• 대한화장품학회지
• /
• 제22권2호
• /
• pp.52-69
• /
• 1996

Nano-Sized TiO$_2$ particles with diameter between 2 and 5 nm are synthesized in Water/Triton X-100/n-Hexane microemulsion. Particles show the amorphous structure and partially hydroxide form. The optical absorbance of particles appears at 250nm and band edge at 340nm. Gold metal is deposited on the surface of TiO$_2$ particles by reduction reaction of Au(III) ion with sodium hypophosphite. The size of gold-deposited particles is 20nm, and the optical absorbance appears at 270nm and at 550nm. So particles show the red color. The dense precipitation is formed by aggregation in the TiO$_2$ nano-sized particles of about 5nm size. But the bulky precipitation is formed by agglomeration phenomena in the gold-deposited particles of 20nm size. And also gold-deposited particles is easily dispersed by being re-dispersed in PEG/Water solution. This study has compared those things measuring the SPF characteristics of the cosmetics made of the synthesized particles. If the particle size is controlled appropriately, then the SPF value will be higher, or more colorless cosmetics will be made.

• 한국재료학회지
• /
• 제13권5호
• /
• pp.285-291
• /
• 2003

The nanosized silver and gold particles are prepared by ERC method in which metal vapors with high temperature is rapidly quenched by coolants such as liquid nitrogen or liquid argon. In order to monitor the crystal structural changes on the internal and the surface of the nanosized noble metal particles, lattice parameter, internal strain and Debye-Waller factor are investigated, and the calculation of X-ray diffraction scattering intensity is performed. The lattice parameters of silver and gold particles agree with those of bulk materials, and crystal internal strain of the metal particles is not changed by rapid cooling. The Debye-Waller factor of gold particles is increased with decreasing particle size because of the surface softening phenomenon of nanosized particles, but the crystal structural change on the surface of the particles is not detected from the comparison the calculated X-ray diffraction profile with the experimental profile on gold particles with the particle size of 4 nm.

• 한국산학기술학회논문지
• /
• 제12권11호
• /
• pp.5365-5369
• /
• 2011

실리카-골드 복합체 입자를 함침법에 의하여 합성하였고, 용매와 전구체가 실리카-골드 입자 합성에 미치는 영향이 연구되었다. 구형 실리카 입자를 지지체로 하여 PVP, hydrogentetrachloroaurate(III) hydrate 수용액을 전구체로 사용했을 때, 연한 분홍색 색상을 띄는 실리카-골드 입자가 성공적으로 합성되었다. 합성된 복합체의 특성은 FE-SEM, FE-TEM과 XRD를 통하여 분석하였다.

• 한국염색가공학회지
• /
• 제21권6호
• /
• pp.39-45
• /
• 2009

The importance of nano gold particles has been increased in the field of bio physics and medicine, recently. In this regard, the study aims to analyze how the harmless nano gold particles can be transformed by respective variables. In this study, electrospun PU nano-webs were impregnated with aqueous $HAuCl_4$ solution and UV light was irradiated on the webs. Au-ions were reduced to nano particles by photocatalytic reduction and these nano gold particles were characterized by SEM, UV-vis, Zetasizer, Spectrophotometer, EDS. $HAuCl_4$ solution concentration and UV irradiation time have heen examined to change the amount of absorption. Nano gold particles size and UV-Vis absorbances were increased with $HAuCl_4$ solution concentration and UV irradiation time.

• Elastomers and Composites
• /
• 제50권4호
• /
• pp.274-278
• /
• 2015

Nanosized gold particles were synthesized by microwave irradiation in a mixture composed of potassium tetrachloroaurate(III) n-hydrate, sodium citrate dihydrate and Tween 20. The synthesized gold particles were characterized by UV-vis spectrophotometer, scanning electron microscopy, and X-ray diffraction techniques. Using UV-vis spectroscopy, it was confirmed that gold nanoparticles act as a catalyst in the reduction of 4-nitroaniline with sodium borohydride to form 1,4-diaminobenzene. Additionally, we studied the kinetics of this reductive reaction in the presence of these gold nanoparticles under various conditions.

• 식물병연구
• /
• 제12권1호
• /
• pp.25-27
• /
• 2006

벼오갈병바이러스(Rice dwarf virus, RDV)는 Phytoreovius 속에 속하며 게놈은 double stranded RNA의 12분절로 이루어져 있는데 전기영동상에서 크기가 큰 것부터 S1에서 S12로 명명한다. 본 실험에서는 RDV 입자 및 P12 단백질의 세포질 내에서의 소재양식을 확인하였다. 바이러스 입자 및 P12 단백질 특이적 항혈청에 protein A-gold 입자를 immunolabelling하여 전자현미경에서 gold입자의 존재양상을 관찰하였다. 바이러스 입자 특이적 항혈청을 사용한 경우에는 gold 입자가 세포질내의 바이러스 입자에 특이적으로 반응한 것이 관찰되었다. P12단백질 특이적 항혈청의 경우 gold 입자가 세포질내의 세포소기관에 특이적으로 존재하지 않고 세포질전체에 산재하여 존재하였다. 이 결과로서 RDV S12가 코드하는 단백질 P12가 세포질내에 존재함을 확인하였다.

• Bulletin of the Korean Chemical Society
• /
• 제28권3호
• /
• pp.439-442
• /
• 2007

A solid state Hg(Au)/HgO reference electrode was prepared utilizing gold amalgam solid particles. Solid fine powder of the gold amalgam was prepared by chemical reduction of Au(III) with NaBH4 followed by reduction of Hg(II) in the presence of gold fine particles. The solid content in the suspension of the gold amalgam particles and fine mercury oxide particles in DMF containing PVC was precipitated by the addition of a large amount of water to give solid Hg(Au)/HgO/PVC mixture. After drying, the mixture was pressure-molded to a physically stable Hg(Au)/HgO composite reference electrode material. The electrochemical characteristics of the electrode as a reference electrode were very similar to an ordinary Hg/HgO reference electrode. The electrode material can be molded and fabricated in any desired shape and size. The surface can be renewed by a simple polishing process whenever contaminated or deactivated. The applicability of the electrode in the electrochemical detection of carbohydrates after anion exchange separation was evaluated.

• Bulletin of the Korean Chemical Society
• /
• 제30권4호
• /
• pp.869-872
• /
• 2009

Double-doped magnetic particles that incorporated magnetites into both the surface and inside the silica cores were fabricated via the sol-gel reaction of citrate-stabilized magnetites with silicon alkoxide. Double-doped magnetic particles were easily fabricated and exhibited an higher magnetism in comparison to the singledoped magnetic particles that were prepared by the erosion of surface-deposited magneties from double-doped magentic particles. Thin gold layer was formed over magnetic silica nanospheres via nanoseed-mediated growth of gold clusters. The plasmon-derived absorption bands of double-doped magnetic silica-gold nanoshells were more broadened and shifted down by ca. 20 nm as compared to those of single-doped magnetic silicagold nanoshells, which were attributed to not only the surface scattering of incident light due to relatively rough surafce morphology, but also heterogeneous permittivity of dielectric cores due to surface-deposited magnetites.

• 센서학회지
• /
• 제18권3호
• /
• pp.226-233
• /
• 2009

In this study, the optical properties of localized surface plasmon resonance sensor using optical fiber was analyzed as the variation of a size and surface density of gold nano particles on the etched optical fiber surface. It is shown that a size and surface density of gold nano particles on optical fiber surface are controlled by $Na_3$ citrate quantity and pH of gold colloid solution. To measure the sensitivity, peak wavelength of absorbance spectrum was detected as the reflective index of the solution. The sensor sensitivity is linearly dependent on the size and surface densities of gold nano particles from the results of optical experiments.

• Parasites, Hosts and Diseases
• /
• 제33권4호
• /
• pp.365-376
• /
• 1995

일록춘폐흡충(Poragonimus iloktsuenensis)의 표피층, 장상피층 및 난황선의 조직항원 성을 발육단계별로, 면역황금표지법(immunogoldlabelingmethod)으로 관찰하였다. 일록춘폐흡충 으로 감염건 횐쥐(Sprague-Dawley)로 부터, 감염후 2주 3주, 4주, 5주 및 33주에 적출한 충체를 항원으로 사용하였고, 감염 후 10주의 흰쥐혈청을 항체로 사용하였다 조직항원성은 조직에 표지된 황금입자로 판정하였다. 표피층은 유약충으로부터 성충에 이르는 발육과정중 전반적으로 황금입자 표지가 많지 않았고 충체가 성숙되어감에 따라서 황금입자 표지가 다소 드물어지는 경향이 있었으나, 충체 개체별 항원 강도에 차이가 많았다. 장상피층과 난황선은 충체의 발육단계에 관계없이 많은 수의 황금입자가 표지되어 강한 항원성을 나타내었다. 이 실험의 결과, 일록춘폐흡충의 표피층 장강피층, 및 난황선은 중요한 조직항원 부위로 보이나, 표피층은 항원성이 낮은 편이고, 발육단계 및 개체별로 항인강도에 차이가 있었다. 장상피층 및 난황선도 개체별로 황금입자 표지강포에 다소의 차이는 있었으나 충체의 발육단계에 관계없이 계속해서 강한 항원성이 유지되는 조직부위로 보인다.