【公開日：2024.07.25】【最終更新日：2024.06.21】

課題データ / Project Data

課題番号 / Project Issue Number

23NU0411

利用課題名 / Title

Development of highly efficient coalescence separation process of microemulsion using nanofibrous membrane

利用した実施機関 / Support Institute

名古屋大学 / Nagoya Univ.

機関外・機関内の利用 / External or Internal Use

内部利用（ARIM事業参画者以外）/Internal Use (by non ARIM members)

技術領域 / Technology Area

【横断技術領域 / Cross-Technology Area】（主 / Main）物質・材料合成プロセス/Molecule & Material Synthesis（副 / Sub）-

【重要技術領域 / Important Technology Area】（主 / Main）次世代ナノスケールマテリアル/Next-generation nanoscale materials（副 / Sub）-

キーワード / Keywords

Zeta-potential, microemulsion,ナノワイヤー・ナノファイバー/ Nanowire/nanofiber

利用者と利用形態 / User and Support Type

利用者名（課題申請者）/ User Name (Project Applicant)

YUE　 Yunpeng

所属名 / Affiliation

名古屋大学大学院 工学研究科

共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes

村瀬 智紀

ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes

利用形態 / Support Type

（主 / Main）機器利用/Equipment Utilization（副 / Sub）-

利用した主な設備 / Equipment Used in This Project

NU-020：粒径測定装置 ゼータ電位・粒径測定システム(ゼータ電位、粒径・粒度分布）

報告書データ / Report

概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)

Nanofibrous membranes have proven to be an effective method for the separation of oil-in-water (O/W) emulsions. Most research has primarily focused on a sieving method, which involves constructing a superhydrophilic and underwater superoleophobic surface to repel oil and selectively allow water to pass through the membrane. However, the sieving method, while achieving a high separation ratio, often limits the permeation flux due to its small pore size. Moreover, the membrane exhibits susceptibility to fouling, leading to the degradation of underwater superoleophobicity. Consequently, this results in the loss of the membrane’s selective separation capacity and further contributes to the diminishment of the permeation flux. As an alternative approach, coalescence separation holds potential for achieving high permeation flux in the separation of O/W emulsion. This method involves the demulsification and coalescence of emulsified oil droplets, resulting in the formation of a continuous oil phase within the intricate nanofiber networks. The continuous oil phase can be efficiently discharged with water, facilitating the facile separation and collection of the floating oil. This research is aim to develop a functionalized nanofibrous membrane with both a high separation ratio and an ultra-high permeation flux for the coalescence separation of O/W emulsions. The electrostatic plays a important role in the demulsification in the coalescence separation of oil-in-water emulsion, therefore the zeta potential was measured by the device provided by ARIM.

実験 / Experimental

 The zeta potential tester (ELSZ-2) manufactured by Otsuka Electronics Co., Ltd., Japan was used to measure the nanofibrous membrane’s zeta potential. 

結果と考察 / Results and Discussion

The PAN nanofibrous membrane showed a zeta potential of −23.2 mV, and the oil-in-water emulsion showed a zeta potential of -50.0 mV. The PAN membrane faced challenges for the demulsification of surfactant-stabilized oil-in-water emulsion due to the strong electrostatic repulsion with negatively charged oil droplets. The separation performance was not stable for PAN nanofibrous membrane because the stabilized oil droplets were unable to undergo demulsification, leading to the formation of a cake layer with high resistivity. Conversely, the positively charged ZIF-8/PAN membrane, characterized by a zeta potential of +2.1 mV, demulsified the negatively charged oil droplets and maintained a stable separation process even at higher flow rates. Notably, ZIF-8/PAN showed an impressively ultra-high permeation flux, reaching 21,177 L m⁻² h⁻¹ when applied to the separation of surfactant-free oil-in-water emulsion, accompanied by a separation ratio of over 99.9 %. For surfactant-stabilized emulsion, the positively charged ZIF-8/PAN effectively demulsified the anionic surfactant SDS-stabilized oil droplets, resulting in a separation ratio exceeding 97.1 % and a flux value of 14,118 L m⁻² h⁻¹ during a steady-state separation without membrane cleaning. This study emphasizes the application of MOF-decorated electrospun nanofibrous membranes in the O/W emulsions coalescence separation, showcasing effective separation with an ultra-high flux.

図・表・数式 / Figures, Tables and Equations

その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)

成果発表・成果利用 / Publication and Patents

論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)

1. Yunpeng Yue, Electrospun hierarchically structured nanofibrous membrane for highly efficient oil-in-water emulsion coalescence separation, Separation and Purification Technology, 322, 124331(2023).
   DOI: https://doi.org/10.1016/j.seppur.2023.124331
   
2. Yunpeng Yue, In situ growth of ZIF-8 on nanofibrous membrane for long-term ultra-high flux coalescence separation of oil-in-water emulsion, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 688, 133681(2024).
   DOI: https://doi.org/10.1016/j.colsurfa.2024.133681
   

口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.

1. 50th Textile Research Symposium (Mauritius), Fabrication of Double-Layered Nanofiber Coalescer with Superior Separation Efficiency and Permeation Flux for Oil-in-Water Emulsion, ○YUE Yunpeng, MUKAI Yasuhito, Oral presentation, 2023.9.8
2. 14th International Symposium on High-Tech Fiber Engineering for Young Researcher (Suzhou, China), Nanofiber-Based Coalescer for Enhanced Separation of Oil-in-Water Emulsion, ○YUE Yunpeng, MUKAI Yasuhito, Oral presentation, 2023.8.29
3. 12th International Conference on Separation Science and Technology (Okinawa, Japan), Enhanced Oil-in-Water Emulsion Separation using Nanofibrous Membrane Coalescers, ○YUE Yunpeng, MUKAI Yasuhito, Poster presentation, 2023.11.17
4. 2023年繊維学会秋季研究発表会（京都）, Development of ZIF-8/Polyacrylonitrile Nanofibrous Membrane for Efficient Coalescence Separation of Oil-in-Water Emulsion, ○YUE Yunpeng, MUKAI Yasuhito, 口頭発表, 2023.11.27
5. 日本膜学会第45年会・膜シンポジウム2023合同大会（東京）, Effective Separation of Emulsified Oil Droplets Based on ZIF-8/PAN Nanofiber Membrane Coalescer, ○YUE Yunpeng, MUKAI Yasuhito, 口頭発表, 2023.11.20
6. 化学工学会第54回秋季大会（福岡）, Efficient Steady-State Coalescence Separation of Emulsified Oil Droplets Using Electrospun Dual-Layered Nanofibrous Membranes, ○YUE Yunpeng, MUKAI Yasuhito, ポスター発表, 2023.9.13
7. 日本繊維機械学会第76回年次大会（大阪）, Electrospun Hierarchical Structured Nanofibrous Coalescing Media for Highly Efficient Separation of Oil-in-Water Emulsion, ○YUE Yunpeng, MUKAI Yasuhito, 口頭発表, 2023.6.1 & ポスター発表, 2023.6.1

特許 / Patents

特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件