title: Silica encapsulation of thiol-stabilized lead selenide (PbSe) quantum dots in aqueous solution.
abstract: Silica encapsulation of lead selenide quantum dots (PbSe QDs) in aqueous solution is reported. Thioglycolic acid (TGA) stabilized PbSe QDs were modified with 3-mercaptopropyl trimethoxysilane (MPS) through vigorous stirring in water for 18-24 h in alkaline solution (pH 10.4-10.6). Silica shell was developed by controlled deposition and precipitation of silicates from sodium silicate solution onto MPS modified QDs surfaces. TEM images showed multiple PbSe QDs encapsulated in silica shell. The size of PbSe-SiO2core-shell nanocrystals was estimated to be 25-30 nm by TEM. Elemental compositions (Pb, Se and Si) were investigated by EDX analysis. The purified colloids of PbSe-SiO2QDs were stable for months when kept at 4 °C.
authors.affiliation: School of Science and Technology, Metropolitan University, San Juan, PR 00926 USA.
authors.forename: Oliva M
authors.initials: OM
authors.lastname: Primera-Pedrozo
authors.forename: Mehmet
authors.initials: M
authors.lastname: Ates
authors.forename: Zikri
authors.initials: Z
authors.lastname: Arslan
keywords: Colloidal stability; Lead selenide; Quantum dot; Silica encapsulation