Numerical Study and Scale Analysis of Inner and Outer Diameters Prediction in Fabrication of Hollow Fiber Membranes for Nerve Regeneration

2008 ◽  
Author(s):  
Jun Yin ◽  
Nicole Coutris ◽  
Yong Huang
Keyword(s):  
Surface Tension ◽  
Hollow Fiber ◽  
Numerical Study ◽  
Hollow Fiber Membrane ◽  
Nerve Repair ◽  
Vof Method ◽  
Fiber Spinning ◽  
Fabrication Process ◽  
Scale Analysis ◽  
And Control

Recently the semi-permeable hollow fiber membrane (HFM) is finding promising applications in promoting axonal outgrowth for nerve repair and regeneration. It is of interest to model the phase inversion-based HFM fabrication process and control the fabricated HFM geometry. The effect of gravity and surface tension which is frequently ignored in general fiber spinning should be carefully addressed in HFM fabrication modeling. Both the volume of fluid (VOF) method and the scale analysis have been applied to appreciate the effect of gravity and surface tension on the HFM geometry profile. The VOF method-based simulation results reveal that both the gravity and/or surface tension significantly reduce the predicted radii/diameters, while the scale analysis reveals that the gravity or surface tension affects the HFM fabrication process dynamics. Both the approaches warrant the need of including the gravity and surface tension in HFM fabrication process modeling.

Groove Formation Modeling in Fabricating Hollow Fiber Membrane for Nerve Regeneration

2010 ◽  
Vol 78 (1) ◽  
Author(s):  
Jun Yin ◽  
Nicole Coutris ◽  
Yong Huang
Keyword(s):  
Nerve Regeneration ◽  
Hollow Fiber ◽  
Phase Inversion ◽  
Hollow Fiber Membrane ◽  
Nerve Repair ◽  
Industrial Applications ◽  
Elastic Cylindrical Shell ◽  
Fiber Membrane ◽  
Membrane Fabrication ◽  
Recent Interest

Hollow fiber membrane (HFM) is one of the most popular membranes used for different industrial applications. Under some controlled fabrication conditions, axially aligned grooves can be formed on the HFM inner surface during typical immersion precipitation-based phase inversion fabrication processes. Such grooved HFMs are finding promising medical applications for nerve repair and regeneration. For better nerve regeneration performance, the HFM groove morphology should be carefully controlled. Toward this goal, this study has modeled the HFM groove number based on the shrinkage-induced buckling model in HFM fabrication. HFM has been modeled as a three-layer long fiber membrane. The HFM inner layer has been treated as a thin-walled elastic cylindrical shell and buckles due to the shrinkage of the compliant intermediate layer during solidification. The groove geometry, especially the groove number, has been reasonably predicted compared with the experimental measurements. This study has laid a mathematical foundation for HFM circumferential instability modeling, which is of recent interest in membrane fabrication.

Investigation of Inner Surface Groove Formation Under Radially Inward Pressure During Immersion Precipitation-Based Hollow Fiber Membrane Fabrication

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Jun Yin ◽  
Nicole Coutris ◽  
Yong Huang
Keyword(s):  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Nerve Repair ◽  
Radial Pressure ◽  
Skin Layer ◽  
Elastic Cylindrical Shell ◽  
Fiber Membrane ◽  
Buckling Mode ◽  
Membrane Fabrication ◽  
Inner Surface

Axially aligned grooves can be formed on the hollow fiber membrane (HFM) inner surface under some controlled fabrication conditions during a typical immersion precipitation-based phase inversion fabrication process. Such grooved HFMs are finding promising medical applications for nerve repair and regeneration. For better nerve regeneration performance, the HFM groove geometry should be carefully controlled. Towards this goal, in this study the polyacrylonitrile (PAN) HFM groove number has been modeled based on the radially inward pressure-induced buckling mechanism. HFM has been modeled as a long six-layer fiber membrane, and the HFM inner skin layer has been treated as a thin-walled elastic cylindrical shell under the shrinkage-induced inward radial pressure. The groove number has been reasonably estimated based on the resulting buckling mode as compared with the experimental measurements.

Preparation of Ceramic Hollow Fiber Membrane Using Phase Inversion and Sintering Technique

2016 ◽  
Vol 1133 ◽  
pp. 141-145 ◽  
Author(s):  
Norfazliana Abdullah ◽  
Mukhlis A. Rahman ◽  
A.F. Ismail ◽  
M.H.D. Othman ◽  
Juhana Jaafar
Keyword(s):  
Hollow Fiber ◽  
Phase Inversion ◽  
Hollow Fiber Membrane ◽  
Fabrication Process ◽  
Asymmetric Structure ◽  
Sintering Process ◽  
Fiber Membrane ◽  
Membrane Fabrication ◽  
Phase Inversion Technique ◽  
The Given

Alumina hollow fiber membrane with asymmetric structure has been developed using phase inversion technique followed by sintering process. The formation of asymmetric alumina hollow fiber was influenced by a phenomenon known as hydrodynamically unstable viscous fingering. A desired morphology of the ceramic hollow fiber membrane, that consists of 52 % of finger-like and the rest is sponge-like structure, is tailored by controlled parameters during membrane fabrication process. The result shows that the ratio of alumina/PESf should be reduced to 6. At this ratio, the finger-like structure can be easily formed with inner and outer diameters were 1.11 mm and 2.05 mm respectively. From the given thickness, approximately 243 µm of finger-like length can be developed originating from the lumen of hollow fiber.

Numerical Study on Droplet Formation in a Microchannel T-Junction Using the VOF Method

2010 ◽  
Author(s):  
Shobeir Aliasghar Zadeh ◽  
Rolf Radespiel
Keyword(s):  
Surface Tension ◽  
Flow Rate ◽  
Capillary Number ◽  
Numerical Study ◽  
Droplet Formation ◽  
Continuous Phase ◽  
Vof Method ◽  
Experimental Results ◽  
Glycerol Solution ◽  
Hexahedral Elements

The liquid-liquid two-phase flow in a T-junction was numerically investigated applying the VOF method and is compared with experimental results. The geometry was generated and meshed using the software Gridgen, and the corresponding equations for the CFD analysis were solved by using the commercial software Fluent (Fluent 12). The generated mesh consists of block-structured grids with hexahedral elements. Water-Glycerol solution (to-be-dispersed phase) and silicone oil (continuous phase) at room conditions are considered as fluids for this work. The effect of various parameters such as flow rate of the phases, width of the channel, viscosity and surface tension on the droplet formation are investigated and compared with available experimental results [1]. The breakup mechanism of droplets in various capillary-number regimes are explained. The numerical results of the length of the generated droplets as a function of the capillary number (varying the flow rate of the continuous phase) are in good agreement with the experimental values, which were measured using the same geometrical and physical properties. Further studies indicate that at a constant flow rate of the continuous phase, the droplet length rises strongly if the flow rate of the disperse phase increases, whereas the relative effects of the viscosity of the continuous phase, and the surface tension between phases on the length of droplets are moderate.

Simulation of Oxygen Permeability of Dual-phase Hollow Fiber Membrane

2012 ◽  
Vol 27 (9) ◽  
pp. 951-955
Author(s):  
Chun-Li YANG ◽  
Qi-Ming XU ◽  
Ming GONG ◽  
Wei LIU
Keyword(s):  
Hollow Fiber ◽  
Oxygen Permeability ◽  
Hollow Fiber Membrane ◽  
Dual Phase ◽  
Fiber Membrane
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