Interactions between an Aryl Thioacetate‐Functionalized Zn(II) Porphyrin and Graphene Oxide

The surface modification of graphene oxide (GO) is carried out via the supramolecular functionalization route using a Zn(II)‐porphyrin which is soluble in common organic solvents on basis of long alkyl chains present at the exocyclic positions. This acts as a dispersing agent and decorates the surface of the graphene oxide uniformly, giving rise to a new nanohybrid denoted Zn(II)‐porphyrin@GO. The resulting Zn(II)‐porphyrin@GO nanohybrid forms a stable dispersion in ethanol (as characterized by several different spectroscopic techniques such as UV–vis, Fourier transform infrared, Raman). The morphology of Zn(II)‐porphyrin@GO nanohybrid is investigated by atomic force microscopy (AFM) and transmission electron microscope (TEM)/selected area electron diffraction. Both TEM and AFM measurements indicate that the Zn(II)‐porphyrin self‐assemble onto the surface of graphene oxide sheets. Steady‐state and time‐resolved fluorescence emission studies in the dispersed phase, and as a thin film, point toward the strongly quenched fluorescence emission and lifetime decay, suggesting that energy transfer occurs from the singlet excited state of Zn(II)‐porphyrin unit to GO sheets.     

Vol. 8 (1998)

Wireless Personal Communications -     

Foreword (Sep. 1982 Transactions)

New Systems continue to require microwave filters with ever more stringent passband and stopband control, smaller size, and lighter weight. Today's communications satellites, as an example, demand the tightest possible packing of channels in specific total bands. This requirement has stimulated especially sophisticated advances in insertion-loss and group-delay performance, more practical and compact configurations, and more versatile and useful theoretical design theory for bandpass two-ports and multiplexer.     

看似节约，实则浪费（1）

好的方面是,这些问题容易预防和解决。不好的方面是,人们的观念完全是错误的,表面上好像省了钱,而实际上是多花了钱。