Shell dyeing, characterization

Years of Purple-Shell Dyeing Characterization of Hyacinthine Purple (Tekhelet)... 

There are many different synthetic methods to prepare silica nanoparticles and in particular dye doped silica nanoparticles (DDSNs), all characterized by simplicity, low costs, versatility and great control over the architecture of the resulting materials. We will discuss in detail the most common procedures in the next section, with some emphasis on a new synthetic strategy that we have developed and patented [64, 65] that affords monodisperse silica nanoparticles with a particularly versatile and readily obtained core-shell architecture. 

The synthesis and characterization of the dye-labeled silicone particles with the core-shell architecture was described [18]. In the first step, the chlorobenzyl-functionabzed core was formed via co-condensation of MeSi(OMe)j and trimethoxy-chlorobenzylsilane (ClSi(OMe)3) in the presence of benzetho-nium chloride under basic conditions. Next, a nonfunctional homogeneous shell was formed by the addition of variable amounts of MeSi(OMe)j. The obtained core-shell particles were coated with a hydrophobic surface layer by the end-cap-ping reaction with Me SiOMe and (Me Sil NH, and isolated from the surfactant. This procedure results in the well-defined silicone nanoparticles having a chlorobenzyl-functionahzed core of 10 nm in size that is surrounded with a non-functional-ized protective shell of the thickness in the range 0-3.2 nm. The dye labels (orfho-nitrostilbene (ONS), rhodamine B, coumarin 343, and pyrene) were chemically attached to the core-shell particles by an esterification reaction of the cesium salt of the chromophores with chlorobenzyl functions present in the core. 

---