• Title/Summary/Keyword: hydrophilic polymer

Search Result 405, Processing Time 0.026 seconds

Preparation of blood-compatible polyurethanes by surface modification (표면개질에 의한 혈액적합성 폴리우레탄의 제조)

  • Han, Dong-Keun;Jeong, Seo-Young;Kim, Young-Ha;Min, Byoung-Goo
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1990 no.11
    • /
    • pp.61-63
    • /
    • 1990
  • To develop better blood compatibility of commercial polyurethane(PU), PU surface was chemically modified wi th a hydrophobic perfluorocarhon or a hydrophilic polyethylene oxide(PEO) and/or sulfonated groups, respectively. The water contact angle of modified PUs varied from $110^{\circ}$ to $0^{\circ}$. All the modified PUs were more blood compatible than untreated PU. In particular, PEO-sulfonate grafted PUs showed a very enhanced antithrombogenicity due to the synergistic effect of PEO and $SO_3$ groups. Therefore more hydrophobic and hydrophilic PU surfaces are promising for improving the blood compatibility.

  • PDF

Hot-Pressing Effects on Polymer Electrolyte Membrane Investigated by 2H NMR Spectroscopy

  • Lee, Sang Man;Han, Oc Hee
    • Bulletin of the Korean Chemical Society
    • /
    • v.34 no.2
    • /
    • pp.510-514
    • /
    • 2013
  • The structural change of Nafion polymer electrolyte membrane (PEM) induced by hot-pressing, which is one of the representative procedures for preparing membrane-electrode-assembly for low temperature fuel cells, was investigated by $^2H$ nuclear magnetic resonance (NMR) spectroscopy. The hydrophilic channels were asymmetrically flattened and more aligned in the membrane plane than along the hot-pressing direction. The average O-$^2H$ director of $^2H_2O$ in polymer electrolyte membrane was employed to extract the structural information from the $^2H$ NMR peak splitting data. The dependence of $^2H$ NMR data on water contents was systematically analyzed for the first time. The approach presented here can be used to understand the chemicals' behavior in nano-spaces, especially those reshaping and functioning interactively with the chemicals in the wet and/or mixed state.

Preparation and Characterization of Solid Dispersions of Eprosartan Using Spray Drying Method (분무 건조 방식으로 제조한 에프로살탄 고체분산체 제조 및 특성 분석)

  • Hwang, Jun Seok;Kim, So Hee;Cho, Sun Hang;Huh, Kang Moo
    • Polymer(Korea)
    • /
    • v.37 no.4
    • /
    • pp.442-448
    • /
    • 2013
  • In this study, we developed and optimized hydrophilic polymer-based solid dispersion formulations (SDs) using a spray drying method for improving the aqueous solubility of eprosartan, one of poorly soluble drugs that has been broadly used for the treatment of high blood pressure. Hydroxylpropylcellulose (HPC) and poly(vinyl pyrrolidone) (PVP) were used as hydrophilic polymer matrices and poloxamer 407 (P407) added as a polymeric surfactant. Various kinds of solid dispersions with different drug/polymer compositions were prepared and their physico-chemical properties were compared. As the polymer content increased, the drug crystallinity in the SDs significantly decreased and the dissolution properties were enhanced. The PVP based SDs were observed to have relatively reduced crystallinity and an enhanced dissolution rate than HPC-based SDs, due to better miscibility between drug and polymer matrix. For PVP based SDs, the drug crystallinity almost disappeared and the dissolution properties significantly increased by more than 3~7 times.

Synthesis and Characterization of Multi-Block Sulfonated Poly (Arylene Ether Sulfone) Polymer Membrane with Different Hydrophilic Moieties for PEMFC (서로 다른 친수성구조를 가지는 고분자전해질 연료전지용 멀티블록형 술폰산화 폴리아릴렌에테르술폰 전해질막의 합성 및 특성 분석)

  • Yuk, Jinok;Lee, Sojeong;Yang, Tae-Hyun;Bae, Byungchan
    • Journal of the Korean Electrochemical Society
    • /
    • v.18 no.2
    • /
    • pp.75-80
    • /
    • 2015
  • Multi-block sulfonated poly(arylene ether sulfone) (SPAES) copolymer was synthesized via nucleophilic aromatic substitution reaction for proton exchange membrane fuel cell application. After synthesizing the hydrophilic and hydrophobic precursor oligomers having different end-groups (F-terminated or OH-terminated), the effect of end group on the molecular weight was investigated. Hydrophilic oligomers with hydroquinone showed better performance as fuel cell membranes. SPAES membranes showed comparable proton conductivity to that of Nafion at $80^{\circ}C$ and above 70% RH. In particular, SPAES 9 with hydroquinone showed higher proton conductivity than SPAES 10 in the whole RH range studied. Increased local concentration of sulfonic acids within hydrophilic block might develop the hydrophilic-hydrophobic phase separation in the block copolymers.

Preparation of Hydrophilic Coating Film Using GPS(Glycidoxypropyl Trimethoxysilane) (GPS(Glycidoxypropyl Trimethoxysilane)을 이용한 친수성 코팅 필름의 제조)

  • Park, Jung Kook;Song, Ki Chang;Kang, Hyun Uk;Kim, Sung Hyun
    • Korean Chemical Engineering Research
    • /
    • v.40 no.6
    • /
    • pp.735-740
    • /
    • 2002
  • In order to improve the anti-fogging property of polymer films, organic-inorganic hybrid coating solutions which have good hydrophilic property and transmission in the range of visible light were synthesized by the sol-gel method. The coating solutions were prepared by adding glycidoxypropyl trimethoxysilane(GPS) to a colloidal silica(15 nm) suspension(Ludox). GPS as silane coupling agent forms strong bonds to the colloidal silica and surrounding polymer matrix and links two different materials together. Solutions prepared by addition of GPS at the acidic condition resulted in coatings that were less prone to cracking, while those at the basic condition caused coatings with more cracking. These resulted in better hydrophilic property and transmission in the range of visible light for the solution prepared at the acidic condition(pH 2). Compared with coatings under acidic conditions, coatings prepared at basic conditions showed worse hydrophilic property and transmission in the range of visible light.

Experimental and Numerical Assessment of Liquid Water Exhaust Performance of Flow Channels in PEM Fuel Cells (고분자 전해질 연료전지 유로의 수분배출 특성의 실험 및 해석적 평가)

  • Kim, Hyun-Il;Nam, Jin-Hyun;Shin, Dong-Hoon;Chung, Tae-Yong;Kim, Young-Gyu
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.33 no.2
    • /
    • pp.85-92
    • /
    • 2009
  • Polymer electrolyte membrane (PEM) fuel cells are a promising technology for short-term power generation required in residential and automobile applications. Proper management of water has been found to be essential for improving the performance and durability of PEM fuel cells. This study investigated the liquid water exhaust capabilities of various flow channels having different geometries and surface properties. Three-pass serpentine flow fields were prepared by patterning channels of 1 mm or 2 mm width onto hydrophilic Acrylic plates or hydrophobic Teflon plates, and the behaviors of liquid water in those flow channels were experimentally visualized. Computational fluid dynamics (CFD) simulations were also conducted to quantitatively assess the liquid water exhaust capabilities of flow channels for PEM fuel cells. Numerical results showed that hydrophobic flow channels have better liquid water exhaust capabilities than hydrophilic flow channels. Flow channels with curved corners showed less droplet stagnation than the channels with sharp corners. It was also found that a smaller width is desirable for hydrophobic flow channels while a larger width is desirable for hydrophilic ones. The above results were explained as being due to the different droplet morphologies in hydrophobic and hydrophilic channels.

Synthesis and Characterization of Biodegradable Elastic Hydrogels Based on Poly(ethylene glycol) and Poly(${\varepsilon}-caprolactone$) Blocks

  • Im, Su-Jin;Choi, You-Mee;Subramanyam, Elango;Huh, Kang-Moo;Park, Ki-Nam
    • Macromolecular Research
    • /
    • v.15 no.4
    • /
    • pp.363-369
    • /
    • 2007
  • Novel biodegradable elastic hydrogels, based on hydrophilic and hydrophobic polymer blocks, were synthesized via the radical crosslinking reaction of diacrylates of poly(ethylene glycol) (PEG) and poly(${\varepsilon}-caprolactone$) (PCL). PEG and PCL diols were diacrylated with acryloyl chloride in the presence of triethylamine, with the reaction confirmed by FT-IR and $^1H-NMR$ measurements. The diacrylate polymers were used as building-blocks for the syntheses of a series of hydro gels, with different block compositions, by simply varying the feed ratios and molecular weights of the block components. The swelling ratio of the hydrogels was controlled by the balance between the hydrophilic and hydrophobic polymer blocks. Usually, the swelling ratio increases with increasing PEG content and decreasing block length within the network structure. The hydrogels exhibited negative thermo-sensitive swelling behavior due to the coexistence of hydrophilic and hydrophobic polymer components in their network structure, and such thermo-responsive swelling/deswelling behavior could be repeated using a temperature cycle, without any significant change in the swelling ratio. In vitro degradation tests showed that degradation occurred over a 3 to 8 month period. Due to their biodegradability, biocompatibility, elasticity and functionality, these hydrogels could be utilized in various biomedical applications, such as tissue engineering and drug delivery systems.

Effects of Hydrophilic Surface Treatment on SUS Substrates by Using Dielectric Barrier Discharge

  • Joa, Sang-Beom;Kang, In-Je;Yang, Jong-Keun;Lee, Heon-Ju
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2012.02a
    • /
    • pp.458-458
    • /
    • 2012
  • Fuel Cell is used stacking metal or polymer substrate. This hydro property of substrate surface is very important. Usually, surface property is hydrophilic. The surface oxidation of SUS is investigated through plasma treatments with an atmospheric-pressure dielectric barrier discharge (DBD) for increasing hydrophilic property. The plasma process makes an experiment under various operating conditions of the DBD, which operating conditions are treatment time, plasma gas mixture ratio, the plasma source supply frequency. Two kinds of SUS substrate, SUS-304 and SUS 316L, were used. Discharge frequency has a crucial impact on equipment performance and gas treatment. After the plasma treatment of a SUS plate, highly improved wettability was noted. But, when high oxygen supply, the substrate damaged seriously.

  • PDF

Preparation and Characterization of Solid Dispersions of Eprosartan with Hydrophilic Polymers (친수성 고분자를 이용한 에프로살탄 고체분산체의 제조 및 특성 분석)

  • Hwang, Jun-Seok;Ko, Ji-Eun;Kim, So-Hee;Huh, Kang-Moo
    • Polymer(Korea)
    • /
    • v.36 no.4
    • /
    • pp.500-506
    • /
    • 2012
  • In this study, we developed and optimized hydrophilic polymer based solid dispersion formulations (SDs) for enhancing the aqueous solubility of eprosartan, one of poorly soluble drugs, that has been broadly used for the treatment of high blood pressure. Poly(ethylene glycol) (PEG) and poly(vinyl pyrrolidone) (PVP) based SDs were prepared by hot melting and solvent evaporation methods and the drug/polymer composition varied in the range of 1:1~1:5 with or without poloxamer 407 (P407) as a polymeric surfactant. The SDs prepared by solvent evaporation showed more reduced crystallinity than ones by hot melting, and PVP based SDs showed more enhanced solubility and lower crystallinity than PEG based SDs. Furthermore, it was observed from DSC and PXRD analysis that the SDs with P407 (drug:polymer: P407 = 1:5:1) demonstrated no crystallinity and the most enhanced solubility (more than 3~4 times).

Syntheses and Characterizations of Polymer-Ceramic Composites Having Increased Hydrophilicity, Air-Permeability, and Anti-Fungal Property (친수성, 통기성 및 항균성이 향상된 고분자-세라믹 복합소재의 제조 및 물성)

  • Cho, Hyung-Joon;Jung, Dong-Woon
    • Journal of the Korean Chemical Society
    • /
    • v.54 no.1
    • /
    • pp.137-141
    • /
    • 2010
  • Generally, polymer materials are not air-permeable and hydrophilic. In addition, they do not possess anti-fungal property. Hydrophilicity, air-permeability, and anti-fungal properties of new composites consisting of polymer, ceramic nanoparticles, and silver ion were investigated by contact angle measurements, air permeation time, and cell culture. The hydrophilic, air-permeable, and anti-fungal composites can be used in health care industry.