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Controllable Soft Template for the Synthesis of Gold Nanoparticles

Author: WangChunRong
Tutor: FangYun
School: Jiangnan University
Course: Applied Chemistry
Keywords: Soft template Gold Nanoparticles Sodium dodecyl sulfate Polyethylene glycol Polyvinylpyrrolidone
CLC: TB383.1
Type: PhD thesis
Year: 2007
Downloads: 390
Quote: 1
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Abstract

Nanotechnology is the most cutting-edge research areas. The morphology and size control of nano-materials is an important part of nanotechnology. Nanomaterials in the size, shape, and surface and body relative to the ratio of the number of atoms and surface properties are very different from ordinary homogeneous material, has an important in the field of optics, microelectronics, magnetic, catalytic and biological Application Nanomaterials are emerging cross-cutting areas of colloid chemistry, materials science and Interface Science, is also very active in the field of scientific research today. This paper examines the surfactant sodium dodecyl sulfate (SDS), macromolecular polyethylene glycol (PEG) or polyvinyl pyrrolidone (PVP) is formed of soft material Clusters with chloroauric acid (HAuCl4) between mutually role as well as soft cluster structure in solution. SDS-PEG soft clusters on the basis of this study, as a template, the use of ultrasound to restore and photoreduction prepared spherical gold nanoparticles with controllable particle size; SDS-PEG soft clusters template prepared using PEG self-restore ability sheet, ring and the curved gold nanoparticles; soft clusters of SDS-PVP as a template, using sodium citrate as a reducing agent, multi-pin-shaped gold nanoparticles prepared under microwave irradiation. Preliminary study of the template effect of the composition of surfactant SDS and macromolecules PEG or PVP soft clusters in the process of the preparation of gold nanoparticles. Which mainly includes the following four parts: the first part is mainly through the surface tension, the steady-state fluorescence quenching fluorescent molecular probes and laser light scattering technology HAuCl4 surfactant SDS aqueous solution composition with the macromolecular PEG or PVP system A first threshold concentration was found HAuCl4 procure SDS-PEG or SDS-PVP system surface tension C1 decreases, while little effect for the second critical concentration c2. SDS-PEG may promote or SDS-PVP system HAuCl4 bound micellar aggregation number and saturated clusters increase in the polarity of the microenvironment decreases, and hydrodynamic radius increases with increasing concentration of SDS. The second part focuses on the SDS-PEG soft clusters as a template, the use of ultrasound and photoreduction means, step-by-step induce the synthesis of spherical gold nanoparticles of different size. Studies found that the SDS and PEG content significantly affect the size and morphology of the synthesized gold nanoparticles, when the SDS concentration is low, as the SDS concentration increases, the particle size of nanoparticles gradually smaller; When the SDS concentration is higher than a certain value, The nanoparticle morphology changes, triangular and truncated triangular irregular shape; narrower distribution of gold particles generated in the reaction solution containing a higher concentration of PEG. In the third part of the study of PEG self-reduction of HAuCl4 synthesis of gold nanoparticles by SDS-PEG soft clusters as a template for the size and morphology of gold nanoparticles. The preparation process, only the SDS-PEG template of the PEG component involved in the reduction reaction, and without adding external reductant. Found that after the first PEG self-reducible HAuCl4 then the effect of a soft template the gold quantum points to self-assemble into the gold nanoplates morphology gold quantum well, and then by controlling the different reaction cycles this gold nanoplates precursor by gold quantum dot is formed; The morphology of gold nanorings aging treatment different void size quantum wells; final gold ring cleavage of gold arc. SDS and PEG soft template to control the scale and morphology of the gold nanoparticles, PEG, both as a stabilizer protected gold structure, and as self-reducing agent to the aqueous solution of gold ions to gold nanoparticles. The fourth part of the formation of SDS-PVP Soft clusters as template under microwave irradiation as a reducing agent, sodium citrate, and quickly restore HAuCl4 and self-assembled into the equivalent diameter of 50 nm and the particle size distribution of narrow multi-pin-shaped gold nanoparticles and under microwave irradiation synthesis of multi-pin shaped gold nanoparticles template discussed. The study found that by changing the content of the SDS and PVP, the implementation of the regulation and control of the gold particle morphology, easily achieved gold nanoparticle spherical - more than foot-shaped - spherical morphology turn shift.

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