Breaking bonds: pulling is more efficient than heating in driving surface retro- Diels-Alder reaction

马宏伟，hwma2008@sinano.ac.cn

中国科学院苏州纳米技术与纳米仿生研究所，苏州，215123

Abstract：Chemistry is all about breaking old bonds and forming new bonds. In this talk, we will show that pulling is more efficient than heating in driving surface retro- Diels-Alder (retro-DA) reaction. First, we developed a "solidified liquid layer" model (SLL) for quartz crystal microbalance (QCM) operated in liuquid ^[1]. This SLL model made QCM a sensitive, online detector for the swelling behavior of surface tethered weak polyelectrolytes, which were prepared via surface initiated polymerization (SIP) ^[2,3]. Second, detailed studies revealed that under proper conditions, such swelling of surface tethered weak polyelectrolytes could be turned into a pN force generator. Enviromental cues, such as pH, salt concentration and Voltage could be applied to finely tune the force ^[4,5]. Finally, SERS, XPS and other tools were combined to show that a retro-DA reaction was possible via pulling but not via heating. Future research efforts of mechanochemistry should be directed into inventing devices that makes pulling more convienient than heating.

关键词：机械力化学，石英晶体微天平，固化水层模型，表面引发聚合反应

References：

[1] Solidified liquid layer model expands the application fields of quartz crystal microbalance, Macro. Rapid Commun., 33, 735-741, 2012

[2] Surface initiated polymerization from substrates of low initiator density and its applications in biosensors, Soft Matter, 7, 11496-11500, 2011

[3] Swelling induced Au-S bond breakage is determined by the molecular composition of surface tethered copolymers-carboxylated poly(OEGMA-r-HEMA), Chem. Commun., 47, 9855-9857, 2011

[4] Directly observed Au-S bond breakage due to swelling of the anchored polyelectrolyte, Chem. Commun. 47, 1190-1192, 201

[5] A proton shelter inspired by the sugar coating of acidophilic archaea, Scientific Reports, 2, 892, 2012