Self-assembly of polyelectrolyte-coated silver nanoparticles with metanil yellow for use in Raman amplification

Keywords

Nanoparticles; Polyelectrolytes; Raman effect; Self assembly (Chemistry)

Abstract

In optical signal transmission, signal attenuation is compensated by use ofamplifiers. Recently, Raman gain has been investigated due to the possibility of optical signal amplification. To increase the gain bandwidth in Raman amplification, an electrostatic self-assembly strategy was used to incorporate multiple strong Raman-active vibration modes to achieve broad Raman scattering bands. Meanwhile, the use of silver nanoparticles to increase the Raman scattering intensity by a surface enhanced Raman scattering (SERS) mechanism was investigated. The bifunctional copolymer poly(4-vinylpyridine-ca-acrylonitrle) was synthesized and characterized by the average viscosity molecular weight measurement, along with 1H NMR, 13C NMR, and FTIR spectroscopy. Nitrile groups were introduced to complex the silver nanoparticles. The pyridine moieties were protonated as the pyridinium salt to spontaneously form ion-pairs with anionic molecules, such as metanil yellow. Metanil yellow was chosen since it includes multiple potential Raman-active vibrational modes. Consequently, the vibration normal modes of the 4-vinyl-pyridine and metanil yellow components were analyzed and assigned. Silver nanoparticles were generated in situ and characterized by UV-vis absorption spectroscopy to estimate the particle size. A self-assembled solid-state polyelectrolyte/dye complex was studied by TGA, DSC, and FTIR spectroscopy. The mechanism of dye ii adsorption and aggregation in the presence of the polyelectrolyte was further investigated by UV-vis spectroscopy. Finally, Raman spectra were obtained for both the copolymer/dye complex and the complex-coated silver nanoparticle composites. An intense, broad band of Raman scattering between 1000 cm·1 and 2000 cm~1 (with bandwith > 800 cm-1) was observed. The intensity ofthis band was enhanced as much as twice, presumably by SERS, for the complex-coated silver nanoparticle composites.

Notes

This item is only available in print in the UCF Libraries. If this is your thesis or dissertation, you can help us make it available online for use by researchers around the world by STARS for more information.

Graduation Date

2003

Advisor

Belfield, Kevin

Degree

Master of Science (M.S.)

College

College of Arts and Sciences

Department

Chemistry

Format

PDF

Pages

71 p.

Language

English

Length of Campus-only Access

None

Access Status

Masters Thesis (Open Access)

Identifier

DP0028724

Subjects

Arts and Sciences -- Dissertations, Academic; Dissertations, Academic -- Arts and Sciences

Accessibility Status

PDF accessibility verified using Adobe Acrobat Pro accessibility checker.

This document is currently not available here.

Share

COinS