• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.3_4 s.141
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• pp.561-568
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• 2005

The irradiation of Ultra-Violet (UV) is an efficient treatment for polymer to improve hydrophilic properties. 4-Channel PET knit fabrics were treated with UVA and UVC to develop functional and environment-friendly fabric. The fabric was treated with various treatment times and distances from UV lamps having different wavelength. FT-IR and XPS investigated the chemical changes. To confirm the change of surface properties, contact angle, surface energy and SEM were examined. The study of UV as a treatment for PET knit fabric shows significant changes in chemical and surface properties, which is proved by analyses. FT-IR and XPS analyses prove the augmentation of carboxylic, Hydrophilic groups on the surfaces treated by UV. The increase of water contact angle and surface energy means more water wettable and surface energy of PET film was substantially increased by UV irradiation time. The ageing after surface treatment had little influence on the surface energy of the irradiated PET film. SEM proves the surface modification of PET such as etching, bubble and crack. The negative effects are increased in accordance with increasing treatment time.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.97-98
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• 1998

1. Introduction : Polypropylene(PP) membrane is widely used in the field of microfiltration and ultrafiltration. However, the hydrophobicity of PP causes the adsorption of hydrophobic and amphoteric solutes in the feed. Surface modification techniques of membrane through the treatment of hydrophilizing agents, coating of hydrophilic compounds, UV, plasma and high energy irradiation, etc. can have a great effect on propensities to prevent the protein from staining membranes. Among them, the modification to hydophilize membrane surface using UV is very simple and effective. Recently many studies for more effective surface modification have been conducted. Iwata et al. prepared membranes by grafting polyethylene glycol diacrylate macromer(PEGDA) onto polysulfone with plasma using a glow discharge reactor which prevent the oil from staining the membrane. The primary mechanism contributing to the membranes is preventing the oil from directly contacting the surface of the membrane as the PEGDA chains dissolved into emulsion. To evaluate their feasibility for use as a anti-fouling separation membrane, we prepared hydrophilic membranes by UV irradiation method and investigated their characteristics.

• Applied Chemistry for Engineering
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• v.9 no.3
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• pp.383-387
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• 1998

The effect of hydrophilic surface modification of low density polyethylene(LDPE) byt the plasma gas($O_2$, $N_2$, and $O_2/N_2$) was investigated from the point of view of the functionalities of the generated LDPE surfaces and the contact angle. By virtue of x-ray photoelectron spectra(XPS) and attenuated total reflectance(FT-IR ATR) analysis, the LDPE surfaces treated with plasma were generated with oxygen functionalities of carbonyl, carboxyl, and the like, nitrogen functionalities by nitrogen plasma and mixing of nitrogen and oxygen plasma treatment were identified with. It was found that nitrogen plasma treatment showed with minimum value at contact angle for rf-power and treatment time, we had obtained optimum condition for hydrophilic surface modification at composite parameter, [(W/FM)t] 520~550GJs/kg.

• Journal of the Korean Wood Science and Technology
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• v.8 no.3
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• pp.64-76
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• 1980

Fig. 8 summarizes the present status of high yield pulp production and the directions of research on modification. A thick line indicates pulping process presently in use. As mentioned previously, one kind of modification is to introduce hydrophilic groups onto the pulp. Still unsolved is whether or not the introduction of hydrophilic groups should be restricted to lignin only. Goring (28) reported that middle lamella lignin has fewer phenolic hydroxyl groups than cell wall lignin and suggested that such a difference in the lignin may be useful in the removal of middle lamella lignin. The introduction of hydrophilic groups onto pulp may not be enough to modify high yield pulp. The removal of some portion of carbohydrate may be also necessary from the standpoint of softening of pulp fibers. There is no information at what lignin and carbohydrate, and how much should be removed. The combination with synthetic high polymers may also be important in modifying high yield pulp. Prof. C. Schuerch of the State University of New York who was a visiting professor at the University of Tokyo in 1974, mentioned that the hydrophilicity of lignin would be promoted, if phenolic hydroxyl or carboxyl groups could be introduced into the aromatic nucleus of lignin. If this were possible. this process would also mean a pulp yield of more than 100%. This idea is just one example of the expectation made possible through lignin chemistry. Instead of the introduction of hydrophilic group, the oxidative degradation of aromatic nucleus of lignin may also be useful in promoting the hydrophilicity of pulp. In this case, ozone may be an excellent chemical. However, there are a lot of problems to be solved such as homogeneity of reaction and selectivity of ozone for lignin. The above ideas are summarized in Fig. 9. There are many problems to be solved in the production of an excellent high yield pulp which is comparable to chemical pulp. The information from wood chemistry hopefully will elucidate some of the problems mentioned above.

• Nuclear Engineering and Technology
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• v.52 no.2
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• pp.373-380
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• 2020

This study was carried out to convert the hydrophobic characteristics of PVDF to hydrophilic. Poly(-vinylidene fluorine) (PVDF) was grafted by electron beam irradiation and sulfonated. The grafting degree of modified PVDF increased with the monomer concentration, but not the conversion degree. From the results of FTIR and XPS, it was shown that the amount of converted sulfur increased with the grafting degree. The radiation-induced graft polymerization led to decrease fluorine from 35.7% to 21.3%. Meanwhile, the oxygen and sulfur content increased up to 8.1% and 3.2%. The pore size of modified membranes was shrunken and the roughness sharply decreased after irradiation. The ion exchange capacity and contact angle were investigated to show the characteristics of PVDF. The enhanced ion exchange capacity and lower contact angle of modified PVDF showed that the hydrophilicity played a role in determining membrane fouling. Electron beam irradiation successfully modified the hydrophobic characteristics of PVDF to hydrophilic.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.161-161
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• 1999

In the field of material science, the interests and efforts to modify the surface of materials in agreement with the need of usage have been extensively increasing. he modification to improve the wettability of surface is very important is terms of adhesion, printing, etc. It is very difficult to modify metal surface into hydrophilic one. therefore, surfactant coating has been generally used in many cases. However, surfactant has disadvantages such as environmental problem, soluble in water. in this study, hydrophilic polymer films as alternative of surfactant were deposited on metal substrate by DC plasma polymerization. Hydrophilic polymer films deposited by DC plasma show many merits such as good wettability, stone adhesion to substrate, high resistance to most chemicals. Monomer gas and reactive gas were used as source plasma polymerization. Plasma polymerized films were fabricated with process parameters of deposition time, ratio of gas mixture, current, pressure, etc. Effects of these variables on wettability of plasma polymer films will be discussed. With XPS and FT-IR analyses of plasma polymeric films, the relation between wettability and chemical state of polymer films by DC plasma was investigated.

• YAKHAK HOEJI
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• v.49 no.1
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• pp.68-73
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• 2005

Epi-xanthatin analogs containing hydrophilic substituents such as carboxylic acid, alcohol, morpholine, amino acid, and glucose derivatives were synthesized and their in vitro cytotoxicity and in vivo antitumor activity were evaluated. The target compounds were generally cytotoxic against tumor cell lines of human origin with $ED_{50}$ values of $0.1{\sim}30{\mu}g/ml$, except the highly hydrophilic analog 6 containing aspartic acid. Contrary to the potent cytotoxicity weakly hydrophilic analogs 2 and 8 were not active in vivo, or even toxic to the test animals. As a result, hydrophilic analog of epi-xanthatin did not show in vitro cytotoxicity and hydrophobic analogs did not show in vivo antitumor activity, thus it is presumed that amphiphilic analogs or those with medium hydrophilicity would exhibit the antitumor potency in vivo.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.5
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• pp.671-675
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• 2014

This paper presents a fabrication of hydrophilic Poly(dimethylsiloxane) (PDMS) with periodic wrinkling surface. The proposed periodic wrinkling surface was fabricated using the sequential processes of typical curing process of PDMS, cutting process, platinum deposition process, and wrinkling transfer process. The surface morphology of the fabricated wrinkling surface was observed by using optical and dynamic atomic force microscopy and discussed. The measured period and amplitude of wrinkling was about $2.2{\mu}m$ and $0.31{\mu}m$, respectively. And, the contact angles of water droplets on the wrinkled surface were measured in order to understand effect of the wrinkling surface on surface modification of hydrophobic PDMS. Our new finding was that the proposed wrinkling surface was hydrophilic and the measured contact angle was about $62^{\circ}$. Moreover, it was found out from the simple cell culture test that the fabricated wrinkling surface was more effective for cell spreading and adhesion than the case of native PDMS substrate.

• Polymer(Korea)
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• v.32 no.5
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• pp.497-500
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• 2008

Polystyrene foam (styrofoam) was treated with low-temperature oxygen plasma by means of immobilization and grafting techniques in order to modify its hydrophobic surface property to hydrophilic one using hydrophilic monomers of acrylic acid and acrylamide, and its surface chemical structure, morphology, and hydrophilicity were examined by ESCA, field emission scanning electron microscope (FESEM), and contactangle meter. The experimental evidences, such as the increases of O/C and N/C ratios in ESCA spectrum, thin film deposition, decrease in contact-angle, strongly suggested that the plasma treatments were useful methods for the preparation of hydrophilic surface. Contact angle diminished drastically from $84^{\circ}$ to $18{\sim}19^{\circ}$. Acrylamide, compared to acrylic acid, appeared to play a decisive role, and to be more powerful agent for improving its surface hydrophilicity.

• Proceedings of the Korean Fiber Society Conference
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• 2007.11a
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• pp.187-188
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• 2007

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