• KSTLE International Journal
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• 제8권1호
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• pp.7-10
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• 2007

The rheological property of hollow PANI malonate suspension in silicone oil was investigated by varying the electric fields and shear rates, respectively. The hollow PANI malonate susepnsion showed a typical electrorheological (ER) response caused by the polarizability of an amide polar group and shear yield stress due to the formation of chains upon application of an electric field. The shear stress for the hollow PANI malonate suspension exhibited an electric field power of 0.90. On the basis of the experimental results, the newly synthesized hollow PANI malonate suspension was found to be an anhydrous ER fluid.

• KSTLE International Journal
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• 제7권1호
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• pp.18-21
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• 2006

The electrorheology of hollow PANI derivative suspensions in silicone oil was investigated by varying the electric fields and shear rates, respectively. The hollow PANI derivative susepnsions showed a typical electrorheological (ER) response caused by the polarizability of an amide polar group and shear yield stress due to the formation of chains upon application of an electric field. The shear stress for the hollow PANI succinate suspension exhibited an electric field power of 0.67. On the basis of the experimental results, the newly synthesized hollow PANI derivative suspensions were found to be an anhydrous ER fluid.

• KSTLE International Journal
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• 제4권1호
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• pp.14-17
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• 2003

The electrical and rheological properties of a chitosan malonate suspension in silicone oil was investigated by varying the electric fields, volume fractions of particles, and shear rates, respectively, The chitosan malonate susepnsion showed a typical electrorheological (ER) response caused by the polarizability of an amide polar group and shear yield stress due to the formation of multiple chains upon application of an electric field. The shear stress fur the suspension exhibited a linear dependence on the volume fraction and an electric field power of 1.88. On the basis of the experimental results, the newly synthesized chitosan malonate suspension was found to be an anhydrous ER fluid.

• KSTLE International Journal
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• 제10권1_2호
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• pp.13-16
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• 2009

The electrorheological(ER) behavior of hollow polyaniline(PANI) sebacate suspension in silicone oil was investigated by varying the electric fields and shear rates, respectively. The hollow PANI sebacate susepnsion acted as a typical Bingham fluid caused by the polarizability of an amide polar group and showed shear yield stress due to the formation of chains upon application of an electric field. The shear stress for the hollow PANI sebacate suspension exhibited an electric field power of 1.24. On the basis of the experimental results, the newly synthesized hollow PANI sebacate suspension was found to be an anhydrous ER fluid.

• 공업화학
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• 제8권3호
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• pp.510-516
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• 1997

Cetyl alcohol과 polyoxyethylene(20) sorbitan monooleate를 혼합한 유화제와 양친매성 resin을 용매에 용해시킨 분산상에 분산매인 물을 첨가하여 O/W 에멀젼을 제조하여 HLB(Hydrophilic Lipophilic Balance) 값과 온도변화에 따른 상변화를 관찰하였다. 양친매성 resin을 함유한 에멀젼은 이를 함유하지 않는 에멀젼보다 온도변화에 따른 상안정성이 좋다는 것을 알 수 있었다. 또한 양친매성 resin이 에멀젼 안정성에 미치는 영향을 파악하기 위해 양친매성 resin에 함유되어 있는 작용기중 하나의 작용기를 갖는 resin을 model compound로 하여 HLB값과 온도변화에 따른 에멀전 상거동을 관찰한 결과, Poly(acrylic acid)

• KSTLE International Journal
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• 제2권1호
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• pp.71-74
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• 2001

The electrorheological(ER) performance of a chitosan sebaciate suspension in silicone oil was investigated by varying the electric fields, volume fractions of particles, and shear rates, respectively. The chitosan sebacicate susepnsion showed a typical ER response caused by the polarizability of an amide polar group and shear yield stress due to the formation of multiple chains upon application of an electric field. The shear stress for the suspension exhibited a linear dependence on the volume fraction of particles and an electric field power of 1.88. On the basis of the results, the newly synthesized chitosan sebacicate suspension was found to be an anhydrous ER fluid.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.345-346
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• 2002

The electrical and rheological properties of a chitosan malonate suspension in silicone oil was investigated by varying the electric fields, volume fractions of particles, and shear rates, respectively. The chitosan malonate susepnsion showed a typical electrorheological (ER) response caused by the polarizability of an amide polar group and shear yield stress due to the formation of multiple chains upon application of an electric field. The shear stress for the suspension exhibited a linear dependence on the volume fraction and an electric field power of 1.88. On the basis of the results, the newly synthesized chitosan malonate suspension was found to be an anhydrous ER fluid.

• 한국염색가공학회지
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• 제11권2호
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• pp.27-37
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• 1999

Polypropylene(PP) films were treated with plasma glow discharge to produce peroxy radicals on the surfaces. The peroxy radicals formed on the PP film surfaces were subsequently used for the graft polymerization of acrylic acid and acrylamide in an aqueous solution by heating, respectively. Introduction of acrylic acid and acrylamide on the PP film could be confirmed by the observation of carbonyl and primary amine absorptions based on carboxylic acid and amide, respectively. And introduction of functional group could be confirmed by weight analysis and ESCA. The water contact angle(90$^{\circ}$) of PP film was constant, irrespective of elapsed time, while plasma-treated and functional monomer-grafted PP films were slowly increased with elapsed time, showing the rearrangement of surface polar groups in air condition. The water contact angle$(90^\circ)$ of PP film was decreased by the plasma treatment$(56^\circ)$ and further decreased by the grafting of acrylic acid$(34^\circ)$ and acrylamide$(37^\circ)$, indicating increased hydrophilicity of the modified surfaces. The water contact angle of plasma-treated PP film increased a little as time elapsing. The half-life periods of surface voltage on acrylic acid-(31sec) and acrylamide-grafted PP(42sec) were significantly decreased when compared to those on PP(950sec) and plasma-treated PP film(241sec). In the experiments using acid, basic and disperse dyes, absorbance and $\Delta{E}$ values of functional monomer-grafted PP films were significantly increased than that of oxygen plasma-treated one.

• 한국수정란이식학회지
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• 제32권3호
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• pp.201-207
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• 2017

소 난자의 체외 성숙 및 발달과정에서 항산화제의 첨가는 발생과정에 생성될 수 있는 ROS를 조절하여 체외발생에 도움을 주는 것으로 알려져 있으나 이에 대한 연구는 아직 미흡하다고 판단된다. 본 연구에서는 소 수정란의 성숙과정과 발생과정에서 ROS에 대한 방어 기작에 필요한 물질로 -SH기(thiol group)을 함유하고 있는 NAC, NACA, GSH 및 CYS를 첨가하여 COCs의 난자 성숙율과 체외 수정 후 수정란의 발생율을 조사하였다. 도축장 유래 난소의 성숙율은 항산화제 처리군과 대조군에서 차이를 보여주지 않았으나(p>0.05), 배반포 형성율은 0.1 mM CYS을 처리한 실험군에서 $32.3{\pm}5.0%$로 유의적으로 높게 관찰되었다(p<0.05). 항산화제 0.3 mM NAC, 0.2 mM NACA 또는 0.5 mM GSH를 처리하는 실험군에서 배반포 형성율은 각각 $18.8{\pm}3.7%$, $21.2{\pm}3.9%$ 및 $26.5{\pm}5.0%$로 조사되었다. 그러므로, 항산화 물질인 NAC, NACA, GSH 및 CYS을 난자의 성숙 및 수정란 배양과정에 첨가하면 난자의 성숙에 영향이 없으나, CYS처리군이 배반포형성율에 효과가 있음을 밝혔다(p<0.05).

• 접착 및 계면
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• 제3권3호
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• pp.7-14
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• 2002

Poly(ethylene-co-methylacrylate)(PEMA)를 KOH, 암모니아 수용액으로 가수분해, ammonolysis 시켜서 측기에 -COOK, $-CONH_2$, -COOH를 갖는 수분산 형태의 변성 폴리에틸렌(m-PE)을 제조하였다. Infrared spectroscopy, 원소 분석 및 atomic absorption 분석 등을 통하여 m-PE 측기의 종류 및 조성비를 조사하였으며 수분산액의 고형분 함량에 따른 점도 및 표면장력을 측정하였다. 제조된 수분산액은 측기의 조성에 따라 안정도, 투명도 등이 변화하였다. 측기 중에서 -COOK가 수분산에 가장 큰 영향을 주었으며 -COOK 조성비가 20 mol% 이상이 되어야 안정한 분산을 얻을 수 있었고 또한 -COOK 조성비가 높을수록 수분산액은 투명하였다. 동일 -COOK 조성비에서는 아마이드의 농도가 높을수록 탁도가 증가하여 친수성이 떨어짐을 알 수 있었다. 분산액의 고형분 함량에 따른 점도를 측정하면 -COOK 조성비가 클 경우 낮은 고형분 함량에서 급격한 점도 증가가 일어나 고분자 사슬사이의 얽힘이 쉽게 일어남을 알 수 있으며 표면장력은 -COOK 조성비가 클 경우 작은 값을 나타내었다.