Article ID Journal Published Year Pages File Type
594486 Colloids and Surfaces A: Physicochemical and Engineering Aspects 2011 9 Pages PDF
Abstract

The surface stabilizing agents often play a major role in determining colloidal stability of the nanoparticles. In the present study a difference in surface coverage of colloidal silver nanoparticles was deliberately introduced by following two soft synthesis approaches: (a) biological process: using aqueous extract of Citrus limon [partial citrate capping] and (b) chemical process: using tri sodium citrate [complete capping]. Their aggregation behaviour in aqueous environmental matrix (lake water, sea water) and biological matrix (Potato Dextrose broth, Luria Bertani broth) was studied through UV–vis spectroscopy, hydrodynamic diameter, zeta potential analyses and theoretical studies (determining agglomeration number). Increase in ionic strength led to increased aggregation of the chemically synthesized nanoparticle whereas an exactly opposite result (decreased particle size in the presence of ions) was obtained for biologically synthesized one. The partially citrate coated nanoparticles [biological synthesis] exhibited significantly more colloidal stability in all the matrices studied compared to chemically synthesized particles. This study demonstrates that complete surface characterization of citrate capped silver nanoparticles is of high importance to understand its aggregation behaviour in aqueous matrices.

Graphical abstract.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Deliberate changes in surface capping of silver nanoparticles introduced during synthesis. ► Differential aggregation behaviour for different surface capping observed irrespective of matrices used. ► Surface characterization of citrate capped nanoparticles crucial to study its aggregation behaviour.

Related Topics
Physical Sciences and Engineering Chemical Engineering Colloid and Surface Chemistry
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