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Ick Soo Kim - One of the best experts on this subject based on the ideXlab platform.
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Antibacterial properties of in situ and surface functionalized impregnation of silver sulfadiazine in polyacrylonitrile nanofiber mats.
International journal of nanomedicine, 2019Co-Authors: Sana Ullah, Motahira Hashmi, Davood Kharaghani, Muhammad Qamar Khan, Yusuke Saito, Takayuki Yamamoto, Jung-soon Lee, Ick Soo KimAbstract:Background Silver, incorporation with natural or synthetic polymers, has been used as an effective antibacterial agent since decades. Silver has potential applications in healthcare especially in nanoparticles form but silver sulfadiazine (AgSD) is the most efficient antibacterial agent especially for burn wound dressings. Method In this report, mechanical, structural, and antibacterial properties of PAN Nanofibers incorporation with silver sulfadiazine are mainly focused. AgSD was loaded for the first time on electrospinning as well as self-synthesized AgSD on PAN Nanofibers by solution immersion method and then compared the results of both. Results Occurrence of chemical reaction among the functional groups of AgSD and PAN were analyzed using FTIR, for both types of specimen. Morphological and surface properties of prepared nanofiber mats were characterized by scanning electron microscope, and it resulted in uniform Nanofibers without bead formation. Diameter of Nanofibers was slightly increased with addition of AgSD by in situ and immersion methods respectively. Nanoparticles distribution was analyzed by transmission electron microscopy. Thermal properties were analyzed by thermo-gravimetric analyzer and it was observed that AgSD decreased thermal stability of PAN which is better from biomedical perspective. X-ray diffraction declared crystalline structure of nanofiber mats. Presence of Ag and S contents in nanofiber mats was analyzed by X-ray photo spectroscopy. Antibacterial properties of nanofiber mats were investigated by disc diffusion method was carried out. E. coli and Bacillus bacteria strain were used as gram-negative and gram-positive respectively. Zone inhibition of the bacteria was used as a tool to determine effectiveness of AgSD released from PAN nanofiber mats. The antibacterial properties of PAN Nanofibers impregnated with AgSD were determined with both types of bacteria strains to compare with control one. Conclusion On the basis of characterization results it is concluded that PAN/AgSD (immersion) nanofiber mats have better structural and antibacterial properties than that of PAN/AgSD (in situ) nanofiber mats. So, from our point of view, self-synthesized AgSD is recommended for further production of nanofiber mats for antibacterial applications.
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Silver sulfadiazine loaded zein nanofiber mats as a novel wound dressing
RSC Advances, 2019Co-Authors: Sana Ullah, Motahira Hashmi, Davood Kharaghani, Muhammad Qamar Khan, Takayuki Yamamoto, Yuseke Saito, Ick Soo KimAbstract:In this report a novel antibacterial wound dressing was prepared and then characterized for required testing. We loaded silver sulfadiazine (AgSD) for the first time by electrospinning. AgSD was added in zein (0.3%, 0.4%, 0.5%, and 0.6% by weight) and was electrospun to fabricate nanofiber mats for wound dressings. Nanofiber mats were characterized by Fourier transform infrared spectroscopy (FTIR) to check if there was any chemical reaction between AgSD and zein. Morphological properties were analyzed by Scanning Electron Microscopy (SEM), which showed uniform Nanofibers without any bead formation. The diameter of the Nanofibers gradually decreased with an increase in the amount of AgSD, which can be associated with strong physical bonding between zein and AgSD. Thermal properties of nanofiber mats were analyzed by Thermogravimetric Analysis (TGA). X-Ray Diffraction (XRD) further demonstrated the crystalline structure of the nanofiber mats, and X-ray Photoelectron spectroscopy (XPS) was performed to confirm Ag and S contents in the prepared wound dressings. In order to investigate antibacterial properties, a disc diffusion method was employed. Bacillus and E. coli bacteria strains were used as Gram-positive and Gram-negative strains respectively. The antibacterial effectiveness of AgSD released from zein Nanofibers was determined from the zone inhibition of the bacteria. The antibacterial activity of zein Nanofibers loaded with drug was observed with both strains of bacteria in comparison to a control. Excellent antibacterial efficacy was attributed to the sample with 0.6% AgSD. Excellent release properties were also associated with the sample with 0.6% AgSD in zein Nanofibers. Keeping in mind the abovementioned characteristics, prepared nanofiber mats would be effective for application in wound dressings.
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Fabrication of Two Polyester Nanofiber Types Containing the Biobased Monomer Isosorbide: Poly (Ethylene Glycol 1,4-Cyclohexane Dimethylene Isosorbide Terephthalate) and Poly (1,4-Cyclohexane Dimethylene Isosorbide Terephthalate)
MDPI AG, 2018Co-Authors: Duy-nam Phan, Hoik Lee, Dongeun Choi, Chang-yong Kang, Ick Soo KimAbstract:The thermal and mechanical properties of two types of polyester nanofiber, poly (1,4-cyclohexanedimethylene isosorbide terephthalate) (PICT) copolymers and the terpolyester of isosorbide, ethylene glycol, 1,4-cyclohexane dimethanol, and terephthalic acid (PEICT), were investigated. This is the first attempt to fabricate PICT nanofiber via the electrospinning method; comparison with PEICT nanofiber could give greater understanding of eco-friendly Nanofibers containing biomass monomers. The Nanofibers fabricated from each polymer show similar smooth and thin-and-long morphologies. On the other hand, the polymers exhibited significantly different mechanical and thermal properties; in particular, a higher tensile strength was observed for PICT nanofiber mat than for that of PEICT. We hypothesized that PICT has more trans-configuration than PEICT, resulting in enhancement of its tensile strength, and demonstrated this by Fourier transform infrared spectroscopy. In addition, PICT Nanofibers showed clear crystallization behavior upon increased temperature, while PEICT Nanofibers showed completely amorphous structure. Both Nanofibers have better tensile properties and thermal stability than the typical polyester polymer, implying that they can be utilized in various industrial applications
Stephen Z D Cheng - One of the best experts on this subject based on the ideXlab platform.
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advanced single polymer nanofiber reinforced composite towards next generation ultralight superstrong tough structural material
2015Co-Authors: Yuris A Dzenis, Stephen Z D Cheng, Frank W HarrisAbstract:Abstract : The goals of this research were to establish feasibility of manufacturing and to evaluate performance of novel continuous polyimide Nanofibers and their nanocomposites. The specific objectives were: (1) demonstrate feasibility of fabrication of continuous Nanofibers from a range of specially synthesized soluble polyimides; (2) characterize their mechanical behavior and properties; and (3) fabricate and characterize polyimide nanofiber-reinforced composites. Continuous Nanofibers were successfully manufactured from several specially designed polyimides and tested in the broad range of diameters. Significant simultaneous improvements in strength and toughness with the reduction of diameter were observed and analyzed. The best Nanofibers were as strong as advanced conventional fibers while maintaining higher toughness. It was shown that chemical structure and processing control nanofiber properties and toughness. Polyimide Nanofibers were also successfully incorporated into nanocomposites. It was demonstrated that continuous Nanofibers may provide unique advantages for future structural nanocomposites.
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electrospun polyacrylonitrile Nanofibers containing a high concentration of well aligned multiwall carbon nanotubes
Chemistry of Materials, 2005Co-Authors: Haoqing Hou, Jun Zeng, Darrell H Reneker, And Andreas Greiner, Stephen Z D ChengAbstract:Composite nanofiber sheets of well-aligned polyacrylonitrile Nanofibers (PAN) containing multiwall carbon nanotubes (MWCNTs) were prepared by electrospinning a MWCNT-suspended solution of PAN in dimethyl formamide using a moving collector. Scanning electron microscopy, atomic force microscopy, transmission electron microscopy (TEM), IR spectroscopy, Raman spectroscopy, X-ray scattering, and the Instron test were used to characterize the nanofiber sheets. TEM observation showed the MWCNTs were parallel and oriented along the axes of the Nanofibers. The mechanical properties of the composite Nanofibers were reinforced by MWCNT fillers. Carbonization processes showed that a higher concentration of MWCNTs effectively resisted heat shrinkage of the composite nanofiber sheet.
Dong Wang - One of the best experts on this subject based on the ideXlab platform.
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polypyrrole poly vinyl alcohol co ethylene nanofiber composites on polyethylene terephthalate substrate as flexible electric heating elements
Composites Part A-applied Science and Manufacturing, 2016Co-Authors: Yuedan Wang, Haiqing Jiang, Mufang Li, Wenwen Wang, Dong WangAbstract:Abstract Polypyrrole/poly(vinyl alcohol- co -ethylene) (PPy/PVA- co -PE) nanofiber composites on polyethylene terephthalate (PET) substrates were prepared using spray coating technique and in situ polymerization process. The electric heating behaviors of composites were investigated as functions of the amounts of nanofiber and PPy. It was observed that, the electrical resistivity of composites decreased significantly with increasing nanofiber and PPy contents. Scanning electron microscope images and infrared spectrum studies confirmed the formation of well dispersed network-like structure of PPy/PVA- co -PE Nanofibers on PET substrate. Furthermore, maximum temperature attained at a given applied voltage for the composites could be well controlled by changing Nanofibers and PPy amounts. PPy/PVA- co -PE nanofiber/PET composites exhibited excellent electric heating performance in aspects of rapid temperature response, long retaining behavior, thermal and operational stability. The incorporation of PPy on PVA- co -PE Nanofibers/PET nonwoven substrates resulted in high conductivity and enhanced heating behavior, which have potential to be used as efficient electric heating elements.
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a novel high flux poly trimethylene terephthalate nanofiber membrane for microfiltration media
Separation and Purification Technology, 2013Co-Authors: Dong Wang, Ru Xiao, Gang Sun, Qinghua ZhaoAbstract:Abstract A novel high flux poly(trimethylene terephthalate) (PTT) nanofiber membrane for microfiltration media was prepared and characterized in this study. The PTT Nanofibers for the membrane preparation were fabricated based on a high throughput, cost effective and environmental friendly method developed by us. The PTT nanofiber membranes were then prepared by a wet-laid process. To enhance the mechanical properties of fabricated PTT nanofiber membrane, two strategies were employed. The structures of PTT nanofiber membrane were compacted by making PTT Nanofibers shrink together under heat. The other one is to facilitate the formation of locally physical cross-linking points by blending PP Nanofibers having lower softening points into PTT nanofiber membranes and the following heat-treatment. The properties of the original nanofiber membrane and two modified nanofiber membranes, including morphology, apparent density, porosity, contact-angle, pore size distribution, water flux and filtration efficiency, were thoroughly investigated. The rejection rates of the prepared nanofiber membranes to TiO 2 suspensions with the average diameter of 100 nm were above 99.6%. The results indicated that the PTT nanofiber membranes prepared by this novel method have great potential for the application of high flux microfiltration media.
Kourosh Kalantarzadeh - One of the best experts on this subject based on the ideXlab platform.
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polyaniline nanofiber based surface acoustic wave gas sensors effect of nanofiber diameter on hbox h _ 2 response
IEEE Sensors Journal, 2007Co-Authors: A Z Sadek, Wojtek Wlodarski, Christina O Baker, David A Powell, Richard B Kaner, Kourosh KalantarzadehAbstract:A template-free rapidly mixed reaction was employed to synthesize polyaniline Nanofibers using chemical oxidative polymerization of aniline. Hydrochloric acid (HCl) and camphor sulfonic acid (CSA) were used in the synthesis to obtain 30- and 50-nm average diameter polyaniline Nanofibers. The Nanofibers were deposited onto layered ZnO/64deg YX LiNbO3 surface-acoustic-wave transducers. The sensors were tested toward hydrogen (H2) gas while operating at room temperature. The dopant for the polyaniline nanofiber synthesis was found to have a significant effect on the device sensitivity. The sensor response was found to be larger for the 50-nm diameter CSA-doped nanofiber based sensors, while the response and recovery times were faster for the 30-nm diameter HCl-doped Nanofibers
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polyaniline nanofiber based surface acoustic wave gas sensors effect of nanofiber diameter on h 2 response escholarship
2007Co-Authors: A Z Sadek, Christina O Baker, David A Powell, Richard B Kaner, Kourosh KalantarzadehAbstract:A template-free rapidly mixed reaction was employed to synthesize polyaniline Nanofibers using chemical oxidative polymerization of aniline. Hydrochloric acid (HCl) and camphor sulfonic acid (CSA) were used in the synthesis to obtain 30- and 50-nm average diameter polyaniline Nanofibers. The Nanofibers were deposited onto layered ZnO/64 degrees YX LiNbO3 surface-acoustic-wave transducers. The sensors were tested toward hydrogen (H-2) gas while operating at room temperature. The dopant for the polyaniline nanofiber synthesis was found to have a significant effect on the device sensitivity. The sensor response was found to be larger for the 50-nmdiameter CSA-doped nanofiber based sensors, while the response and recovery times were faster for the 30-nm diameter HCl-doped Nanofibers.
Hiroyuki Saimoto - One of the best experts on this subject based on the ideXlab platform.
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preparation of high strength transparent chitosan film reinforced with surface deacetylated chitin Nanofibers
Carbohydrate Polymers, 2013Co-Authors: Shinsuke Ifuku, Akiko Ikuta, Mayumi Egusa, Hironori Kaminaka, Hironori Izawa, Minoru Morimoto, Hiroyuki SaimotoAbstract:Abstract Surface-deacetylated chitin nanofiber reinforced chitosan films were prepared. The nano-composite films were highly transparent of approximately 84% at 600 nm due to the nanometer-sized fillers and chitosan matrix, which were embedded in the cavities and on the rough surface of the nanofiber networks. Due to the extended crystalline structure, the Nanofibers worked effectively as reinforcement filler to improve the Young's modulus and the tensile strength of the chitosan film. After 10% blending of nanofiber, these properties were increased by 65% and 94%, respectively. Moreover, thermal expansion was also significantly decreased from 35.3 to 26.1 ppm K −1 after 10% addition of Nanofibers. Surface-deacetylated chitin nanofiber and the nano-composite films showed antifungal activity against A. alternata .
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chitin Nanofibers preparations modifications and applications
Nanoscale, 2012Co-Authors: Shinsuke Ifuku, Hiroyuki SaimotoAbstract:Chitin Nanofibers are prepared from the exoskeletons of crabs and prawns by a simple mechanical treatment after the removal of proteins and minerals. The obtained Nanofibers have fine nanofiber networks with a uniform width of approximately 10–20 nm and a high aspect ratio. The method used for chitin-nanofiber isolation is also successfully applied to the cell walls of mushrooms. They form a complex with glucans on the fiber surface. A grinder, a Star Burst atomization system, and a high speed blender are all used in the mechanical treatment to convert chitin to Nanofibers. Mechanical treatment under acidic conditions is the key to facilitate fibrillation. At pH 3–4, the cationization of amino groups on the fiber surface assists nano-fibrillation by electrostatic repulsive force. By applying this finding, we also prepared chitin Nanofibers from dry chitin powder. Chitin Nanofibers are acetylated to modify their surfaces. The acetyl DS can be controlled from 1 to 3 by changing the reaction time. An acetyl group is introduced heterogeneously from the surface to the core. Nanofiber morphology is maintained even in the case of high acetyl DS. Optically transparent chitin nanofiber composites are prepared with 11 different types of acrylic resins. Due to the nano-sized structure, all of the composites are highly transparent. Chitin Nanofibers significantly increase the Young's moduli and the tensile strengths and decrease the thermal expansion of all acrylic resins due to the reinforcement effect of chitin Nanofibers. Chitin Nanofibers show chiral separation ability. The chitin nanofiber membrane transports the D-isomer of glutamic acid, phenylalanine, and lysine from the corresponding racemic amino acid mixtures faster than the corresponding L-isomer. The chitin Nanofibers improve clinical symptoms and suppress ulcerative colitis in a DSS-induced mouse model of acute ulcerative colitis. Moreover, chitin Nanofibers suppress myeloperoxidase activation in the colon and decrease serum interleukin-6 concentrations.
