RESUMO
The production and physical properties of nanowires and nanoribbons formed by methylphosphonic acid (MPA)--CH3PO(OH)2--were investigated. These structures are formed on an aluminum coated substrate when immersed in an ethanolic solution of MPA for several days. A careful investigation of the growth conditions resulted in a narrow window of solution concentrations and temperatures for the successful development of nanowires and nanoribbons. Several different techniques were employed to characterize these nanostructures: (1) Photoluminescence experiments showed a strong emission at 2.3 eV (green), which is visible to the naked eye; (2) X-ray diffraction experiments indicated a significant cristalinity, in agreement with atomic force microscopy (AFM) and transmission electron microscopy (TEM) morphology images, which show organized nano-scale wires and ribbons, (furthermore, AFM-Phase and TEM images also suggest that nanoribbons are formed by well-aligned nanowires); (3) Conductive-AFM experiments revealed an intermediary conductivity for these structures (10(-1)/Ohm x m), which is similar to some intrinsic semiconductors and; (4) finally, Infrared, Raman, and X-Ray Photoelectron Spectroscopies produced information about the contents, structure, and composition of both wires and ribbons.
Assuntos
Nanopartículas/química , Nanotubos de Carbono/química , Nanofios/química , Compostos Organofosforados/química , Absorção , Alumínio/química , Luz , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Nanotecnologia/métodos , Espectrofotometria Infravermelho/métodos , Análise Espectral Raman/métodos , Temperatura , Difração de Raios XRESUMO
There are few reports of pulmonary hypertension in Gaucher disease. We report a patient who showed significant clinical improvement after treatment with sildenafil.