In situ nanoparticle formation embedded into hydrogel matrix, acting as container and stabilizer for nanoparticle reaction was the focus in this research; this method was realized using AgNO 3 (0.75 and 1.0 M) as silver source for nanoparticle formation; also, monomers (HEMA), cross-linker agents (DEGDMA) and a photoinitiator (Irgacure 651) were used for the hydrogel synthesis. For the reduction of Ag ? ? Ag 0 , the reaction mixture was irradiated with an UV lamp at 365 nm for 30 min; parallel to this process, the hydrogel photopolymerization occurs. All these systems were studied by Infrared and Raman Spectroscopy, optical studies: UV/Vis absorption, thermal studies: differential scanning calorimetry and thermogravimetric analysis, X-ray diffraction, fluorescence X-ray spectroscopy and transmission electronic microscopy. Characterization techniques are capable to detect the presence of non-agglomerated silver nanoparticles homogeneously distributed in all the systems. X-Ray photoemission spectroscopy establishes the presence of Ag 0 and Ag ? as mixture in the synthesized composite. Quantitative assays show that the sample Ag_Hg3-89.5 % (1.0 M) presents an important biocide property, by reducing 99.9 % of bacterium Escherichia coli ATCC 25922 as compared with the alone hydrogel used as control.

Soluble pure silicon or germanium-containing poly(amide)s and their metallic composites (Cu or Au) were synthesized and characterized. Optical band gaps of pure polymer were comparable to an insulator behavior; however, the conductivity of some composites at several concentrations shows a diode-like behavior. Samples exhibit a monoclinic lattice mixed with amorphous structures. Specifically, polymer–Au composites showed distortion of this unit cell, associated with an increase in the conductance. This effect would be related to the coordination of the central atom (Si or Ge) to the incorporated metal, producing a homogeneous distribution of metallic particles within the system.MECESUP UCH 0601 and the corresponding authors thank the financial support provided by FONDECYT project: Nr 1095151, 1100015 and 1100882

Optically active poly(amide-imide) oligomers were synthesized by direct polycondensation between an aromatic diamine and a dicarboxylic acid both containing a diphenylsilylene unit. The reaction was carried out using triphenyl phosphite/pyridine in the presence of CaCl2 and N-methyl-2-pyrrolidone as solvent. Oligomers were obtained in good yields and showed high solubility in common aprotic polar solvents. The precursors, monomers and poly(amide-imide) oligomers were characterized using elemental analysis and Fourier transform infrared and NMR (1H, 13C, 29Si) spectroscopy. Additionally, themain vibrations of the functional groups (C O, C C or N–H) in the oligomers with respect to temperature were characterized using Raman spectroscopy. The glass transition temperature was determined by studying the Raman spectra and corroborated using differential scanning calorimetry. The thermal stability was studied using thermogravimetric analysis. The molecular mass of the compounds was obtained from matrix-assisted laser desorption ionization time-of-flight mass spectrometry and their optical properties were analyzed using UV-visible diode array spectrophotometry. The electronic properties of the oligomers as well as the delocalization of charge carriers within their structures were analyzed using conductance-voltage curves, which showed that thesematerials are excellent candidates for integrated optoelectronic applications.MECESUP UCH 0601 and FONDECYT (grants 1100015, 1095151, 1100882

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