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

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.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.476-478.2363 ◽

2012 ◽

Vol 476-478 ◽

pp. 2363-2367 ◽

Cited By ~ 2

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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Structure and Performance of PP Porous Membrane Prepared with Adipic Acid and NA-40 as Nucleating Agent via TIPS

Materials Science Forum ◽

10.4028/www.scientific.net/msf.848.733 ◽

2016 ◽

Vol 848 ◽

pp. 733-737

Author(s):

Hui Xia Xuan ◽

Chun Ju He

Keyword(s):

Adipic Acid ◽

Water Flux ◽

Nucleating Agent ◽

Porous Membrane ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Sem Images ◽

Thermally Induced ◽

Cooling Temperature ◽

And Performance

Polypropylene (PP) membranes were respectively prepared using adipic acid (APA) and Sorbitol (NA-40) as nucleating agent via thermally induced phase separation (TIPS) method. The effects of nucleating agent content and cooling temperature on the structure and performance of membrane were investigated using scanning electron microscopy (SEM), wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC). WAXD spectrogram indicates that three kinds of α, β and γ-form crystal were formed in this preparation process and the relative content of β-form crystal in membrane prepared by NA-40 system is higher than that of membrane formed by adipic acid. SEM images show that porous structure and cellular structure were observed on the surface and cross-section of membrane. The water flux, tensile strength and elongation increase with the addition of nucleating agent content and decrease with cooling temperature rising. This paper aims to choose proper nucleating agent NA-40 and coagulation temperature to improve the properties of PP membranes.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.789.205 ◽

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.

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