The Experts below are selected from a list of 2433 Experts worldwide ranked by ideXlab platform
Hak Yong Kim - One of the best experts on this subject based on the ideXlab platform.
-
biocompatible and photoluminescent keratin poly vinyl alcohol carbon quantum dot nanofiber a novel multipurpose Electrospun Mat
Macromolecular Research, 2016Co-Authors: Chohye Lee, Soojin Park, Bishweshwar Pant, Almahmnur Alam, Heajong Chung, Seongtshool Hong, Mira Park, Hak Yong KimAbstract:Carbon quantum dots (C-dots) triggered photoluminescent keratin/poly(vinyl alcohol) (PVA)/C-dots nanofibers (NFs) with optical transparency and biocompatibility were prepared by an electrospinning process. The synthesized NFs were characterized by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy, and spectrofluorometer. C-dots are capable of emitting excitation dependent photoluminescence (PL) emission spectra at room temperature and are nontoxic at reasonably high concentrations. Optically transparent keratin/PVA/C-dots NFs were found to exhibit excitation dependent PL emission at the wavelengths of 488, 535, and 625 nm during excitation at the wavelengths of 360, 480, and 545 nm, respectively, similar to the C-dots. In vitro cytotoxicity tests against NIH-3T3 cell lines revealed a good biocompatible nature of keratin/PVA/C-dots. The results indicated that the fabricated composite NFs Mat not only exhibited a well preserved quantum confinement effect of the C-dots along with its transparency but also showed biocompatibility in the living cell environment.
-
biocompatible and photoluminescent keratin poly vinyl alcohol carbon quantum dot nanofiber a novel multipurpose Electrospun Mat
Macromolecular Research, 2016Co-Authors: Chohye Lee, Soojin Park, Bishweshwar Pant, Almahmnur Alam, Heajong Chung, Seongtshool Hong, Mira Park, Hak Yong KimAbstract:Carbon quantum dots (C-dots) triggered photoluminescent keratin/poly(vinyl alcohol) (PVA)/C-dots nanofibers (NFs) with optical transparency and biocompatibility were prepared by an electrospinning process. The synthesized NFs were characterized by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy, and spectrofluorometer. C-dots are capable of emitting excitation dependent photoluminescence (PL) emission spectra at room temperature and are nontoxic at reasonably high concentrations. Optically transparent keratin/PVA/C-dots NFs were found to exhibit excitation dependent PL emission at the wavelengths of 488, 535, and 625 nm during excitation at the wavelengths of 360, 480, and 545 nm, respectively, similar to the C-dots. In vitro cytotoxicity tests against NIH-3T3 cell lines revealed a good biocompatible nature of keratin/PVA/C-dots. The results indicated that the fabricated composite NFs Mat not only exhibited a well preserved quantum confinement effect of the C-dots along with its transparency but also showed biocompatibility in the living cell environment. Open image in new window
-
neMatic shaped cadmium sulfide doped Electrospun nanofiber Mat highly efficient reusable solar light photocatalyst
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2012Co-Authors: R Afeesh, Salem S Aldeyab, Nasser A M Barakat, Ayman Yousef, Hak Yong KimAbstract:Abstract In this study, novel neMatic shaped CdS-doped poly (vinyl acetate) Electrospun Mat is introduced as a highly efficient and reusable photocatalyst. Preparation of the introduced Mat was achieved by using simple, effective, low cost and high yield technology; electrospinning of the CdS/PVAc colloid. The introduced Mat successfully catalyzes the photodegradation of two models of dyes (methylene blue and methyl red) under the sun light radiation. The photocatalytic activity of the introduced Mats was not affected by multiple reusing. Moreover, the physiochemical characterizations affirmed nonexistence of the CdS nanoparticles (NPs) in the treated waters due to well incorporation of these NPs inside the polymeric nanofibers which also overcomes the photocorrosion problem. Overall, the introduced Mat is highly recommended to be used as low cost, reusable, efficient and healthily safe photocatalyst in the field of water treatment under solar-light irradiation. This solar-light driven reusable CdS doped PVAc hybrid Mat photocatalyst can be easily applied for industrial application, especially in the open water surface.
-
fabrication of highly porous poly ɛ caprolactone fibers for novel tissue scaffold via water bath electrospinning
Colloids and Surfaces B: Biointerfaces, 2011Co-Authors: Hem Raj Pant, Bishweshwar Pant, Madhav Prasad Neupane, Gopal Panthi, Minho Lee, Hak Yong KimAbstract:Highly porous fibers were prepared by water-bath electrospinning from pure poly(ɛ-caprolactone) (PCL), and its blends with methoxy poly(ethylene glycol) (MPEG). These fibers were further analyzed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and gravimetric as well as contact angle measurement. SEM images showed that the fibers diameters as well as pores diameter on the fibers were affected by the weight ratio of MPEG/PCL. DSC and XRD not only revealed suppression of crystallinity of PCL but also indicated the presence of trace amount of MPEG in PCL water-bath collected fibers. The potential use of these hydrophilic porous Electrospun fibrous Mats as scaffolding Materials was evaluated in vitro using mouse osteoblasts (MC3T3-E1) as reference cell lines. Cytotoxicity assessment of the fiber Mats indicated that the porous Electrospun Mat containing trace amount of MPEG was nontoxic to the cell. Cell culture results showed that porous fibrous Mats were good in promoting the cell attachment and proliferation. This novel Electrospun Matrix could be used as potential tissue scaffold Material.
-
biodegradable Electrospun Mat novel block copolymer of poly p dioxanone co l lactide block poly ethylene glycol
Journal of Polymer Science Part B, 2003Co-Authors: Narayan Bhattarai, Myungseob Khil, Dong Il Cha, Shanta Raj Bhattarai, Hak Yong KimAbstract:Ultrafine fibers of a laboratory-synthesized new biodegradable poly(p-diox-anone-co-L-lactide)-block-poly(ethylene glycol) copolymer were Electrospun from solution and collected as a nonwoven Mat. The structure and morphology of the Electrospun membrane were investigated by scanning electron microscopy, differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and a mercury porosimeter. Solutions of the copolymer, ranging in the lactide fraction from 60 to 80 mol % in copolymer composition, were readily Electrospun at room temperature from solutions up to 20 wt % in methylene chloride. We demonstrate the ability to control the fiber diameter of the copolymer as a function of solution concentration with dimethylformamide as a cosolvent. DSC and WAXD results showed the relatively poor crystallinity of the Electrospun copolymer fiber. Electrospun copolymer membrane was applied for the hydrolytic degradation in phosphate buffer solution (pH = 7.5) at 37 °C. Preliminary results of the hydrolytic degradation demonstrated the degradation rate of the Electrospun membrane was slower than that of the corresponding copolymers of cast film.
Gregory C Rutledge - One of the best experts on this subject based on the ideXlab platform.
-
three dimensional imaging of Electrospun fiber Mats using confocal laser scanning microscopy and digital image analysis
Prof. Rutledge via Erja Kajosalo, 2015Co-Authors: Looh Tchuin Choong, Gregory C RutledgeAbstract:Confocal laser scanning microscopy with fluorescent markers and index Matching has been used to collect three-dimensional (3D) digitized images of Electrospun fiber Mats and of a borosilicate glass fiber Material. By embedding the fluorescent dye in either the Material component (fibers) or pore space component (the index-Matching fluid), acquisitions of both positive and negative images of the porous fibrous Materials are demonstrated. Image analysis techniques are then applied to the 3D reconstructions of the fibrous Materials to extract important morphological characteristics such as porosity, specific surface area, distributions of fiber diameter and of pore diameter, and fiber orientation distribution; the results are compared with other experimental measurements where available. The topology of the pore space is quantified for an Electrospun Mat for the first time using the Euler-Poincare characteristic. Finally, a method is presented for subdividing the pore space into a network of cavities and the gates that interconnect them, by which the network structure of the pore space in these Electrospun Mats is determined.
-
effect of fiber diameter pore size and seeding method on growth of human dermal fibroblasts in Electrospun poly ɛ caprolactone fibrous Mats
Biomaterials, 2010Co-Authors: Joseph L Lowery, Neha Datta, Gregory C RutledgeAbstract:Abstract Nonwoven fiber Mats of poly(ɛ-caprolactone) (PCL) and PCL blended with poly(ethylene oxide) (PEO) were generated by electrospinning. Differential scanning calorimetry, scanning electron microscopy, and gravimetric measurement confirm the removal of PEO after immersion in water, as well as an increase in the PCL crystallinity. The reorganization of PCL resulted in the macroscopic alteration of the Electrospun Mat, decreasing the peak pore diameter up to a factor of 3 while only minimally affecting the fiber diameter. This technique was used to create Electrospun PCL scaffolds with similar fiber diameters but different pore diameters to examine the effect of pore diameter on cell growth. Human Dermal Fibroblasts (HDF) were seeded into multiple samples using a perfusion seeding technique to guarantee successful cell deposition. Fluorescence analysis at 7, 14, and 21 days found that cells proliferated at a faster rate on scaffolds with peak pore diameters greater than 6 μm, as determined by mercury porosimetry. Cell conforMation was also found to change as the peak pore diameter grew from 12 to 23 μm; cells began aligning along single fibers instead of attaching to multiple fibers. Knowledge of the effect of void architecture on cell proliferation and conforMation could lead to the development of more effective scaffolds for tissue engineering.
-
effect of fiber diameter pore size and seeding method on growth of human dermal fibroblasts in Electrospun poly epsilon caprolactone fibrous Mats
Biomaterials, 2010Co-Authors: Joseph L Lowery, Neha Datta, Gregory C RutledgeAbstract:Nonwoven fiber Mats of poly(epsilon-caprolactone) (PCL) and PCL blended with poly(ethylene oxide) (PEO) were generated by electrospinning. Differential scanning calorimetry, scanning electron microscopy, and gravimetric measurement confirm the removal of PEO after immersion in water, as well as an increase in the PCL crystallinity. The reorganization of PCL resulted in the macroscopic alteration of the Electrospun Mat, decreasing the peak pore diameter up to a factor of 3 while only minimally affecting the fiber diameter. This technique was used to create Electrospun PCL scaffolds with similar fiber diameters but different pore diameters to examine the effect of pore diameter on cell growth. Human Dermal Fibroblasts (HDF) were seeded into multiple samples using a perfusion seeding technique to guarantee successful cell deposition. Fluorescence analysis at 7, 14, and 21 days found that cells proliferated at a faster rate on scaffolds with peak pore diameters greater than 6 microm, as determined by mercury porosimetry. Cell conforMation was also found to change as the peak pore diameter grew from 12 to 23 microm; cells began aligning along single fibers instead of attaching to multiple fibers. Knowledge of the effect of void architecture on cell proliferation and conforMation could lead to the development of more effective scaffolds for tissue engineering.
-
Electrospun poly styrene block dimethylsiloxane block copolymer fibers exhibiting superhydrophobicity
Langmuir, 2005Co-Authors: M M, Joseph L Lowery, Randal M Hill, Sergey V Fridrikh, Gregory C RutledgeAbstract:Block copolymer poly(styrene-b-dimethylsiloxane) fibers with submicrometer diameters in the range 150-400 nm were produced by electrospinning from solution in tetrahydrofuran and dimethylformamide. Contact angle measurements indicate that the nonwoven fibrous Mats are superhydrophobic, with a contact angle of 163 degrees and contact angle hysteresis of 15 degrees . The superhydrophobicity is attributed to the combined effects of surface enrichment in siloxane as revealed by X-ray photoelectron spectroscopy and surface roughness of the Electrospun Mat itself. Additionally, the fibers are shown by transmission electron microscopy to exhibit microphase-separated internal structures. Calorimetric studies confirm the strong segregation between the polystyrene and poly(dimethylsiloxane) blocks.
-
Electrospun poly styrene block dimethylsiloxane block copolymer fibers exhibiting superhydrophobicity
Langmuir, 2005Co-Authors: Randal M Hill, Joseph L Lowery, Sergey V Fridrikh, Gregory C RutledgeAbstract:Block copolymer poly(styrene-b-dimethylsiloxane) fibers with submicrometer diameters in the range 150−400 nm were produced by electrospinning from solution in tetrahydrofuran and dimethylformamide. Contact angle measurements indicate that the nonwoven fibrous Mats are superhydrophobic, with a contact angle of 163° and contact angle hysteresis of 15°. The superhydrophobicity is attributed to the combined effects of surface enrichment in siloxane as revealed by X-ray photoelectron spectroscopy and surface roughness of the Electrospun Mat itself. Additionally, the fibers are shown by transmission electron microscopy to exhibit microphase-separated internal structures. Calorimetric studies confirm the strong segregation between the polystyrene and poly(dimethylsiloxane) blocks.
Hem Raj Pant - One of the best experts on this subject based on the ideXlab platform.
-
multi layered macroporous three dimensional nanofibrous scaffold via a novel gas foaming technique
Chemical Engineering Journal, 2015Co-Authors: Chan Hee Park, Hem Raj Pant, Mahesh Kumar Joshi, Arjun Prasad Tiwari, Han Joo Kim, Cheol Sang KimAbstract:In the past decade, considerable efforts have been made to fabricate the biomimetic scaffolds from Electrospun nanofibers for tissue engineering applications. However, one of the major concerns with Electrospun nanofibrous scaffolds is the densely packed fibers in two-dimensional (2-D) array which impedes their applicability in tissue regeneration. To overcome this problem, a simple and facile post-electrospinning procedure was developed to modify a densely packed 2-D Electrospun membrane into low density three-dimensional (3-D) scaffolds. In this strategy, an Electrospun nanofibrous Mat was immersed in a sodium borohydride (SB) solution. The interconnected pores of a Mat are filled with the SB solution driven by capillary forces where it undergoes hydrolysis to produce hydrogen gas. The in situ generated gas molecules form clusters to minimize the free energy resulting in pore nucleation that reorganizes the nanofibers to form a low density, macroporous, spongy and multi-layered 3-D scaffold. Electrospun Mats of various polar and non-polar polymers were subjected to post-electrospinning process to monitor the fabrication process. It has been found that the solvent for sodium borohydride (either water or methanol) played a crucial role in post-electrospinning process. Only the Electrospun Mat of polar polymers were amended into 3-D architecture using aqueous SB solution while methanol solution was found equally effective for both polar and non-polar polymers. Moreover, the fabrication process was fast in methanol solution compared to an aqueous solution due to the rapid liberation of hydrogen gas from the methanolysis reaction compared to the hydrolysis reaction. This process will reveal a new approach for the fabrication of a three-dimensional, low-density, nanofibrous Materials for biomedical and industrial applications using a wide variety of polymers.
-
incorporation of silver loaded zno rods into Electrospun nylon 6 spider web like nanofibrous Mat using hydrothermal process
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013Co-Authors: Altangerel Amarjargal, Hem Raj PantAbstract:Abstract Silver-doped zinc oxide rods were incorporated in a nylon-6 Electrospun Mat by a facile hydrothermal process. The rods exhibited excellent characteristics as a durable filter media with good antibacterial properties. ZnO nano-seeds blended with a nylon-6 solution were typically able to form ZnO-NPs-embedded spider-web-like nanonets during electrospinning. The simultaneous crystal growth of Ag NPs and ZnO rods from their precursor solutions on the surface of as-fabricated Electrospun ZnO/nylon-6 fibers was carried out via a hydrothermal process. FE-SEM, TEM, UV–visible spectra, and photoluminescence spectra not only confirmed the forMation of ZnO-nano-seeds-loaded Electrospun nylon-6 composite fibers but also showed that ZnO rods doped with Ag NPs (approxiMately 50 nm in size) were grown on the surface of the nylon-6 composite fibers during hydrothermal treatment. The antibacterial properties of different Mats were tested against Escherichia coli. The as-synthesized Ag-NP-loaded nanocomposite revealed better antibacterial properties than those of composite Mat without Ag NPs. The excellent stability of Ag-loaded ZnO rods (caused by ZnO nano-seeds) on the surface of Electrospun fibers provides a new dimension in the fabrication of inorganic/organic nanocomposite.
-
fabrication of highly porous poly ɛ caprolactone fibers for novel tissue scaffold via water bath electrospinning
Colloids and Surfaces B: Biointerfaces, 2011Co-Authors: Hem Raj Pant, Bishweshwar Pant, Madhav Prasad Neupane, Gopal Panthi, Minho Lee, Hak Yong KimAbstract:Highly porous fibers were prepared by water-bath electrospinning from pure poly(ɛ-caprolactone) (PCL), and its blends with methoxy poly(ethylene glycol) (MPEG). These fibers were further analyzed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and gravimetric as well as contact angle measurement. SEM images showed that the fibers diameters as well as pores diameter on the fibers were affected by the weight ratio of MPEG/PCL. DSC and XRD not only revealed suppression of crystallinity of PCL but also indicated the presence of trace amount of MPEG in PCL water-bath collected fibers. The potential use of these hydrophilic porous Electrospun fibrous Mats as scaffolding Materials was evaluated in vitro using mouse osteoblasts (MC3T3-E1) as reference cell lines. Cytotoxicity assessment of the fiber Mats indicated that the porous Electrospun Mat containing trace amount of MPEG was nontoxic to the cell. Cell culture results showed that porous fibrous Mats were good in promoting the cell attachment and proliferation. This novel Electrospun Matrix could be used as potential tissue scaffold Material.
-
effect of successive electrospinning and the strength of hydrogen bond on the morphology of Electrospun nylon 6 nanofibers
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2010Co-Authors: Hem Raj Pant, Madhab Prasad Bajgai, Chuan Yi, R Nirmala, Wooil BaekAbstract:Abstract We demonstrate for the first time herein that the successive electrospinning can change the fiber morphology in the Electrospun Mat of the polymer at the same electrospinning parameters. Two types of fibers (nano and sub-nano size) arranged in a spider-net like structure were obtained from the single polymer nylon-6 by electrospinning. FE-SEM images of the Mats at different applied voltage showed that this network consisted of thin nanofibers with diameters of about 8–29 nm and thick nanofibers with diameters of about 80–292 nm, arranged in a spider-net like structure. The successive electrospinning sufficiently decreased the diameter of the main nanofibers and hardly change the diameter of the thinner fibers. The study of FT-IR spectra and the conductivity of the different Mats in acidic solution showed that the forMations of spider-net structure were due to the forMation of stronger hydrogen bonds between ionized oligomer/monomer and polymer molecules. The possible mechanism of hydrogen bonds forMation during electrospinning was proposed. These spider-net structures with high aspect ratio were responsible to increase the mechanical strength of nylon-6 Mat.
-
forMation of Electrospun nylon 6 methoxy poly ethylene glycol oligomer spider wave nanofibers
Materials Letters, 2010Co-Authors: Hem Raj Pant, Madhab Prasad Bajgai, Soojin ParkAbstract:A methoxy poly(ethylene glycol) (MPEG) oligomer with a viscous nylon-6 supporting solution was fabricated and polymerized simultaneously to form a nanofiber network structure via electrospinning. This network consisted of thin MPEG nanofibers and thick nylon-6 nanofibers, which were arranged in a spider-web like structure. These two different nanofibers were separated from the Electrospun Mat by extraction of MPEG using water. This result showed that the hybrid nanocomposite Mat consisted of two different interconnecting polymeric nanofibers. We propose that this interconnection is due to the forMation of hydrogen bonds between MPEG and nylon-6 molecules. This spider-web structure formed by electrospinning was responsible for increasing the mechanical strength and the wetability of nylon-6 Mat in the presence of small amounts of MPEG.
Joseph L Lowery - One of the best experts on this subject based on the ideXlab platform.
-
effect of fiber diameter pore size and seeding method on growth of human dermal fibroblasts in Electrospun poly ɛ caprolactone fibrous Mats
Biomaterials, 2010Co-Authors: Joseph L Lowery, Neha Datta, Gregory C RutledgeAbstract:Abstract Nonwoven fiber Mats of poly(ɛ-caprolactone) (PCL) and PCL blended with poly(ethylene oxide) (PEO) were generated by electrospinning. Differential scanning calorimetry, scanning electron microscopy, and gravimetric measurement confirm the removal of PEO after immersion in water, as well as an increase in the PCL crystallinity. The reorganization of PCL resulted in the macroscopic alteration of the Electrospun Mat, decreasing the peak pore diameter up to a factor of 3 while only minimally affecting the fiber diameter. This technique was used to create Electrospun PCL scaffolds with similar fiber diameters but different pore diameters to examine the effect of pore diameter on cell growth. Human Dermal Fibroblasts (HDF) were seeded into multiple samples using a perfusion seeding technique to guarantee successful cell deposition. Fluorescence analysis at 7, 14, and 21 days found that cells proliferated at a faster rate on scaffolds with peak pore diameters greater than 6 μm, as determined by mercury porosimetry. Cell conforMation was also found to change as the peak pore diameter grew from 12 to 23 μm; cells began aligning along single fibers instead of attaching to multiple fibers. Knowledge of the effect of void architecture on cell proliferation and conforMation could lead to the development of more effective scaffolds for tissue engineering.
-
effect of fiber diameter pore size and seeding method on growth of human dermal fibroblasts in Electrospun poly epsilon caprolactone fibrous Mats
Biomaterials, 2010Co-Authors: Joseph L Lowery, Neha Datta, Gregory C RutledgeAbstract:Nonwoven fiber Mats of poly(epsilon-caprolactone) (PCL) and PCL blended with poly(ethylene oxide) (PEO) were generated by electrospinning. Differential scanning calorimetry, scanning electron microscopy, and gravimetric measurement confirm the removal of PEO after immersion in water, as well as an increase in the PCL crystallinity. The reorganization of PCL resulted in the macroscopic alteration of the Electrospun Mat, decreasing the peak pore diameter up to a factor of 3 while only minimally affecting the fiber diameter. This technique was used to create Electrospun PCL scaffolds with similar fiber diameters but different pore diameters to examine the effect of pore diameter on cell growth. Human Dermal Fibroblasts (HDF) were seeded into multiple samples using a perfusion seeding technique to guarantee successful cell deposition. Fluorescence analysis at 7, 14, and 21 days found that cells proliferated at a faster rate on scaffolds with peak pore diameters greater than 6 microm, as determined by mercury porosimetry. Cell conforMation was also found to change as the peak pore diameter grew from 12 to 23 microm; cells began aligning along single fibers instead of attaching to multiple fibers. Knowledge of the effect of void architecture on cell proliferation and conforMation could lead to the development of more effective scaffolds for tissue engineering.
-
Electrospun poly styrene block dimethylsiloxane block copolymer fibers exhibiting superhydrophobicity
Langmuir, 2005Co-Authors: M M, Joseph L Lowery, Randal M Hill, Sergey V Fridrikh, Gregory C RutledgeAbstract:Block copolymer poly(styrene-b-dimethylsiloxane) fibers with submicrometer diameters in the range 150-400 nm were produced by electrospinning from solution in tetrahydrofuran and dimethylformamide. Contact angle measurements indicate that the nonwoven fibrous Mats are superhydrophobic, with a contact angle of 163 degrees and contact angle hysteresis of 15 degrees . The superhydrophobicity is attributed to the combined effects of surface enrichment in siloxane as revealed by X-ray photoelectron spectroscopy and surface roughness of the Electrospun Mat itself. Additionally, the fibers are shown by transmission electron microscopy to exhibit microphase-separated internal structures. Calorimetric studies confirm the strong segregation between the polystyrene and poly(dimethylsiloxane) blocks.
-
Electrospun poly styrene block dimethylsiloxane block copolymer fibers exhibiting superhydrophobicity
Langmuir, 2005Co-Authors: Randal M Hill, Joseph L Lowery, Sergey V Fridrikh, Gregory C RutledgeAbstract:Block copolymer poly(styrene-b-dimethylsiloxane) fibers with submicrometer diameters in the range 150−400 nm were produced by electrospinning from solution in tetrahydrofuran and dimethylformamide. Contact angle measurements indicate that the nonwoven fibrous Mats are superhydrophobic, with a contact angle of 163° and contact angle hysteresis of 15°. The superhydrophobicity is attributed to the combined effects of surface enrichment in siloxane as revealed by X-ray photoelectron spectroscopy and surface roughness of the Electrospun Mat itself. Additionally, the fibers are shown by transmission electron microscopy to exhibit microphase-separated internal structures. Calorimetric studies confirm the strong segregation between the polystyrene and poly(dimethylsiloxane) blocks.
Soojin Park - One of the best experts on this subject based on the ideXlab platform.
-
biocompatible and photoluminescent keratin poly vinyl alcohol carbon quantum dot nanofiber a novel multipurpose Electrospun Mat
Macromolecular Research, 2016Co-Authors: Chohye Lee, Soojin Park, Bishweshwar Pant, Almahmnur Alam, Heajong Chung, Seongtshool Hong, Mira Park, Hak Yong KimAbstract:Carbon quantum dots (C-dots) triggered photoluminescent keratin/poly(vinyl alcohol) (PVA)/C-dots nanofibers (NFs) with optical transparency and biocompatibility were prepared by an electrospinning process. The synthesized NFs were characterized by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy, and spectrofluorometer. C-dots are capable of emitting excitation dependent photoluminescence (PL) emission spectra at room temperature and are nontoxic at reasonably high concentrations. Optically transparent keratin/PVA/C-dots NFs were found to exhibit excitation dependent PL emission at the wavelengths of 488, 535, and 625 nm during excitation at the wavelengths of 360, 480, and 545 nm, respectively, similar to the C-dots. In vitro cytotoxicity tests against NIH-3T3 cell lines revealed a good biocompatible nature of keratin/PVA/C-dots. The results indicated that the fabricated composite NFs Mat not only exhibited a well preserved quantum confinement effect of the C-dots along with its transparency but also showed biocompatibility in the living cell environment.
-
biocompatible and photoluminescent keratin poly vinyl alcohol carbon quantum dot nanofiber a novel multipurpose Electrospun Mat
Macromolecular Research, 2016Co-Authors: Chohye Lee, Soojin Park, Bishweshwar Pant, Almahmnur Alam, Heajong Chung, Seongtshool Hong, Mira Park, Hak Yong KimAbstract:Carbon quantum dots (C-dots) triggered photoluminescent keratin/poly(vinyl alcohol) (PVA)/C-dots nanofibers (NFs) with optical transparency and biocompatibility were prepared by an electrospinning process. The synthesized NFs were characterized by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy, and spectrofluorometer. C-dots are capable of emitting excitation dependent photoluminescence (PL) emission spectra at room temperature and are nontoxic at reasonably high concentrations. Optically transparent keratin/PVA/C-dots NFs were found to exhibit excitation dependent PL emission at the wavelengths of 488, 535, and 625 nm during excitation at the wavelengths of 360, 480, and 545 nm, respectively, similar to the C-dots. In vitro cytotoxicity tests against NIH-3T3 cell lines revealed a good biocompatible nature of keratin/PVA/C-dots. The results indicated that the fabricated composite NFs Mat not only exhibited a well preserved quantum confinement effect of the C-dots along with its transparency but also showed biocompatibility in the living cell environment. Open image in new window
-
forMation of Electrospun nylon 6 methoxy poly ethylene glycol oligomer spider wave nanofibers
Materials Letters, 2010Co-Authors: Hem Raj Pant, Madhab Prasad Bajgai, Soojin ParkAbstract:A methoxy poly(ethylene glycol) (MPEG) oligomer with a viscous nylon-6 supporting solution was fabricated and polymerized simultaneously to form a nanofiber network structure via electrospinning. This network consisted of thin MPEG nanofibers and thick nylon-6 nanofibers, which were arranged in a spider-web like structure. These two different nanofibers were separated from the Electrospun Mat by extraction of MPEG using water. This result showed that the hybrid nanocomposite Mat consisted of two different interconnecting polymeric nanofibers. We propose that this interconnection is due to the forMation of hydrogen bonds between MPEG and nylon-6 molecules. This spider-web structure formed by electrospinning was responsible for increasing the mechanical strength and the wetability of nylon-6 Mat in the presence of small amounts of MPEG.