Effect of coagulation bath temperature on formation mechanism of poly(vinylidene fluoride) membrane

2008 ◽  
Vol 110 (3) ◽  
pp. 1656-1663 ◽  
Author(s):  
Xuyun Wang ◽  
Lin Zhang ◽  
Dahai Sun ◽  
Quanfu An ◽  
Huanlin Chen
2012 ◽  
Vol 534 ◽  
pp. 8-12 ◽  
Author(s):  
Yun Qing Li ◽  
Dan Li Xi ◽  
Shun Li Fan

Poly(vinylidene fluoride)(PVDF), poly(vinyl chloride)(PVC), and poly(methyl methacrylate)(PMMA) were used as the main materials in the preparation of novel blend five-hole membrane. Dimethylacetamide (DMAC) and polyvinyl pyrrolidone (PVP) were used as solvent and additive, respectively. The effect of some external coagulation conditions on the property of five-hole membrane was studied. The external coagulation conditions investigated in the work were the coagulation temperature and the DMAC content in coagulation bath. The result showed that the flux increased along with the increase of coagulation bath temperature and could reach the max at 35°C, then decreased gradually. The effect of the DMAC content in coagulation bath on flux is very similar to that of the temperature. The cross-sectional structures were examined by scanning electron microscopy.


2015 ◽  
Vol 713-715 ◽  
pp. 2723-2726
Author(s):  
Yue Rong Shi ◽  
Gui Fang Zhang ◽  
Xing Tian Liu ◽  
Xue Tao Tian ◽  
Yi Ping Zhao ◽  
...  

In this study, poly (vinylidene fluoride) (PVDF) hybrid membranes were prepared from polymeric blend of PVDF/tannic acid (TA)-Attapulgite (ATP)/PEG system via phase inversion induced by immersion precipitation in water coagulation bath. The membrane formation mechanism of PVDF/TA-ATP/PEG casting solutions in water bath thermodynamics at different temperatures and the process of membrane formation were investigated via cloud point determination and ultrasonic time-domain reflectometry (UTDR). The structures and properties of the membrane were characterized by scanning electron microscopy (SEM), and water permeation experiment, respectively. It was found that the rate of precipitation controlled by the Coagulation-Bath thermodynamics. With the coagulation temperature increasing, the gelation line was moved to non-solvent axis and the pure water flux were decreased.


2015 ◽  
Vol 713-715 ◽  
pp. 2681-2684
Author(s):  
Xiao Tong Liang ◽  
Meng Xin Gu ◽  
Jin Ling Li ◽  
Xue Wang ◽  
Yi Ping Zhao ◽  
...  

In this work, poly (vinylidene fluoride)-graft-poly (N-isopropylacrylamide) (PVDF-g-PNIPAAm) thermo-sensitive polymer and poly (NIPAAm-co-AAc-L-Phe) chiral micro-gels were synthesized firstly. A chiral thermo-sensitive membrane for phenylalanine separation of the racemic mixture was prepared by phase inversion method with the blend of poly (NIPAAm-co-AAc-L-Phe) and PVDF-g-PNIPAAm. The blend membrane formation mechanism of the casting solutions in water bath thermodynamics at different temperatures and the process of membrane formation were investigated via cloud point determination and ultrasonic time-domain reflectometry (UTDR). The results showed that the inversion between hydrophilicity and hydrophobicity of PNIPAAm contributed to the membrane formation process. From the time needed in membrane forming recorded by ultrasonic signal spectra, it can be found that the speed for solidification was increased when the coagulation-bath temperature was higher than 30°C.


Membranes ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 87 ◽  
Author(s):  
Daria Nevstrueva ◽  
Arto Pihlajamäki ◽  
Juha Nikkola ◽  
Mika Mänttäri

Supported cellulose ultrafiltration membranes are cast from a cellulose-ionic liquid solution by the immersion precipitation technique. The effects of coagulation bath temperature and polymer concentration in the casting solution on the membrane morphology, wettability, pure water flux, molecular weight cut-off, and fouling resistance are studied. Scanning electron microscopy, contact angle measurements, atomic force microscopy, and filtration experiments are carried out in order to characterise the obtained ultrafiltration cellulose membranes. The results show the effect of coagulation bath temperature and polymer concentration on the surface morphology and properties of cellulose ultrafiltration membranes. Optimisation of the two parameters leads to the creation of dense membranes with good pure water fluxes and proven fouling resistance towards humic acid water solutions.


Author(s):  
Rizki Firsta Wahyuliswari ◽  
Siswanto ◽  
Prihartini Widiyanti

Polysulfone is synthetic polymer widely used as basic material for dialyzer membrane and hydrophobic so it tends to cause fouling. Cellulose acetate is non-synthetic, hydrophilic polymer which has low tendency of fouling and has good thermal stability and permeability so it is considered as alternative material for hollow fiber dialyzer. A proper hollow fiber can be achieved by setting a proper temperature of coagulation bath along the spinning process. This research aims to understand the effect of coagulation bath temperature variations on the physical characteristic such as pore size, tensile strength, swelling rate and creatinine clearance of cellulose acetate – D-glucose monohydrate hollow fibers. Hollow fibers were fabricated using spinneret at temperature variations 5°C, 10°C, 15°C dan 20°C. Physical characteristics were estimated by doing morphology test using SEM, tensile test, swelling test towards Simulated Body Fluid (SBF) and filtration test towards creatinine. Result revealed that the hollow fibers from 5°C coagulation bath temperature gives the best characteristic and performance with tensile strength 27,421 N mm-2, pore size 0,0295–0,0858 nm, swelling rate 4,18%, elongation rate 4,4 %, flux rate 1,6032–1,7956 mL cm-2 min-1 and creatinine clearance rate 40,14–48,30% so it is potential to be applied as dialyzer membrane.


Sign in / Sign up

Export Citation Format

Share Document