Assembling nanoparticle-assembled capsules on a planar substrate

Abstract

In this thesis, a technique to assemble nanoparticle-assembled capsules (NACs) onto a planar substrate has been demonstrated. NACs are micron-sized spherical capsules produced from organic and inorganic materials. New sensing materials of various length scales are needed for numerous sensing needs of today, and NACs on substrate are interesting to investigate. Several parameters were optimized to achieve maximum surface density of capsules (0.09 NACs/mum 2). NACs are best adsorbed onto negatively charged surface. The NaCl concentration in the poly(diallyldimethylammonium chloride) and poly(styrene sulfonic acid) solutions used to coat the glass coverslip substrate should be at least 1 M. In addition, a minimum of one bilayer of PDADMAC/PSS is required. The deposition time required to achieve the maximum density was at least 10 minutes. Finally, aging NACs before assembling them on the substrate decreased NAC coverage on the surface which could be attributed to change in NACs' surface charge