19 research outputs found
Core shell hybrids based on noble metal nanoparticles and conjugated polymers: synthesis and characterization
Noble metal nanoparticles of different sizes and shapes combined with conjugated functional polymers give rise to advanced core shell hybrids with interesting physical characteristics and potential applications in sensors or cancer therapy. In this paper, a versatile and facile synthesis of core shell systems based on noble metal nanoparticles (AuNPs, AgNPs, PtNPs), coated by copolymers belonging to the class of substituted polyacetylenes has been developed. The polymeric shells containing functionalities such as phenyl, ammonium, or thiol pending groups have been chosen in order to tune hydrophilic and hydrophobic properties and solubility of the target core shell hybrids. The Au, Ag, or Pt nanoparticles coated by poly(dimethylpropargylamonium chloride), or poly(phenylacetylene-co-allylmercaptan). The chemical structure of polymeric shell, size and size distribution and optical properties of hybrids have been assessed. The mean diameter of the metal core has been measured (about 10-30 nm) with polymeric shell of about 2 nm
Core shell hybrids based on noble metal nanoparticles and conjugated polymers: synthesis and characterization
<p>Abstract</p> <p>Noble metal nanoparticles of different sizes and shapes combined with conjugated functional polymers give rise to advanced core shell hybrids with interesting physical characteristics and potential applications in sensors or cancer therapy. In this paper, a versatile and facile synthesis of core shell systems based on noble metal nanoparticles (AuNPs, AgNPs, PtNPs), coated by copolymers belonging to the class of substituted polyacetylenes has been developed. The polymeric shells containing functionalities such as phenyl, ammonium, or thiol pending groups have been chosen in order to tune hydrophilic and hydrophobic properties and solubility of the target core shell hybrids. The Au, Ag, or Pt nanoparticles coated by poly(dimethylpropargylamonium chloride), or poly(phenylacetylene-co-allylmercaptan). The chemical structure of polymeric shell, size and size distribution and optical properties of hybrids have been assessed. The mean diameter of the metal core has been measured (about 10-30 nm) with polymeric shell of about 2 nm.</p
Soluble polymers of monosubstituted acetylenes with quaternary ammonium pendant groups. Structure and morphology
Soluble conjugatedpolymerswereobtained inthe presence ofPd(II),Pt(II)andRh(I) complexes frommonosubstituted acetylene
3-dimethylamino-1-propyne (H–C CCH2N(CH3)2, 1) and the corresponding hydrochloride (H–C CCH2N(CH3)2·HCl, 2) and
hydrobromide (H–C CCH2N(CH3)2·HBr, 3) derivatives. A series of reactionswere performed to achieve the optimization of the
polymerization conditions.Thehighest yieldswere foundforpolymers synthesized usingPd(II)bisacetylides specially prepared,
i.e. trans-[Pd(PPh3)2(C CCH2N(CH3)2)2], trans-[Pd(PPh3)2(C CCH2N(CH3)2)2HCl] and trans-[Pd(PPh3)2(C CCH2N(CH3)2)2HBr],
respectively. The dimension and size distribution of the polymers were investigated using dynamic light scattering. Polymers
containing quaternary ammonium groups showed evidence of a hydrodynamic radius of about 300 nm if prepared with the
Rh(I) catalyst and of 160 nm if prepared with the Pd(II) catalysts. Polymers obtained from 1 showed smaller hydrodynamic
radius compared to polymers obtained from 2 and 3, regardless the polymerization catalyst. The ionic polymericmaterials were
soluble in organic solvents and, more interestingly, in water. The formation of nanoparticles with pearl-like morphology was
achieved using a recently developed osmosis-based method, with dimensions varying from 60 nm up to micrometres.
c 2011 Society of Chemical Industr
"Soluble poly(monosubstituted)acetylenes with quaternary ammonium pendant groups. Structure and morphology"
Definizione di un protocollo operativo per il monitoraggio degli spostamenti superficiali
Self-assembled nanoparticles of functional copolymers for photonic applications
A modified emulsion copolymerization of phenylacetylene (PA) with hydrophilic monomers having different functions, i.e., acrylic acid (AA) and N,N-dimethylpropargylamine (DMPA) respectively, yields functionalized polymeric P(PA-co-AA) and P(PA-co-DMPA) nanoparticles. The systematic investigation on the experimental parameters affecting size, surface charge and polydispersity of the copolymers (initiator concentration, reaction time, cosolvent and PA/comonomer ratios) allows to modulate the nanoparticle physico-chemical properties. Spherical shaped particles with diameters in the range 80-500 nm, low polydispersity (PI values in the range 1.11-1.30) and different surface charge densities, between 0.44 and 2.87 mu C/cm(2), have been consistently obtained and characterized by means of Dynamic Light Scattering (DLS), laser Doppler electrophoretic and Scanning Electron Microscopy (SEM) studies. XPS measurements have provided information on the nanoparticles chemical surface structure and suggest that AA and DMPA units are preferentially distributed on the surface of the spheres. The nanospheres self-assemble giving large domains (9.5 x 14.5 mu m). Photonic analysis of the self-assembled copolymeric nanoparticles has been performed by means of Spectroscopic Ellipsometry (SE) and Bragg reflection spectroscopy, both of them demonstrating a three-dimensional photonic crystal property of these systems. (C) 2010 Elsevier Inc. All rights reserved