Masaki Mugisawa

Architecture of Linear Arrays of Fluorinated Co-oligomeric Nanocomposite-Encapsulated Gold Nanoparticles: A New Approach to the Development of Gold Nanoparticles Possessing an Extremely Red-Shifted Absorption Characteristic

Fluoroalkyl end-capped co-oligomeric nanoparticles, which were prepared by the reaction of fluoroalkanoyl peroxide with 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and 1-hydroxy-5-adamantylacrylate (Ad-HAc), were applied to the preparation of novel fluorinated co-oligomeric nanocomposite-encapsulated gold nanoparticles. These fluorinated gold nanocomposites were easily prepared by the reductions of gold ions with poly(methylhydrosiloxane) (PMHS) in the presence of the corresponding fluorinated nanoparticles and tri -n-octylamine (TOA) in 1,2-dichloroethane (DE) at room temperature. These fluorinated gold nanoparticles were isolated as wine-red powders and were found to exhibit good dispersibility in a variety of traditional organic solvents such as DE, methanol, and t-butyl alcohol to afford transparent wine-red solutions. The morphology and stability of these fluorinated co-oligomeic nanocomposite-encapsulated gold nanoparticles were characterized using transmission electron microscopy (TEM), dynamic light scattering measurements (DLS), and UV-vis spectroscopy. DLS measurements and UV-vis spectroscopy showed that these particles are nanometer-size-controlled very fine nanoparticles (185-218 nm) that exhibit a plasmon absorption band at around 530 nm. TEM images also showed that gold nanoparticles are tightly encapsulated into fluorinated co-oligomeric nanoparticle cores. Interestingly, these fluorinated co-oligomeric nanocomposites-encapsulated gold nanoparticles were found to afford linear arrays of these fluorinated nanoparticles with increases in the feed amounts of TOA. More interestingly, these fluorinated gold nanoparticles were able to afford the extremely red-shifted plasmon absorption band at around 960 nm.

Cross-Linked Fluoroalkyl End-Capped Co-Oligomeric Nanoparticle-Encapsulated Fullerene—A New Approach to the Surface Modification of Traditional Organic Polymers with Fullerene-Containing Nanoparticles

Cross-linked fluoroalkyl end-capped co-oligomeric nanoparticle-encapsulated fullerenes, prepared by deprotecting a fluoroalkyl end-capped isocyanatoethyl methacrylate 2-butanone oxime adduct-1-hydroxy-5-adamantylacrylate co-oligomer in the presence of fullerene, were of well-defined size in the nanometer range (28-82 nm) and exhibited good dispersibility in a variety of solvents such as methanol, ethanol, isopropyl alcohol, tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide, and 1,2-dichloroethane. Transmission electron microscopy images also showed that these nanocomposites were particles with a mean diameter of 45 nm and that the fullerenes were tightly encapsulated into fluorinated nanoparticle cores. In methanol, these fluorinated nanoparticles emitted fluorescence related to the presence of fullerene and were applied in the surface modification of traditional organic polymers such as poly(methyl methacrylate) (PMMA) to effect good oleophobicity imparted by fluorine on the modified film surfaces. Interestingly, a higher fluorescent intensity of fullerene was observed on the modified PMMA surfaces, although the reverse side of these film surfaces yielded an extremely weak fluorescent intensity. More interestingly, a fluorescence microscopy image of the cross-section of the modified PMMA film showed that encapsulated fullerene was arranged regularly above the modified PMMA film surface.