• Title/Summary/Keyword: chlorine dioxide gas

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Preparation and Characterization of ClO2 Self-Releasing Smart Sachet (이산화염소 자체 방출 스마트 샤쉐의 제조 및 특성 연구)

  • Junseok Lee;Hojun Shin;Sadeghi Kambiz;Jongchul Seo
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.29 no.1
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    • pp.1-7
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    • 2023
  • Chlorine dioxide (ClO2) is widely used for post-harvest sterilization treatment. However, there are limitations in the retail application of ClO2 due to difficulties in handling, expensive facilities, and safety concerns. Therefore, it is necessary to develop a ClO2 technology that can be easily applied and continuously released for a long period. In this study, a series of ClO2 self-releasing sachets were developed. First, poly(ether-block-amide) (PEBAX) and polyethylene-glycol (PEG) composite films containing different ratios of citric acid (CA) were prepared using the solution casting method. The as-prepared PEBAX/PEG-CA composite films were evaluated using FT-IR, DSC, and TGA to confirm chemical structure and thermal properties. Subsequently, PEBAX/PEG-CA composite films were designed in the form of a sachet and NaClO2 powder was transferred into the sachet to achieve a ClO2 self-releasing system. The ClO2-releasing behavior of the sachet was investigated by measuring the release amount of the gas using UV-vis. The release amount of ClO2 increased with increasing CA contents owing to the existence of higher protons (trigger) in the polymer matrix. Further, ClO2 gas was released for a longer time. Therefore, the as-prepared smart sachet can be tuned according to applications and packaging sizes to serve an optimal sterilization effect.

Formation of Optical Fiber Preform Using Octamethylcyclotetrasiloxane (Octamethylcyclotetrasiloxane를 이용한 광섬유 클래드 프리폼 형성)

  • Choi, Jinseok;Lee, Tae Kyun;Park, Seong Gyu;Lee, Ga Hyoung;Jun, Gu Sik;An, Sung Jin
    • Korean Journal of Materials Research
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    • v.28 no.1
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    • pp.6-11
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    • 2018
  • There are various manufacturing processes for pure $SiO_2$ that is used as abrasives, chemicals, filters, and glasses, and in metallurgy and optical industries. In the optical fiber industry, to produce $SiO_2$ preform, $SiCl_4$ is utilized as a raw material. However, the combustion reaction of $SiCl_4$ has caused critical environmental issues, such as ozone deficiency by chlorine compounds, the greenhouse effect by carbon dioxide and corrosive gas such as hydrochloric acid. Thus, finding an alternative source that does not have those environmental issues is important for the future. Octamethylcyclotetrasiloxane (OMCTS or D4) as a chlorine free source is recently promising candidate for the $SiO_2$ preform formation. In this study, we first conducted a vaporizer design to vaporize the OMCTS. The vaporizer for the OMCTS vaporization was produced on the basis of the results of the vaporizer design. The size of the primary particle of the $SiO_2$ formed by OMCTS was less than 100 nm. X-ray diffraction patterns of the $SiO_2$ indicated an amorphous phase. Fourier-transform infrared spectroscopy analysis revealed the Si-O-Si bond without the -OH group.

Effects of Combined Chlorine Dioxide Gas Treatment Using Low-Concentration Generating Sticks on the Microbiological Safety and Quality of Paprika during Storage (저농도 서방형 이산화염소 가스 병합처리가 파프리카의 저장 중 미생물 성장과 품질에 미치는 영향)

  • Kang, Ji Hoon;Park, Shin Min;Kim, Hyun Gyu;Son, Hyun Jung;Song, Kyoung Ju;Cho, Miae;Kim, Jong Rak;Lee, Jeong Yong;Song, Kyung Bin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.4
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    • pp.619-624
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    • 2016
  • Chlorine dioxide ($ClO_2$) gas treatment (75 ppmv, 30 min) has been suggested to improve the microbial safety of postharvest paprika in a previous study. Based on these results, in this study, an additional combined treatment using low-concentration $ClO_2$ gas-generating sticks (3 ppmv) in paprika samples during storage was carried out at $8^{\circ}C$ and 90% relative humidity to further enhance the quality and reduce the decay rate of paprika for the purpose of lengthy storage. After the combined treatment, the initial populations of total aerobic bacteria as well as yeast and molds in the paprika samples decreased by 3.04 and 2.70 log CFU/g, respectively, compared with those of the control samples, and this microbial inactivation was maintained by the low-concentration $ClO_2$ gas-generating sticks during storage. In particular, the decay rate of samples with combined treatment was significantly lower than that of the control. Vitamin C content, hardness, and color quality parameters of paprika samples were not altered by treatment, while weight loss of the samples treated with the combined $ClO_2$ gas was lower than that of the control during storage. These results indicate that the combination of two different $ClO_2$ gas treatments is effective for retaining the quality of paprika during prolonged storage.

Chlor-alkali Membrane Process and its Prospects (클로알칼리 멤브레인법과 전망)

  • Park, In Kee;Lee, Chang Hyun
    • Membrane Journal
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    • v.25 no.3
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    • pp.203-215
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    • 2015
  • Chlor-alkali (CA) membrane process is based on salined water electrolysis employing cation condutive polymer electrolytes, which has been used for the conventional production of both sodium hydroxide and chlorine gas. The CA membrane process has advantages such as relatively low environmental impacts and fairly reduced energy consumption, when compared with diaphragm and mercury process. In this review articles, basic concepts, fundamental characteristics, key technologies of CA membrane process are dealt with in detail. In addition, advanced technologies associated with CA membrane process are described. They include zerogap and oxygen depolarized cathode technologies to improve energy efficiency during the electrolysis. Carbon dioxide mineralization technology will also be introduced as an example of hybridization with different technologies. Finally, current market trend in CA membrane process will be presented.

Antimicrobial Effects of Chlorine Dioxide Gas on Pathogenic Escherichia coli and Salmonella spp. Colonizing on Strawberries for Export (수출 딸기 중 이산화염소 가스 처리를 통한 병원성 Escherichia coli와 Salmonella spp. 저감화 효과)

  • Lee, Hyo-Sub;Shim, Won-Bo;An, Hyun Mi;Ha, Ji-Hyoung;Lee, Eun-Seon;Kim, Won-Il;Kim, Hwang-Yong;Kim, Se-Ri
    • Journal of Food Hygiene and Safety
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    • v.31 no.6
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    • pp.451-457
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    • 2016
  • The purpose of this study was to determine the antimicrobial effects of $ClO_2$ gas on pathogenic E. coli and Salmonella spp. colonizing on the fruit surface of strawberries for export. Factorial design was employed to treat strawberries inoculated with pathogenic E. coli or Salmonella spp. with a combination of $ClO_2$ gas concentrations (10, 20, 30, 40, and 50 ppmv), RH (50, 70, and 90%), and treatment time (0, 5, 10, 20, and 30 min). Interaction between the factors was observed to note that the reduced levels of microbial population were the highest when RH is set at 90% with gas concentration- and treatment time-dependent manner. With RH and gas concentration fixed at 90% and 50 ppmv, the populations of E. coli and Salmonella spp. decreased by 2.07 and 2.28 log CFU/g when treated for 20 min whereas population reduction by 0.5 and 0.7 log CFU/g were observed when treated for 5 min, respectively. The results help establish most effective conditions for $ClO_2$ gas treatment to enhance microbial safety of strawberries for export.

Conducted to Verify the Effect of Chlorine Dioxide (ClO2) on Odor Reduction at a Compost Facility (이산화염소 가스분무에 의한 퇴비장 악취저감 효과)

  • Song, J.I.;Jeon, J.H.;Lee, J.Y.;Park, K.H.;Cho, S.B.;Hwang, Y.H.;Kim, D.H.
    • Journal of Animal Environmental Science
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    • v.18 no.sup
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    • pp.1-6
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    • 2012
  • This study was conducted to verify the effect of chlorine dioxide ($ClO_2$) on odor reduction at a commercial swine facility consisting of a compost ficility. Compost facility in $NH_3$ concentration was around 550 ppm and less than 78 ppm before and after the $ClO_2$ spraying, respectively, which was over 86% reduction. There was no H2S detection. $NH_3$ concentration was around 420 ppm and less than 35 ppm before and after the $ClO_2$ spraying, respectively, which was over 83% reduction. $H_2S$ concentration was around 210 ppb and less than 32 ppb before and after the $ClO_2$ spraying, respectively, which was over 85% reduction. Hence, $ClO_2$ spraying at windowless barns was compost facility decreased malodor such as $NH_3$.

Quality Changes in 'Elliot' Blueberries and 'Sulhyang' Strawberries Packed with Two Different Packaging Materials during Refrigerated Storage (기체투과도가 다른 포장재로 포장한 '엘리오트' 블루베리와 '설향' 딸기의 냉장 저장 중 품질 변화)

  • Jung, Seung Hun;Kang, Ji Hoon;Park, Seung Jong;Seong, Ki Hyun;Song, Kyung Bin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.6
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    • pp.901-908
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    • 2014
  • Blueberries and strawberries are highly perishable and easily contaminated with microorganisms. To maintain the quality of these commodities during refrigerated storage, the effects of two packaging materials as well as passive modified atmosphere packaging on the quality of blueberries and strawberries were investigated. The harvested blueberries and strawberries were first treated with combined non-thermal treatment of aqueous chlorine dioxide and fumaric acid, followed by packaging with polyolefin film (6,000 mL $O_2/m^2{\cdot}24hr{\cdot}atm$ at $24^{\circ}C$) and polyamide/polyamide/polyethylene film (PA/PA/PE, 60 mL $O_2/m^2{\cdot}24hr{\cdot}atm$ at $24^{\circ}C$), respectively. After combined sanitizer treatment, the populations of total aerobic bacteria in blueberries and strawberries were reduced by 2.50 and 1.97 log CFU/g while those of yeast and molds were reduced by 1.95 and 2.18 log CFU/g, respectively, compared with the control. In particular, microbial growth in these samples packed with PA/PA/PE film was reduced during refrigerated storage. In addition, the blueberries and strawberries packed with PA/PA/PE film underwent lower weight loss than those packed with polyolefin film during storage. These results suggest that appropriate packaging with proper gas permeability is necessary to maintain the quality of blueberries and strawberries during refrigerated storage.