Castro M.E. – TechConnect Briefs

Nanoscaled Science and Engineering for Sensing : Quantum Dots Fluorescence Quenching for Organic NO2 Sensing

Nieto S., Santana A., Delgado R., Hernandez S.P., Chamberlain R.T., Lareau R., Castro M.E., The University of Puerto Rico Chemical Imaging Center, US

We report on femtosecond laser off-resonance excitation of quantum dots-TNT assemblies in solution. The fluorescence emission from quantum dots shifts toward lower wavelengths and the relative peak intensity decreases with the amount of TNT added [...]

Growth Kinetics of Gold Nanoparticles in Reverse Micelles

Herrera A.P., Vicuña E., Rinaldi C., Castro M.E., Irizarry R., Briano J.G., University of Puerto Rico, US

Gold nanoparticles were formed from the reduction of gold (III) in reverse micelles and monitored with a stopped flow analyzer. The gold and the reducing agent micelles were formed in isooctane and AOT (as surfactant). [...]

A New Wet Chemical Approach to the Selective Synthesis of Silver Nanowires

Hernandez E.A., Posada B., Irizarry R., Castro M.E., The University of Puerto Rico, US

A new wet chemical approach is presented for the selective synthesis of silver nanowires based on the assembly of silver nanoparticles covered with a bi-functional thiol. The particles are formed spontaneously upon the addition of [...]

Density Functional Calculations as a Tool for the Characterization of Ultra Thin Organic Films: Synthesis and spectroscopic characterization of RDX monolayers on glass substrates

Torres P., Cotte I., Mina N., Hernandez S.P., Chamberlain R.T., Garcia J., Lareau R., Castro M.E., The University of Puerto Rico, US

Density functional theory calculations (DFT), Raman and atomic force microscopy (AFM) were employed to study the surface chemistry of ultra thin films of RDX on glass substrates. The preparation method played a major role in [...]

Real Time Kinetic Measurements of Silver Nanocluster Growth

Mercado L., Castro M.E., Castro W., Vicuña E., Briano J.G., Ishikawa Y., Irizarry R., Solá L., Castro M.E., Castro W., University of Puerto Rico, US

Metallic clusters of noble metals are of tremendous technological importance due to their conduction properties, size, low reactivity and optical properties. Clusters containing as few as two and four silver atoms have been prepared in [...]

Growth Kinetics of Gold Nanoparticles

Murillo L.E., Viera O., Vicuña E., Briano J.G., Castro M.E., Ishikawa Y., Irizarry R., Solá L., University of Puerto Rico, US

We have measured the growth kinetics of gold nanoparticles in real time. Gold nanoparticles were formed from the reduction of gold (III) in aqueous solution and monitored with a stopped-flow reactor equipped with a diode [...]