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Title
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Utilization of chlorine dioxide gas in food packaging application
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Creator
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Netramai, Siriyupa
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Date
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2011
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Collection
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Electronic Theses & Dissertations
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Description
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UTILIZATION OF CHLORINE DIOXIDE GAS IN FOOD PACKAGING APPLICATIONBySiriyupa NetramaiChlorine dioxide (ClO2) in its gaseous form has been utilized in numerous studies for vapor-phase decontamination, both in treating the produces before packaging, and sanitizing the products inside their packages. Yet, very little is known about its compatibilities with packaging materials, as well as its performances as affected by food packaging system.In this study, mass transfer...
Show moreUTILIZATION OF CHLORINE DIOXIDE GAS IN FOOD PACKAGING APPLICATIONBySiriyupa NetramaiChlorine dioxide (ClO2) in its gaseous form has been utilized in numerous studies for vapor-phase decontamination, both in treating the produces before packaging, and sanitizing the products inside their packages. Yet, very little is known about its compatibilities with packaging materials, as well as its performances as affected by food packaging system.In this study, mass transfer profiles (permeability, solubility and diffusion coefficients) of ClO2 for 10 types of polymeric packaging materials were determined by an isostatic method using a continuous system for measuring ClO2 concentration with an electrochemical sensor as a detector. The study showed that PET, PLA, BOPP, nylon, and multilayer of EVA/EVOH/EVA have high ClO2 barrier, while PS, LLDPE, LDPE, HDPE, and PVC have low barrier to ClO2. Effects of gaseous ClO2 on physical, mechanical, chemical, and barrier properties of polymeric packaging materials were also studied by exposing selected materials to ClO2 gas. After 14 days of exposure, significant changes, such as increases in barriers to O2 and CO2 of nylon, changes in permselectivity (PCO2/PO2) ratio of up to 46.8% in treated PE, PS, PET, and nylon films, and changes in FT-IR spectra of PET, PLA, and EVA/EVOH/EVA, indicate possible changes in chemical profiles and performance of the materials. Study on influences of packaging design on sanitizing effect of ClO2 gas, on shredded Romaine lettuce, indicated that minimizing the distance between gas releasing spot and target surfaces, as well as, maximizing gas releasing surface could significantly improve antimicrobial activity of ClO2 gas in particular packaging system. Once the interior of the package was optimized, it was observed that the amount of ClO2 gas used per package could be reduced to half of its original dose, and still achieved the same level of log10 CFU reduction of Escherichia coli O157:H7 in packaged shredded lettuce.Once ClO2 is in contact with food products, it will decontaminate the surfaces, as well as being absorbed by the product. The latter amount could not be accounted for its sanitizing capacity. Study on absorption behaviors of Romaine lettuce showed that increasing ClO2 level and/or time of exposure increased residual ClO2 and chlorite (ClO2-) recovered from lettuce sample. The presence of cuts significantly increased the amount of ClO2 consumed, while exceed water did not increased ClO2 absorption by lettuce.The research approach could be of great importance when considering antimicrobial packaging with ClO2 gas as a safety measure. Information generated could also be used to generate parameter for computational modeling of packaging systems.
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Title
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Characterization of metal organic framework and polymer composites and the method of their preparation
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Creator
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Elangovan, Dhayalan
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Date
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2010
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Collection
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Electronic Theses & Dissertations
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Description
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ABSTRACTCHARACTERIZATION OF METALLIC ORGANIC FRAMEWORK AND POLYLACTIC ACID COMPOSITE AND THE METHOD OF THEIR PREPARATIONByDHAYALAN ELANGOVANThe research in this paper develops biodegradable functional polyester membranes based on poly(lactic acid) (PLA) and metallic organic frameworks (MOFs). PLA without and with the addition of 1, 3, and 5 w/w % MOF was melt compounded in a twin microextruder-compounder. Disc, rectangular and dumb-bell shaped samples were produced and their optical, physical...
Show moreABSTRACTCHARACTERIZATION OF METALLIC ORGANIC FRAMEWORK AND POLYLACTIC ACID COMPOSITE AND THE METHOD OF THEIR PREPARATIONByDHAYALAN ELANGOVANThe research in this paper develops biodegradable functional polyester membranes based on poly(lactic acid) (PLA) and metallic organic frameworks (MOFs). PLA without and with the addition of 1, 3, and 5 w/w % MOF was melt compounded in a twin microextruder-compounder. Disc, rectangular and dumb-bell shaped samples were produced and their optical, physical, thermal, mechanical, thermo-mechanical and barrier properties were evaluated. The PLA and MOF composites showed poor interfacial adhesion between the PLA matrix and the MOF particles, which was previously predicted by using the Hansen's solubility parameters. The FTIR, UV and colorimetric studies showed selective absorption at particular wavelengths due to the presence of the MOF. The DMA results revealed that the heat deflection temperature (HDT), storage modulus, loss modulus and Tan ∆ of the PLA/MOF composites did not change when compared to the PLA samples. However, there was a significant decrease in the brittleness of the PLA/MOF composite as evidenced by an increase of 15% in Izod impact strength and of 170% in elongation at break with respect to the PLA control samples. The permeability of PLA/MOF composite films to oxygen and water did not change when compared to the neat PLA film. However, the sorption capacity of the PLA/MOF composites films increased up to two fold at each relative humidity to which the films were exposed. The sorption and desorption curves of the PLA/MOF composite films showed a hysteresis phenomenon.
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Title
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An exploration of changes in environmental sustainability of packaging, 1971 to 2011
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Creator
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Park, Jonghun
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Date
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2011
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Collection
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Electronic Theses & Dissertations
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Description
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This study investigated trends in environmental sustainability of US consumer packaging from 1971 to 2011, comparing twenty-three "current" packages to twenty-three "old" packages. A Life Cycle Assessment (LCA) methodology, using COMPASS® software was employed. The scope of the LCA in this study includes the manufacturing, the conversion, and the end-of-life phases of the primary packaging. Five life cycle impact indicators were selected in this study: fossil fuel consumption, water...
Show moreThis study investigated trends in environmental sustainability of US consumer packaging from 1971 to 2011, comparing twenty-three "current" packages to twenty-three "old" packages. A Life Cycle Assessment (LCA) methodology, using COMPASS® software was employed. The scope of the LCA in this study includes the manufacturing, the conversion, and the end-of-life phases of the primary packaging. Five life cycle impact indicators were selected in this study: fossil fuel consumption, water consumption, biotic resource consumption, mineral resource consumption, and greenhouse gas (GHG) emissions. The results show that packages produced by companies in the U.S have become more environmentally sustainable over time. If the old and new packages are made from the newer, same materials, the lighter, package had less environmental impacts. When a glass jar was changed to a steel can, PET, and paperboard carton, the alternatives have less environmental impacts than the glass jar. However, when an EPS clamshell and a steel can were changed to a paperboard clamshell and a rigid plastic container each, the old package had less environmental impact than the current alternatives.The main contributor to the impact indicators for most packages was the manufacturing phase, because of the extraction of raw material and production of resins. The exceptions to this were the GHG emissions for paperboard cartons and the water, biotic, and mineral consumption for rigid plastic containers.
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