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Xia Wang - One of the best experts on this subject based on the ideXlab platform.
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Borneol-Shellac Nanofiber Membranes Fabricated Using a Modified Coaxial Electrospinning
Advanced Materials Research, 2014Co-Authors: Song Liu, Yu Hai Wang, Xiao Duan, Xia WangAbstract:A modified Coaxial Electrospinning process is developed for producing medicated nanofiber membranes of shellac. With pure ethanol as a sheath fluid, high quality borneol-loaded shellac nanofibers have been successfully fabricated using the modified Coaxial process. Electron scanning microscopic observations demonstrated that the nanofibers had better quality than those fabricated using a single fluid Electrospinning in terms of nanofiber diameters and their distributions. The former had an average diameter of 570 ± 80 nm under a sheath-to-core flow rate ratio of 0.25, whereas the later was 940 ± 230 nm. X-ray diffraction results verified that borneol existed in the shellac matrix in an amorphous state. The medicated nanofiber membranes could significantly improved the physical stability of borneol due to the favorable hydrogen bonding between the drug and the polymer matrix, as demonstrated by the weight loss experiments. The modified Coaxial Electrospinning process described here expands the capability of Electrospinning process in generating high quality functional membranes.
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Coaxial Electrospinning using a concentric teflon spinneret to prepare biphasic release nanofibers of helicid
RSC Advances, 2013Co-Authors: Deng-guang Yu, Xia Wang, S Annie W BlighAbstract:A special concentric spinneret with a section of Teflon tubing as sheath nozzle was manufactured and used to perform Coaxial Electrospinning for generating biphasic-release core–sheath nanofibers of helicid. Two experiments were designed to investigate the interfacial interactions of working fluids with the components of the spinneret nozzle. Appropriate solvent systems were selected and used to prepare (1) an electrospinnable sheath fluid consisting of helicid and polymer filament-forming matrix, and (2) an unspinnable core fluid consisting of Eudragit® L100-55 and a relatively high content of helicid. At a 5 : 1 sheath-to-core flow-rate ratio, helicid-loaded nanofibers with an average diameter of 660 ± 210 nm, clear core–sheath structure, as well as smooth surface and cross-section were successfully produced, as verified by SEM and TEM observations. DSC and XRD analyses indicated that the nanofibers were essentially polymeric matrix composites with homogeneously distributed guest helicid molecules on the sheath and core part. ATR–FTIR spectra verified that hydrogen bonding occurred between the drug and core–sheath matrices. In vitro dissolution tests showed that the core–sheath nanofibers can provide biphasic-release profiles with 52.4% immediate release in simulated gastric fluid and 46.3% sustained release of the remaining drug in pH 7 simulated gastric fluid. These findings indicated that the non-metallic concentric spinneret could be exploited to conduct Coaxial Electrospinning and facilitated the smooth and continuous preparation of electrospun core–sheath nanofibers for providing biphasic drug release profiles.
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zero order drug release cellulose acetate nanofibers prepared using Coaxial Electrospinning
Cellulose, 2013Co-Authors: Deng-guang Yu, Xia Wang, Yaozu Liao, Xiaoyan Li, Wei Chian, Ying LiAbstract:Novel drug-loaded cellulose acetate (CA) nanofibres were prepared by a modified Coaxial Electrospinning process, after which their zero-order drug release profiles were determined. Using 2 % (w/v) unspinnable CA solution as a sheath fluid, Coaxial Electrospinning can be conducted smoothly to generate ketoprofen (KET)-loaded CA nanofibres coated with a thin layer of blank CA. Scanning electron microscopy images demonstrated that nanofibres obtained from the modified Coaxial process have a smaller average diameter, a narrower size distribution, more uniform structures, and smoother surface morphologies than those generated from single-fluid Electrospinning. Transmission electron microscopy observations demonstrated that the nanofibres have a thin coating layer of blank CA on their surface with a thickness of ca. 15 nm. X-ray diffraction and differential scanning calorimetry verified that KET molecules in all of the nanofibres presented an amorphous state. Fourier transform infrared spectra demonstrated that CA has good compatibility with KET, which is brought about by hydrogen bonding. In vitro dissolution tests showed that the nanofibres coated with blank CA have no initial burst release effects and can provide a zero-order drug release profile over 96 h via a diffusion mechanism. The modified Coaxial Electrospinning method can provide new approaches in developing cellulose-based nano products with definite structural characteristics and improved functional performance.
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Linear drug release membrane prepared by a modified Coaxial Electrospinning process
Journal of Membrane Science, 2013Co-Authors: Wei Chian, Xia Wang, Yaozu LiaoAbstract:Abstract This study investigated a novel type of drug-delivery membrane prepared by a modified Coaxial Electrospinning process. Using 1% (w/v) unspinnable zein solution as sheath fluid, the Coaxial Electrospinning process can be smoothly conducted to generate ketoprofen (KET)-loaded zein nanofibers coated with a thin layer of blank zein. Scanning electron microscopy and transmission electron microscopy images demonstrated that the nanofibers had a ribbon morphology with a smooth surface, as well as average diameters of 860±210 nm (coating thickness of ca. 20 nm) and 680±140 nm (coating thickness of ca. 30 nm) at sheath-to-core flow rate ratios of 0.11 and 0.25, respectively. X-ray diffraction and differential scanning calorimetry verified that KET presented an amorphous state in all nanofibers. Attenuated total reflectance Fourier transform infrared spectroscopy demonstrated that zein had good compatibility with KET because of hydrogen bonding. In vitro dissolution tests showed that the nanofibers coated with blank zein did not exert any initial burst release effect, and can enable linear drug release over a period of 16 h via a diffusion mechanism. The modified Coaxial Electrospinning process can provide new approaches to the development of nanofiber membranes with improved structural characteristics and performance.
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Electrospun Ketoprofen Sustained Release Nanofibers Prepared Using Coaxial Electrospinning
Applied Mechanics and Materials, 2013Co-Authors: Wen Zhou, Bi Yu Chen, Xia WangAbstract:The present study investigates the preparation of sustained release drug-loaded nanofibers using a modified Coaxial Electrospinning process where only solvent is exploited as sheath fluid. Drug-loaded ethyl cellulose (EC) nanofibers are successfully generated smoothly and continuously without any clogging through the Coaxial process, in which ethanol is used as sheath fluid and EC and ketoprofen (KET) are taken as the filament-forming matrix and active pharmaceutical ingredient, respectively. Field-emission scanning electron microscopic observations demonstrated that the nanofibers diameter can be manipulated through the sheath fluid flow rate. The composite nanofibers are in essential a molecular solid dispersion of EC and KET based on the hydrogen bonding between them, as verified by XRD and ATR-FTIR results. In vitro dissolution tests show that KET in the nanofibers has a fine sustained release profile via a typical Fickian diffusion mechanism. The modified Coaxial Electrospinning with solvent as sheath fluid can be a useful tool for developing novel sustained release drug delivery nanofibers.
Shane Hague - One of the best experts on this subject based on the ideXlab platform.
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fabrication of pvdf pva microtubules by Coaxial Electrospinning
Polymer, 2012Co-Authors: Pei Chen, Shing Chung Josh Wong, Shane HagueAbstract:Abstract This paper presents a unique approach to fabricating poly(vinylidene fluoride) (PVDF)/poly(vinyl alcohol) (PVA) microtubules in Coaxial Electrospinning. This methodology includes two objectives, namely, microtubular formation and mitigation of secondary erosion. In the first step, PVDF solution and ethanol mixed PVA solution are directly electrospun to PVDF/PVA microtubules. Then, the obtained PVDF/PVA microtubules are treated by a water assisted route to remove the residual solvents and mitigate the secondary erosion. Without solvent erosion, PVDF/PVA microtubules exhibit smooth inner and outer surfaces and hollow structure. Furthermore, in this technique, the microtubule diameter and wall thickness are controllable by the feed rate of PVA solution in Electrospinning. Thinner-walled microtubules are prepared under a high feed rate. Differential scanning calorimetry, X-ray Diffraction and Fourier Transformed Infrared Spectroscopy are respectively used to characterize the crystallization of PVDF. High degree of PVDF crystallinity is shown in thin PVDF/PVA microtubules. β -phase crystallite is dominant. PVDF/PVA microtubule evidently exhibits capillary action. The wicking rate of silicone oil is 8.08 μm/s, as calculated by a wicking test.
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Fabrication of PVDF/PVA microtubules by Coaxial Electrospinning
Polymer, 2012Co-Authors: Pei Chen, Shing Chung Josh Wong, Shane HagueAbstract:Abstract This paper presents a unique approach to fabricating poly(vinylidene fluoride) (PVDF)/poly(vinyl alcohol) (PVA) microtubules in Coaxial Electrospinning. This methodology includes two objectives, namely, microtubular formation and mitigation of secondary erosion. In the first step, PVDF solution and ethanol mixed PVA solution are directly electrospun to PVDF/PVA microtubules. Then, the obtained PVDF/PVA microtubules are treated by a water assisted route to remove the residual solvents and mitigate the secondary erosion. Without solvent erosion, PVDF/PVA microtubules exhibit smooth inner and outer surfaces and hollow structure. Furthermore, in this technique, the microtubule diameter and wall thickness are controllable by the feed rate of PVA solution in Electrospinning. Thinner-walled microtubules are prepared under a high feed rate. Differential scanning calorimetry, X-ray Diffraction and Fourier Transformed Infrared Spectroscopy are respectively used to characterize the crystallization of PVDF. High degree of PVDF crystallinity is shown in thin PVDF/PVA microtubules. β -phase crystallite is dominant. PVDF/PVA microtubule evidently exhibits capillary action. The wicking rate of silicone oil is 8.08 μm/s, as calculated by a wicking test.
Andrew J. Steckl - One of the best experts on this subject based on the ideXlab platform.
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Coaxial Electrospinning Formation of Complex Polymer Fibers and their Applications
ChemPlusChem, 2019Co-Authors: Daewoo Han, Andrew J. StecklAbstract:The formation of fibers by Electrospinning has experienced explosive growth in the past decade, recently reaching 4,000 publications and 1,500 patents per year. This impressive growth of interest is due to the ability to form fibers with a variety of materials, which lend themselves to a large and rapidly expanding set of applications. In particular, Coaxial Electrospinning, which forms fibers with multiple core-sheath layers from different materials in a single step, enables the combination of properties in a single fiber that are not found in nature in a single material. This article is a detailed review of Coaxial Electrospinning: basic mechanisms, early history and current status, and an in-depth discussion of various applications (biomedical, environmental, sensors, energy, catalysis, textiles). We aim to provide readers who are currently involved in certain aspects of Coaxial Electrospinning research an appreciation of other applications and of current results.
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Photocatalytic Self Cleaning Textile Fibers by Coaxial Electrospinning
ACS Applied Materials & Interfaces, 2010Co-Authors: Nicholas M. Bedford, Andrew J. StecklAbstract:Photocatalytic self-cleaning textile fibers have been created using Coaxial Electrospinning. This is accomplished by Electrospinning cellulose acetate as the core phase and a dispersion of nanocrystalline TiO2, a well-known photocatalyst, in the sheath phase. A simple deacetylation step after the initial Electrospinning yields self-cleaning textile fibers. Self-cleaning activity is exhibited at moderate power densities in indoor lighting conditions. Nanofibers created from Coaxial Electrospinning outperform TiO2 surface-loaded nanofibers obtained by conventional Electrospinning. Surface-loaded fibers degrade blue dye stains only to a minimum of 20% of the initial concentration, whereas fibers created by Coaxial Electrospinning fully degrade stains (in 7−8 h).
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Superhydrophobic and Oleophobic Fibers by Coaxial Electrospinning
Langmuir : the ACS journal of surfaces and colloids, 2009Co-Authors: Daewoo Han, Andrew J. StecklAbstract:Control of surface wetting properties to produce strongly hydrophobic or hydrophilic effects is at the heart of many macro- and microfluidic applications. In this work, we have investigated Coaxial Electrospinning to produce core−sheath-structured nano/microfibers that combine different properties from individual core and sheath materials. Teflon AF is an amorphous fluoropolymer that is widely utilized as a hydrophobic material. Hydrophobic fluoropolymers are normally not electrospinnable because their low dielectric constant prevents sufficient charging for a solution to be electrospun. The first Teflon electrospun fibers are reported using Coaxial Electrospinning with Teflon AF sheath and poly(e-caprolactone) (PCL) core materials. Using these core/sheath fibers, superhydrophobic and oleophobic membranes have been successfully produced. These Coaxial fibers also preserve the core material properties as demonstrated with mechanical tensile tests. The fact that a normally nonelectrospinnable material such ...
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Versatile Core-Sheath Biofibers using Coaxial Electrospinning
MRS Online Proceedings Library, 2008Co-Authors: Daewoo Han, Steven T. Boyce, Andrew J. StecklAbstract:We have investigated Coaxial Electrospinning to produce core-sheath fibers for tissue engineering. We have successfully produced core-sheath structured fibers of poly(ε-caprolactone) (PCL) and gelatin using the Coaxial Electrospinning technique. The core-sheath scaffold exhibits better mechanical properties compared to gelatin scaffold. We have characterized the resulting core and core-sheath fiber diameters and the scaffold porosity, etc.
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Versatile Core-Sheath Biofibers using Coaxial Electrospinning
MRS Proceedings, 2008Co-Authors: Daewoo Han, Steven T. Boyce, Andrew J. StecklAbstract:We have investigated Coaxial Electrospinning to produce core-sheath fibers for tissue engineering. We have successfully produced core-sheath structured fibers of poly(e-caprolactone) (PCL) and gelatin using the Coaxial Electrospinning technique. The core-sheath scaffold exhibits better mechanical properties compared to gelatin scaffold. We have characterized the resulting core and core-sheath fiber diameters and the scaffold porosity, etc.
Yaozu Liao - One of the best experts on this subject based on the ideXlab platform.
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zero order drug release cellulose acetate nanofibers prepared using Coaxial Electrospinning
Cellulose, 2013Co-Authors: Deng-guang Yu, Xia Wang, Yaozu Liao, Xiaoyan Li, Wei Chian, Ying LiAbstract:Novel drug-loaded cellulose acetate (CA) nanofibres were prepared by a modified Coaxial Electrospinning process, after which their zero-order drug release profiles were determined. Using 2 % (w/v) unspinnable CA solution as a sheath fluid, Coaxial Electrospinning can be conducted smoothly to generate ketoprofen (KET)-loaded CA nanofibres coated with a thin layer of blank CA. Scanning electron microscopy images demonstrated that nanofibres obtained from the modified Coaxial process have a smaller average diameter, a narrower size distribution, more uniform structures, and smoother surface morphologies than those generated from single-fluid Electrospinning. Transmission electron microscopy observations demonstrated that the nanofibres have a thin coating layer of blank CA on their surface with a thickness of ca. 15 nm. X-ray diffraction and differential scanning calorimetry verified that KET molecules in all of the nanofibres presented an amorphous state. Fourier transform infrared spectra demonstrated that CA has good compatibility with KET, which is brought about by hydrogen bonding. In vitro dissolution tests showed that the nanofibres coated with blank CA have no initial burst release effects and can provide a zero-order drug release profile over 96 h via a diffusion mechanism. The modified Coaxial Electrospinning method can provide new approaches in developing cellulose-based nano products with definite structural characteristics and improved functional performance.
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Linear drug release membrane prepared by a modified Coaxial Electrospinning process
Journal of Membrane Science, 2013Co-Authors: Wei Chian, Xia Wang, Yaozu LiaoAbstract:Abstract This study investigated a novel type of drug-delivery membrane prepared by a modified Coaxial Electrospinning process. Using 1% (w/v) unspinnable zein solution as sheath fluid, the Coaxial Electrospinning process can be smoothly conducted to generate ketoprofen (KET)-loaded zein nanofibers coated with a thin layer of blank zein. Scanning electron microscopy and transmission electron microscopy images demonstrated that the nanofibers had a ribbon morphology with a smooth surface, as well as average diameters of 860±210 nm (coating thickness of ca. 20 nm) and 680±140 nm (coating thickness of ca. 30 nm) at sheath-to-core flow rate ratios of 0.11 and 0.25, respectively. X-ray diffraction and differential scanning calorimetry verified that KET presented an amorphous state in all nanofibers. Attenuated total reflectance Fourier transform infrared spectroscopy demonstrated that zein had good compatibility with KET because of hydrogen bonding. In vitro dissolution tests showed that the nanofibers coated with blank zein did not exert any initial burst release effect, and can enable linear drug release over a period of 16 h via a diffusion mechanism. The modified Coaxial Electrospinning process can provide new approaches to the development of nanofiber membranes with improved structural characteristics and performance.
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Coaxial Electrospinning with triton x 100 solutions as sheath fluids for preparing pan nanofibers
Macromolecular Materials and Engineering, 2012Co-Authors: Nicholas P. Chatterton, Xia Wang, Junhe Yang, Yaozu LiaoAbstract:Coaxial Electrospinning using surfactants as sheath fluid for preparing high-quality polymer nanofibers is studied. PAN nanofibers are fabricated using this process with Triton X-100 solutions in DMF. FESEM demonstrates that the Triton X-100 solution has a significant influence on the quality of the nanofibers. The nanofiber diameters can be controlled by adjusting the concentration of Triton X-100 in the sheath fluids with a scaling law D = 640 C -0.32 . The mechanism of the influence of Triton X-100 solutions on the formation of PAN fibers is discussed and it is demonstrated that Coaxial Electrospinning with surfactant solution is a facile method for achieving high-quality polymer nanofibers.
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Coaxial Electrospinning with Triton X‐100 Solutions as Sheath Fluids for Preparing PAN Nanofibers
Macromolecular Materials and Engineering, 2011Co-Authors: Nicholas P. Chatterton, Xia Wang, Junhe Yang, Yaozu LiaoAbstract:Coaxial Electrospinning using surfactants as sheath fluid for preparing high-quality polymer nanofibers is studied. PAN nanofibers are fabricated using this process with Triton X-100 solutions in DMF. FESEM demonstrates that the Triton X-100 solution has a significant influence on the quality of the nanofibers. The nanofiber diameters can be controlled by adjusting the concentration of Triton X-100 in the sheath fluids with a scaling law D = 640 C -0.32 . The mechanism of the influence of Triton X-100 solutions on the formation of PAN fibers is discussed and it is demonstrated that Coaxial Electrospinning with surfactant solution is a facile method for achieving high-quality polymer nanofibers.
Pei Chen - One of the best experts on this subject based on the ideXlab platform.
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fabrication of pvdf pva microtubules by Coaxial Electrospinning
Polymer, 2012Co-Authors: Pei Chen, Shing Chung Josh Wong, Shane HagueAbstract:Abstract This paper presents a unique approach to fabricating poly(vinylidene fluoride) (PVDF)/poly(vinyl alcohol) (PVA) microtubules in Coaxial Electrospinning. This methodology includes two objectives, namely, microtubular formation and mitigation of secondary erosion. In the first step, PVDF solution and ethanol mixed PVA solution are directly electrospun to PVDF/PVA microtubules. Then, the obtained PVDF/PVA microtubules are treated by a water assisted route to remove the residual solvents and mitigate the secondary erosion. Without solvent erosion, PVDF/PVA microtubules exhibit smooth inner and outer surfaces and hollow structure. Furthermore, in this technique, the microtubule diameter and wall thickness are controllable by the feed rate of PVA solution in Electrospinning. Thinner-walled microtubules are prepared under a high feed rate. Differential scanning calorimetry, X-ray Diffraction and Fourier Transformed Infrared Spectroscopy are respectively used to characterize the crystallization of PVDF. High degree of PVDF crystallinity is shown in thin PVDF/PVA microtubules. β -phase crystallite is dominant. PVDF/PVA microtubule evidently exhibits capillary action. The wicking rate of silicone oil is 8.08 μm/s, as calculated by a wicking test.
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Fabrication of PVDF/PVA microtubules by Coaxial Electrospinning
Polymer, 2012Co-Authors: Pei Chen, Shing Chung Josh Wong, Shane HagueAbstract:Abstract This paper presents a unique approach to fabricating poly(vinylidene fluoride) (PVDF)/poly(vinyl alcohol) (PVA) microtubules in Coaxial Electrospinning. This methodology includes two objectives, namely, microtubular formation and mitigation of secondary erosion. In the first step, PVDF solution and ethanol mixed PVA solution are directly electrospun to PVDF/PVA microtubules. Then, the obtained PVDF/PVA microtubules are treated by a water assisted route to remove the residual solvents and mitigate the secondary erosion. Without solvent erosion, PVDF/PVA microtubules exhibit smooth inner and outer surfaces and hollow structure. Furthermore, in this technique, the microtubule diameter and wall thickness are controllable by the feed rate of PVA solution in Electrospinning. Thinner-walled microtubules are prepared under a high feed rate. Differential scanning calorimetry, X-ray Diffraction and Fourier Transformed Infrared Spectroscopy are respectively used to characterize the crystallization of PVDF. High degree of PVDF crystallinity is shown in thin PVDF/PVA microtubules. β -phase crystallite is dominant. PVDF/PVA microtubule evidently exhibits capillary action. The wicking rate of silicone oil is 8.08 μm/s, as calculated by a wicking test.