The Experts below are selected from a list of 25692 Experts worldwide ranked by ideXlab platform
Ick Soo Kim - One of the best experts on this subject based on the ideXlab platform.
-
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.
-
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.
-
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
Dong Wang - One of the best experts on this subject based on the ideXlab platform.
-
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.
-
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.
Sana Ullah - One of the best experts on this subject based on the ideXlab platform.
-
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.
-
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.
Seeram Ramakrishna - One of the best experts on this subject based on the ideXlab platform.
-
morphologically robust nife2o4 Nanofibers as high capacity li ion battery anode material
ACS Applied Materials & Interfaces, 2013Co-Authors: C T Cherian, Seeram Ramakrishna, Jayaraman Sundaramurthy, M V Reddy, Palanisamy Suresh Kumar, Kalaivani Mani, Damian Pliszka, Chorng Haur Sow, B V R ChowdariAbstract:In this work, the electrochemical performance of NiFe2O4 Nanofibers synthesized by an electrospinning approach have been discussed in detail. Lithium storage properties of Nanofibers are evaluated and compared with NiFe2O4 nanoparticles by galvanostatic cycling and cyclic voltammetry studies, both in half-cell configurations. Nanofibers exhibit a higher charge-storage capacity of 1000 mAh g–1 even after 100 cycles with high Coulmbic efficiency of 100 % between 10 and 100 cycles. Ex situ microscopy studies confirmed that cycled Nanofiber electrodes maintained the morphology and remained intact even after 100 charge–discharge cycles. The NiFe2O4 Nanofiber electrode does not experience any structural stress and eventual pulverisation during lithium cycling and hence provides an efficient electron conducting pathway. The excellent electrochemical performance of NiFe2O4 Nanofibers is due to the unique porous morphology of continuous Nanofibers.
-
electrospun inorganic and polymer composite Nanofibers for biomedical applications
Journal of Biomaterials Science-polymer Edition, 2013Co-Authors: R Sridhar, Subramanian Sundarrajan, Jayarama Reddy Venugopal, Rajeswari Ravichandran, Seeram RamakrishnaAbstract:Engineered Nanofibers are generally focused on filtration, solar cells, sensors, smart textile fabrication, tissue engineering, etc. Electrospun Nanofibers have potential advantages in tissue engineering and regenerative medicine, because of the ease in the incorporation of drugs, growth factors, natural materials, and inorganic nanoparticles in to these Nanofiber scaffolds. Electrospun Nanofiber scaffolds composed of synthetic and natural polymers are being explored as scaffolds similar to natural extracellular matrix for tissue engineering. The requirement of the inorganic composites in the Nanofiber scaffolds for favouring hard and soft tissue engineering applications is dealt in detail in the present review. Regarding drug delivery applications of the composite Nanofibers, the review emphasizes on wound healing with silver nanoparticles incorporated Nanofibers, bone tissue engineering, and cancer chemotherapy with titanium and platinum complexes loaded Nanofibers. The review also describes gold nanopa...
-
electrospun p lla cl Nanofiber a biomimetic extracellular matrix for smooth muscle cell and endothelial cell proliferation
Biomaterials, 2004Co-Authors: Masaya Kotaki, Seeram RamakrishnaAbstract:Abstract Poly( l -lactide- co - e -caprolactone) [P(LLA-CL)] with l -lactide to e -caprolactone ratio of 75 to 25 has been electrospun into Nanofibers. The relationship between electrospinning parameters and fiber diameter has been investigated. The fiber diameter decreased with decreasing polymer concentration and with increasing electrospinning voltage. The X-ray diffractometer and differential scanning colorimeter results suggested that the electrospun Nanofibers developed highly oriented structure in CL-unit sequences during the electrospinning process. The biocompatibility of the Nanofiber scaffold has been investigated by culturing cells on the Nanofiber scaffold. Both smooth muscle cell and endothelial cell adhered and proliferated well on the P(LLA-CL) Nanofiber scaffolds.
-
recent advances in polymer Nanofibers
Journal of Nanoscience and Nanotechnology, 2004Co-Authors: Krishnan Jayaraman, Yanzhong Zhang, Masaya Kotaki, Seeram RamakrishnaAbstract:Polymer Nanofibers, with diameters in the nanometer range, possess larger surface areas per unit mass and permit easier addition of surface functionalities compared with polymer microfibers. Hence, polymer Nanofiber mats are being considered for use as filters, scaffolds for tissue engineering, protective clothing, reinforcement in composite materials and sensors. Although some of these applications are in the development stage, a few have been commercially exploited. Research on polymer Nanofibers, Nanofiber mats, and their applications has seen a remarkable growth over the last few years. However, a review of the various issues related to these Nanofibers has not been published. This article presents a review of the recent trends in the processing methods and characterization techniques for polymer Nanofibers. Research challenges and future trends in the processing and characterization of polymer Nanofibers are discussed in the article. Five processing methods have been examined in this review, namely drawing, template synthesis, phase separation, self-assembly, and electrospinning. Among these methods, electrospinning has been used to convert a large variety of polymers into Nanofibers and may be the only process that has the potential for mass production. The structure, morphology, and geometry of Nanofibers and the porosity and tensile properties of Nanofiber mats can be investigated through conventional techniques and instruments. But new techniques are needed for the mechanical testing of single Nanofibers. Although measurement of mechanical properties such as tensile modulus, strength, and elongation is difficult because of the small diameters of the fibers, these properties are crucial for the proper use of Nanofiber mats.
Stephen Z D Cheng - One of the best experts on this subject based on the ideXlab platform.
-
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.
-
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.
