Fabrication and characterization of novel asymmetric polyvinylidene fluoride (PVDF) membranes by the nonsolvent thermally induced phase separation (NTIPS) method for membrane distillation applications

Xiao, Tonghu; Wang, Peng; Yang, Xing; Cai, Xinhai; Lu, Jianying

doi:10.1016/j.memsci.2015.03.081

Cited by 133 publications

(49 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The enhancement of mechanical strength is due to the change of the membrane structure from a long finger-like pore to a cellular pore structure, which led to decreased pore size and a narrower pore size distribution, as the total polymer concentration increased (Figure 1). This is also consistent with the decreasing porosity, as shown in Figure 2, which was also observed in previous work [25]. …”

Section: Resultssupporting

confidence: 93%

“…The pore structure of the bottom surface is mainly formed via the TIPS mechanism, as observed in a previous study [25]. Detailed explanations on the membrane formation mechanism will be provided in Section 3.2.…”

Section: Resultsmentioning

confidence: 67%

“…The solution was heated up in an oil bath under the protection of nitrogen at 140 °C and stirred at a constant speed of 120 rpm to form a homogeneous dope solution. The solutions were degassed at the preparation temperatures and then were rapidly casted on the glass plate by an automated high-temperature casting machine described elsewhere [25], which was preheated to 140 °C. The nascent membrane was quickly and smoothly immersed into a water coagulant bath (25 °C).…”

Section: Methodsmentioning

confidence: 99%

“…In other words, the high temperature of the TIPS process is not suitable for the fabrication of hydrophilically-modified PVDF membranes. In our previous work [25], a novel water-soluble diluent ε-caprolactam (CPL) was first used to dissolve PVDF and obtained homogeneous PVDF casting solutions at a much lower fabrication temperature of 130 °C by a nonsolvent thermally-induced phase separation (NTIPS) method, which has combined the advantages of NIPS and TIPS. With the appropriately-selected diluent for the PVDF polymer, the low solution temperature can substantially eliminate the effects of high temperature on the stability of the hydrophilic polymer used for fabricating hydrophilically-modified PVDF membranes with the desired pore structure and performance.…”

Section: Introductionmentioning

confidence: 99%

“…In this study, to obtain the desired membrane characteristics under simpler fabrication conditions, a nonsolvent thermally-induced phase separation approach (NTIPS) [25] is first used to prepare hydrophilically-modified PVDF/PVA blend membranes. ε-caprolactam is used as the diluent of PVDF at a fabrication temperature of 140 °C.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Preparation and Characterization of Hydrophilically Modified PVDF Membranes by a Novel Nonsolvent Thermally Induced Phase Separation Method

Xiao

Cai

et al. 2016

Membranes

Self Cite

View full text Add to dashboard Cite

In this study, a nonsolvent thermally-induced phase separation (NTIPS) method was first proposed to fabricate hydrophilically-modified poly(vinylidene fluoride) (PVDF) membranes to overcome the drawbacks of conventional thermally-induced phase separation (TIPS) and nonsolvent-induced phase separation (NIPS) methods. Hydrophilically-modified PVDF membranes were successfully prepared by blending in hydrophilic polymer polyvinyl alcohol (PVA) at 140 °C. A series of PVDF/PVA blend membranes was prepared at different total polymer concentrations and blend ratios. The morphological analysis via SEM indicated that the formation mechanism of these hydrophilically-modified membranes was a combined NIPS and TIPS process. As the total polymer concentration increased, the tensile strength of the membranes increased; meanwhile, the membrane pore size, porosity and water flux decreased. With the PVDF/PVA blend ratio increased from 10:0 to 8:2, the membrane pore size and water flux increased. The dynamic water contact angle of these membranes showed that the hydrophilic properties of PVDF/PVA blend membranes were prominently improved. The higher hydrophilicity of the membranes resulted in reduced membrane resistance and, hence, higher permeability. The total resistance Rt of the modified PVDF membranes decreased significantly as the hydrophilicity increased. The irreversible fouling related to pore blocking and adsorption fouling onto the membrane surface was minimal, indicating good antifouling properties.

show abstract

Section: Resultssupporting

confidence: 93%

Section: Resultsmentioning

confidence: 67%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Preparation and Characterization of Hydrophilically Modified PVDF Membranes by a Novel Nonsolvent Thermally Induced Phase Separation Method

Xiao

Cai

et al. 2016

Membranes

Self Cite

View full text Add to dashboard Cite

show abstract

Membrane Distillation: Now and Future

2019

View full text Add to dashboard Cite

Robust Preparation and Pore Structure Design of Homogeneous Braid‐Reinforced PVDF Hollow Fiber Membrane

Yan

Xiao

2022

Adv Materials Inter

View full text Add to dashboard Cite

In this work, the homogeneous braid‐reinforced poly(vinylidene fluoride) (PVDF) hollow fiber membrane with multiple pore structure is prepared successfully based on a nonsolvent‐induced phase separation (NIPS) method by adding different dioctyl phthalate (DOP) contents into the casting solution. The addition of DOP will restrict the phase separation process to avoid forming finger‐like macropores, while the placeholder and movement of DOP are conducive to the formation of more microporous and through holes. It is found that when the DOP content is 13%, the membrane has a porous surface layer with large surface pores and a cross section with bicontinuous structure. Compared with the membrane prepared without DOP, the separation flux of the membrane increases by 407% while maintaining a higher separation efficiency. Moreover, the prepared membranes reveal outstanding mechanical properties, and their tensile strength all exceeds 100 MPa. These findings indicate that the method may open more opportunities for the pore structure design based on the NIPS method.

show abstract

Fabrication and characterization of novel asymmetric polyvinylidene fluoride (PVDF) membranes by the nonsolvent thermally induced phase separation (NTIPS) method for membrane distillation applications

Cited by 133 publications

References 51 publications

Preparation and Characterization of Hydrophilically Modified PVDF Membranes by a Novel Nonsolvent Thermally Induced Phase Separation Method

Preparation and Characterization of Hydrophilically Modified PVDF Membranes by a Novel Nonsolvent Thermally Induced Phase Separation Method

Membrane Distillation: Now and Future

Robust Preparation and Pore Structure Design of Homogeneous Braid‐Reinforced PVDF Hollow Fiber Membrane

Contact Info

Product

Resources

About