Extraction of Au nanoparticles having narrow size distributions from within dendrimer templates.

نویسندگان

  • Joaquin C Garcia-Martinez
  • Richard M Crooks
چکیده

Here, we show that Au nanoparticles having diameters of less than 2.2 nm can be extracted from within the interior of PAMAM dendrimers using n-alkanethiol extractants. Extraction proceeds quickly, regardless of the size of the nanoparticle, the dendrimer generation, or the peripheral functionalization of the dendrimer. The extraction rate is fastest for the lowest generation dendrimers, the smallest nanoparticles, and the shortest chain-length n-alkanethiols. Other important results of this study include the following. First, within the accuracy of absorbance spectroscopy, the extraction yield is quantitative. Second, NMR and FT-IR spectroscopy indicate that after extraction the dendrimer remains in the aqueous phase and can be used to template additional metal particles. Third, the size and optical characteristics of the extracted nanoparticles are the same as the precursor dendrimer-encapsulated nanoparticles (DENs). Fourth, a 100-fold excess of n-alkanethiol molecules is required to prevent aggregation of DENs during extraction.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Electrochemical properties of monolayer-protected Au and Pd nanoparticles extracted from within dendrimer templates.

The electrochemical properties of Au and Pd monolayer-protected clusters (MPCs), prepared by dendrimer-templating and subsequent extraction, are described. Differential pulse voltammetry was used to estimate the size of the MPCs, and the results were compared to microscopic data and calculated values. Purification of the extracted Au and Pd nanoparticles was not required to obtain well-defined ...

متن کامل

Synthesis of small gold nanoparticles: Au(I) disproportionation catalyzed by a persulfurated coronene dendrimer.

Gold nanoparticles with average diameter of 1.0 nm and narrow size distribution can be easily obtained by disproportionation of Au(+) ions, in the presence of a persulfurated coronene dendrimer that favors encounters between Au(+) ions and protects the resulting small nanoparticles from further aggregation.

متن کامل

Extraction of monodisperse palladium nanoparticles from dendrimer templates.

We describe a strategy for extracting nearly size-monodisperse, 1.7-nm-diameter Pd nanoparticles from within dendrimer hosts. The approach involves two steps. First, an aqueous solution of dendrimer-encapsulated Pd nanoparticles is prepared, followed by the addition of a toluene solution containing an n-alkanethiol. When the two-phase system is stirred, n-alkanethiols presumably self-assemble o...

متن کامل

Synthesis of Mono- and Bimetallic Au-based Nanoparticle Catalysts Utilizing Solid Phase Dendrimer Templates

Introduction The desire to controllably tune catalyst properties has generated increased interest in the controlled preparation of supported nanoparticle catalysts. Particle size, composition, and morphology may have substantial influences on catalytic activity and, more importantly, selectivity. However, few preparative routes exist to prepare supported catalysts of welldefined morphologies. S...

متن کامل

Air and water free solid-phase synthesis of thiol stabilized au nanoparticles with anchored, recyclable dendrimer templates.

Solid-phase synthetic templates for Au nanoparticles were developed using Merrifield resins and polyamidoamine (PAMAM) dendrimers. This synthetic scheme affords the opportunity to prepare metal nanoparticles in the absence of air and water, and it does not necessitate phase transfer agents that can be difficult to remove in subsequent steps. Amine-terminated generation 5 PAMAM (G5NH2) dendrimer...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Journal of the American Chemical Society

دوره 126 49  شماره 

صفحات  -

تاریخ انتشار 2004