The improvement of water flux and mechanical strength of PVDF hollow fiber membranes by stretching and annealing conditions

2015 ◽  
Vol 23 (7) ◽  
pp. 592-600 ◽  
Author(s):  
Tae Hwan Kim ◽  
Ki Yong Jee ◽  
Yong Taek Lee
Keyword(s):  
Mechanical Strength ◽  
Hollow Fiber ◽  
Water Flux ◽  
Hollow Fiber Membranes ◽  
Annealing Conditions ◽  
Fiber Membranes

Structure Morphology of Polyethersulfone Hollow Fiber Membrane via Immersion Precipitation Phase Inversion Process

2012 ◽  
Vol 152-154 ◽  
pp. 574-578 ◽  
Author(s):  
Ping Lan ◽  
Wei Wang
Keyword(s):  
Hollow Fiber ◽  
Phase Inversion ◽  
Hollow Fiber Membrane ◽  
Pure Water ◽  
Water Flux ◽  
Additive Concentration ◽  
Hollow Fiber Membranes ◽  
Fiber Membrane ◽  
Fiber Membranes ◽  
And Performance

Polyethersulfone (PES) hollow fiber membranes have been widely used in many fields, such as ultrafiltration, microfiltration, reverse osmosis, liquid/liquid or liquid/solid separation, gas separation, hemodialysis, and so on. In this paper, the sheet PES hollow fiber membranes were prepared. The morphology and performance of membranes can be controlled. By studying the influence of the compositions and conditions on the morphology and performance of PES hollow fiber membrane, the relationship of morphology and performance of the membrane is acquired. The additives were used such as glycerol, BuOH and PEG. In addition, immerse phase inversion was used as membranes preparation method. The morphology of the membrane was controlled by changing kinds of additive, concentration of additive and so on. It was found that the membrane morphologies were changed by additive obviously. Porosity , pure water flux, scanning electron microscopy(SEM) were used to characterize the morphology and performance of the membranes.

A MORPHOLOGICAL STUDY OF NICKEL OXIDE HOLLOW FIBER MEMBRANES: EFFECT OF AIR GAP & SINTERING TEMPERATURE

2016 ◽  
Vol 78 (12) ◽  
Author(s):  
Mohd Izzat Iqbal Mohd Zahar ◽  
Mohd Hafiz Dzarfan Othman ◽  
Mukhlis A Rahman ◽  
Juhana Jaafar ◽  
Siti Khadijah Hubadillah
Keyword(s):  
Mechanical Strength ◽  
Nickel Oxide ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Air Gap ◽  
Hollow Fibers ◽  
Asymmetric Structure ◽  
Hollow Fiber Membranes ◽  
Fiber Membrane ◽  
Fiber Membranes

A systematic study of the air gap effects on morphology and mechanical strength of Nickel Oxide (NiO) hollow fiber membranes has been carried out. The hollow fibers were prepared using the dry-jet wet spinning process using a dope solution containing NiO/N-methyl-2-pyrrolidone (NMP)/Arlacel/Poly(ethylene sulphide) with a weight ratio of 70/22.9/0.1/7. Tap water was used as internal and external coagulants. The cross-sectional structure of precursors hollow fiber membrane was studied by scanning electron microscopy (SEM). The results showed that both inner and outer finger-like voids of the hollow membrane were determined by the air gap distance. Experimental results indicated that an increase in air gap distance, from 100 mm to 200 mm, gave a hollow fiber with a lower mechanical strength and higher percentages of cross section surface area covered by finger-like voids structures. This study also revealed that the air gap introduced an elongation stress because of gravity on the internal or external surfaces of the NiO hollow fibers. A more effective hollow fiber membrane which is in asymmetric structure instead of symmetric structure can be produced by using air gap higher than 200 mm. 

Preparation for PTFE Hollow Fiber Membranes Used in Water Treatment and Optimization for its Extrusion Process

2013 ◽  
Vol 750-752 ◽  
pp. 828-831 ◽  
Author(s):  
Chao Zhuang ◽  
Zhi Qing Luo ◽  
Wen Qing Chen
Keyword(s):  
Water Treatment ◽  
Hollow Fiber ◽  
Retention Rate ◽  
Pure Water ◽  
Water Flux ◽  
Chemical Properties ◽  
Hollow Fiber Membranes ◽  
High Fracture ◽  
Processing Methods ◽  
Fiber Membranes

For their excellent physical and chemical properties, PTFE hollow fiber membranes can be used in harsh environment of water treatment. But the membranes cannot be prepared by conventional methods, such as the melting processing methods and the dry-wet spinning processing methods, because of a high melting point of 327°C and chemical stability. In this paper a method of extrusion-stretching-sintering is used, and using this method we get the membranes with high fracture strength (10MPa) and high pure water flux (1500L/(m2*h)), also the retention rate of bovine serum albumin reaching 50%, which meets the laboratory microfiltration membrane requirements.

Preparation and Properties of Two-Dimensional Braid Heterogeneous-Reinforced Polyvinylidene Fluoride Hollow Fiber Membrane

2014 ◽  
Vol 936 ◽  
pp. 218-225 ◽  
Author(s):  
Quan Quan ◽  
Chang Fa Xiao ◽  
Hai Liang Liu ◽  
Wei Zhao ◽  
Xiao Yu Hu ◽  
...  
Keyword(s):  
Hollow Fiber ◽  
Polyvinylidene Fluoride ◽  
Polymer Solutions ◽  
Coating Layer ◽  
Pure Water ◽  
Water Flux ◽  
Two Dimensional ◽  
Hollow Fiber Membranes ◽  
Fiber Membranes ◽  
Pure Water Flux

The two-dimensional braid heterogeneous-reinforced (BHR) polyvinylidene fluoride (PVDF) hollow fiber membranes which include PVDF polymer solutions (coating layer) and the two-dimensional braid as a reinforcement were prepared through the dry-wet spinning process. The influence of PVDF concentration in polymer solutions on performance of BHR hollow fiber membranes were investigated by terms of pure water flux, protein rejection, a mechanical strength test, and morphology observations by a scanning electron microscope (SEM). The results of this study indicated that the tensile strength of the BHR PVDF hollow fiber membranes was nearly 75 MPa and the hollow fiber membranes were endowed with better flexibility performance. The BHR PVDF hollow fiber membranes had a favorable interfacial bonding between the coating layer and the two-dimensional braid. The pure water flux decreased, while the rejection ratio increased with the increase of polymer concentration.

scholarly journals Study of polyamide-6 hollow fiber membranes prepared via a thermally induced phase-separation method

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhao-Hui Jiang ◽  
Chang-Fa Xiao ◽  
Xiao-Yu Hu
Keyword(s):  
Hollow Fiber ◽  
Pure Water ◽  
Polymer Concentration ◽  
Water Flux ◽  
Bath Temperature ◽  
Coagulation Bath ◽  
Hollow Fiber Membranes ◽  
Fiber Membranes ◽  
Pure Water Flux ◽  
Coagulation Bath Temperature

AbstractHollow fiber membranes of polyamide-6(PA6) with porous structure were prepared by a thermally induced phase-separation method. N-Ethyl-o/p-toluene sulfonamide was chosen as diluent. On the basis of scanning electron microscopy (SEM) images, porosity, bubble point pore diameter and pure water flux, the influential factors including polymer concentration, coagulation bath temperature, post-stretching were investigated. The results indicate that with the increasing of PA6 concentration ‘slit-shaped’ pores in inner surfaces and cellular structure in cross-sections disappear, correspondingly, the properties of membranes such as porosity and pure water flux become poor. As the coagulation bath temperature varied from 20 °C to 50°C, the pure water flux of membranes is improved from 136 to 244 L·m-2·h-1. Post-stretching make the ‘interfacial micro-pores’ expand due to ‘stress concentration’ phenomenon, thus changing the structure and improving the properties of membranes. PA6 hollow fiber membranes with rational structure and high performance could be obtained by altering polymer concentration, coagulation bath temperature and post-stretching.

Post-Processing and Properties of Polyethersulfone Hollow Fiber Membrane

2012 ◽  
Vol 476-478 ◽  
pp. 2389-2392
Author(s):  
Ping Lan ◽  
Wei Wang ◽  
Jian Da Cao
Keyword(s):  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Pure Water ◽  
Water Flux ◽  
Hot Water ◽  
Hollow Fiber Membranes ◽  
Post Processing ◽  
Glycerol Water ◽  
Fiber Membranes ◽  
Pure Water Flux

Polyethersulfone (PES) hollow fiber membranes have been widely used in many fields, such as ultrafiltration, microfiltration, reverse osmosis, liquid/liquid or liquid/solid separation, gas separation, hemodialysis, and so on. In this paper, the sheet PES hollow fiber membranes were prepared and post-processing of membranes were studied. Suction method and pressing hot water method can both increase pure water flux of membrane. Suction method is more efficient and with a smaller time to increase pure water flux. After membrane was soaked into glycerol/water solution, pure water flux of membrane increased greatly and the length shrinkage ratio of the membrane was more smaller.

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