The Experts below are selected from a list of 960 Experts worldwide ranked by ideXlab platform
Douglas L. Gin - One of the best experts on this subject based on the ideXlab platform.
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crosslinked bicontinuous cubic lyotropic liquid crystal butyl rubber composites highly selective breathable barrier materials for chemical agent protection
Advanced Materials, 2006Co-Authors: Vinh Dinh Nguyen, Xiaohui Zeng, Brian J Elliott, Meijuan Zhou, Jizhu Jin, Douglas L. GinAbstract:Effective personal protection against exposure to toxic chemical agents in vapor form is a major operational safety concern in industry. This concern has also become extremely important in the military and in civilian defense because of the combined threats of chemical warfare and terrorism. One widely used and highly effective Protective Garment material is butyl rubber (BR), i.e., linear poly(methylpropene-co-2methyl-1,3-butadiene), which can be crosslinked to varying degrees via the residual double bonds in the polymer. Crosslinked BR has excellent chemical resistance and very low permeability to most toxic chemical agents in vapor or liquid form. However, one serious drawback of BR is that it also has very low permeability to water vapor and respiratory gases. Under heavy workload and warm temperatures, an individual wearing a BR Protective Garment can easily develop heat stress due to ineffective evaporative cooling. The ideal Protective Garment material should have the ability to selectively block toxic substances while being permeable to water vapor and air (i.e., “breathable”) to avoid discomfort and heat stress. Advanced Protective Garments containing functional entities such as selectively permeable membranes, and reagents and catalytic entities that degrade or neutralize chemical agents have recently been developed. Recently, our research groups demonstrated a new approach to making selectively permeable BR-based materials that permit good water vapor transport as well as a high degree of chemical-agent rejection. This method involves blending and radically copolymerizing BR with a crosslinkable lyotropic liquid crystal (LLC) monomer (1) that self-organizes around H2O to yield domains with ordered, cylindrical aqueous nanopores that are ca. 1.2 nm in diameter (Fig. 1). The LLC nanopores provide small, discrete hydrophilic pathways for water transport through the material. Chemical agents generally have low water solubility at ambient temperature, and are unable to easily dissolve in, or diffuse through, the crosslinked BR domains or the aqueous nanopores. Although the LLC nanopores are too large to selectively block small vapor molecules via size discrimination, they do exhibit large capillary and ionic attraction forces that allow the pores to reC O M M U N IC A TI O N
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cross linked lyotropic liquid crystal butyl rubber composites promising breathable barrier materials for chemical protection applications
Chemistry of Materials, 2005Co-Authors: Jizhu Jin, Brian J Elliott, Vinh Nguyen, Douglas L. GinAbstract:A lyotropic liquid crystal (LLC) monomer was successfully blended and cross-linked with commercial butyl rubber (BR) to afford ordered, nanoporous polymer composites. These materials retain much of the excellent chemical resistance of BR but also provide a measure of water vapor permeability, which is lacking in pure BR materials but essential for Protective Garment applications.
Richard D Noble - One of the best experts on this subject based on the ideXlab platform.
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breathable polydopamine coated nanoporous membranes that selectively reject nerve and blister agent simulant vapors
Industrial & Engineering Chemistry Research, 2019Co-Authors: Gregory E Dwulet, Andrew J Basalla, John J Malecha, Sarah M Dischinger, Michael J Mcgrath, Richard D NobleAbstract:A laminated thin-film composite (TFC) membrane system consisting of an ultrafiltration support, an ordered, nanoporous, polymerized lyotropic liquid crystal (LLC) intermediate layer, and an ultrathin, dense polydopamine top layer was developed for use as a “breathable” chemical-Protective Garment material. These membranes exhibit a high water vapor transport rate (ca. 500 g m–2 day–1) and excellent rejection of both CEES (a blister agent simulant) and DMMP (a nerve agent simulant) vapors under ambient conditions. The (water:CEES) and (water:DMMP) molar vapor selectivity values of this new composite membrane system were found to be 170 ± 40 and >3400, respectively, which exceed those of any previously reported LLC-based membrane system.
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breathable polydopamine coated nanoporous membranes that selectively reject nerve and blister agent simulant vapors
Industrial & Engineering Chemistry Research, 2019Co-Authors: Gregory E Dwulet, Andrew J Basalla, John J Malecha, Sarah M Dischinger, Michael J Mcgrath, Richard D NobleAbstract:A laminated thin-film composite (TFC) membrane system consisting of an ultrafiltration support, an ordered, nanoporous, polymerized lyotropic liquid crystal (LLC) intermediate layer, and an ultrathin, dense polydopamine top layer was developed for use as a “breathable” chemical-Protective Garment material. These membranes exhibit a high water vapor transport rate (ca. 500 g m–2 day–1) and excellent rejection of both CEES (a blister agent simulant) and DMMP (a nerve agent simulant) vapors under ambient conditions. The (water:CEES) and (water:DMMP) molar vapor selectivity values of this new composite membrane system were found to be 170 ± 40 and >3400, respectively, which exceed those of any previously reported LLC-based membrane system.
Gregory E Dwulet - One of the best experts on this subject based on the ideXlab platform.
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breathable polydopamine coated nanoporous membranes that selectively reject nerve and blister agent simulant vapors
Industrial & Engineering Chemistry Research, 2019Co-Authors: Gregory E Dwulet, Andrew J Basalla, John J Malecha, Sarah M Dischinger, Michael J Mcgrath, Richard D NobleAbstract:A laminated thin-film composite (TFC) membrane system consisting of an ultrafiltration support, an ordered, nanoporous, polymerized lyotropic liquid crystal (LLC) intermediate layer, and an ultrathin, dense polydopamine top layer was developed for use as a “breathable” chemical-Protective Garment material. These membranes exhibit a high water vapor transport rate (ca. 500 g m–2 day–1) and excellent rejection of both CEES (a blister agent simulant) and DMMP (a nerve agent simulant) vapors under ambient conditions. The (water:CEES) and (water:DMMP) molar vapor selectivity values of this new composite membrane system were found to be 170 ± 40 and >3400, respectively, which exceed those of any previously reported LLC-based membrane system.
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breathable polydopamine coated nanoporous membranes that selectively reject nerve and blister agent simulant vapors
Industrial & Engineering Chemistry Research, 2019Co-Authors: Gregory E Dwulet, Andrew J Basalla, John J Malecha, Sarah M Dischinger, Michael J Mcgrath, Richard D NobleAbstract:A laminated thin-film composite (TFC) membrane system consisting of an ultrafiltration support, an ordered, nanoporous, polymerized lyotropic liquid crystal (LLC) intermediate layer, and an ultrathin, dense polydopamine top layer was developed for use as a “breathable” chemical-Protective Garment material. These membranes exhibit a high water vapor transport rate (ca. 500 g m–2 day–1) and excellent rejection of both CEES (a blister agent simulant) and DMMP (a nerve agent simulant) vapors under ambient conditions. The (water:CEES) and (water:DMMP) molar vapor selectivity values of this new composite membrane system were found to be 170 ± 40 and >3400, respectively, which exceed those of any previously reported LLC-based membrane system.
Jizhu Jin - One of the best experts on this subject based on the ideXlab platform.
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crosslinked bicontinuous cubic lyotropic liquid crystal butyl rubber composites highly selective breathable barrier materials for chemical agent protection
Advanced Materials, 2006Co-Authors: Vinh Dinh Nguyen, Xiaohui Zeng, Brian J Elliott, Meijuan Zhou, Jizhu Jin, Douglas L. GinAbstract:Effective personal protection against exposure to toxic chemical agents in vapor form is a major operational safety concern in industry. This concern has also become extremely important in the military and in civilian defense because of the combined threats of chemical warfare and terrorism. One widely used and highly effective Protective Garment material is butyl rubber (BR), i.e., linear poly(methylpropene-co-2methyl-1,3-butadiene), which can be crosslinked to varying degrees via the residual double bonds in the polymer. Crosslinked BR has excellent chemical resistance and very low permeability to most toxic chemical agents in vapor or liquid form. However, one serious drawback of BR is that it also has very low permeability to water vapor and respiratory gases. Under heavy workload and warm temperatures, an individual wearing a BR Protective Garment can easily develop heat stress due to ineffective evaporative cooling. The ideal Protective Garment material should have the ability to selectively block toxic substances while being permeable to water vapor and air (i.e., “breathable”) to avoid discomfort and heat stress. Advanced Protective Garments containing functional entities such as selectively permeable membranes, and reagents and catalytic entities that degrade or neutralize chemical agents have recently been developed. Recently, our research groups demonstrated a new approach to making selectively permeable BR-based materials that permit good water vapor transport as well as a high degree of chemical-agent rejection. This method involves blending and radically copolymerizing BR with a crosslinkable lyotropic liquid crystal (LLC) monomer (1) that self-organizes around H2O to yield domains with ordered, cylindrical aqueous nanopores that are ca. 1.2 nm in diameter (Fig. 1). The LLC nanopores provide small, discrete hydrophilic pathways for water transport through the material. Chemical agents generally have low water solubility at ambient temperature, and are unable to easily dissolve in, or diffuse through, the crosslinked BR domains or the aqueous nanopores. Although the LLC nanopores are too large to selectively block small vapor molecules via size discrimination, they do exhibit large capillary and ionic attraction forces that allow the pores to reC O M M U N IC A TI O N
-
cross linked lyotropic liquid crystal butyl rubber composites promising breathable barrier materials for chemical protection applications
Chemistry of Materials, 2005Co-Authors: Jizhu Jin, Brian J Elliott, Vinh Nguyen, Douglas L. GinAbstract:A lyotropic liquid crystal (LLC) monomer was successfully blended and cross-linked with commercial butyl rubber (BR) to afford ordered, nanoporous polymer composites. These materials retain much of the excellent chemical resistance of BR but also provide a measure of water vapor permeability, which is lacking in pure BR materials but essential for Protective Garment applications.
Reed W. Hoyt - One of the best experts on this subject based on the ideXlab platform.
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applications of real time thermoregulatory models to occupational heat stress validation with military and civilian field studies
Journal of Strength and Conditioning Research, 2012Co-Authors: Miyo Yokota, Anthony J. Karis, William Santee, Larry G. Berglund, Mark J. Buller, Warren S Roberts, John S Cuddy, Brent C Ruby, Reed W. HoytAbstract:A real-time thermoregulatory model using non-invasive measurements as inputs was developed for predicting physiological responses of individuals working long hours. The purpose of the model is to reduce heat related injuries and illness by predicting the physiological effects of thermal stress on individuals while working. The model (Comput Biol Med 38: 1187-1193. 2008) was originally validated mainly by using data from controlled laboratory studies. The present study expands the validation of the model with field data from 26 test volunteers, including US Marines, Australian soldiers, and US wildland fire fighters (WLFF). These data encompass a range of environmental conditions (air temperature: 19°C - 30°C; relative humidity: 25% - 63%) and clothing (i.e., battle dress uniform, chemical-biological Protective Garment, WLFF Protective gear), while performing diverse activities (e.g., marksmanship, marching, extinguishing fires, and digging). The predicted core temperatures (Tc), calculated using environmental, anthropometric, clothing, and heart rate measures collected in the field as model inputs, were compared with subjects' Tc collected with ingested telemetry temperature pills. Root mean square deviation (RMSD) values, used for goodness of fit comparisons, indicated that overall, the model predictions were in close agreement with the measured values (grand mean of RMSD: 0.15°C - 0.38°C). Although the field data showed more individual variability in the physiological data relative to more controlled laboratory studies, this study showed that the performance of the model was adequate. Language: en
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Applications of real-time thermoregulatory models to occupational heat stress: validation with military and civilian field studies.
Journal of strength and conditioning research, 2012Co-Authors: Miyo Yokota, Anthony J. Karis, William Santee, Larry G. Berglund, Mark J. Buller, Warren S Roberts, John S Cuddy, Brent C Ruby, Reed W. HoytAbstract:A real-time thermoregulatory model using noninvasive measurements as inputs was developed for predicting physiological responses of individuals working long hours. The purpose of the model is to reduce heat-related injuries and illness by predicting the physiological effects of thermal stress on individuals while working. The model was originally validated mainly by using data from controlled laboratory studies. This study expands the validation of the model with field data from 26 test volunteers, including US Marines, Australian soldiers, and US wildland fire fighters (WLFF). These data encompass a range of environmental conditions (air temperature: 19-30° C; relative humidity: 25-63%) and clothing (i.e., battle dress uniform, chemical-biological Protective Garment, WLFF Protective gear), while performing diverse activities (e.g., marksmanship, marching, extinguishing fires, and digging). The predicted core temperatures (Tc), calculated using environmental, anthropometric, clothing, and heart rate measures collected in the field as model inputs, were compared with subjects' Tc collected with ingested telemetry temperature pills. Root mean standard deviation (RMSD) values, used for goodness of fit comparisons, indicated that overall, the model predictions were in close agreement with the measured values (grand mean of RMSD: 0.15-0.38° C). Although the field data showed more individual variability in the physiological data relative to more controlled laboratory studies, this study showed that the performance of the model was adequate.
