Bulk poly-m-phenylene isophthalamide （PMIA） can achieve flexibility upon dissolution by a LiCI/dimethylacetamide co-solvent, but remains hydrophobic despite the occasional emergence of cis amide groups providing a w...Bulk poly-m-phenylene isophthalamide （PMIA） can achieve flexibility upon dissolution by a LiCI/dimethylacetamide co-solvent, but remains hydrophobic despite the occasional emergence of cis amide groups providing a weak negative charge. In this study, based on the significant surface differences between PMIA membranes processed by nanofiber electrospinning and casting, a series of chemical analyses, in-situ Au nanoparticle depositions, and dye-adsorption experiments revealed that more cisconfiguration amide groups appeared on the surface of the electrospun PMIA membrane than on that of the cast membrane. Based on this surface difference, a strategy was proposed to improve the dyeing properties of PMIA by reversibly changing the cisltrans configurations of electrospun and cast membranes. The reversible chain-segment switch mechanism is a novel method for tuning the macroscale properties of polymer materials based on inherent molecular characteristics.展开更多
基金We thank the National Natural Science Foundation of China （Grant Nos. 51471153 and 51372227） and the 521 Talent Project of Zhejiang Sci-Tech University, Science and Technology Department of Zhejiang Province Foundation （No. 2017C37017） for providing financial support.
文摘Bulk poly-m-phenylene isophthalamide （PMIA） can achieve flexibility upon dissolution by a LiCI/dimethylacetamide co-solvent, but remains hydrophobic despite the occasional emergence of cis amide groups providing a weak negative charge. In this study, based on the significant surface differences between PMIA membranes processed by nanofiber electrospinning and casting, a series of chemical analyses, in-situ Au nanoparticle depositions, and dye-adsorption experiments revealed that more cisconfiguration amide groups appeared on the surface of the electrospun PMIA membrane than on that of the cast membrane. Based on this surface difference, a strategy was proposed to improve the dyeing properties of PMIA by reversibly changing the cisltrans configurations of electrospun and cast membranes. The reversible chain-segment switch mechanism is a novel method for tuning the macroscale properties of polymer materials based on inherent molecular characteristics.
