• 공업화학
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• 제9권5호
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• pp.680-688
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• 1998

친수성 단량체 glycidylmethacrylate (GMA)에 가교제인 divinylbenzene (DVB)과 세공형성제인 2,2,4-trimethylpentane (TMP)량을 각각 0~10 mol %과 0~100 vol %로 변화시켜 현탁중합법으로 macroreticular (MR)형 GMA-DVB 공중합체 (RG라 칭함)을 합성하였다. 이들 공중합체를 벤젠 존재하에서 인산으로 인산화시켜 인산기를 갖는 거대망상형 양이온 교환수지 (macroreticular type cation exchange resins containing phosphoric acid groups, RGP)을 제조하였으며, 이들 수지에 대한 물성과 우라늄의 흡착능을 고찰하였다. RGP수지들의 물성은 합성시 가교도와 희석제량에 따라 영향이 있었으며, 우라늄의 흡착능은 가교도 영향인 경우 $$RGP-10(50){\sim_=}RGP-1(50)>RGP-2(50)>RGP-5(50)>RGP-0(50)$$ 이며, 희석제량의 영향인 경우는 RGP-2(100)>RGP-2(75)>RGP-2(50)>RGP-2(30)>RGP-2(0)순이였다. RGP수지들의 물성과 우라늄의 흡착능에서 가교도의 영향인 경우 RGP 수지의 세공구조, 양이온 교환 용량 및 팽윤비에 의존하며, 희석제량의 영향인 경우는 양이온 교환 용량보다도 비표면적과 세공구조에 더 영향이 있었다.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.193-198
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• 2001

Preparation of antibacterial biopolymer film which is suitable for food packaging film was investigated using K-carrageenan as a base material. K-Carrageenan showed good biodegradability and film-forming characteristic but poor mechanical properties under humid condition. Also, various bacteria grew well on its surface. The poor mechanical properties could be improved by mixing with alginate at a 1:1 ratio and crosslinking with $CaCl_2$ solution. Antibacterial property coul be provided by modifying the K-carrageenan film surface with acrylic acid plasma followed by ion-exchange with $Ag^+$ ions. Such prepared film still showed good biodegradability by various fongi.

• Fibers and Polymers
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• 제5권2호
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• pp.95-104
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• 2004

A series of superabsorbents based on acrylic acid (AA), sodium acrylate, 2-acrylamido-2-methylpropane sulphonic acid, N,N'-methylene bis-acrylamide (MBA) were prepared by inverse suspension polymerization. These hydrogels were further crosslinked on the surface with polyethylene glycol-600 (PEG-600). The water absorbency or swelling behaviors for these xerogels in water and 0.9% saline solutions, both under free condition and under load were investigated. Absorption characteristics of these hydrogels were found to depend on nature and concentration of crosslinker in the system. It was also found that the saline absorption was significantly improved as the incorporation of AMPS in the polymer was increased. The surface crosslinking introduced in the polymers was found to improve the absorption under load characteristics without lowering the free water absorption capacities of the polymer to a considerable extent.

• 한국염색가공학회지
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• 제11권4호
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• pp.31-38
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• 1999

The purpose of this study is to develop multifunctional fabric that has improved antimicrobial activity and reduction rate of gas by treatment of mixture of chito colla and crosslinking material for polyester. The surface morphology of treated PET fabric was studied by scanning electron microscopy(SEM). The properties of the PET fabric, such as antimicrobial activity, whiteness, moisture regain, water absorption and static voltage, and handle were investigated. Antimicrobial activity of treated PET fabric was proved 99%. The surface of treated PET fabric showed harshness and irregularity. The whiteness of treated PET fabric on the baking condition was decreased as time and temperature was increased. The moisure regain of treated PET fabric equally was maintained. Water absorption and static voltage of treated PET fabric were improved. KOSHI of treated PET fabric was increased compared with the untreated PET fabric H/W of treated PET fabric was improved compared with the untreated PET fabric and 2HB/B of treated PET fabric were reduced.

• Macromolecular Research
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• 제11권4호
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• pp.291-295
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• 2003

Dextran as a candidate material for colon-specific drug delivery has been studied. Crosslinked dextran hydrogels were prepared by mixing dextran, $MgCl_2$, glutaraldehyde (GA) and polyethyleneglycol (PEG 400) in water. The dextran hydrogels were characterized by measuring equilibrium swelling ratios and mechanical strengths. Response surface methodology (Central Composite Design) was used to evaluate the swelling behaviors and mechanical strengths as functions of concentrations of $MgCl_2$, GA, and PEG 400, which was found to be useful for the evaluation. It showed that the swelling behavior and mechanical strengths were influenced significantly by PEG 400 and $MgCl_2$ concentrations.

• 한국염색가공학회지
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• 제30권4호
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• pp.264-274
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• 2018

Immobilization of lysozyme on chitosan non-woven using glutaraldehyde(GA) was investigated. For this, 100 % chitosan non-woven was prepared as novel support for the enzyme immobilization. In addition, free lysozyme activity was examined depending on various pH and temperature by measuring time. Moreover, the optimum immobilization conditions depending on various pH, temperature, immobilization time and lysozyme concentration was evaluated. In addition, thermal stability and storage stability of immobilized lysozyme were measured. The characteristics of immobilized lysozyme was examined by FT-IR, surface morphology, and MTT assay. The results are follows: the optimal immobilization of lysozyme were pH 7.0, $25^{\circ}C$, lysozyme concentration 1.5 mg/ml, immobilization time 240 min. The immobilized lysozyme showed higher thermal stability than the free trypsin. The immobilized lysozyme activity was retained 80 % of its initial activity at $4^{\circ}C$ over 30 days of storage. The lysozyme was immobilized effectively on chitosan non-woven by observation of surface morphology.

• Elastomers and Composites
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• 제47권1호
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• pp.54-64
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• 2012

본 연구에서는 polar 한 silica 와 non-polar 한 고무사이의 친화력을 증대시키기 위하여 SBR 분자 주쇄에 acrylonitrile 을 도입시킨 acrylonitirle functionalized emulsion SBR 의 물성에 관하여 연구하였다. Acrylonitrile의 nitrile group 은 silica 표면의 silanol group 과 H-bond 를 형성할 수 있음으로 polar 한 silica 표면에 흡착되는 가교촉진제를 줄이고 가황반응을 촉진시키는 것으로 판단된다. SBR 및 AN-SBR 에 PEG 를 적용한 컴파운드의 경우 PEG 와 silica 표면의 silanol group 과의 상용성이 높아 가교촉진제가 polar 한 silica 표면에 흡착됨을 줄여 가교시간이 단축된 것으로 판단된다. 기계적 물성에서 AN-SBR 컴파운드는 SBR 1721 컴파운드 대비 100%, 300%에서 높은 모듈러스 값을 나타내었다. 이러한 결과는 AN-SBR 의 높은 분자량 및 nitrile group 의 도입에 따른 가교도의 상승에 의한 결과로 판단된다. 동적점탄특성 결과에서 AN-SBR 컴파운드는 SBR 1721 컴파운드 대비 $60^{\circ}C$ 에서 낮은 tan ${\delta}$ 값을 나타내었으며, 이는 nitrile group 과 silica 사이의 친화력에 따른 filler-rubber interaction의 향상에 의해 반복변형에 의한 energy dissipation 이 낮은 것으로 판단된다.

• 한국재료학회지
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• 제10권1호
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• pp.77-82
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• 2000

1 keV $Ar^+$ 이온빔을 이용하여 polytetrafluoroethylene (PTFE)의 표면을 개질하고 그 위에 $5000\;{\AA}$의 구리 박막을 이온빔 스퍼터링법을 이용하여 증착하였다. 이온빔 조사에 의하여 PTFE의 표면에는 cone이 형성되며 cone의 높이는 이온 조사량이 증가함에 따라 점차로 증가함을 알 수 있었다. x-ray photoelectron spectroscopy (XPS) 분석을 통하여 조사된 PTFE의 표면에서는 이온 조사량이 증가함에 따라 Fls peak의 강도가 감소하며 이는 F 원자의 선택적인 스퍼터링에 기인한 것으로 생각된다. 또한 이온 조사에 의해 생성된 불안정한 사슬들은 crosslinking에 의하여 새로운 C-F 계열의 결합들을 생성하였다. 이온빔 스퍼터링법에 의하여 증착된 구리 박막은 PTFE 표면의 cone을 따라 균일하게 증착되며 PTFE의 표면 거칠기가 증가함에 따라 (111) 방향으로 우선 성장함을 알 수 있었다. 증착된 구리 박막의 비저항은 개질전 PTFE의 $2.7{\mu}{\Omega}cm$에서 $1{\tiems}10^{16}/\textrm{cm}^2$의 이온 조사량으로 개질된 PTFE의 $4.3{\mu}{\Omega}cm$까지 이온 조사량에 따라 점차로 증가하였다. $1{\tiems}10^{17}/\textrm{cm}^2$의 이온 조사량으로 개질된 PTFE 위에 증착된 구리 박막의 갑작스런 비저항 증가는 구리 박막의 단락에 의한 것으로 보인다.

• 폴리머
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• 제35권4호
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• pp.363-369
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• 2011

콘크리트 제조 시 사용되는 잉여수를 지연 흡수시키기 위하여 역유화중합법으로 중합된 가교 poly(sodium acrvlate) (cPSA)를 ethylene glycol dimethacrylate(EGDMA)로 표면 가교시켰다. cPSA의 제조에서 연속상은 paraffin liquid, 단량제는 8 M 농도의 NaOH 수용액으로 90% 중화된 acrylic acid(AA), 가교제는 N,N-methylene bisacrylamide(MBA), redox 개시제는 ammonium persulfate(APS)와 sodium metabisulfite(SMBS)를 사용하여 역유화중합법으로 제조하였다. 제조된 cPSA는 EGDMA플 사용하여 표면 가교 반응을 수행하였다. 시멘트 수용액에서 $Ca^{2+}$ 이온과 cPSA의 상호 작용을 관찰하기 위하여 FTIR spectroscopy 분석법을 사용하였다. 제조된 흡수제들을 탈이온수 $Ca(OH)_2$ 수용액(pH 12) 및 시멘트 포화 수용액에서의 팽윤비를 측정하였으며, cPSA는 2시간만에 팽윤이 완료되었지만, 표면이 가교된 cPSA-EGDMA는 3시간 후 팽윤이 거의 완료되는 것을 관찰하였다. 또한 합성한 cPSA-EGDMA를 첨가함으로써 시멘트의 응결시간과 모르타르의 압축강도 증가를 관찰하였다.

• 한국의류학회지
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• 제29권7호
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• pp.987-996
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• 2005

For cationization, if chitosan, which has the affinity for a human body and reacts easily without inducing any pollution, is used, cationization of Tencel blended fabrics can be expected and further expansion of its use as a new susceptible material can be expected. Therefore, in this study, in order to compare a Tencel/cotton and a Tencel/Cotton/PET as Tencel blended fabrics with a Tencel single fabric, the fabric samples were used and processed with chitosan after NaOH pretreatment and enzyme treatment thereof, and then its adherent efficiency was enhanced by using a crosslinking agent, and then it was got to be finished with a softener. The fibril of Tencel fabric was controlled by enzyme treatment so that the surface of the Tencel blended fabrics got to be smooth. Chitosan adhered to the surface of the Tencel blended fabrics in the form of particles through its processing with chitosan. Chitosan treatment caused little change in the crystal structure thereof and the thermal stability of the Tencel/Cotton/PET fabric was slightly improved. The total hand value(THV) calculated on the basis of the change due to chitosan treatment was increased in all samples.