Fabrication of Inner Grooved Hollow Fiber Membranes Using Microstructured Spinneret for Nerve Regeneration

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Jun Yin ◽  
Zonghuan Wang ◽  
Wenxuan Chai ◽  
Guangli Dai ◽  
Hairui Suo ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Nerve Regeneration ◽  
Flow Rate ◽  
Hollow Fiber ◽  
Groove Width ◽  
Fine Tuning ◽  
Fluid Flow Rate ◽  
Hollow Fiber Membranes ◽  
Fiber Membranes

Nerve conduits with topographical guidance have been recognized as the efficient repair of damaged peripheral nerves. In this study, polymeric hollow fiber membranes (HFMs) with grooved inner surface have been fabricated from a microstructured spinneret using a dry-jet wet spinning process for nerve regeneration studies. The effectiveness of HFM inner grooves has been demonstrated during an in vitro study of chick forebrain neuron outgrowth. It is of great importance that the groove geometry can be controllable to meet various needs in promoting nerve regeneration performance. While the overall groove geometry is determined by the spinneret design, fabrication conditions are also indispensable in fine-tuning the final groove geometry such as the groove height and width on the order of 10 μm or less. It is found that the bore fluid flow rate can be utilized to effectively adjust the resulting groove height by at most 52% and groove width by at most 61%, respectively, without modifying the spinneret geometry. This enables a new approach to fabricate different grooved HFMs using the same spinneret. By comparing to the influences of bore fluid flow rate, the dope fluid flow rate is less effective in regulating the groove height and width when using the same microstructured spinneret. Both bore and dope fluid flow rates should be carefully selected for fine groove width tuning.

scholarly journals Preparation and characterization of different geometrical shapes of multi-bore hollow fiber membranes and application in vacuum membrane distillation

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Elham M. El-Zanati ◽  
Eman Farg ◽  
Esraa Taha ◽  
Ayman El-Guindi ◽  
Heba Abdallah
Keyword(s):  
Mechanical Properties ◽  
Flow Rate ◽  
Hollow Fiber ◽  
Amorphous Structure ◽  
Membrane Distillation ◽  
Operating Conditions ◽  
Hollow Fiber Membranes ◽  
Preparation Conditions ◽  
Geometrical Shapes ◽  
Fiber Membranes

Abstract Multi-bore hollow fiber membranes were prepared through phase inversion spinning process using new locally designed spinnerets of various geometrical shapes. The spun cylindrical-like, rectangular or ribbon-like, and triangular-like are prepared, dried, and characterized by scanning electronic microscope. Fibers of circular (seven, five, and four bores) shape, rectangular of five bores, and triangular of three bores were chosen to study the effect of both geometrical configuration and the number of bores on the amorphous structure and the mechanical properties of the membranes. Membrane geometry, surface amorphous, and bore arrangements are very sensitive to the operating conditions, especially the extrusion and drawing rates. Three polymeric blends of different compositions are used to prepare multi-bore hollow fiber membranes. This study revealed that the blend composition of PES 16%, PVP 2%, PEG 2%, diethylene glycol 2%, and NMP 78% gives excellent mechanical properties. Optimization of the preparation conditions also developed, where the dope flow rate, the bore flow rate, and the air gap were 1.14 cm3 s−1, 1.1 cm3 s−1, and 0 cm, respectively. Furthermore, this study proved that the circular arrangement has high mechanical strength. The prepared seven-MBHF membranes were applied in the membrane distillation process, a solution of 35 g/l NaCl was used to test the membrane performance, and the achieved flux and rejection were 28.32 L/m2 h and 98.9%, respectively. This performance demonstrated that the prepared membrane in this way is suitable to compete with conventional reverse osmosis technology that uses single track hollow fibers.

scholarly journals Fabrication of Defect-Free P84® Polyimide Hollow Fiber for Gas Separation: Pathway to Formation of Optimized Structure

Membranes ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 4 ◽  
Author(s):  
Miren Etxeberria-Benavides ◽  
Oguz Karvan ◽  
Freek Kapteijn ◽  
Jorge Gascon ◽  
Oana David
Keyword(s):  
Hollow Fiber ◽  
Theoretical Study ◽  
Solvent Mixture ◽  
Fine Tuning ◽  
Hollow Fiber Membranes ◽  
Selective Layer ◽  
Fiber Membranes ◽  
Additional Defect ◽  
Fiber Manufacturing ◽  
Treatment Step

The elimination of the additional defect healing post-treatment step in asymmetric hollow fiber manufacturing would result in a significant reduction in membrane production cost. However, obtaining integrally skinned polymeric asymmetric hollow fiber membranes with an ultrathin and defect-free selective layer is quite challenging. In this study, P84® asymmetric hollow fiber membranes with a highly thin (~56 nm) defect-free skin were successfully fabricated by fine tuning the dope composition and spinning parameters using volatile additive (tetrahydrofuran, THF) as key parameters. An extensive experimental and theoretical study of the influence of volatile THF addition on the solubility parameter of the N-methylpyrrolidone/THF solvent mixture was performed. Although THF itself is not a solvent for P84®, in a mixture with a good solvent for the polymer, like N-Methyl-2-pyrrolidone (NMP), it can be dissolved at high THF concentrations (NMP/THF ratio > 0.52). The as-spun fibers had a reproducible ideal CO2/N2 selectivity of 40, and a CO2 permeance of 23 GPU at 35 °C. The fiber production can be scaled-up with retention of the selectivity.

scholarly journals Sinusoidal shaped hollow fibers for enhanced mass transfer

2019 ◽  
Author(s):  
Matthias Wessling
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Hollow Fiber ◽  
Liquid Flow Rate ◽  
Transport Processes ◽  
Membrane Properties ◽  
Hollow Fiber Membranes ◽  
Wide Range ◽  
Fiber Membranes ◽  
Secondary Vortices

Geometrically structured flow channels induce secondary flows and vortices enhancing mass and heat transport rates. In particular, these vortices may reduce concentration polarization and subsequent fouling in membrane transport processes. In this work we present a new method of producing hollow fiber membranes with a sinusoidal change in diameter along the fiber length. We engineered a pulsation module that imposes a sinusoidally fluctuating bore liquid flow rate. Harmonic bore flow conditions can be varied over a wide range of operational settings. The fluctuating bore liquid flow rate translates into axial membrane properties varying with respect to inner bore diameter and wall thickness.We suggest that the resulting narrowing and widening of the membrane lumen channel induces secondary vortices to the liquid feed inside the membrane lumen. In gas/liquid membrane absorption processes these secondary vortices reduce the diffusional resistance, also known as the Bellhouse effect. For the produced hydrophobic PVDF membranes, improved oxygen transport from shell-to-lumen side prove superiority over straight hollow fiber membranes in G/L absorption process by a factor of 2.5 at higher liquid flow rates. We anticipate the dynamic flow module to be easily integrated into currently existing hollow fiber membrane spinning processes.

Improved hemodialysis with hemocompatible polyethersulfone hollow fiber membranes: In vitro performance

2017 ◽  
Vol 106 (3) ◽  
pp. 1286-1298 ◽  
Author(s):  
Surendra Kumar Verma ◽  
Akshay Modi ◽  
Atul Kumar Singh ◽  
Rohit Teotia ◽  
Jayesh Bellare
Keyword(s):  
Hollow Fiber ◽  
Hollow Fiber Membranes ◽  
Fiber Membranes ◽  
In Vitro Performance

scholarly journals In vitro study of dual layer mixed matrix hollow fiber membranes for outside-in filtration of human blood plasma

2021 ◽  
Author(s):  
O.E.M. ter Beek ◽  
M.K. van Gelder ◽  
C. Lokhorst ◽  
D.H.M. Hazenbrink ◽  
B.H. Lentferink ◽  
...  
Keyword(s):  
Blood Plasma ◽  
Human Blood ◽  
Hollow Fiber ◽  
In Vitro Study ◽  
Vitro Study ◽  
Human Blood Plasma ◽  
Hollow Fiber Membranes ◽  
Mixed Matrix ◽  
Fiber Membranes

In vitro removal of human IgG autoantibodies by affinity filtration using immobilized l-histidine onto PEVA hollow fiber membranes

2001 ◽  
Vol 17 (2) ◽  
pp. 71-74 ◽  
Author(s):  
Roberta Cristina Arena Ventura ◽  
Ricardo de Lima Zollner ◽  
Cécile Legallais ◽  
Mookambeswaran Vijayalakshmi ◽  
Sonia Maria Alves Bueno
Keyword(s):  
Hollow Fiber ◽  
Hollow Fiber Membranes ◽  
Human Igg ◽  
Fiber Membranes

CO2 Desorption by Hydrophilic PTFE Hollow Fiber Membranes via a Membrane Flash Process

2015 ◽  
Vol 671 ◽  
pp. 293-299
Author(s):  
Peng Peng Lv ◽  
Feng Wang ◽  
Yu Hai Guo ◽  
Hong Yan Tang
Keyword(s):  
Flow Rate ◽  
Thermal Energy ◽  
Hollow Fiber ◽  
Solution Flow Rate ◽  
Hollow Fiber Membranes ◽  
Solution Flow ◽  
Desorption Process ◽  
Fiber Membranes ◽  
Rich Solution ◽  
Release Ratio

In this study, hydrophilic PTFE hollow fiber membranes were prepared and applied for CO2 desorption via a membrane flash process, which is a new CO2 desorption process by utilizing waste thermal energy. The methyldiethanolamine was selected as the absorbent. Effects of the flashing temperature, flashing pressure, rich solution flow rate and MDEA concentration on CO2 release ratio and CO2 desorption flux were deeply investigated. The results show that flashing temperature is positive to the CO2 release ratio and CO2 desorption flux. However, the flashing pressure, rich solution flow rate and MDEA concentration are negative to the CO2 release ratio and CO2 desorption flux.

scholarly journals Design and fabrication of ceramic hollow fiber membrane derived from waste ash using phase inversion-based extrusion/sintering technique for water filtration

2020 ◽  
Author(s):  
Zhong Sheng Tai ◽  
Mohd Hafiz Dzarfan Othman ◽  
Mohd Irfan Hatim Mohamed Dzahir ◽  
Siti Khadijah Hubadillah ◽  
Khong Nee Koo ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Hollow Fiber ◽  
Phase Inversion ◽  
Sintering Temperature ◽  
Pure Water ◽  
Air Gap ◽  
Fluid Flow Rate ◽  
Palm Oil Fuel Ash ◽  
Suspension Viscosity

Abstract Low-cost green ceramic hollow fiber membranes (CHFM) were successfully designed and fabricated from the industrial waste ash, palm oil fuel ash (POFA) via phase inversion-based extrusion/sintering techniques for water filter application. The extrusion process parameters such as suspension viscosity, air gap distance, and bore fluid flow rate were systematically explored to produce the membrane with the desired morphology. A high suspension viscosity would result in a small macro-voids structure. Moreover, a high air gap distance would induce fiber with long macro-voids structure, while a low bore fluid flow rate would lead to the formation of distorted lumen structure. The effect of sintering temperature towards CHFM was also studied in detail. An increase in sintering temperature improved the membrane bending strength, but also adversely affected the pure water flux due to lower porosity and higher tortuosity. The developed membranes achieved excellent bending strengths of > 75 MPa at relatively low sintering temperatures than the alternative ceramic counterparts, due to its high potassium oxide, K2O content, which acted as the low melting point sintering aid. The relatively low sintering temperature of POFA-derived CHFMs could reduce the energy consumption and sintering duration, which could be more economically attractive, as compared to their ceramic counterparts, thus benefiting industrial users.

Tongkat Ali Extraction using Hollow Fiber Membranes Modified by Negatively Charged-modifying Marcromolecules

2014 ◽  
Vol 70 (2) ◽  
Author(s):  
N. Bolong ◽  
S. Kumaresan ◽  
I. Saad ◽  
T. Thasan ◽  
R. Ramli
Keyword(s):  
Flow Rate ◽  
Hollow Fiber ◽  
Membrane Separation ◽  
Hollow Fiber Membranes ◽  
Feed Concentration ◽  
Plant Parts ◽  
Eurycoma Longifolia ◽  
Peptide Fraction ◽  
Phase Inversion Technique ◽  
Fiber Membranes

Eurycoma longifolia Jack is an herbal medicinal plant popularly recognized as 'Tongkat Ali.' The plant parts have been traditionally used for its antimalarial, aphrodisiac, anti-diabetic, antimicrobial and anti-pyretic activities, which have also been proved scientifically. This study attempt to isolate and concentrate the targeted 4.3 kDa peptide fraction from the Tongkat Ali water extracts which consist of many other fractions of peptides, proteins and phytochemicals by membrane separation. The hollow fiber membranes made of Polyethersulfone (PES) were fabricated in-house using phase inversion technique with synthesized Charged-Surface Modifying Macromolecules (cSMM) which anticipated by the end-capped group of cSMM namely Hydroxybenzene carboxylate (HBC). The influence of stock feed concentration and system flow rate were investigated in this work. The results obtained showed that the permeate is 10 times concentrated than the actual overall extract with linear influence on protein permeate concentration with increasing feed concentration. Whereas the flow rate of the feed stream has contribute to the flow rate and the concentration of the permeate stream an increased protein concentration by 5 % with the doubled feed flow rate.

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