Molecularly-mediated assembly of gold nanoparticles with interparticle rigid, conjugated and shaped aryl ethynyl structures.

The rigidity, conjugation, and shape-persistent architectures of aryl ethynyls of V, Y, and X shapes serve as an ideal model system for defining interparticle structures, which have been demonstrated for the mediated assembly of gold nanoparticles.

One-step functionalization of multi-walled carbon nanotubes with Ag/polymer under γ-ray irradiation.

We reported an easy strategy of using γ-ray irradiation to functionalize multi-walled carbon nanotubes (MWCNTs) without the use of aggressive acid treatment, all in a single processing step. In this paper, we tried to decorate MWCNTs with Ag nanoparticles relying on covalently bonded polymers, via one-step covalent grafting of the polymer to the surface of MWCNTs, and simultaneous reducing of Ag(+) ions to Ag which are then efficiently anchored onto the MWCNTs. Herein, the polymer involved was the commercially available polymer poly(vinyl alcohol) (PVA) and two of its derivatives, polyvinylacetone with ketalization degree D(H) = 0.22 and 0.53. It is envisioned that this simple but efficient method could be extended to fabricate other CNT-based hybrids for both theoretical study and applications in biological and technological fields.

Propeller-like multicomponent microstructures: Self-assemblies of nanoparticles of poly(vinyl alcohol)-coated Ag and/or Cu2O.

Novel propeller-like multicomponent microstructures, which are actually self-assemblies of nanoparticles of poly(vinyl alcohol) (PVA)-coated Ag and/or Cu2O, were synthesized in aqueous solution of amphiphilic polyvinylacetone (PVKA) (ketalization degree D(H) = 0.549), via one-step in situ reduction of Ag+ and Cu2+ under gamma-ray irradiation, utilizing the low hydrolysis rate of PVKA in the dilute acidic solution. Herein, PVA chains are obtained from hydrolyzed PVKA. The reaction mechanism and the formation mechanism are proposed. The room temperature photoluminescence spectrum has also been applied to explore the optical property.

Synthesis and characterization of water-soluble multiwalled carbon nanotubes grafted by a thermoresponsive polymer.

Water-soluble multiwalled carbon nanotubes (MWNTs) with temperature-responsive shells were successfully prepared by grafting poly (N-isopropylacrylamide) (PNIPAM) from the sidewalls of MWNTs, via surface reversible addition-fragmentation chain transfer (RAFT) polymerization using RAFT agent functionalized MWNTs as the chain transfer agent. Thermogravimetric analysis (TGA) measurements showed that the weight composition of the as-grown PNIPAM polymers on the MWNTs can be well controlled by the feed ratio (in weight) of NIPAM to RAFT agent functionalized MWNTs (MWNT-SC(S)Ph). The MWNT-g-PNIPAM has good solubility in water, chloroform, and tetrahydrofuran (THF). Transmission electron microscope (TEM) and scanning electron microscope (SEM) images also showed that the MWNT-g-PNIPAM was dispersed individually and eventually bonded with the polymer layer by surface RAFT polymerization. The PNIPAM shell is very sensitive to a change of temperature. This method could find potential applications by grafting other functional polymer chains onto MWNTs.

In situ formation of Ag flowerlike and dendritic nanostructures in aqueous solution and hydrolysis of an amphiphilic block copolymer.

Silver flowerlike and dendritic nanostructures were synthesized in an aqueous solution of a hydrolysable amphiphilic block copolymer polyvinylacetone (PVKA) via in situ reduction of Ag(+) and hydrolysis of PVKA at room temperature. Compared with a previous result, the complete hydrolysis time of PVKA is greatly shortened in this process.