The present invention is directed to compositions (“Nanomaterial Polymer Compositions”) comprising a silicone polymer and a nanomaterial, including but not limited to, a single or multi-walled nanotube, a nanowire, a nanodot, a quantum dot, a nanorod, a nanocrystal, a nanotetrapod, a nanotripod, a nanobipod, a nanoparticle, a nanosaw, a nanospring, a nanoribbon, a branched nanomaterial, or any combination thereof. The Nanomaterial Polymer Compositions are useful for optical and sensing devices including but not limited to noise suppression, passive Q-switching, mode-locking, waveform shaping, optical switching, optical signal regeneration, phase conjugation or filter devices, dispersion compensation, wavelength conversion, a soliton stabilization, microcavity applications, interferometers; optical, magneto-optical or electro-optical modulation; and biochemical sensors and photodetectors. The Nanomaterial Polymer Compositions are also useful in soft lithography processes.

Nanomaterial polymer compositions and uses thereof

We report on the use of amines as reducing agents in the formation of gold nanoparticles. We can predict whether the amines will function as reducing agents in this reaction based on their redox properties. The kinetics of AuNP formation can be understood in terms of Marcus electron transfer theory, where the slower reactions proceed in the inverted region owing to the difference between the Au reduction potential and the amine oxidation potential. For a certain number of the amine reducing agents, following reduction of HAuCl4, a subsequent reaction of the amine radical cation with other reducing agent molecules in solution can form poly(amine)s. These findings point collectively to the utility of amines as reducing agents in AuNP formation and provide information on the conditions under which these reactions will proceed.

Formation of gold nanoparticles using amine reducing agents.

Spontaneous formation and efficient stabilization of gold nanoparticles with an average diameter of 7∼20 nm from hydrogen tetrachloroaureate(III) hydrate (HAuCl4·3H2O) were achieved in air-saturated aqueous poly(ethylene oxide)−poly(propylene oxide)−poly(ethylene oxide) (PEO−PPO−PEO) block copolymer solutions at ambient temperature in the absence of any other reducing agent. The particle formation mechanism is considered here on the basis of the block copolymer concentration dependence of absorption spectra, the time dependence (kinetics) of AuCl4- reduction, and the block copolymer concentration dependence of particle size. The effects of block copolymer characteristics such as molecular weight (MW), PEO block length, PPO block length, and critical micelle concentration (cmc) are explored by examining several PEO−PPO−PEO block copolymers. Our observations suggest that the formation of gold nanoparticles from AuCl4- comprises three main steps:  (1) reduction of metal ions by block copolymer in solution, (...

Mechanism of gold metal ion reduction, nanoparticle growth and size control in aqueous amphiphilic block copolymer solutions at ambient conditions

A single-step synthesis of gold nanoparticles with an average diameter of ∼10 nm from hydrogen tetrachloroaureate(III) hydrate (HAuCl4·3H2O) has been achieved in air-saturated aqueous solutions that contain poly(ethylene oxide)−poly(propylene oxide)−poly(ethylene oxide) (PEO−PPO−PEO) block copolymers but not any other reducing agent. These amphiphilic block copolymers act as both reductants and colloidal stabilizers and prove very efficient in both functions. The formation of gold nanoparticles is controlled by the overall molecular weight and relative block length of the block copolymer. The synthesis procedure reported here is environmentally benign and economic, as it involves the minimum possible number of components:  it uses water as the solvent, it uses commercially available polymers, it proceeds fast to completion, and it results in a “ready-to-use” product.

Single-step synthesis and stabilization of metal nanoparticles in aqueous pluronic block copolymer solutions at ambient temperature

The potential ability of a new yeast strain, Pichia kudriavzevii, in the synthesis of zinc oxide nanoparticles (ZnO-NPs) through a green method was explored in this study The effect of reaction time (12, 24 and 36 h) on the structure of the resulting ZnO nanoparticles was investigated From the XRD and TEM results, the ZnO-NPs with a hexagonal wurtzite structure and a particle crystal size of ~10–61 nm was formed at different reaction times Combing XRD, TEM, and PL results, it was revealed that the sample prepared at intermediate duration (24 h) has the most favorable nanosized structure with the lowest defect concentration The biomedical properties of ZnO-NPs as free radical scavenging activity, cytotoxicity and antibacterial agents were characterized Biosynthesized ZnO-NPs showed strong DPPH free radical scavenging and a dose dependent toxicity with non-toxic effects on Vero cells for concentrations below 190 µg/mL Desirable bactericidal activity was shown by the ZnO-NPs on Gram-positive bacteria (Bacillus subtilis, Staphylococcus epidermidis and Staphylococcus aurous) and Gram-negative bacteria (Escherichia coli and Serratia marcescens) A maximum inhibition zone of ~19 mm was observed for Staphylococcus epidermidis at a concentration of 100 µg/mL for sample prepared at 24 h The results from this study reveal that ZnO-NPs possesses potential for many medical and industrial applications

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Biosynthesis of ZnO Nanoparticles by a New Pichia kudriavzevii Yeast Strain and Evaluation of Their Antimicrobial and Antioxidant Activities.

Recently, production methods of metal nanoparticles have been investigated extensively, not only for a research use in laboratory, but also for an industrial use. However, it is difficult to obtain metal nanoparticles in high amounts and concentrations with simple methods. In this study, a gold nanoparticle-polymer composite was prepared with a simple procedure using a gold salt and a melted polymer. The composite, which is in a wax state at room temperature, was highly soluble in water and lower alcohols, moreover the composite was melted at about 50 °C.

K. Kuroda

Papers

Production of gold nanoparticles-polymer composite by quite simple method

Size evolution effect of the reduction rate on the synthesis of gold nanoparticles