High water flux poly(acrylonitrile-co-methyl acrylate) membranes fabricated via thermally induced phase separation

2018 ◽  
Vol 120 ◽  
pp. 73-87 ◽  
Author(s):  
Linli Tan ◽  
Na Han ◽  
Longfei Zhang ◽  
Zhenyu Cui ◽  
Wei Li ◽  
...  
Keyword(s):  
Phase Separation ◽  
Methyl Acrylate ◽  
Water Flux ◽  
High Water ◽  
Thermally Induced Phase Separation ◽  
Thermally Induced ◽  
Poly Acrylonitrile

Effect of Modified NanoSiO2 Agents on the Morphologies and Performances of UHMWPE Microporous Membrane via Thermally Induced Phase Separation

2016 ◽  
Vol 848 ◽  
pp. 726-732 ◽  
Author(s):  
Rong Liu ◽  
Yan Wang ◽  
Jing Zhu ◽  
Zu Ming Hu ◽  
Jun Rong Yu
Keyword(s):  
Phase Separation ◽  
Water Flux ◽  
Microporous Membranes ◽  
Thermally Induced Phase Separation ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Thermally Induced ◽  
And Performance ◽  
Surface Modified ◽  
Ultra High Molecular Weight

The effects of Modified NanoSiO2 Agents on the morphology and performance of ultra-high-molecular weight polyethylene (UHMWPE) microporous membranes via thermally induced phase separation were investigated in this work. The NanoSiO2 was surface modified by silane coupling agent KH570 (KH570-NanoSiO2). Differential scanning calorimetry (DSC) and X-Ray Diffraction (XRD) were performed to obtain crystallization of UHMWPE/white oil/ KH570-NanoSiO2 doped system. The morphology and performance of the prepared UHMWPE microporous membranes were characterized with scanning electron microscopy (SEM) and microfiltration experiments. The results showed that the morphology of UHMWPE membrane could be disturbed by KH570-NanoSiO2. Porosity and the rejection of Bovine serum albumin (BSA) of the blend membrane increased with increasing concentration of Modified NanoSiO2, while the water flux slightly decreased.

Effect of the molecular weight and its distribution of polyvinylidene fluoride on the relationship between the spinning process, microstructure and properties of hollow fiber membranes via thermally induced phase separation

2018 ◽  
Vol 89 (7) ◽  
pp. 1311-1320 ◽  
Author(s):  
Nana Li ◽  
Zhe Chang ◽  
Qingchen Lu ◽  
Changfa Xiao ◽  
Junyi Wu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Phase Separation ◽  
Polyvinylidene Fluoride ◽  
Crystallization Behavior ◽  
Water Flux ◽  
Thermally Induced Phase Separation ◽  
Thermally Induced ◽  
Molecular Weights ◽  
Spinning Process ◽  
The Relationship

Polyvinylidene fluoride (PVDF) is an important material in the preparation of ultrafiltration membranes via the thermally induced phase separation (TIPS) method. In this paper, four PVDF hollow fiber membranes with different molecular weights were prepared via the TIPS method by using dibutyl phthalate and dioctyl phthalate as a mixed diluent. The relationship between the molecular weight of PVDF and its distribution, phase separation, crystallization behavior and spinning process has been systematically studied. The effects of three factors on the microstructure and properties of the PVDF membrane have been analyzed. The flow behaviors of the PVDF/diluent and PVDF melt were tested by a capillary rheometer and a melt flow rate instrument, respectively. A phase diagram of the membrane solution was determined by thermal polarizing microscope and differential scanning calorimetry. The crystallization behavior and angle of orientation of the membrane were tested by using a differential scanning calorimeter and a sound velocity orientation measurement instrument. The microstructures, such as the pore structure and crystalline grain structure, were observed by field emission scanning electron microscopy. Meanwhile, the properties of the membrane were examined from the view of water flux, porosity and tensile testing. The results showed that changes in the polymer molecular weights affected not only the dynamics but also the thermodynamics of phase separation in membrane formation. As the PVDF molecular weight increased, the phase separation region increased, but the membrane structure became denser. A wide molecular weight distribution easily produced large pores. Then, the water flux decreased first and then increased.

Preparation and Characterization of Polyacrylonitrile Membranes with High Strength via Thermally Induced Phase Separation Process

2014 ◽  
Vol 789 ◽  
pp. 205-208
Author(s):  
Chun Yi Liu ◽  
Chun Ju He
Keyword(s):  
Phase Separation ◽  
Performance Enhancement ◽  
Water Flux ◽  
High Strength ◽  
Thermally Induced Phase Separation ◽  
Elongation At Break ◽  
Thermally Induced ◽  
Structure Modulation ◽  
And Performance

Polyacrylonitrile (PAN) membranes were prepared via thermally induced phase separation (TIPS) process using polyethylene glycol (PEG) as plasticizing agent and polyvinyl pyrrolidone (PVP) as porogen, which presented high strength, i.e. 6MPa. A systematic study was carried out to investigate the effect of PVP content, PAN concentration and cooling conditions on the pore shape, pore size, water flux and mechanical properties of the membranes, which were characterized by scanning electron microscope, filtration measurement and tensile test. PAN membranes with uniformly distributed pores were fabricated by adjusting the mixed diluent composition. Results of filtration confirm that water flux of PAN membranes mainly depends on the pore structure. Moreover, while PVP content is increased, water flux first increases and then declines, and tensile strength and elongation at break first declines and then increases. In conclusion, the successful application of TIPS provides a new route to the structure modulation and performance enhancement of PAN membranes.

scholarly journals A Facile Way to Prepare Hydrophilic Homogeneous PES Hollow Fiber Membrane via Non-Solvent Assisted Reverse Thermally Induced Phase Separation (RTIPS) Method

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 269 ◽  
Author(s):  
Min Liu ◽  
Anne Ladegaard Skov ◽  
Sheng-Hui Liu ◽  
Li-Yun Yu ◽  
Zhen-liang Xu
Keyword(s):  
Phase Separation ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Pure Water ◽  
Water Flux ◽  
Solution Temperature ◽  
Thermally Induced Phase Separation ◽  
Thermally Induced ◽  
Polyethylene Glycol 200 ◽  
Forming Temperature

Sulfonated polyethersulfone (SPES) was used as an additive to prepare hydrophilic poly(ethersulfone) (PES) hollow fiber membranes via non-solvent assisted reverse thermally induced phase separation (RTIPS) process. The PES/SPES/N,N-dimethylacetamide (DMAc)/ polyethylene glycol 200 (PEG200) casting solutions are lower critical solution temperature (LCST) membrane forming systems. The LCST and phase separation rate increased with the increase of SPES concentrations, while the casting solutions showed shear thinning. When the membrane forming temperature was higher than the LCST, membrane formation mechanism was controlled by non-solvent assisted RTIPS process and the also membranes presented a more porous structure on the surface and a bi-continuous structure on the cross section. The membranes prepared by applying SPES present higher pure water flux than that of the pure PES membrane. The advantages of the SPES additive are reflected by the relatively high flux, good hydrophilicity and excellent mechanical properties at 0.5 wt.% SPES content.

Preparation of Ultra-High Molecular Weight Polyethylene Microporous Membranes via Thermally Induced Phase Separation

2012 ◽  
Vol 476-478 ◽  
pp. 2363-2367 ◽  
Author(s):  
Ling Ling Zhu ◽  
Zu Ming Hu ◽  
Jun Rong Yu ◽  
Guo Ping Tang ◽  
Lei Chen ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Phase Separation ◽  
High Molecular Weight ◽  
Diffusion Rate ◽  
Water Flux ◽  
Crystallization Rate ◽  
Microporous Membranes ◽  
Thermally Induced Phase Separation ◽  
Thermally Induced ◽  
Ultra High Molecular Weight

Ultra-high molecular weight polyethylene (UHMWPE) microporous membranes were fabricated via thermally induced phase separation (TIPS). Thermogravimetric analyzer was used to obtain the true concentration of films. To characterize the permeation property, the testing of water flux was carried out and it was found that with the increase of thickness, concentration and molecular weight, a decrease in water flux occurred. However, the water flux changed slightly when the thickness turned into 150μm and the molecular weight reached 4,000,000. Moreover, the pore structure investigated by Field emission scanning electron microscopy (FESEM) was consistent with the above phenomena. It is known that the pore size is affected by two factors: crystallization rate and the diffusion rate of diluent. The curves of the relative crystallinity (Xt) with time for the various films under the cooling rate of 10°C/min showed that the difference between crystallization rate of various membranes was small. So it was considered that the viscosity of system did greater influence on diffusion rate of diluent. In addition, the disparity between cloud points (Tcd) and crystallization temperature (T0) was not obvious, indicating that only solid-liquid phase separation could be observed in the range of cooling rates during the non-isothermal process.

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