• Journal of the Korean institute of surface engineering
• /
• v.49 no.2
• /
• pp.111-118
• /
• 2016

A method to quantitatively analyze the defects formed by the hydrogen evolution during electroplating was suggested based on the theoretical approach of the small angle neutron scattering technique. In case of trivalent chrome layers, an isolated defect size due to the hydrogen evolution was about 40 nm. Direct and pulse plating conditions gave the average defect size of about 4.9 and $4.5{\mu}m$ with rod or calabash shape, respectively. Current density change of the pulse plating from $1.5A/dm^2$ to $2.0A/dm^2$ enlarged the average defect size from 3.3 to $7.8{\mu}m$. The defect morphology like rod or calabash was originated by inter-connecting the isolated defects. Small angle neutron scattering was useful to quantitatively evaluate defect morphology of the deposit.

• Journal of the Korean institute of surface engineering
• /
• v.37 no.3
• /
• pp.175-178
• /
• 2004

The size and number of nano-size defects of thin trivalent chrome layers were determined by small angle neutron scattering (SANS) without breaking the thin chrome layers. Most of defect size of the trivalent chromium prepared in this test conditions is in the range of about 40nm. The number of nano-size defects less than about 40nm of the trivalent chromium layer increases with plating voltage at constant current density From this study, SANS is proved as one of useful techniques to evaluate nano-size defects of thin film layer.

• Journal of the Korean Vacuum Society
• /
• v.14 no.3
• /
• pp.126-131
• /
• 2005

Small-angle neutron scattering (SANS) is a very powerful techniques for nanostructure characterization. In this paper, we report the conceptual design and technical description of the 40 in small angle neutron scattering (SANS) insoument which is being developed by KAIST and KAERI for installation at 30 MW HANARO research reactor. For the optimal design of 40 m SANS, a series of computer simulation were pe.to.mod. The Q-.ange of the 40m SANS inst.ument is $0.0005\;\AA^{-1}-1.0\AA^{-1}$ which is a world top-class SANS Q-range. When the cold neutron spectrum used in the simulation is realized, the neutron flux at sample position is expected to be comparable to the current state-of-art SANS instrument in the world.

• Macromolecular Research
• /
• v.10 no.6
• /
• pp.311-317
• /
• 2002

The quantitative analysis of polymer micelles consisting of amphiphilic block copolymers was carried out by small-angle neutron scattering (SANS). The block copolymers, made of poly(2-ethoxyethyl vinyl ether-b-2-hydroxyethyl vinyl ether)(poly(EOVE-b-HOVE)), exhibited a sharp morphological transition from a homogeneous solution to a micelle structure with increasing temperature. This transition is accompanied by a formation of spherical domains of poly(EOVE) with a radius around 200 $\AA$. The variations of the size and its distribution of the domains were investigated as a function of polymer concentration and temperature. The validity of SANS analysis, including the wavelength- and incident-beam-smearing effects of the SANS instrument, was examined with a pre-calibrated polystyrene latex.

• Journal of the Korean Vacuum Society
• /
• v.14 no.3
• /
• pp.115-118
• /
• 2005

Structure analysis of model polymeric micelles, both for non-asosciative and associative cases is done by small angle neutron scattering method. Aggregation number of the hydrophobic cores and the lyotropic ordering transitions of aqueous solutions of poly(ethylene glycol)(PEG) (6 K or 10 K g/mol) end-capped with perfluoroalkyl groups $(-(CH_2)_2C_OnF_{2n+1}$ (n =6,8, or 10) are characterized. Aggregation number is mainly determined by the hydrophobe end group only, and is insensitive to polymer concentration or temperature. Also, there is no difference between non-associative micelles and associative micelles in terms of aggregation number. The model systems order into a BCC structure with increasing concentration.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.10a
• /
• pp.787-788
• /
• 2005

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2002.05a
• /
• pp.89-89
• /
• 2002

• Proceedings of the Korea Crystallographic Association Conference
• /
• 2002.11a
• /
• pp.51-51
• /
• 2002

나노기공물질은 특정 기반물질(matrix) 내부에 대략 나노미터크기의 기공을 함유하고 있는 물질이며 나노기공물질의 특성은 기반물질의 특성과 더불어 기공의 형태, 크기, 분포에 의해서 결정된다. 나노기공물질의 기공에 대한 정보를 측정하는 방법으로는 TEM, 흡착법, FE-SEM과 더불어 중성자 또는 X-ray 빔의 산란을 이용하는 소각중성자산란 (Small-Angle Neutron Scatering, SANS), 소각 X-ray 산란 (Small-Angle X-ray Scattering, SAXS), 중성자반사율측정 (Neutron Relfectimetry, NR), X-ray 반사율측정 (X-Ray Reflectometry, XRR) 등이 사용되고 있다. 본 발표는 대략 1 nm - 100 nm 영역의 bulk 구조와 층상구조를 측정할 수 있는 소각 중성자 산란과 중성자 반사율 측정기법을 이용한 나노기공 측정기술을 다룬다.

• Macromolecular Research
• /
• v.16 no.1
• /
• pp.62-65
• /
• 2008

The morphology of the $D_2O$-induced reverse micellar structure of an amphiphilic block copolymer of poly( ethylene oxide )-b-poly(propylene oxide )-b-poly( ethylene oxide )($EO_{76}PO_{29}EO_{76}$) was investigated in hydrophobic media by small angle neutron scattering (SANS). Increasing $D_2O$ in the styrene/divinylbenzene solution of $EO_{76}PO_{29}EO_{76}$ led to a change in morphology of the reverse micelles from a short range ordered molecular aggregate to a hexagonally arranged micelle, and further to a spherical micelle.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2003.03a
• /
• pp.153-153
• /
• 2003