The Experts below are selected from a list of 81 Experts worldwide ranked by ideXlab platform
Mitsuhiro Ebara - One of the best experts on this subject based on the ideXlab platform.
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towards a rational design of zeolite Polymer Composite Nanofibers for efficient adsorption of creatinine
Journal of Nanomaterials, 2016Co-Authors: Ryo Takai, Rio Kurimoto, Yasuhiro Nakagawa, Yohei Kotsuchibashi, Koki Namekawa, Mitsuhiro EbaraAbstract:This report describes the compositional and structural design strategy of a zeolite-Polymer Composite nanofiber mesh for the efficient removal of uremic toxins towards blood purification application. The nanofiber is fabricated by electrospinning Composite solution of biocompatible poly(ethylene-co-vinyl alcohol) (EVOH) and zeolite particles which are capable of selectively adsorbing uremic toxins such as creatinine. By controlling electrospinning conditions carefully, the incorporated zeolites in EVOH were found to correspond closely to the feed ratios. Elemental mapping images of Si show that zeolites were uniformly blended within the fibers. The fabricated Composite fibers successfully adsorbed creatinine from solution and the adsorption capacity reached a maximum at 12 h. The crystallinity of the nanofiber was also controlled by varying the composition of ethylene content in EVOH. Less crystallinity resulted in higher creatinine adsorption capacity due to the barrier property of EVOH. Cytotoxicity assay demonstrated that the Composite fibers showed less toxicity than free zeolite particles which killed more than 95% of cells. The proposed Composite fibers, therefore, have the potential to be utilized as a new approach to removing creatinine selectively from the bloodstream.
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fabrication of zeolite Polymer Composite Nanofibers for removal of uremic toxins from kidney failure patients
Biomaterials Science, 2014Co-Authors: Koki Namekawa, Makoto Tokoro Schreiber, Takao Aoyagi, Mitsuhiro EbaraAbstract:There is a need to develop a simple, cheap, and accessible method of treating patients with kidney failure, especially in resource-limited environments such as disaster areas and the developing world due to the inaccessibility of conventional hemodialysis treatments. In this study, we develop a zeolite–Polymer Composite nanofiber mesh to remove uremic toxins for blood purification. The nanofiber is composed of blood compatible poly(ethylene-co-vinyl alcohol) (EVOH) as the primary matrix Polymer and zeolites which are capable of selectively adsorbing uremic toxins such as creatinine. The Composite fiber meshes were produced by a cost-effective electrospinning method: electrospinning Composite solutions of EVOH and zeolites. Scanning electron microscope (SEM) images revealed that the 7 w/v% EVOH solution produced non-woven fibers with a continuous and smooth morphology. The SEM also showed that over 90% of zeolites in the solution were successfully incorporated into the EVOH Nanofibers. Although the barrier properties of the EVOH matrix lowered the creatinine adsorption capacity of the zeolites in the fiber when compared with adsorption to free zeolites, their adsorption capacity was still 67% of the free zeolites. The proposed Composite fibers have the potential to be utilized as a new approach to removing nitrogenous waste products from the bloodstream without the requirement of specialized equipment.
Jin Nam - One of the best experts on this subject based on the ideXlab platform.
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Composition-dependent sensing mechanism of electrospun conductive Polymer Composite Nanofibers
Sensors and Actuators B: Chemical, 2015Co-Authors: Karen Low, Christopher B. Horner, Gerardo Ico, Wayne Bosze, Nosang V. Myung, Jin NamAbstract:Abstract Electrospinning provides a means to synthesize nanofibrous structures with very high surface area-to-volume ratio, which enhance the sensitivity of conductive Polymer (CP)-based gas sensors in a cost effective manner. To enhance processability, insulating host Polymers are often used with the CP for electrospinning. Unlike CPs, however, the contribution of insulating Polymers on overall sensing performance of Composites has not been systemically investigated. In this study, we examined the effects of insulating Polymers in electrospun Composite Nanofibers on the sensitivity to various analytes. Different composition ratios of polyaniline (PANI)/poly(ɛ-caprolactone) (PCL) Nanofibers were produced by electrospinning, and their structure and chemistry were characterized. The PANI/PCL electrospun Composite Nanofibers were configured in a chemiresistor and subjected to different analytes, including H2O vapor, NH3, and NO2. H2O vapor and NO2 showed a polarity change in sensitivity, having a compositional threshold of PANI-to-PCL ratio. To investigate this polarity change, the temperature dependence of electrical conductivity was examined. When H2O vapor was exposed to the Composite with the highest PANI content at 20 wt%, there was a decrease in hopping distance; on the other hand, an increase in hopping distance was observed when H2O vapor was exposed to the Composite with the lowest PANI content at 9 wt%. These results show an existence of competition between the conductive Polymer, PANI, and the insulating host Polymer, PCL, for analyte interaction, both of which integratively determine the overall sensitivity. The work demonstrates that the host Polymer plays an important role in structural swelling as well as chemical interaction with analytes, which critically modulate sensing behavior.
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electrospun polyaniline poly ethylene oxide Composite Nanofibers based gas sensor
Electroanalysis, 2014Co-Authors: Nicha Chartuprayoon, Karen Low, Wayne Bosze, Jin Nam, Kyu Hwan Lee, Nosang V. MyungAbstract:Electrospinning as a cost-effective process to synthesize nanofiber with controlled morphology and structure has regained attention in the last decade as result of rapid advancements in nanoscale science and engineering and their applications. Although there are a few works demonstrated the ability to fabricate nano gas sensor using electrospun Nanofibers as sensing materials, there are limited works to show the optimization of the sensing performance by understanding the electron transport properties and their sensing mechanism. The overall objective of this work is to electrospun conducting Polymer/insulating Polymer Composite Nanofibers (i.e., (+)- camphor-10-sulfonic acid (HCSA) doped polyanline PANI (conductive) blended with PEO (non-conductive)) with different compositions (i.e., 12 to 68 wt.%) and apply them as chemiresistive sensing material to detect ammonia at room temperature. The diameter, defects, and morphology of Nanofibers were adjusted by controlling solution composition, processing parameters and their effect toward the sensing performance were also investigated. Viscosity of electrospinning solutions was found to have a pronounced impact on fiber diameter and morphology of PANI/PEO Nanofibers. Diameters around 350nm of different compositions of PANI/PEO Nanofibers were achieved, where decreasing solution viscosity by increasing the PANI content resulted in a morphology changing from individual fibers to junctions. Although all the compositions of PANI/PEO Nanofibers show semiconducting behavior and fit a three dimensional variable hopping range model, the activation energy and hopping distance increased as the PANI content decreased. The PANI/PEO Nanofibers exhibited excellent sensitivity towards NH3 with fast response and recovery times where a low detection limit of 0.5 ppm with the sensitivity of 5.6 %/ppm of NH3 was achieved from 26 wt.% PANI/PEO Nanofibers. Additionally, the PANI/PEO Nanofibers response toward water vapor changed from positive to negative indicating the humidity independent ammonia gas sensor can be fabricated by controlling the composition of PANI/PEO Nanofibers.
Nosang V. Myung - One of the best experts on this subject based on the ideXlab platform.
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Composition-dependent sensing mechanism of electrospun conductive Polymer Composite Nanofibers
Sensors and Actuators B: Chemical, 2015Co-Authors: Karen Low, Christopher B. Horner, Gerardo Ico, Wayne Bosze, Nosang V. Myung, Jin NamAbstract:Abstract Electrospinning provides a means to synthesize nanofibrous structures with very high surface area-to-volume ratio, which enhance the sensitivity of conductive Polymer (CP)-based gas sensors in a cost effective manner. To enhance processability, insulating host Polymers are often used with the CP for electrospinning. Unlike CPs, however, the contribution of insulating Polymers on overall sensing performance of Composites has not been systemically investigated. In this study, we examined the effects of insulating Polymers in electrospun Composite Nanofibers on the sensitivity to various analytes. Different composition ratios of polyaniline (PANI)/poly(ɛ-caprolactone) (PCL) Nanofibers were produced by electrospinning, and their structure and chemistry were characterized. The PANI/PCL electrospun Composite Nanofibers were configured in a chemiresistor and subjected to different analytes, including H2O vapor, NH3, and NO2. H2O vapor and NO2 showed a polarity change in sensitivity, having a compositional threshold of PANI-to-PCL ratio. To investigate this polarity change, the temperature dependence of electrical conductivity was examined. When H2O vapor was exposed to the Composite with the highest PANI content at 20 wt%, there was a decrease in hopping distance; on the other hand, an increase in hopping distance was observed when H2O vapor was exposed to the Composite with the lowest PANI content at 9 wt%. These results show an existence of competition between the conductive Polymer, PANI, and the insulating host Polymer, PCL, for analyte interaction, both of which integratively determine the overall sensitivity. The work demonstrates that the host Polymer plays an important role in structural swelling as well as chemical interaction with analytes, which critically modulate sensing behavior.
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electrospun polyaniline poly ethylene oxide Composite Nanofibers based gas sensor
Electroanalysis, 2014Co-Authors: Nicha Chartuprayoon, Karen Low, Wayne Bosze, Jin Nam, Kyu Hwan Lee, Nosang V. MyungAbstract:Electrospinning as a cost-effective process to synthesize nanofiber with controlled morphology and structure has regained attention in the last decade as result of rapid advancements in nanoscale science and engineering and their applications. Although there are a few works demonstrated the ability to fabricate nano gas sensor using electrospun Nanofibers as sensing materials, there are limited works to show the optimization of the sensing performance by understanding the electron transport properties and their sensing mechanism. The overall objective of this work is to electrospun conducting Polymer/insulating Polymer Composite Nanofibers (i.e., (+)- camphor-10-sulfonic acid (HCSA) doped polyanline PANI (conductive) blended with PEO (non-conductive)) with different compositions (i.e., 12 to 68 wt.%) and apply them as chemiresistive sensing material to detect ammonia at room temperature. The diameter, defects, and morphology of Nanofibers were adjusted by controlling solution composition, processing parameters and their effect toward the sensing performance were also investigated. Viscosity of electrospinning solutions was found to have a pronounced impact on fiber diameter and morphology of PANI/PEO Nanofibers. Diameters around 350nm of different compositions of PANI/PEO Nanofibers were achieved, where decreasing solution viscosity by increasing the PANI content resulted in a morphology changing from individual fibers to junctions. Although all the compositions of PANI/PEO Nanofibers show semiconducting behavior and fit a three dimensional variable hopping range model, the activation energy and hopping distance increased as the PANI content decreased. The PANI/PEO Nanofibers exhibited excellent sensitivity towards NH3 with fast response and recovery times where a low detection limit of 0.5 ppm with the sensitivity of 5.6 %/ppm of NH3 was achieved from 26 wt.% PANI/PEO Nanofibers. Additionally, the PANI/PEO Nanofibers response toward water vapor changed from positive to negative indicating the humidity independent ammonia gas sensor can be fabricated by controlling the composition of PANI/PEO Nanofibers.
Karen Low - One of the best experts on this subject based on the ideXlab platform.
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Composition-dependent sensing mechanism of electrospun conductive Polymer Composite Nanofibers
Sensors and Actuators B: Chemical, 2015Co-Authors: Karen Low, Christopher B. Horner, Gerardo Ico, Wayne Bosze, Nosang V. Myung, Jin NamAbstract:Abstract Electrospinning provides a means to synthesize nanofibrous structures with very high surface area-to-volume ratio, which enhance the sensitivity of conductive Polymer (CP)-based gas sensors in a cost effective manner. To enhance processability, insulating host Polymers are often used with the CP for electrospinning. Unlike CPs, however, the contribution of insulating Polymers on overall sensing performance of Composites has not been systemically investigated. In this study, we examined the effects of insulating Polymers in electrospun Composite Nanofibers on the sensitivity to various analytes. Different composition ratios of polyaniline (PANI)/poly(ɛ-caprolactone) (PCL) Nanofibers were produced by electrospinning, and their structure and chemistry were characterized. The PANI/PCL electrospun Composite Nanofibers were configured in a chemiresistor and subjected to different analytes, including H2O vapor, NH3, and NO2. H2O vapor and NO2 showed a polarity change in sensitivity, having a compositional threshold of PANI-to-PCL ratio. To investigate this polarity change, the temperature dependence of electrical conductivity was examined. When H2O vapor was exposed to the Composite with the highest PANI content at 20 wt%, there was a decrease in hopping distance; on the other hand, an increase in hopping distance was observed when H2O vapor was exposed to the Composite with the lowest PANI content at 9 wt%. These results show an existence of competition between the conductive Polymer, PANI, and the insulating host Polymer, PCL, for analyte interaction, both of which integratively determine the overall sensitivity. The work demonstrates that the host Polymer plays an important role in structural swelling as well as chemical interaction with analytes, which critically modulate sensing behavior.
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electrospun polyaniline poly ethylene oxide Composite Nanofibers based gas sensor
Electroanalysis, 2014Co-Authors: Nicha Chartuprayoon, Karen Low, Wayne Bosze, Jin Nam, Kyu Hwan Lee, Nosang V. MyungAbstract:Electrospinning as a cost-effective process to synthesize nanofiber with controlled morphology and structure has regained attention in the last decade as result of rapid advancements in nanoscale science and engineering and their applications. Although there are a few works demonstrated the ability to fabricate nano gas sensor using electrospun Nanofibers as sensing materials, there are limited works to show the optimization of the sensing performance by understanding the electron transport properties and their sensing mechanism. The overall objective of this work is to electrospun conducting Polymer/insulating Polymer Composite Nanofibers (i.e., (+)- camphor-10-sulfonic acid (HCSA) doped polyanline PANI (conductive) blended with PEO (non-conductive)) with different compositions (i.e., 12 to 68 wt.%) and apply them as chemiresistive sensing material to detect ammonia at room temperature. The diameter, defects, and morphology of Nanofibers were adjusted by controlling solution composition, processing parameters and their effect toward the sensing performance were also investigated. Viscosity of electrospinning solutions was found to have a pronounced impact on fiber diameter and morphology of PANI/PEO Nanofibers. Diameters around 350nm of different compositions of PANI/PEO Nanofibers were achieved, where decreasing solution viscosity by increasing the PANI content resulted in a morphology changing from individual fibers to junctions. Although all the compositions of PANI/PEO Nanofibers show semiconducting behavior and fit a three dimensional variable hopping range model, the activation energy and hopping distance increased as the PANI content decreased. The PANI/PEO Nanofibers exhibited excellent sensitivity towards NH3 with fast response and recovery times where a low detection limit of 0.5 ppm with the sensitivity of 5.6 %/ppm of NH3 was achieved from 26 wt.% PANI/PEO Nanofibers. Additionally, the PANI/PEO Nanofibers response toward water vapor changed from positive to negative indicating the humidity independent ammonia gas sensor can be fabricated by controlling the composition of PANI/PEO Nanofibers.
Koki Namekawa - One of the best experts on this subject based on the ideXlab platform.
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towards a rational design of zeolite Polymer Composite Nanofibers for efficient adsorption of creatinine
Journal of Nanomaterials, 2016Co-Authors: Ryo Takai, Rio Kurimoto, Yasuhiro Nakagawa, Yohei Kotsuchibashi, Koki Namekawa, Mitsuhiro EbaraAbstract:This report describes the compositional and structural design strategy of a zeolite-Polymer Composite nanofiber mesh for the efficient removal of uremic toxins towards blood purification application. The nanofiber is fabricated by electrospinning Composite solution of biocompatible poly(ethylene-co-vinyl alcohol) (EVOH) and zeolite particles which are capable of selectively adsorbing uremic toxins such as creatinine. By controlling electrospinning conditions carefully, the incorporated zeolites in EVOH were found to correspond closely to the feed ratios. Elemental mapping images of Si show that zeolites were uniformly blended within the fibers. The fabricated Composite fibers successfully adsorbed creatinine from solution and the adsorption capacity reached a maximum at 12 h. The crystallinity of the nanofiber was also controlled by varying the composition of ethylene content in EVOH. Less crystallinity resulted in higher creatinine adsorption capacity due to the barrier property of EVOH. Cytotoxicity assay demonstrated that the Composite fibers showed less toxicity than free zeolite particles which killed more than 95% of cells. The proposed Composite fibers, therefore, have the potential to be utilized as a new approach to removing creatinine selectively from the bloodstream.
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fabrication of zeolite Polymer Composite Nanofibers for removal of uremic toxins from kidney failure patients
Biomaterials Science, 2014Co-Authors: Koki Namekawa, Makoto Tokoro Schreiber, Takao Aoyagi, Mitsuhiro EbaraAbstract:There is a need to develop a simple, cheap, and accessible method of treating patients with kidney failure, especially in resource-limited environments such as disaster areas and the developing world due to the inaccessibility of conventional hemodialysis treatments. In this study, we develop a zeolite–Polymer Composite nanofiber mesh to remove uremic toxins for blood purification. The nanofiber is composed of blood compatible poly(ethylene-co-vinyl alcohol) (EVOH) as the primary matrix Polymer and zeolites which are capable of selectively adsorbing uremic toxins such as creatinine. The Composite fiber meshes were produced by a cost-effective electrospinning method: electrospinning Composite solutions of EVOH and zeolites. Scanning electron microscope (SEM) images revealed that the 7 w/v% EVOH solution produced non-woven fibers with a continuous and smooth morphology. The SEM also showed that over 90% of zeolites in the solution were successfully incorporated into the EVOH Nanofibers. Although the barrier properties of the EVOH matrix lowered the creatinine adsorption capacity of the zeolites in the fiber when compared with adsorption to free zeolites, their adsorption capacity was still 67% of the free zeolites. The proposed Composite fibers have the potential to be utilized as a new approach to removing nitrogenous waste products from the bloodstream without the requirement of specialized equipment.