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

Abstract

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.

Selective preparation of novel fluoroalkyl end-capped co-oligomeric nanocomposite-encapsulated magnetites and magnetite-adsorbing co-oligomeric nanoparticles

“…50,51 In contrast, fluoroalkyl end-capped betaine-type co-oligomeric nanoparticles containing adamantane segments can exhibit LCST behavior in organic media such as t-butyl alcohol because of the effective oleophilic-oleophobic balance between the oleophilic character from adamantyl segments and the oleophobic character from endcapped fluoroalkyl groups. 43,44 This is the first example of LCST behavior in organic media, although the LCST behavior of hydrocarbon polymers in ionic liquids has been previously reported by Watanabe et al 52 Thus, it is of particular interest to study the LCST behavior of our present fluoroalkyl end-capped betaine-type co-oligomeric nanocomposite-encapsulated Magnt in organic media. We measured the size of fluorinated betaine-type co-oligomeric nanocomposite-encapsulated Magnt by the use of DLS in t-butyl alcohol at temperatures ranging from 40 to 80 1C.…”

“…43,44 The mixture was stirred at room temperature for 6 h under ultrasonic irradiation conditions. After centrifugal separation (2000 r.p.m./30 min) at room temperature, the supernatant solution was evaporated under reduced pressure to yield purified fluorinated betaine-type co-oligomeric nanocomposite-encapsulated Magnt (112 mg).…”

“…41,42 We have also found that fluoroalkyl end-capped 2-acrylamido-2-methylpropanesulfonic acid co-oligomers containing adamantane segments can form nanometer-scale particles, not only in water but also in various traditional organic solvents. 43,44 The architecture of such fluorinated fine nanoparticles is because of the moderate oleophilic-oleophobic balance in these co-oligomeric nanoparticles, corresponding to the oleophilic character of the bulky adamantyl segments and the oleophobic character of end-capped fluoroalkyl groups. [41][42][43][44] Therefore, it is expected that these fluorinated co-oligomeric nanoparticle cores should interact with magnetic nanoparticles as a guest molecule to form colloidal-stable fluorinated co-oligomeric nanocomposite-encapsulated magnetic particles.…”

“…43,44 The architecture of such fluorinated fine nanoparticles is because of the moderate oleophilic-oleophobic balance in these co-oligomeric nanoparticles, corresponding to the oleophilic character of the bulky adamantyl segments and the oleophobic character of end-capped fluoroalkyl groups. [41][42][43][44] Therefore, it is expected that these fluorinated co-oligomeric nanoparticle cores should interact with magnetic nanoparticles as a guest molecule to form colloidal-stable fluorinated co-oligomeric nanocomposite-encapsulated magnetic particles. Here, we report that magnetic nanoparticles can be encapsulated into crosslinked fluoroalkyl end-capped co-oligomeric nanoparticle cores containing adamantyl segments to form colloidally stable magnetic nanoparticles.…”

Coloring–decoloring behavior of fluoroalkyl end‐capped 2‐acrylamido‐2‐methylpropanesulfonic acid oligomer/acetone composite in methanol

“…The fluorinated co‐oligomeric nanoparticles exhibit the low critical solution temperature (LCST) of around 52 °C, because of the oleophobic–oleophobic (fluorophilic–fluorophilic) interaction between end‐capped fluoroalkyl segments in organic media, such as t ‐butyl alcohol . These fluorinated co‐oligomeric nanoparticles have been used to encapsulate a variety of metal nanoparticles to afford stable colloidal fluorinated nanocomposites . Therefore, it is particularly desirable to develop fluoroalkyl end‐capped AMPS co‐oligomeric nanoparticles for encapsulating organic guest molecules.…”