution but could also act as an agent to modify the affection of the reaction temperature.

With NaBH4 the control of reduction rate is very important process. dialysis could decrease the impurities by large portion and same time can improve the quality of stablized nanoparticles.