• 한국염색가공학회지
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• 제29권4호
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• pp.284-290
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• 2017

The glyoxal has been used as formaldehyde free DP(durable press) agents in wrinkle free treatment for cotton fabrics. However, the yellowing problem is a disadvantage of DP finishing process for cotton fabrics with glyoxal. In order to improve the whiteness, it was investigated that the effect of coreactant and treatment method with various whitening additives such as STB(sodium tetraborate, $Na_2B_4O_7$), SPB(sodium perborate, $NaBO_3$), SC(sodium chlorite, $NaClO_2$) and SPC(sodium percarbonate, $Na_2CO_3{\cdot}1.5$ $H_2O_2$). The increasing the concentration of whitening additives(STB, SPB, SC and SPC), the whiteness and the strength retention ratio of cotton fabrics were increased but the wrinkle recovery angles were decreased in one bath method. It was not suitable to improve whiteness because the whiteness value is about 60. In the case of SC used two bath method, the whiteness is near 70, which is similar to untreated fabrics, without decreasing of WRA and strength.

• 공업화학
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• 제5권5호
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• pp.857-861
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• 1994

독성이 있는 아크릴 모노머를 비닐에테르로 대체시켜 우레탄아크릴레이트와 배합시키는 것을 특징으로 하는 자외선 경화형 하이브리드 시스템을 조사하였다. 일반적으로 하이브리드 시스템의 코팅 물성은 자유 라디칼계보다은 우수하나 양이온계보다는 열세하게 나타났다. 아크릴계 올리고머 함량이 70% 이상으로 배합된 경우의 하이브리드계는 코팅물성과 경화물성면에서 자유라디칼계와 양이온계보다 뛰어나게 나타났다. 다양한 코팅 시스템의 경화과정을 조사하기 위해서 광열분석기를 적용하였다. 그 결과 코팅 배합물의 경화속도에 미치는 결정적인 인자는 배합물 특성에 따라 달라짐을 알 수 있었다. 동류의 하이브리드계의 경우에는 광경화개시제의 효율보다는 모노머/올리고머 비가 더욱 중요함을 알 수 있었다.

• 폴리머
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• 제30권4호
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• pp.286-292
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• 2006

Super water-absorbent resins were prepared by inverse suspension copolymerization of sodium acrylate, acrylamide and 2-hydroxyethyl acrylate using N, N'-methylene-bis-acrylamide as cross-linker. For the suspension copolymerization, monohexadecyl phosphate was employed as the dispersing agent, cyclohexane as the dispersing medium and potassium persulfate as the initiator. The dependence of water-absorption capacity on the amount of crosslinking agent, oil/water ratio, degree of neutralization and the composition of the copolymer were systematically investigated. Furthermore, the swelling kinetics of the super water-absorbent copolymer was carried out. The absorption of the resins is more than 1800 g/g for deionized water and 100 g/g for 0.9% NaCl solution, respectively. The copolymers showed an increased salt resistance and enhanced water retention of soil.

• 한국염색가공학회지
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• 제17권3호
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• pp.16-25
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• 2005

In this research, we investigated hydrolysis of the ester crosslinking on cotton fabric treated with polymer of maleic acid(PMA), citric acid(CA) and combination of polymer of maleic acid and citric acid using Fourier transform infrared spectroscophy. The rate of hydrolysis of the ester crosslinkage increased with pH regardless of the type of polycarboxylic acid used and even after hydrolysis for 256 hour in pH 13_4 solution, the treated fabric retained $10-20\%$ ester crosslinkage. The durability to alkaline hydrolysis of the ester crosslinkage formed by CA was lower than that of by PMA and combination of poly(maleic acid) and citric acid indicating that the ester formed by CA on the cotton fabric is more susceptible to hydrolysis than that formed by PMA and combination of PMA and CA. The total amount of ester and polycarboxylic acid molecules removed from fabric increased with increasing hydrolysis time but the rate of hydrolysis of ester linkage were higher than that of removal of polycarboxylic acid molecule from the fabric. The characteristic of hydrolysis of fabric treated with combination of PMA and CA was related with the mixing ratio of PMA and CA in treating fabric.

• 한국재료학회지
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• 제29권12호
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• pp.735-740
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• 2019

The purpose of this study is to fabricate an ophthalmic lens by copolymerizing two types of carbon nanotubes and hydrophilic hydrogel lens materials, and to investigate its application as an ophthalmic lens material by analyzing its physical properties and antimicrobial effect. For polymerization, HEMA (2-hydroxyethyl methacrylate), EGDMA (ethylene glycol dimethacrylate), a crosslinking agent, and AIBN (azobisisobutyronitrile), an initiator, are used as a basic combination, and a single-walled carbon nanotube and a single-walled, carboxylic-acid-functionalized carbon nanotube are used as additives. To analyze the physical properties, the water content, refractive index, breaking strength, and antimicrobial effect of the fabricated lenses are measured. The fabricated lenses satisfies all the basic properties of the basic hydrogel ophthalmic lens. The water content increases with increasing amount of additive and decreases with addition of 0.2 % ratio of nanoparticles. The refractive index is inversely proportional to the water content result. As a result of the antimicrobial test of the fabricated lens, the addition of carbon nanotubes shows an excellent antimicrobial effect. Therefore, it is considered that the fabricated lens can be applied as a functional material for basic ophthalmic hydrogel lenses.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.567-570
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• 2000

DFA IV를 생산하는 levan fructotransferase를 ${\kappa}\;-carrageenan$을 이용하여 고정화한 결과 카라기난의 농도가 2%일 때 가장 높은 활성을 나타내었다. 이 때에 고정화 담체에 포괄되어지는 효소의 활성도는 0.81 units으로서 soluble enzyme 7.7 units에 비해 상대적으로 낮은 활성을 보여주었다. 고정화 및 soluble enzyme의 최고 활성온도와 최적 pH는 동일하게 $55^{\circ}C$, pH6.0 이었다. 가교제를 처리할 경우에 적당한 농도는 0.5%로 생각되어진다. $37^{\circ}C$에서 시간에 따른 고정화 및 soluble enzyme의 DFA IV 생산량을 HPLC로 분석한 결과 60시간 이후의 전환률이 각각 32%, 61%로 나타났다.

• 한국수소및신에너지학회논문집
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• 제27권4호
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• pp.378-385
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• 2016

In this study, we synthesized a biocatalyst consisting of glucose oxidase (GOx), polyethyleneimine (PEI) and carbon nanotube (CNT) with addition of glutaraldehyde (GA)(GA/[GOx/PEI/CNT])for fabrication of glucose sensor. Main bonding of the GA/[GOx/PEI/CNT] catalyst was formed by crosslinking of functional end groups between GOx/PEI and GA. Catalytic activity of GA/[GOx/PEI/CNT] was quantified by UV-Vis and electrochemical measurements. As a result of that, high immobilization ratio of 199% than other catalyst (with only physical adsorption) and large sensitivity value of $13.4{\mu}A/cm^2/mM$ was gained. With estimation of the biosensor stability, it was found that the GA/[GOx/PEI/CNT] kept about 88% of its initial activity even after three weeks. It shows GA minimized the loss of GOx and improved sensing ability and stability compared with that using other biocatalysts.

• 폴리머
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• 제25권2호
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• pp.270-278
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• 2001

의료용 고분자로 널리 알려진 poly(vinylalcohol)(PVA)와 poly(N-vinylpyrrolidone)(PVP)를 이용하여 상처치료용 하이드로겔을 제조하였다. PVP 하이드로겔의 기계적 강도를 향상시키기 위해 PVA/PVP 혼합용액에 \"freezing and thawing (동결융해)\"을 반복한 후 방사선 ($^{60}$Co${\gamma}$-rays)을 조사하여 하이드로겔을 얻었다. PVA와 PVP의 조성비 (30 : 70 ~ 100 : 0), 동결융해의 반복횟수, PVA 분자량을 변화시키면서 PVA/PVP 하이드로겔의 겔화율, 팽윤도, 겔강도를 측정하였다. PVA/PVP 하이드로겔은 방사선 조사로만 제조되었을 때 보다 동결융해 반복 후 방사선조사했을 때 겔화율과 겔강도가 향상되었다. 이외에 동결융해의 반복정도에 따른 물성의 특징을 논의하였다.특징을 논의하였다.

• Macromolecular Research
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• 제17권7호
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• pp.483-490
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• 2009

Stable poly(styrene-co-divinylbenzene) [P(St-co-DVB)] micro spheres with narrow size distribution were synthesized in the presence of 2,2'-azobis(2,4-dimethyl valeronitrile) (V-65) and co-initiator in an acetone/water mixture in the precipitation polymerization at $53^{\circ}C$ for 24 h. Potassium peroxodisulfate (KPS), ammonium peroxodisulfate (APS) and sodium peroxodisulfate (NaPS) were used as co-initiators. The optimum ratio of acetone to water for the formation of a narrow distribution of P(St-co-DVB) particles was 49:11 (g/g). The optimum co-initiator compositions for narrow distribution were 9:1 (g/g) for V-65 to KPS, 11:1 for V-65 to APS and 6:1 for V-65 to NaPS. The yield for these compositions was $54{\sim}57%$ and the largest particle size was obtained with the lowest zeta-potential and CV values. From the XPS measurements, the charge density was increased but the zeta potential decreased with increasing sulfur content, implying that the sulfate group provides the electrostatic stabilization on the particle surface. This suggested that the self-crosslinking between styrene and DVB, the electrostatic stabilization of initiators, and the balanced hydrophobic and hydrophilic properties of the solvents are responsible for the formation of stable P(St-co-DVB) spherical particles with narrow size distribution.

• 대한화학회지
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• 제45권3호
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• pp.230-235
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• 2001

양 밀단에 methacryl기를 함유한 polydimethylsiloxane(PDMS)을 가교제로 하여 poly(N-isopropylacrylamide)(PNIPAAm)을 합성하여 PDMS를 함유한 PNIPAAm을 얻었다. IR, DSC를 이용하여 그것들의 성질을 조사하였으며 DSC 조사결과 PNIPAAm과 PDMS는 각각 분리된 상으로 존재하는 것이 확인되었으며, PNIPAAm의 $T_g$는 PDMS의 함량이 증가하면 약간씩 감소하였다. 또한 온도에 따른 팽윤도를 조사한 결과 PDMS의 함량이 증가하면 팽윤도는 감소하였으나 lower critical solution temperature(LCST)는 큰 변화가 없었다. 수팽윤된 중합체의 DSC 측정결과도 LCST는 PDMS의 함량에 영향을 받지 않는 다는 것을 확인하였다.