• Title/Summary/Keyword: Functional polymer

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Polymeric Nano-materials: Applications & Research Trends (고분자 나노 소재의 응용 및 연구 현황)

  • 박영준
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.28 no.2
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    • pp.55-57
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    • 2002
  • The fabrication, characterization and manipulation of nanosystems brings together physics, chemistry, materials science and biology in an unprecedented way, Phenomena occurring in such systems are fundamental to the workings of electronic devices, but also to living organisms. The ability to fabricate nanostructures is essential in the further development of functional devices that incorporate nanoscale features. Even more essential is the ability to introduce a wide range of chemical and materials flexibility into these structures to build up more complex nanostructures that can ultimately rival biological nanosystems. In this respect, polymers are potentially ideal nanoscale building blocks because of their length scale, well-defined architecture, controlled synthesis, ease of processing and wide range of chemical functionality that can be incorporated. In this presentation, we will look at a number of promising polymer-based nanofabrication strategies that have been developed recently, with an emphasis on those techniques that incorporate nanostructured polymers into devices and that exploit intrinsic polymer properties.

Enhanced thermomechanical properties of poly(ethylene oxide) and functionalized bacterial cellulose nanowhiskers composite nanofibers

  • Yun, Ok-Ja
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.376-376
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    • 2016
  • Poly(ethylene oxide) (PEO)/functionalized bacterial cellulose nanowhiskers (f-BCNW) (0.1 wt%) composite nanofibers were fabricated by electrospinning process and the thermomechanical properties were significantly enhanced more than the PEO and PEO/bacterial cellulose nanowhiskers (BCNW) (0.1 wt%) composite nanofibers. The functionalization of BCNW (f-BCNW) was performed by microwave plasma treatment for effects of nitrogen functionalization of chemically-driven BCNW. The N-containing functional groups of f-BCNW enhanced chemical bonding between the hydroxyl groups of the polymer chains in the PEO matrix and diameter size of PEO/f-BCNW (0.1 wt%) composite nanofibers were decreased more than PEO and PEO/BCNW (0.1 wt%) composite nanofibers on the same concentration. The strong interfacial interactions between the f-BCNW nanofillers and polymer matrix were improved the thermomechanical properties such as crystallization temperature, weight loss and glass transition temperature (Tg) compared to PEO and PEO/BCNW composites nanofibers. The results demonstrated that N2 plasma treatment of BCNW is very useful in improving thermal stability for bio-applications.

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Poly-$\alpha$-methylstyrene Films by Plasma Polymerization(I) (플라즈마 중합된 Poly-$\alpha$-methylstyrene 박막(I))

  • Park, Sang-Hyun;Lee, Chwi-Cwung;Han, Sang-Ok;Lim, Youg-Hoon;Lee, Deok-Chool
    • Proceedings of the KIEE Conference
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    • 1991.11a
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    • pp.304-306
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    • 1991
  • A new gas-flow type reactor for plasma polymerization was developed to symthesize functional polymer, which enhances the reaction of radicals activated in discharge. $\alpha$-Methylstyrene was used for the polymerization, which are known as starting monomers for the polymer with degradating characteristics. The molecular structure and molecular weight distribution of the polymers were studied.

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Deinking of Used Paper by Modified Cellulase with Polymer (고분자 가공 셀룰라아제에 의한 고지의 탈묵에 관한 연구)

  • 박진원;박귀남;이주한;이병준
    • KSBB Journal
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    • v.13 no.5
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    • pp.593-598
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    • 1998
  • Biological deinking process of used papers was studied by the polymer modified cellulase. Cellulase was modified with copolymers which consist of polyoxyethylene derivative and maleic anhydride(MA). The MA functional groups of copolymer can react with amino acids groups of the cellulase without much loss of activity. Modified degree of amino acids was controlled by the added copolymer. The maximum modified degree was about 60% and it was obtained when the weight ratio of copolymer and cellulase was 4. The remained activity of the maximum modified cellulase(MMC) was higher than 80% of native cellulase. The MMC's concentration was 0.05-2.0 wt% relative to the dry paper. In mechanical pulping process, cellulase enhanced the detachment of the ink particle from the used paper by partial hydrolysis of the fiber. The polyoxyethylene of modified cellulase produced the forms which can float the separated ink particle. Compared to the convention deinking method with NaOH or organic chemicals, the new biological deinnking process improved the physical properties such as freeness, tearing strength and whiteness.

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Molecularly Imprinted Monolithic Stationary Phases for Liquid Chromatographic Separation of Tryptophan and N-CBZ-Phenylalanine Enantiomers

  • Yan, Hong-Yuan;Row, Kyung-Ho
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.4
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    • pp.357-363
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    • 2006
  • Monolithic molecularly imprinted columns were designed and prepared by an in-situ thermal-initiated copolymerization technique for rapid separation of tryptophan and N- CBZ-phenylalanine enantiomers. The influence of polymerization conditions and separation conditions on the specific molecular recognition ability for enantiomers and diastereomers was investigated. The specious molecular recognition was found to be dependent on the stereo structures and the arrangement of functional groups of the imprinted molecule and the cavities in the molecularly imprinted polymer (MIP). Moreover, hydrogen bonding interactions and hydrophobic interactions played an important role in the retention and separation. Compared to conventional MIP preparation procedures, the present method is very simple, and its macroporous structure has excellent separation properties.

Development of functional microsphere (I) - Formation and characteristics of poly(ethylene-co-vinyl acetate) microspheres via thermally induced phase separation - (기능성 마이크로스피어의 개발 (I) - 열유도 상분리에 의한 Poly(ethylene-co-vinyl acetate) 마이크로스피어의 제조와 특성 -)

  • 이신희;김효정;박수민
    • Textile Coloration and Finishing
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    • v.15 no.4
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    • pp.57-64
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    • 2003
  • Poly(ethylene-co-vinyl acetate)(EVA) microspheres were prepared by a thermally induced phase separation. The microsphere formation occurred by the nucleation and growth mechanism in the metastable region. The diluent used was toluene. The microsphere formation and growth was followed by the cloud point of the optical microscope measurement. The microsphere size distribution, which was obtained by SEM observation and particle size analyzer, became broader when the polymer concentration was higher, the content of vinyl acetate in EVA copolymer was higher, and the cooling rate of EVA copolymer solution was lower.

Photo-grafting Dyeing of Wool Fabrics with Dimethacrylated Quinizarin Dye (반응성 염료의 광그라프트에 의한 양모직물의 염색)

  • Dong, Yuanyuan;Jang, Jin-Ho
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2012.03a
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    • pp.26-26
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    • 2012
  • The hydrophobic nature of the wool surface give rise to difficult penetration of dye molecules. Among all the methods of modification, graft polymerization is an attractive method to impart a variety of functional groups to a polymer. Grafting has been made by irradiating the light on the polymer in the presence of a solvent containing monomer. The energy source commonly used are high-energy electrons, X-rays, UV and visible light. UV irradiation is a relatively low-energy radiation in comparison with others since it has the least possibility to change bulk properties. In the present paper, a photo-reactive dye was synthesized from quinizarin by the reaction with methacryloyl chloride. The synthesized dye was continuously grafted onto wool fabric at room temperature by UV irradiation. Several key parameters including UV energy, dye concentration and pH have been examined to understand their influence on the photoreactive coloration.

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A Study on the dynamic viscoelasticity of UV curing polymer and alkyd resin composite materials (UV경화성 수지와 Alkyd수지 복합재료의 경화거동과 동적 점탄성에 관한 연구)

  • 정원식;최정병;김용욱
    • Journal of the Korean Graphic Arts Communication Society
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    • v.16 no.3
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    • pp.29-41
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    • 1998
  • The ultraviolet(UV)-curable materials wildly have been used as a ink and coating materials. A according to measure UV polymerization phase separation of acryl groups 2,3,4-functional monomer, a few experiments were performed gel fraction, dynamic viscosity of alkyd resin blend system. Dependence of photoiniator concentration and various monomer, alkyd resin content investigated structural changes of films cured by UV irradiation. Curing rate measured UV irradiation under $25^{\circ}C$, cell gap 7cm and film thickness 100${\mu}{\textrm}{m}$. In results, it was through that the viscoelastic properties of films cured with increasing the ratios of monomer/alkydresin contents are network polymer in properties such as viscoelasticity.

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Controlling Intermolecular Interactions, Optical Property, and Charge Transport in Conjugated Polyelectrolytes for Applications in Opto-electronics Devices

  • Nguyen, Thuc-Quyen;Garcia, Andres;Yang, Renqiang;Bazan, Guillermo
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.229-229
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    • 2006
  • Recently there has been significant interest in utilizing functional semiconductor polymers for electronic and opto-electronic devices such as Light-emitting diodes, thin film field effect transistors, solar cells, displays, and chemical and biosensors. However, better materials and further understanding of their electronic properties are critical for devices based on these materials. In this work, we use various scanning probe techniques, spectroscopy, and device fabrication to study the molecular interactions, optical and charge transport properties in conjugated polyelectrolytes. Using chemical synthesis approach, we are able to tune the molecular packing and interactions in these materials, which in turn, influence their electronic properties and device performance.

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Detection of ${\alpha}-Cyclodextrin$ and E.coli Cell Using Polydiacetylene Supramolecules

  • Lee, Gil-Sun;Choi, Hyun;Lee, Chung-Wan;Ahn, Dong-June;Oh, Min-Kyu;Kim, Jong-Man
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.306-306
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    • 2006
  • We immobilized and patterned PDA vesicles on solid substrate using micro arrayer, which have moieties to react with chemical and biological materials. Immobilized vesicle system was developed since it possesses many advantages in multiple screening, durable stability, and higher sensitivity. We applied polydiacetylene supramolecules to chemical and biological sensors for detection of ${\alpha}-cyclodextrin$ and E.coli cell selectively. This detection method could be applied as DNA chip, protein chip, and cell chip for multiple screening as well as chemical sensor by modifying the functional groups of diacetylene monomer.

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