• Title/Summary/Keyword: 공중 합체

Search Result 920, Processing Time 0.026 seconds

Effect of Dispersion Control of Multi-walled Carbon Nanotube in High Filler Content Nano-composite Paste for the Fabrication of Counter Electrode in Dye-sensitized Solar Cell (다중벽 탄소 나노튜브 기반 고충전 나노복합 페이스트를 이용한 염료 감응 태양 전지용 상대 전극의 제조에 있어서 분산 제어의 효과)

  • Park, So Hyun;Hong, Sung Chul
    • Polymer(Korea)
    • /
    • v.37 no.4
    • /
    • pp.470-477
    • /
    • 2013
  • Multi-walled carbon nanotube (MWCNT) based nano-composite pastes having a high filler content are prepared for the facile fabrication of a counter electrode (CE) of dye-sensitized solar cell (DSSC). A polystyrene-based functional block copolymer is prepared through a controlled "living" radical polymerization technique, affording a surface modifier for the dispersion control of MWCNT in the paste. Physical dispersion through a ball-milling method additionally confirms the importance of the dispersion control, providing DSSC with enhanced processibility and improved solar-to-electricity energy conversion efficiency (${\eta}$) values. The performances of the DSSCs are further improved through the incorporation of minor amount of platinum (Pt) nanoparticles into the MWCNT pastes. The DSSC with the Pt/MWCNT hybrid CE exhibits very high ${\eta}$ values, which is superior to that of DSSC with the standard Pt CE.

Gradient Structures and Surface Composition of Polypropylene/Ethylene-Propylene Rubber Blends (폴리프로필렌/에틸렌-프로필렌 고무 블렌드 경사구조 및 표면조성)

  • Kim, Seog Je;Lee, Sung-Goo;Lee, Jae Heung;Choi, Kil-Yeong
    • Journal of Adhesion and Interface
    • /
    • v.2 no.4
    • /
    • pp.24-31
    • /
    • 2001
  • Polypropylenes(PP) with different melt index values were mixed with ethylene-propylene rubber(EPR) or ethylene-propylene diene monomer rubber(EPDM) and an ethylene copolymer containing carboxylic acid group in a twin screw extruder. Then test specimens were prepared from the pellets of the blends with an injection molding machine. The mechanical properties and morphology of fractured surfaces were measured. Relative peak intensities of carboxylic acid group on the specimen surface were measured with an attennuated total reflection infrared spectrometer (ATR-IR) and compared with each other. The blend specimens were found to have the gradient morphology of rubber domains in PP matrix in the core region and PP skin layer. The blends containing PP of higher melt index showed greater content of ethylene copolymer containing carboxylic acid on the surface when the relative peak intensities of ATR-IR for carboxylic acid were compared. As the melt index values were increased, the decrease tendency in mechanical propeties such as tensile strength and impact strength was more significant for PP/EPR blends than PP/EPDM blends.

  • PDF

Manufacture of Core-Shell Composite Polymer Materials for Nonwoven binder (부직포 바인더용 Core-Shell 복합소재의 제조)

  • Lee, Sun Ryong;Lim, Jae Keel;Seul, Soo Duk
    • Journal of Adhesion and Interface
    • /
    • v.3 no.4
    • /
    • pp.27-36
    • /
    • 2002
  • The organic/organic core-shell composite polymer for nonwomen binder were synthesized by stage polymerization of methyl methacrylate and styrene with ammonium persulfate after preparing monomer pre-emulsion in the presence of anionic surfactant. We study the effect of initiator concentration, $0.79{\times}10^{-3}{\sim}3.16{\times}10^{-3}mol/L$ for core polymer, $2.0{\times}10^{-4}{\sim}8.0{\times}10^{-4}mol/L$ for shell polymer, sulfactant concentration, $1.45{\times}10^{-5}{\sim}4.15{\times}10^{-5}mol/L$ for core polymer, $0.73{\times}10^{-5}{\sim}2.91{\times}10^{-5}mol/L$ for shell polymer on core-shell structure of polymethyl methacrylate/polystyrene and polystyrene/polymethyl methacrylate. Emulsion stability was major test method, particle size and particle size distribution were measured using particle size analyzer and the morphology of the core-shell composite polymer was determined using transmission electron microscope, glass temperature was also measured using differential scanning calorimeter.

  • PDF

Manufacture of PMMA/PBA and PBA/PMMA core Shell Composite Particles - Effect of emulsifier - (PMMA/PBA와 PBA/PMMA Core Shell 복합입자의 제조 - 유화제의 영향 -)

  • Seul, Soo Duk
    • Journal of Adhesion and Interface
    • /
    • v.11 no.3
    • /
    • pp.112-119
    • /
    • 2010
  • Poly(methyl methacrylate)/poly(butyl acrylate) PMMA/PBA core-shell composite particles were prepared by the emulsion polymerization of MMA and BA in the presence of different concentration of sodium dodecyl benzene sulfonate (SDBS). The following conclusions are drawn from the measured conversion and particle size distribution, morphology, average molecular weight distribution, observation of film formation and particle formation, glass transition temperature and physical properties of polymerized core-shell composition particles for using adhesive binder. When the concentration of 0.03 wt% surfactant, the conversions of PMMA and PBA core polymerization are excellent as 95.8% for PMMA core and 92.3% for PBA core. Core-shell composite particles are obtained 90.0% for PMMA/PBA core-shell composite particles and 89.0% for PMMA/PBA core-shell composite particles. It is considered that the core and shell particles are polymerized to be confirmed FT-IR spectra and average molecular weight measured with a GPC, formation of the composite particles is confirmed by the film formation from normal temperature, and composition of inside and outside of the composite particle is confirmed by TEM photograph. The synthesized polymer has two glass transition temperatures, suggesting that the polymer is composed of core polymer and shell polymer unlike general copolymers. It is considered that each core-shell composite particle can be used as a high functionality adhesion binder by the measurement of tensile strength and elongation.

Effect of glass beads on dispersion properties of EVA/MWCNT foams (유리비드가 EVA/MWCNT 발포체의 분산특성에 미치는 영향)

  • Kim, Taeyoon;Lee, Seunghyun;Ching, Ildoo
    • Journal of Adhesion and Interface
    • /
    • v.19 no.2
    • /
    • pp.68-73
    • /
    • 2018
  • In this study, conductive EVA foams including multi-wall carbon nanotubes (MWCNT), glass beads were prepared. The electrical conductivity and physical properties of the foams were confirmed with varying amount of MWCNT, mixing time, and amount of glass beads. The electrical conductivity increased with the amount of MWCNT. Dispersity of MWCNT in EVA foams were improved with glass beads. It can be suggested that conductive EVA foams can be successfully prepared with improved dispersity of MWCNT in ethylene-vinyl acetate by using glass beads.

Synthesis and Characterization of Sulfonated Poly (Arylene ether Sulfone) Multi-Block Copolymer for PEMFC Application (고분자연료전지용 설폰산화 폴리아릴렌에테르설폰 멀티블록공중합체의 합성 및 특성 분석)

  • Ahn, Jinju;Choi, Young-Woo;Yang, Tae-Hyun;Kim, Chang-Soo;Bae, Byungchan
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.23 no.5
    • /
    • pp.461-467
    • /
    • 2012
  • Multi-block sulfonated poly (arylene ether sulfone) (SPES) membranes were synthesized by post-sulfonation and its properties characterized. Two types of oligomers, F-terminated and OH-terminated telechelic oligomers, were synthesized by controlling the feed ratio of dihydroxyl- and difluoro-monomers. Their number of repeating unit (X and Y) was analyzed by GPC and $^1H$ NMR. Copolymerization with F-terminated and OH-terminated telechelic oligomers via nucleophilic aromatic substitution, gave high-molecular-weight multi-block PESs. Each block length was controlled to have different values with X5Y10, X10Y10, X20Y10 and X20Y20. Successful polymerization and its successful sulfonation was confirmed by GPC and $^1H$ NMR. RH dependence of proton conductivity of multi-block SPES membranes was comparable to that of Nafion 212 at high RH conditions.

A Study on the Fluidity Retention of Cement Paste Added by Naphthalene Sulfonated Condensate and Polycarboxylic Acid Admixture (나프탈렌술폰산축합물과 폴리카르본산계 혼화제가 첨가된 시멘트 페이스트의 유동성 유지에 관한 연구)

  • 노재성;홍성수;김도수
    • Magazine of the Korea Concrete Institute
    • /
    • v.7 no.5
    • /
    • pp.189-199
    • /
    • 1995
  • Naphthalene sulfonated condensate has been widely used as a superplasticizer for cement and concrete, but the application was limited due to its large slump loss with elapsed time. To complement this demerit of NSF, polycarboxylic acid copolymer from nlaleic anhydride and acryl~c acid(MA) was synthesized to retain the mobility of cement and concrete, and then mixed with NSF. The physical properties, such as fluidity, fluidityretention and rheology, were measured by applying these admixtures to cement paste as a function of elapsed time. And also compressive strength of mortar was measured with curing time. NIv-l and NM-2 containing 10, 20 wt% of MA respectively had a excellent fluidity and a fluidity- retention. In rheological property, the increases of shear stress and viscosity with elapsed time were delayed with the increasing of shear rate in cornparision with NSF only. The marked slump loss of cement paste could be controlled by these admixture. Also the added ainount of admixture and the ratio of water to cement affected these properties.

Microstructure of TiO2 sensor electrode on nano block copolymertemplates using an ALD (나노 블록공중합체 템플레이트에 ALD로 제조된 센서용 TiO2 박막의 미세구조 연구)

  • Park, Jong-Sung;Han, Jeung-Jo;Song, Oh-Sung;Jeon, Seung-Min;Kim, Hyeong-Ki
    • Journal of Sensor Science and Technology
    • /
    • v.18 no.3
    • /
    • pp.239-244
    • /
    • 2009
  • We fabricated nano-templates by low temperature BCP(block copolymer) process at 180 $^{\circ}C$, then we deposited 10 nm-thick $TiO_2$ layers with ALD(atomic layer deposition) at low temperature of 150 $^{\circ}C$. Through FE-SEM analysis, we confirmed the successful formation of the groove-type(width of crest : 30 nm, width of trough : 18 nm) and the cylinder-type(diameter : 10 nm, distance between hole : 25 nm) templates. Moreover, after $TiO_2$-ALD processing, we confirmed the deposition of the uniform nano layers of $TiO_2$ on the nano-templates. Through AFM analysis, the pitches of the crest-through(in groove-type) and hole-hole(in cylinder-type) were the same before and after $TiO_2$-ALD processing. In addition, we indirectly determined the existence of the uniform $TiO_2$ layers on nano-templates as the surface roughness decreased drastically. We successfully fabricated nano-template at low temperature and confirmed that the three-dimensional nano-structure for sensor application could be achieved by $TiO_2$-ALD processing at extremely low temperature of 150 $^{\circ}C$.

Adsorption of Uranium(VI) Ion Utilizing Cryptand Ion Exchange Resin (Cryptand 이온교환 수지를 이용한 우라늄(VI) 이온의 흡착)

  • Park, Seong-Kyu;Kim, Joon-Tae
    • Analytical Science and Technology
    • /
    • v.17 no.2
    • /
    • pp.91-97
    • /
    • 2004
  • Cryptand ion exchange resins were synthesized with 1-aza-15-crown-5 macrocyclic ligand attached to styrene divinylbenzene (DVB) copolymer with crosslink of 1%, 2%, 5% and 10% by substitution reaction. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, dielectric constant of solvent and crosslink on adsorption of uranium ($UO{_2}^{2+}$) ion were investigated. The uranium ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium ($UO{_2}^{2+}$), magnesium ($Mg^{2+}$), neodymium ($Nd^{3+}$) ion. The adsorption was in order of 1%, 2%, 5%, and 10% crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvents.

Compatibilization of PC/SAN Blends via Ultrasound-irradiated Melt Mixing (초음파가 조사되는 용융 혼합에 의한 폴리카보네이트/스티렌-아크릴로니트릴 혼합물의 상용화)

  • 김형수
    • Polymer(Korea)
    • /
    • v.28 no.3
    • /
    • pp.225-231
    • /
    • 2004
  • High intensity ultrasound was irradiated to induce mechano-chemical degradation during melt processing of polycarbonate (PC) and styrene-co-acrylonitrile (SAN) in an intensive mixer. It was found that macroradicals of PC and SAM can be generated during ultrasound assisted melt processing; which, in turn, provides a useful route to achieve in-situ compatibilization for the blends of PC and SAM by their mutual coupling. Effectiveness of compatibilization was assessed by investigating phase morphology and mechanical properties of the blends. It was observed that domain size was reduced and the stability of morphology was well maintained even after annealing treatment of the blends. In audition, the enhancement of mechanical properties such as elongation at break and tensile strength was evident, which added further confirmation on the desirable feature that sonication of melt-blends is able to enhance intermolecular interaction by promoting chemical bonds between dissimilar polymers without use of any compatibilizers.