• Title/Summary/Keyword: PVP

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Study of the Intraction between PVP and Silver Cation (은 양이온과 PVP의 상호작용에 대한 연구)

  • Lee, Chul-Jae;Kim, Dong-Yeub;Nam, Ki-Young
    • Journal of the Korean Chemical Society
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    • v.53 no.5
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    • pp.565-569
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    • 2009
  • The interaction between polyvinylpyrrolidone(PVP) and silver cation has been studied in water at room temperature and atmospheric pressure. The PVP and PVP/Ag composite was observed by transmission electron microscopy (TEM), UV-VIS absorption spectroscopy, Raman spectroscopy and oxygen/carbon dioxide analyzer. We identified silver cations interacting with nonbonding electrons of the oxygen atom in the carbonyl group of PVP. It was shown that PVP/Ag formed stable composites.

Synthesis of PVA/PVP Hydrogel by Irradiation Crosslinking (방사선 가교에 의한 PVA/PVP 하이드로겔 제조 및 드레싱에의 응용)

  • 김태훈;노영창
    • Polymer(Korea)
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    • v.25 no.2
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    • pp.270-278
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    • 2001
  • Hydrogels for wound dressing were manufactured using poly(vinylalcohol)(PVA) and poly(N-vinylpyrrolidone)(PVP). The hydrogels were obtained by exposing to $^{60}$ Co${\gamma}$-rays after freezing and thawing of aqueous solutions of PVA and PVP to improve mechanical strength. Mechanical properties such as gelation, water absorptivity and gel strength were examined after repeating the \"freezing and thawing\" of PVA/PVP hydrogels, and then irradiating them at 40 kGy. The PVA/PVP ratio was in the range of 30:70 ~ 100:0, and the solid concentration of PVA/PVP was 20 wt%. The gelation and strength of hydrogels were much higher when \"freezing and thawing\" and the irradiation process were used than when only the irradiation process was utilized. In addition, the mechanical properties of PVA/PVP hydrogels after repetition of \"freezing and thawing\" are discussed. thawing\" are discussed.ssed.

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Effect of Various Supplements on Embryo Development and Quality of Bovine Embryos during In Vitro Maturation (한우 난포란의 체외성숙 시 여러 가지 첨가물이 배 발생과 품질에 미치는 영향)

  • Park Hum-Dae;Jang Mi-Jin;Park Yong-Soo
    • Reproductive and Developmental Biology
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    • v.30 no.1
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    • pp.21-26
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    • 2006
  • This study was examined the effects of concentrations of polyvinylpyrrolidone(PVP) and supplementation of EGF, cysteine and PVP during in vitro maturation on the development of bovine embryos. In experiment 1, 0.1 to 3.0% PVP was supplemented to IVM medium before IVF. The development rates to the blastocyst stage was significantly higher in 0.5% PVP group than 3.0% PVP group (P<0.05). In experiment 2, EGF, rysteine and PVP were supplemented to IVM medium. The hight cleavage rate was obtained from cysteine group, but blastocyst formation rates did not differ among groups. The highest total cell number and inner cell mass (ICM) cell number were observed in cysteine group. In PVP group, ICM cell number was significantly low than those of cysteine and control groups (P<0.05). After embryo transfer, pregnancy rate was significantly low in PVP group compared to other groups (P<0.05). These results indicate that the supplementation of PVP in IVM medium support the embryo development, but has a deteriorate effect on the blastocyst quality.

Formation of PVP- Based Organic Insulating Layers and Fabrication of OTFTs (PVP-기반 유기 절연막 형성과 OTFT 제작)

  • Jang, Ji-Geun;Seo, Dong-Gyoon;Lim, Yong-Gyu
    • Korean Journal of Materials Research
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    • v.16 no.5
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    • pp.302-307
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    • 2006
  • The formation and processing of organic insulators on the device performance have been studied in the fabrication of organic thin film transistors (OTFTs). The series of polyvinyls, poly-4-vinyl phenol(PVP) and polyvinyltoluene (PVT), were used as solutes and propylene glycol monomethyl ether acetate(PGMEA) as a solvent in the formation of organic insulators. The cross-linking of organic insulators was also attempted by adding the thermosetting material, poly (melamine-co-formaldehyde) as a hardener in the compound. The electrical characteristics measured in the metal-insulator-metal (MIM) structures showed that insulating properties of PVP layers were generally superior to those of PVT layers. Among the layers of PVP series: PVP(10 wt%) copolymer, 5 wt% cross-linked PVP(10 wt%), PVP(20 wt%) copolymer, 5 wt% cross-linked PVP(20 wt%) and 10 wt% cross-linked PVP(20 wt%), the 10 wt% cross-linked PVP(20 wt%) layer showed the lowest leakage current characteristics. Finally, inverted staggered OTFTs using the PVP(20 wt%) copolymer, 5 wt% cross-linked PVP(20 wt%) and 10 wt% cross-linked PVP(20 wt%) as gate insulators were fabricated on the polyether sulphone (PES) substrates. In our experiments, we could obtain the maximum field effect mobility of 0.31 $cm^2/Vs$ in the device from 5 wt% cross-linked PVP(20 wt%) and the highest on/off current ratio of $1.92{\times}10^5$ in the device from 10 wt% cross-linked PVP(20 wt%).

Preparation and Properties of PVP (poly-4-vinylphenol) Gate Insulation Film For Organic Thin Film Transistor (유기박막 트랜지스터용 PVP (poly-4-vinylphenol) 게이트 절연막의 제작과 특성)

  • Baek, In-Jae;Yoo, Jae-Hyouk;Lim, Hun-Seung;Chang, Ho-Jung;Park, Hyung-Ho
    • Journal of the Microelectronics and Packaging Society
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    • v.12 no.4
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    • pp.359-363
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    • 2005
  • The organic insulation devices with MIM (metal-insulator-metal) structures as PVP gate insulation films were prepared for the application of organic thin film transistors (OTFT). The co-polymer organic insulation films were synthesized by using PVP(poly-4-vinylphenol) as solute and PGMEA (propylene glycol monomethyl ether acetate) as solvent. The cross-linked PVP insulation films were also prepared by addition of poly (melamine-co-formaldehyde) as thermal hardener. The leakage current of the cross-linked PVP films was found to be about 300 pA with low current noise. and showed better property in electrical properties as compared with the co-polymer PVP insulation films. In addition, cross-linked PVP insulation films showed better surface morphology (roughness), showing about 0.11${\~}$0.18 nF in capacitance for all PVP film samples.

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Preparation and Characterization of Hydrogels of PVA and PVP Containing Chitosan by Radiation (방사선에 의한 키토산을 포함하는 PVA와 PVP 하이드로겔의 제조 및 특성)

  • 박경란;노영창
    • Polymer(Korea)
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    • v.25 no.5
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    • pp.728-735
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    • 2001
  • In this study, hydrogels from mixtures of chitosan/poly(vinyl alcohol) (PVA) and chitosan/poly(N-vinylpyrrolidone) (PVP) were prepared by ${\gamma}$-ray irradiation, and the mechanical properties such as gelation, water absorptivity and gel strength were examined to evaluate the applicability of these for wound dressing. The PVA : chitosan and PVP : chitosan ratio were in the range of 97:3 ~ 90:10, and the solid concentration of PVA/chitosan and PVP/chitosan solution were 15 wt%. Gamma irradiation with doses of 25, 35, 50, 60 and 70 kGy, was exposed to mixtures of PVA/chitosan and PVP/chitosan to evaluate the effect of irradiation dose. Gel content and gel strength increased as chitosan concentrations in PVA/chitosan and PVP/chitosan decreased, and as irradiation dose increased. Swelling degree increased as chitosan concentrations in PVP/chitosan and PVA/chitosan increased, and as irradiation dose decreased.

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Enhancement of fingerprint in blood deposited on the surface of thermal paper by using the mixture of polyvinylpyrrolidone and 1,2-indanedione (Polyvinylpyrrolidone과 1,2-indanedione 혼합물을 이용한 감열지에 부착된 혈흔지문의 증강)

  • Kim, Dongman;Ryu, Heayeon;Jeong, Seunghoon;Joo, Inseon;Hong, Sungwook
    • Analytical Science and Technology
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    • v.34 no.3
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    • pp.122-127
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    • 2021
  • A mixture of polyvinylpyrrolidone and 1,2-indanedione (PVP-IND) is known to be the best reagent for developing latent fingerprints deposited on the surface of a thermal paper. However, no study has evaluated whether PVP-IND could enhance fingerprints in blood deposited on the surface of thermal paper. Therefore, in this study, the ability of PVP-IND to enhance the fingerprints in blood was investigated. Furthermore, aqueous amido black solution, which is known to be the best reagent for enhancing fingerprints in blood deposited on the surface of thermal paper, was used for comparison with PVP-IND. Therefore, while enhancing the fingerprints in diluted blood, PVP-IND enhanced the quality of fingerprints compared to aqueous amido black solution. The ridge diffused when the undiluted fingerprints in blood were enhanced with PVP-IND because PVP reacted with amino acids in blood; however, amido black solution yielded better results. When treated with PVP-IND, it is presumed that the ridge diffused due to the reaction of PVP and amino acids contained in the blood.

Effects of Polymer Adsorption on Stabilities and CMP Performance of Ceria Abrasive Particles

  • Shimono Norifumi;Kawaguchi Masami;Koyama Naoyuki
    • Transactions on Electrical and Electronic Materials
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    • v.7 no.3
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    • pp.112-117
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    • 2006
  • In this paper we present that the effects of polymer adsorption on stabilities and CMP performance of ceria abrasive particles. Characterization of ceria abrasive particles in the presence of poly(vinyl pyrrolidone) (PVP) was performed by the measurements of adsorbed amounts of PVP, average sizes, and the back scattering intensities of the ceria abrasive particles as functions of PVP molecular weight and PVP concentration. The ceria abrasive particles in the presence of PVP were used to polish $SiO_2\;and\;Si_3N_4$ films deposited on Si wafers in order to understand the effect of PVP adsorption on chemical mechanical polishing (CMP) performance, together with ceria abrasive particles without PVP. Adsorption of PVP on the ceria abrasive particles enhanced the stability of ceria abrasive particles due to steric stabilization of the thick adsorbed layer of PVP. Removal rates of the deposited $SiO_2\;and\;Si_3N_4$ films by the ceria abrasive particles in the presence of PVP were much lower than those in the absence of PVP and their magnitudes were decreased with an increase in the concentration of free PVP chains in the dispersion media. This suggests that the CMP performance in the presence of PVP could be mainly controlled by the hydrodynamic interactions between the adsorbed PVP chains and the free ones. Moreover, the molecular weight dependence of PVP on the removal rates of the deposited films was hardly observed. On the other hand, high removal rate selectivity between the deposited films in the presence of PVP was not observed.

Organic Thin Film Transistors with Cross-Linked PVP Gates (Cross-Linked PVP 게이트 유기 박막트랜지스터)

  • Jang Ji-Geun;Oh Myung-Hwan;Chang Ho-Jung;Kim Young-Seop;Lee Jun-Young;Gong Myoung-Seon;Lee Young-Kwan
    • Journal of the Microelectronics and Packaging Society
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    • v.13 no.1
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    • pp.37-42
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    • 2006
  • The preparation and processing of PVP-gate insulators on the device performance have been studied in the fabrication of organic thin film transistors (OTFTs). One of polyvinyl series, poly-4-vinyl phenol(PVP) was used as a solute and propyleneglycol monomethyl etheracetate(PGMEA) as a solvent in the formation of organic gate solutions. The cross-linking of organic insulators was also attempted by adding the thermosetting material, poly (melamine-co-formaldehyde) as a hardener in the compounds. From the measurements of electrical insulating characteristics of metal-insulator-metal (MIM) samples, PVP-based insulating layers showed lower leakage current according to the increase of concentration of PVP and poly (melamine-co-formaldehyde) to PGMEA in the formation of organic solutions. The PVP(20 wt%) copolymer with composition of 20 wt% PVP to PGMEA and cross-linked PVPs in which 5 wt% and 10 wt% poly (melamine-co-formaldehyde) hardeners had been additional]y mixed into PVP(20 wt%) copolymers were used as gate dielectrics in the fabrication of OTFTs, respectively. In our experiments, the maximum field effect mobility of $0.31cm^2/Vs$ could be obtained in the 5 wt% cross-linked PVP(20 wt%) device and the highest on/off current ratio of $1.92{\times}10^5$ in the 10 wt% cross-linked PVP(20 wt%) device.

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Influence of PVP on the Thickness of Ferroelectric (Na,K)NbO3 Film by Sol-Gel (솔-젤 법을 통해 제조된 강유전체 (Na,K)NbO3 막의 두께에 미치는 PVP의 영향)

  • Kim, Dae-Gun;Yoo, In-Sang;Kim, Sae-Hoon;Kim, Jin-Ho
    • Korean Journal of Materials Research
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    • v.22 no.12
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    • pp.696-700
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    • 2012
  • (Na, K) $NbO_3$ thick film was successfully achieved using a sol-gel coating process with the addition of polyvinylpyrrolidone (PVP) to a metal alkoxide solution. The transparent coating solution, mixed with Nb:PVP = 1:1 in a molar ration, was synthesized by evaporating the solvent to over 62.5 wt%. Additive PVP increased the viscosity of the solution so that the coating thickness could be enhanced. The thickness of the (Na, K) $NbO_3$ film assisted by PVP was ca. 320 nm at the time of deposition; this value is four times thicker than that of the sample fabricated without PVP. Also, due to PVP binding with the OH groups of the metal alkoxide, the condensation reaction in the film was suppressed. The crystalline size of the (Na, K) $NbO_3$ films assisted by PVP was ca. 15 nm smaller than that of the film fabricated without PVP. After the sintering process at $700^{\circ}C$, the (Na, K) $NbO_3$ films were mainly composed of randomly oriented (Na, K) $NbO_3$ phase of perovskite crystal structure, including a somewhat secondary phase of $K_2Nb_4O_{11}$. However, by adding PVP, the content of the secondary phase became quite smaller than that of the sample without PVP. It was thought that the addition of PVP might have the effect of restraining the loss of potassium and that PVP could hold metalloxane by strong hydrogen bonding before complete decomposition. Therefore, the film thickness of the (Na, K) $NbO_3$ films could be considerably advanced and made more crack-free by the addition of PVP.