Journal
JOURNAL OF MEMBRANE SCIENCE
Volume 543, Issue -, Pages 1-9Publisher
ELSEVIER
DOI: 10.1016/j.memsci.2017.08.032
Keywords
PVDF; L-TIPS; Water-soluble non-solvent; Liquid-liquid phase separation; Tensile strength
Categories
Funding
- National Natural Science Foundation of China [21576210]
- Research Program of Application Foundation and Advanced Technology, Tianjin, China [15JCZDJC37500]
- Program for Changjiang Scholars and Innovative Research Team in University (PCSIRI) of Ministry of Education of China [IRI13084]
- Marine Science and Technology Project of Tianjin Province [KJXH2014-03]
Ask authors/readers for more resources
In the NIPS method, polyethylene glycol-400 (PEG400) was a common water-soluble additive and usually played the role of a pore-forming agent due to NIPS double-diffusion. In this paper, the new role of non-solvent PEG400 in the low temperature thermally-induced phase separation (L-TIPS) was analyzed. PEG400 were used to regulate the phase separation mechanism of the dope solution, and then to improve the membrane structure and performance. The membrane structure was regulated by gradually increasing the PEG400 content, the role evolution of water-soluble non-solvent PEG400 on the phase transformation mechanism and the effect on tensile strength of the polyvinylidene fluoride (PVDF) membrane were studied. The results show that the increase of PEG400 content can increase the cloud point temperature of dope solution, accelerate the thermally induced phase separation (TIPS) effect and inhibit the negative effect of the non-solvent induced phase separation (NIPS) effect on membrane structure. Meanwhile, the increase of PEG400 content can shift the TIPS effect of the dope solution system from solid-liquid phase separation to liquid-liquid phase separation and inhibit the growth of PVDF spherulites during the TIPS process. The dual role mechanism of PEG400 together eliminates the NIPS finger-like voids and the TIPS sphere-packed aggregation structure, which have the negative impact on tensile strength of the PVDF membrane. The PVDF membrane shows excellent mechanical properties; the tensile strength of the membrane reaches 3.12 MPa (more than 3-6 times higher than the membranes reported), pure water flux reaches 391 L m(-2) h(-1), and the rejection rate of carbon ink is 100%.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available