5 research outputs found
The Progress of Buddha-land thought of Silla and its historical meanings
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Όλ¬Έ(λ°μ¬)--μμΈλνκ΅ λνμ :κ΅μ¬νκ³Ό,2000.Docto
Study on the Surface-Enhanced Raman Scattering Mechanism and Application to Probing the Surface Potential of Metal Nanostructures
1μ₯μμλ κΈ°λ³Έμ μΈ λΌλ§ λΆκ΄ νμκ³Ό μ΅κ·Ό λ€μ΄ κ°κ΄λ°κ³ μλ νλ©΄ μ¦κ° λΌλ§ νμ (Surface Enhanced Raman Scattering: SERS) μ λν΄ κ°λ΅ν μκ°νμλ€.
2μ₯μμλ λΌλ§ νμμ λ λ©μ»€λμ¦ μ€ νλμΈ μ μκΈ° μ¦κ° λ©μ»€λμ¦μ λν΄ μ°κ΅¬νμλ€. λ κ°μ κΈ λλ
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μ μ¬μ΄μ 1,4-PDI (1,4-phenylenediisocyanide) λΆμλ₯Ό μμΉνκ² νμ¬ λΌλ§μ μΈ‘μ νμλ€. μ€νκ°κ³Ό FDTD (Finite-difference time domain) κ³μ°λ°©λ²μ μ΄μ©νμ¬ μ»μ κ²°κ³Όλ₯Ό μ΄μ©ν΄ νλ©΄ μ¦κ° λΌλ§ νμμ μ΄μ (hot site) μ ν¬κΈ°λ₯Ό λμΆν΄ λΌ μ μμλ€. 10nm μ§λ¦μ κ°λ λ²μ λ΄μ μμΉν μ½ 400κ°μ λΆμλ€μ΄ μ 체 λΌλ§ μ νΈμ 99%μ΄μμ κΈ°μ¬νλ€λ μ¬μ€μ λ°νλ€.
3.1μ₯μμλ νλ©΄ μ¦κ° λΌλ§ νμμ νν μ¦κ° λ©μ»€λμ¦μ λν΄ μ°κ΅¬νμλ€. νν μ¦κ° νμμ μ΄ν΄νκΈ° μν΄ μ£Όλ‘ λ§μ΄ μ¬μ©λμ΄μ¨ 4-ABT (4-aminobenzenethiol) λΆμλ₯Ό κ°μ§κ³ μ°κ΅¬νμλ€. λ¨Όμ 3.1μ₯μμλ νλ©΄ μ¦κ° νμ±μ κ°λ κΈ κΈ°μ§μ ν‘μ°©ν 4-ABTλΆμμ b2-type λ λ₯Ό μ£Όμ¬ λ μ΄μ μΈκΈ°μ κΈ°μ§μ μ¨λμ λ°λΌ λ³ννλ μμμ κ΄μΈ‘νμλ€. κ·Έ κ²°κ³Ό, 4-ABTλΆμκ° νν μ¦κ° νμμ λνλ΄λ νν νμ± μλ¦¬λ‘ μμΉνκΈ° μν΄μλ μκ³ μλμ§ μ΄μμ μλμ§κ° νμνλ€λ λͺ¨λΈμ μΈμ°κ² λμλ€.
3.2μ₯μμλ μ§κΈκΉμ§ 4-ABTλΆμμμλ§ κ΄μΈ‘λμ΄μ¨ b2-typeμ λ λ€μ΄ 4-ABT λΏλ§ μλλΌ λ€μν 4-ABT μ λ체 λΆμλ€μμλ λμΌνκ² κ΄μΈ‘λ¨μ λ°νλ€. λ¨Όμ , 4-BDBT (4-(benzylideneamino)benzenethiol) λΆμμ 4-DMABT (4-(diethylamino)benzenethiol) λΆμλ₯Ό μ΄μ©ν΄ b2-typeμ λ λ€μ΄ μμ±λλ κ²μ΄ κ΄λ°μκ³Όλ μκ΄μ΄ μλ νμμμ λ°νλ€. κ·Έλ¦¬κ³ λ€μν 4-ABTμ λ체 λΆμλ€μ μ κ·Ήμ μμμ‘΄ νλ©΄ μ¦κ° λΌλ§ μ€νμ ν΅ν΄ b2- typeμ λ λ€μ΄ λͺ¨λ λΉμ·ν νΉμ±μ κ°μ§μ νμΈνμλ€.
4μ₯μμλ κ·Ήμ± μ κΈ° νλ° μ©λ§€μ λν κΈ λλ
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μμ νλ©΄ μ μ λ³νλ₯Ό ννν κΈ μ κ·Ή μμ κΈ λλ
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μλ‘ μ΄λ£¨μ΄μ§ νμ μμΉν 1,4-PDI λΆμλ₯Ό μ΄μ©ν΄ κ°μ§νλ κΈ°μ μ κ°λ°νμλ€. μ κ·Ή μ μ μμ‘΄ νλ©΄μ¦κ°λΌλ§ μΈ‘μ μ ν΅ν΄, μ μ μμΈν€κ³Ό μλͺ¨λμλ₯Ό νλ €μ£Όμμ λμ κΈ λλ
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μμ νλ©΄μ μκ° ν¬ν AgAgCl μ κ·Ήκ³Ό λΉκ΅ν΄λ³Ό λ +0.7 V μμ -0.6 VκΉμ§ λ³ννλ€λ μ¬μ€μ νμΈν μ μμλ€.Chapter 1 describes general introduction of the thesis. Classical Raman Scattering and Surface-enhanced Raman scattering (SERS) Spectroscopy are introduced briefly.
In Chapter 2, I estimated the size of hot sites for SERS located within the gap between two 1,4-phenylene diisocyanide-incorporated Au nanoparticles by using both Raman experiment and finite-difference time-domain calculation. About 400 molecules residing within a 10-nm diameter area of the center of the gap irradiated by a laser light, must contribute more than 99% to the total Raman signal of 1,4-phenylene diisocyanide. This apparently indicates that the size of hot site is very limited.
In Chapter 3.1, temperature dependent Raman scattering measurements were conducted for 4-aminobenzenethiol adsorbed on the gold surface. It was verified that some threshold energy is required for 4-aminobenzenethiol to occupy the gold surface sites capable of leading to the appearance of surface-enhanced Raman scattering peaks via a charge transfer resonance enhancement mechanism.
In Chapter 3.2, it is examined the SERS spectral pattern of various 4-aminobenzenethiol derivatives adsorbed on Ag substrates. At first, is is found in the SERS spectra of 4-(diethylamino)benzenethiol and 4-(benzylideneamino)benzenethiol that no photoreaction had taken place at all but the b2-type bands appeared distinctly as is usual in the SERS of 4-ABT. The b2-type bands were also observed in the SERS spectra of other 4-ABT derivatives while, surprisingly, no such b2-type bands were observed at all in the SERS spectra of para-substituted (but not amino) benzenethiol derivatives. The appearance of the b2-type bands in the SERS spectra seemed thus a common feature of 4-ABT derivatives. The difference between 4-ABT derivatives and para-substituted (but not amino) benzenethiol derivatives was supposedly associated with the LUMO-HOMO energy gap. The energy gap computed for 4-ABT derivatives (~300 nm) was consonant with the interpretation that the appearance of the b2-type bands in the SERS spectrum of 4-ABT is associated with an intensity borrowing from an intense * molecular transition (1A1 1B2) at 300 nm.
In Chapter 4, large peak shift was observed for the NC stretching band of 1,4-phenylene diisocyanide (1,4-PDI) situated at the gap between gold nanoparticles and gold electrode when gold nanoparticles are exposed to polar organic solvent like acetone and ammonia. The peak shift amounted to as much as 22 cm-1, corresponding to the variation of surface potential of Au nanoparticles from +0.7 V to -0.6 V vs a saturated Ag/AgCl electrode. The peak shift observed in this work must be due to the large surface-to-volume ratio of Au nanoparticlesDocto
Fabrication of various nanotextured materials and relaxation dynamics of TiOβAg nanocomposite systems
Thesis (master`s)--μμΈλνκ΅ λνμ :ννλΆ λ¬Όλ¦¬ννμ 곡,2004.Maste