• Title, Summary, Keyword: Polyvinylpyrrolidone (PVP)

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The shelf life of 1,2-indandione/zinc and polyvinylpyrrolidone solutions used to develop latent fingermarks deposited on the surface of thermal paper (감열지에 부착된 잠재지문을 현출하는데 사용하는 1,2-indandione/zinc와 polyvinylpyrrolidone 용액의 보존기한)

  • Hong, Sungwook;Kim, Yujin;Kim, Hyunjung;Kim, Hyerim;Lee, Junchul;Yu, Seoungho
    • Analytical Science and Technology
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    • v.30 no.6
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    • pp.312-318
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    • 2017
  • The shelf life of 1,2-indandione/zinc (1,2-IND/Zn) solution and polyvinylpyrrolidone (PVP) solution, which are known as reagents for developing latent fingermarks deposited on the surface of thermal paper, was studied. The standard latent fingermarks used for comparisons were artificial latent fingermarks printed on thermally sensitive and non-sensitive surfaces with the same intensity. Upon treatment of standard latent fingermarks with the pre-mixed 1,2-IND/Zn and PVP solutions, the fingermarks could be successfully developed until 3 days after the preparation of the mixture. However, from the third day after mixing the reagents, blackening was observed on the surface of the thermal paper, indicating deterioration of the reagent performance. The 1,2-IND/Zn and PVP solutions separately stored without mixing in advance were mixed immediately before use, and the development efficiency of the latent fingermarks deposited on the surface of thermal paper was observed. The performance of the PVP solution decreased after 20 days from the preparation of the reagent. It was also found that the shelf life of 1,2-IND/Zn and PVP mixture was determined by the PVP solution. The effect of oxygen and moisture on the degradation of PVP was investigated. It was found that the performance of the PVP solution deteriorated because of the influence of moisture, though it was not affected by oxygen.

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.

Influence of polyvinylpyrrolidone on rebar corrosion in sulphate solution

  • Gurten, A. Ali;Bayol, Emel;Kayakirilmaz, Kadriye;Erbil, Mehmet
    • Steel and Composite Structures
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    • v.9 no.1
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    • pp.77-87
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    • 2009
  • This paper reports the results of an experimental investigation of the polyvinylpyrrolidone (PVP) influence on the steel reinforcement corrosion and compressive strength of concretes in sulphate medium. The effect of admixture of PVP in concrete on the corrosion resistance of steel reinforced concrete was assessed by measuring electrochemical test during 60 days immersion in two different external solutions. AC impedance spectrum indicated that the resistance of PVP mixed electrodes were higher than those without PVP. The compressive strength of concrete specimens containing PVP was measured and an increase of 19%~24% was observed.

A Study on the Photographic Characteristics and Crystalline Forms about Photographic Emulsion Prepared from Photographic Gelatine with Polyvinylpyrrolidone (사진용(寫眞用) 제라틴과 Polyvinylpyrrolidone으로 제조(製造)된 사진유제(寫眞乳劑)의 할로겐은(銀) 결정(結晶) 및 사진특성(寫眞特性) 연구(硏究))

  • Kang, Tai-Sung
    • Journal of radiological science and technology
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    • v.1 no.1
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    • pp.55-59
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    • 1978
  • The photographic characteristics have been studied in relation with various molecular weights of Polyvinylpyrrolidone(PVP). The shape of silver halogen crystals by physical ripening of mixture of photographic gelatine and various molecular weights of PVP were observed. Then, the photographic characteristics have been studied by chemical ripening. Results were concluded as follows: 1. All of the crystals have formed in the shape of (100) or (111). 2. Photographic characteristics were inferior by using PVP of higher molecular weight. 3. Photographic characteristics were superior by using PVP of lower molecular weight. 4. Photographic characteristic were compared with various Emulsion thickness and Tested Resolving power.

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Effect of Polyvinylpyrrolidone on the Copolymerization of Acrylonitrile and Methylacrylate Initiated by Azobisisobutyronitrile in Dimethylformamide Solution System (Acrylonitrile과 Methylacrylate의 Dimethylformamide(DMF) 용액중합에 있어 Polyvinylpyrrolidone의 영향)

  • Lee, Shin-Hee;Kim, Sung-Hong;Park, Soo-Min
    • Textile Science and Engineering
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    • v.34 no.9
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    • pp.591-597
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    • 1997
  • The mechanism of the solution copolymerization of acrylonitrile and methylacrylate in DMF at 7$0^{\circ}C$ initiated by azobisisobutyronitrile (AIBN) has been investigated in the presence of polyvinylpyrrolidone (PVP) as an additive. Data of fractional conversion of the copolymers, fractional polymerization rate, instantaneous and cumulative composition of the copolymer and instantaneous monomer feed composition as a function of the reaction time or conversion are presented. The monomer reactivity ratio determined by the Finemann-Ross method in the presence and absence of PVP (3 wt%) were $r_1=1.122,\;r_2=0.858\;and\;r_1=0.995,\;r_2=0.744$, respectively. The PVP was found to affect the polymerization rate, conversion, and degree of polymerization of polyacrylonitrile copolymer. The PVP in the polymerization solution was found to increase the initial polymerization rate and limiting conversion. The conversion and degree of polymerization at limiting conversion time increased.

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Properties of a Nanosilver-Silica Composite Synthesized with Different Molecular Weights and Polyvinylpyrrolidone Concentrations (PVP 분자량과 농도 변화에 따른 은-실리카 나노복합체의 특성에 관한 연구)

  • Son, Eun-Jong;Jeong, Sung-Hoon
    • Textile Science and Engineering
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    • v.54 no.5
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    • pp.309-314
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    • 2017
  • Well-dispersed nanosilver particles were synthesized by a chemical reduction method, where silica was treated with amino groups, mercapto groups, and polyvinylpyrrolidone (PVP) as a dispersant. Transmission electron microscopy (TEM) images showed that both the concentration and the molecular weight of PVP considerably affected the size of the silver nanoparticles. The average size of the silver nanoparticles prepared with amino-treated silica increased with increasing PVP concentration, whereas the size of the silver nanoparticles prepared with mercapto-treated silica was not affected by the PVP concentration. As the molecular weight of PVP increased, the average size of the silver nanoparticles also increased. The number of silver particles formed with mercapto-treated silica was larger, and the size distribution was narrower than those formed from aminotreated silica.

Preparation of Polyvinylpyrrolidone/AgBF4/Al(NO3)3 Electrolyte Membranes for Facilitated Gas Transport (기체 촉진수송을 위한 polyvinylpyrrolidone/AgBF4/Al(NO3)3 전해질 분리막 제조)

  • Yoon, Ki Wan;Kang, Sang Wook
    • Membrane Journal
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    • v.26 no.1
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    • pp.38-42
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    • 2016
  • Polyvinylpyrrolidone (PVP), which is glassy polymer to have amide functional group, was induced to fabricate the facilitated olefin transport membranes for olefin/paraffin separation. Separation performance for the mixed gas consisting of propylene and propane (50 : 50 vol%) was measured by gas chromatography and bubble flow meter. The properties of membranes were confirmed by scanning electron microscope and FT-IR. The results of long-term separation tests showed the selectivity of 15 and permeance of 1.3 GPU. The membranes was compared with poly(2-ethyl-2-oxazoline) $(POZ)/AgBF_4/Al(NO_3)_3$ membranes and the characteristics were confirmed as polymer matrix for facilitated transport membranes.

Characteristics of Carbon Nano Fluid Added PVP (PVP가 첨가된 탄소나노유체의 특성에 대한 연구)

  • Seo, Hyang-Min;Park, Sung-Seek;Kim, Nam-Jin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.22 no.5
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    • pp.289-295
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    • 2010
  • In this study, the enhancement of the thermal conductivity of water in the presence of multi-walled carbon nanotubes, MWCNT, was investigated. Sodium Dodecyl Sulfate, SDS, and Polyvinylpyrrolidone, PVP, were employed as the dispersant. SDS or PVP was added in pure water. And then, MWCNT of 0.0005, 0.001, 0.002, 0.003, 0.004, 0.005, 0.01, and 0.02 vol% was dispersed respectively. The thermal conductivity and the viscosity were measured with a transient hot-wire instrument built for this study and the DV II+ Pro viscometer. The results showed that PVP had good thermal conductivity at 300 wt% and this was better than that of SDS 100 wt%, also, the viscosity of nano fluid added PVP rapidly increased until 0.02 vol%.

Influence of Wetting Agents on Physical Properties of Soft Contact Lens (친수성 소프트 콘택트렌즈의 물리적 특성에 미치는 습윤성 재료의 영향)

  • Lee, Min-Jae;Sung, A-Young;Kim, Tae-Hun
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.1
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    • pp.43-49
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    • 2014
  • Purpose: The physical and optical characteristics of hydrophilic contact lens polymerized with addition of glycerin and PVP(polyvinylpyrrolidone) in the basic hydrogel contact lens material were evaluated. Methods: This study used glycerin and PVP(polyvinylpyrrolidone) with the cross-linker EGDMA (ethylene glycol dimethacrylate), HEMA (2-hydroxyethyl methacrylate) and the initiator AIBN (azobisisobutyronitrile) for copolymerization. Results: Measurements of the physical characteristics of the copolymerized material including PVP(polyvinylpyrrolidone) showed the refractive index of 1.4382~1.4288, tensile strength of 0.3446~2542 kgf and water content and contact angle of sample showed the increase of 13.49% and decrease of 21.44% independently. And also, the physical characteristics of the copolymerized material including glycerin showed the refractive index of 1.4330~1.4328, tensile strength of 0.2974~0.2854 kgf, water content 35.58~36.53% and contact angle of sample showed the decrease of 37.64%. Conclusions: Based on the results of this study, the produced copolymers is suitable for conventional lens with high wettability. Also, glycerin minimized the changes of water content and refractive index at the same time, increased the wettability of the hydrogel lens materials.

Effect of Polyvinylpyrrolidone on the Copolymerization of Acrylonitrile and Methylacrylate Initiated by Aqueous Sulfite-Chlorate Redox System (Acrylonitrile과 Methyl acrylate의 수계 Redox 공중합에 있어서 Polyvinylpyrrolidone의 영향)

  • 김홍성;이신희
    • Textile Science and Engineering
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    • v.33 no.3
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    • pp.224-230
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    • 1996
  • The kinetics of copolymerization of acrylonitrile with methyl acrylate initiated by aqueous sulite-chlorate redox system were studied in the presence of polyvinylpyrrolidone (PVP) as an emulsifier. The PVP was found to affect the polymerization rate, conversion, and relative molecular mass of polyacrylonitrile copolymer. The PVP in the polymerization solution was found to increase the polymerization rate particularly by reducing radical induction periods and the polymerization activation energy. A suitable kinetic scheme has been proposed and discussed to account for the experimental data.

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