Ag Nanoparticles Aqueous Dispersion

Silver Ag Dispersion Description :

There are many ways silver nanoparticles can be synthesized; one method is through monosaccharides. This includes glucose, fructose, maltose, maltodextrin, etc., but not sucrose.

Ag Nanoparticles Aqueous Dispersion is also a simple method to reduce silver ions back to silver nanoparticles as it usually involves a one-step process. There have been methods that indicated that these reducing sugars are essential to the formation of silver nanoparticles.

Many studies indicated that this method of green synthesis, specifically using Cacumen platycladi extract, enabled the reduction of silver. Additionally, the size of the nanoparticle could be controlled depending on the concentration of the extract. Ag Nanoparticles Aqueous Dispersion that the higher concentrations correlated to an increased number of nanoparticles.

Smaller nanoparticles were formed at high pH levels due to the concentration of the monosaccharides. Another method of silver nanoparticle synthesis includes the use of reducing sugars with alkali starch and silver nitrate.

The reducing sugars have free aldehyde and ketone groups, which enable them to be oxidized into gluconate. The monosaccharide must have a free ketone group because to act as a reducing agent it first undergoes tautomerization. Besides, if the aldehydes are bound, it will be stuck in cyclic form and cannot act as a reducing agent.

For example, glucose has an aldehyde functional group that can reduce silver cations to silver atoms and is then oxidized to gluconic acid. The reaction for the sugars to be oxidized occurs in aqueous solutions.

The capping agent is also not present when heated.The growth of nanoseeds involves placing the seeds into a growth solution. The growth solution requires a low concentration of a metal precursor, ligands that will readily exchange with preexisting seed ligands, and a weak or very low concentration of reducing agent. The reducing agent must not be strong enough to reduce metal precursors in the growth solution in the absence of seeds.

Otherwise, the growth solution will form new nucleation sites instead of growing on preexisting ones (seeds). Growth is the result of the competition between surface energy (which increases unfavorably with growth) and bulk energy (which decreases favorably with growth).

The balance between the energetics of growth and dissolution is the reason for uniform growth only on preexisting seeds (and no new nucleation). Growth occurs by the addition of metal atoms from the growth solution to the seeds, and ligand exchange between the growth ligands (which have a higher binding affinity) and the seed ligands.

The range and direction of growth can be controlled by nano speed, the concentration of metal precursor, ligand, and reaction conditions (heat, pressure, etc.). Controlling stoichiometric conditions of growth solution controls the ultimate size of the particle. For example, a low concentration of metal seeds to metal precursors in the growth solution will produce larger particles.

Capping agent has been shown to control the direction of growth and thereby shape. Ligands can have varying affinities for binding across a particle. Differential binding within a particle can result in dissimilar growth across particles. This produces anisotropic particles with nonspherical shapes including prisms, cubes, and rods.

Silver Ag Dispersion Related Information

Storage Conditions:

Airtight sealed, avoid light and keep dry at room temperature.