Based on the noncovalent functionalization of ferrocene-grafted polyethylenimine （PEI-Fc） and carbon nanotubes （CNTs）, CNT bundles are exfoliated by PEI-Fc solution and thus form stable compounds PEI-Fc@CNTs, whic...Based on the noncovalent functionalization of ferrocene-grafted polyethylenimine （PEI-Fc） and carbon nanotubes （CNTs）, CNT bundles are exfoliated by PEI-Fc solution and thus form stable compounds PEI-Fc@CNTs, which is used to construct the PEI-Fc@CNTs/DNA multilayers through layer-by-layer assembly. The multilayers show a highly uniform and homogeneous characteristic, which significantly improve the electrical property of the multilayers. Upon the oxidation electrical potential, the ferrocene groups are switched from reduction state （[Fe（C5H5）2]） to oxidation state （[Fe（C5H5）2]^＋）, leading to change of microenvironments＇ charge density, resulting in swelling of the multilayers and a final degree of swelling of 37 % and the decrease of multilayer stiffness. We maintain that electrochemical control over the swelling behavior of multilayers could have important implications for responsive coatings of nanoscale devices, including mechanically tunable surfaces which are used to modulate cellular activities and control drug delivery.展开更多
基金supported by the National Natural Science Foundation of China(21174126,51333005,21374095)the National Basic Research Program of China(2011CB606203)+2 种基金Research Fund for the Doctoral Program of Higher Education of China(20110101110037,20120101130013)the Qianjiang Excellence Project of Zhejiang Province(2013R10035)International Science&Technology Cooperation Program of China(2014DFG52320)
文摘Based on the noncovalent functionalization of ferrocene-grafted polyethylenimine （PEI-Fc） and carbon nanotubes （CNTs）, CNT bundles are exfoliated by PEI-Fc solution and thus form stable compounds PEI-Fc@CNTs, which is used to construct the PEI-Fc@CNTs/DNA multilayers through layer-by-layer assembly. The multilayers show a highly uniform and homogeneous characteristic, which significantly improve the electrical property of the multilayers. Upon the oxidation electrical potential, the ferrocene groups are switched from reduction state （[Fe（C5H5）2]） to oxidation state （[Fe（C5H5）2]^＋）, leading to change of microenvironments＇ charge density, resulting in swelling of the multilayers and a final degree of swelling of 37 % and the decrease of multilayer stiffness. We maintain that electrochemical control over the swelling behavior of multilayers could have important implications for responsive coatings of nanoscale devices, including mechanically tunable surfaces which are used to modulate cellular activities and control drug delivery.
