Influence of the covalent grafting of organic radicals to graphene on its magnetoresistance
作者:Concha Bosch-Navarro、Filippo Busolo、Eugenio Coronado、Yan Duan、Carlos Martí-Gastaldo、Helena Prima-Garcia
DOI:10.1039/c3tc30799a
日期:——
obtained by direct exfoliation of graphite in o-dichlorobenzene (oDCB) or benzylamine, and further functionalized with 4,4′-[(1,3-dioxo-1,3-propanediyl)bis(oxy)]bis[2,2,6,6-tetramethyl-1-piperidinyloxy] (1-TEMPO) organic radicals by using the Bingel–Hirsch cyclopropanation reaction. Here, the use of different solvents permits variation of the density of radicals anchored to the carbon layers. Covalent grafting
石墨烯是通过在石墨中直接剥落而获得的 邻二氯苯 (oDCB)或 苄胺,并进一步用4,4'-[((1,3-dioxo-1,3-propanediyl)bis(oxy)] bis [2,2,6,6-tetramethyl-1-piperidinyloxy](1-TEMPO)官能化通过使用Bingel-Hirsch环丙烷化反应生成有机自由基。在此,使用不同的溶剂可以改变锚定在碳层上的自由基的密度。TGA,μ-拉曼光谱,XPS和EPR测量清楚地证明了共价接枝,这也排除了杂散的物理吸附。我们的传输测量结果表明,传导机制随接枝到碳层上的自由基密度的变化而变化。而且,顺磁性部分的存在通过低场磁阻(LFMR)效应的出现影响系统的磁阻行为。最后,用抗磁性丙二酸乙酯分子将石墨烯衍生化,