<p>Nanoporous polypropylene (PP) membranes are increasingly vital for diverse applications, driving the demand for facile fabrication methods that yield controlled pore structures and high performance. This study introduces a novel approach for creating PP membranes with aligned nanopores through a two-step thermal infiltration and directional crystallization process. A crystallizable solvent, arachidic acid (AA), is thermally infiltrated into PP films, followed by directional crystallization under a temperature gradient. Subsequent selective extraction of the crystallized AA results in the formation of internally aligned nanopores. To enhance porosity and interconnectivity, a two-step infiltration strategy was employed—initial infiltration at a high temperature (160&#xa0;℃), followed by isothermal holding at intermediate temperatures (130–150&#xa0;℃). This approach enabled precise control over crystallization kinetics with maintaining PP crystalline phases, leading to the formation of improved nanopore networks. As a result, membranes with a porosity up to 56% exhibited improved filtration flux. Thermal analysis and mechanical testing revealed that the crystallinity and mechanical strength of the membranes varied significantly depending on the thermal infiltration history. The proposed method shows great potential for the development of environmentally friendly, scalable, and high-performance functional membranes.</p> Graphical abstract <p></p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Two-step thermal infiltration and crystallization of solvent for preparation of nanoporous polypropylene membranes

  • Dayeon Lee,
  • Jonghwi Lee

摘要

Nanoporous polypropylene (PP) membranes are increasingly vital for diverse applications, driving the demand for facile fabrication methods that yield controlled pore structures and high performance. This study introduces a novel approach for creating PP membranes with aligned nanopores through a two-step thermal infiltration and directional crystallization process. A crystallizable solvent, arachidic acid (AA), is thermally infiltrated into PP films, followed by directional crystallization under a temperature gradient. Subsequent selective extraction of the crystallized AA results in the formation of internally aligned nanopores. To enhance porosity and interconnectivity, a two-step infiltration strategy was employed—initial infiltration at a high temperature (160 ℃), followed by isothermal holding at intermediate temperatures (130–150 ℃). This approach enabled precise control over crystallization kinetics with maintaining PP crystalline phases, leading to the formation of improved nanopore networks. As a result, membranes with a porosity up to 56% exhibited improved filtration flux. Thermal analysis and mechanical testing revealed that the crystallinity and mechanical strength of the membranes varied significantly depending on the thermal infiltration history. The proposed method shows great potential for the development of environmentally friendly, scalable, and high-performance functional membranes.

Graphical abstract