Silver Nanoparticle Lab Report

INTRODUCTION

Silver nanoparticles are particles of silver of between 1 nm and 100 nm in size. Some of the conventional methods of synthesis of silver nanoparticles are as follows:-

1) Reduction with Reducing Sugars

Reducing sugars like glucose, fructose, maltose, maltodextrin, etc. except sucrose, and is the simplest method to reduce silver ions back to silver nanoparticles. If the pH is above 7 the glucose molecule in the reducing sugar will open its ring structure and attach to the surface of the nanoparticles, thereby acting as a weak stabilizing agent.

2) Citrate reduction

A very common, method for synthesizing silver nanoparticles is citrate reduction. It involves the reduction of silver nitrate, AgNO3, to colloidal silver using trisodium citrate, Na3C6H5O7 at high temperatures (~100 °C). Here, the citrate ion acts as reducing agent. This method is useful due to its relative ease and short reaction time. However, the silver particles formed may exhibit broad size distributions or form several different particle geometries simultaneously.

3) Reduction via sodium borohydride

A similar method is the reduction of silver nitrate using sodium borohydride, NaBH4.Sodium borohydride is a stronger reducing agent than citrate, but it does not participate in surface stabilization. Thus, a separate capping molecule must be used in addition to the sodium borohydride. Examples of stabilizers or capping molecules used include citrate, poly(vinyl pyrrolidone) (PVP),bovine serum