,Controlling the Coffee Ring Effect on Graphene and Polymer by Cations

• 作 者: Haijun Yang Yizhou Yang Shiqi Sheng Binghai Wen Nan Sheng Xing Liu Rongzheng Wan Long Yan Zhengchi Hou Xiaoling Lei Guosheng Shi Haiping Fang
• 机 构: Shanghai Synchrotron Radiation Facility, Zhangjiang Laboratory(SSRF, ZJLab),Shanghai Advanced Resear
• 出 处: 中国物理快报（英文版）
• 发表日期: 2020年2期

Recently,there are great efforts that have been taken to suppressing/controlling the coffee ring effect,but it is of challenge to achieve inexpensive and efficient control with less disturbance,suitable for scalable production and highly enhancing the printing/dyeing color fastness.By only adding trace amounts of salt into the suspensions,here we experimentally achieve the facile and highly efficient control of the coffee ring effect of suspended matter on substrates of graphene,natural graphite,and polyethylene terephthalate surfaces.Notably,friction force measurements show that ion-controlled uniform pattes also greatly enhance color fastness.Molecular dynamics simulations reveal that,due to strong hydrated cation-π interactions between hydrated cations and aromatic rings in the substrate surface,the suspended matters are adsorbed on the surfaces mediated by cations so that the suspended matters are uniformly distributed.These findings will open new avenues for fabricating functional pattes on graphene substrates and will benefit practical applications including printing,coating,and dyeing.