کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
602011 879960 2010 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Growth of different morphologies (quantum dots to nanorod) of Ag-nanoparticles: Role of cysteine concentrations
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Growth of different morphologies (quantum dots to nanorod) of Ag-nanoparticles: Role of cysteine concentrations
چکیده انگلیسی

This work describes an easy chemical method for the preparation of orange-red color silver sol by the cysteine reduction of silver (I) in the presence of cetyltrimethylammonium bromide (CTAB). The obtained sol was found to have very small particles in the order of quantum dots for the first time. Transmission electron microscope (TEM) images show that the silver sol consists of aggregated as well as cross-linking arrangement of spherical silver quantum dots (size in the range ca. ≤16 nm). In addition, we observed the changes in the morphologies of the Ag-nanoparticles from quantum dots to nanorod of diameter 60 nm and pearl-necklace shaped which occurred due to the cross-linking aggregation of silver quantum dots. For a certain reaction time, i.e., 100 min, the absorbance of reaction mixture first increased until it reached a maximum, then decreased with [cysteine]. The rate of Ag-nanoparticles formation decreases with the increase in [cysteine] whereas [CTAB] and [Ag+] have no effect on the reaction rate. Interestingly, at higher [cysteine] (≥20.0 × 10−4 mol dm−3), white precipitate was formed instead of transparent silver sol. Cysteine acts as a reducing, cross-linking, stabilizing and buffering agent during the growth of different shape and size of silver nanoparticles.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Colloids and Surfaces B: Biointerfaces - Volume 76, Issue 1, 1 March 2010, Pages 164–169
نویسندگان
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