Superhydrophilic polyvinyl alcohol-formaldehyde composite sponges with hierachical pore structure for oil/water emulsion separation

Sha, Di; Zheng, Run; Wang, Baolong; Xu, Jiuduo; Shi, Kai; Yang, Xu; Ji, Xiangling

doi:10.1016/j.reactfunctpolym.2021.104975

Cited by 18 publications

(5 citation statements)

References 49 publications

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“…The water content in emulsion and filtrate was detected by headspace gas chromatography according to our previous literature . The separation efficiency ( E ff ) was calculated based on water concentration in original emulsion and filtrate according to eq . where C 0 and C f are the water concentrations in original emulsion and filtrate, respectively.…”

Section: Methodsmentioning

confidence: 99%

Evaluation of Intrinsic-Type and Hydrophobic Three-Dimensional Melamine/Polyvinyl-Alcohol Formaldehyde Sponges Containing a Hierarchical Porous Structure for Emulsion Separation

Wang

Zheng

Shi

et al. 2022

ACS Appl. Polym. Mater.

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Emulsion separation of emulsified oil wastewater has been an urgent problem from both environmental and economic perspectives to be dealt with. Here, to overcome the emulsion separation material-prepared process involving expensive equipment and consuming large energy and the composite componentfunctionalized running off problem during application, a series of intrinsic-type and hydrophobically functionalized three-dimensional (3D) melamine/polyvinyl-alcohol formaldehyde (MF/PVF-Cn-x) sponges containing interpenetrating polymer networks (IPNs) and a hierarchical porous structure were synthesized by introducing a PVF network into a commercial melamine (MF) sponge by coacetalation crosslinking reaction first and further acylating chlorination chemical grafting reactions. Water contact angles of as-prepared sponges were higher than 114.7°. Cross-sectional SEM morphological observation and pore size distribution curves demonstrated that interpenetrating polymer networks (IPN) and a hierarchical porous structure were constructed successfully. Their pore size scope was from 1 to 100 μm, and the average pore size was around 20 μm (15.7 and 25.1 μm), which was similar to a stable emulsion droplet size of 20 μm, which satisfied the size sieving requirement for emulsion separation. Compared with the separation performance of 2D membrane materials, MF/PVF-Cn-x 3D hierarchical porous materials exhibited excellent separation performance and antifouling property. Among them, the MF/PVF-C16-46.8% sponge had the most prominent emulsion separation performance with a flux of 9.55 × 10 4 L m −2 h −1 bar −1 and an efficiency of nearly 100%. Furthermore, the separation flux of MF/PVF-Cn-x was still higher than 2.22 × 10 4 L m −2 h −1 bar −1 and the efficiency was nearly 100% after seven cycles. On the other hand, the mechanical properties of MF/PVF-Cn-x sponges were strengthened by the introduced PVF network, and their compress stress was higher than 3.2 MPa. All the comprehensive performances made MF/PVF-Cn-x sponges become a suitable candidate as a highly effective emulsion separation material.

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Section: Methodsmentioning

confidence: 99%

Evaluation of Intrinsic-Type and Hydrophobic Three-Dimensional Melamine/Polyvinyl-Alcohol Formaldehyde Sponges Containing a Hierarchical Porous Structure for Emulsion Separation

Wang

Zheng

Shi

et al. 2022

ACS Appl. Polym. Mater.

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“…Then the PVDF-CC membrane was immersed in a 2 M sodium citrate solution for 5 minutes to prepare the coating by salting-out method. Finally, the PVDF-CC membrane is obtained by using the salting-out method [4][5].…”

Section: Preparation Of Pvdf-cc Membranementioning

confidence: 99%

Study on efficient oil-containing wastewater purification with super-hydrophilic PVDF coating

Wang,

Qi,

Xia

et al. 2024

J. Phys.: Conf. Ser.

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The sustainable, low-energy, and cost-effective treatment of oily wastewater has become an important issue for aquatic ecosystems, environmental protection, and economic development. Improper treatment could have a significant impact on aquatic ecosystems, resulting in eutrophication and fish deaths. The method for preparing PVDF-CC by impregnation involves using polyvinylidene fluoride (PVDF), chitosan, and sodium citrate. Moreover, these performance improvements can be achieved at a lower cost compared to using many other chemical agents in membrane processing.

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“…Chang et al 31 prepared a highly absorbent PVF/SiO 2 sponge with an average pore size of 50−80 μm using the simultaneous acidification of the water glass solution aspect. Sha et al 32 first prepared a PVF sponge using Trition X-100 and then mixed PVA solution containing chitosan, diatomite, and sodium alginate into the PVF sponge for acetal treatment again and finally obtained composite sponges with average pore sizes of 20−30 μm. The results were all higher than 97% separation efficiency for surfactant-stabilized oil-in-water emulsions.…”

Section: Introductionmentioning

confidence: 99%

Tailored Pore Size and Hydrophilicity: Advancing Poly(vinyl formal) Sponges for Efficient Emulsion Separation

Zhang,

Dai,

Hui

et al. 2024

ACS Appl. Polym. Mater.

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In the field of emulsion separation, the application of porous hydrophilic sponge materials is of paramount importance; however, the conventional preparation process of hydrophilic poly(vinyl formal) (PVF) restricts the simultaneous enhancement of separation efficiency and water flux. In this work, by introducing two poly(vinyl alcohol) (PVA) and aldehyde feedstocks with different molecular weights and functional group contents into the reaction system, the differences in the mobility and reactivity of the feedstocks were exploited to successfully achieve tailoring of the pore size and hydrophilicity. The PVF sponge prepared by using this method exhibited high separation efficiency and water flux in emulsion separation. This preparation method not only avoided the requirement for pore-forming agents in traditional preparations but also significantly reduced the amount of formaldehyde by adding trace amounts of glutaraldehyde, ensuring the hydrophilicity of the sponge and markedly reducing the pore size. The experimental results showed that the addition of 1.5 × 10 −3 mol/L glutaraldehyde could effectively reduce the average pore size of the PVF sponge from 26.5 to 7.2 μm while maintaining excellent hydrophilicity. The preparation mechanism of PVF sponges was thoroughly explored, and the effects of different concentrations of formaldehyde and glutaraldehyde on the sponge properties were extensively investigated. Experimental results demonstrated that the prepared PVF sponge achieved a separation efficiency of up to 98.5% for the OP-10-stabilized oil-inwater emulsion and exhibited outstanding recyclability. This cost-effective and easily scalable method for PVF sponge preparation could be employed to produce a range of highly efficient filtration materials, effectively separating target oil-in-water emulsions.

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Superhydrophilic polyvinyl alcohol-formaldehyde composite sponges with hierachical pore structure for oil/water emulsion separation

Cited by 18 publications

References 49 publications

Evaluation of Intrinsic-Type and Hydrophobic Three-Dimensional Melamine/Polyvinyl-Alcohol Formaldehyde Sponges Containing a Hierarchical Porous Structure for Emulsion Separation

Evaluation of Intrinsic-Type and Hydrophobic Three-Dimensional Melamine/Polyvinyl-Alcohol Formaldehyde Sponges Containing a Hierarchical Porous Structure for Emulsion Separation

Study on efficient oil-containing wastewater purification with super-hydrophilic PVDF coating

Tailored Pore Size and Hydrophilicity: Advancing Poly(vinyl formal) Sponges for Efficient Emulsion Separation

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