Preparation of silver nanoparticles was carried out by semicontinuous reduction of Ag + ions at low temperatures. Silver nitrate was used as the Ag 0 precursor, the carboxymethyl cellulose (CMC) as stabilizer and primary reducing agent, and sodium borohydride as reducing agent. Weight ratios of 1 : 1 and 1 : 2 of AgNO 3 : CMC were used for carrying out the reactions. Silver nanoparticles were characterized by UV-VIS spectroscopy, transmission electronic microscopy (TEM), and X-ray diffraction (XRD). The formation of silver nanoparticles was confirmed by XRD spectroscopy and by the presence of an absorption peak around 400 nm in the UV-visible spectrum. Unimodal size distributions of spheroidal nanoparticles were observed by TEM. Greater productivities than those reported by other authors were obtained with the advantage of using a lower temperature and minor reaction times. By using a higher CMC/AgNO 3 weight ratio or a higher concentration of AgNO 3 , AgNPs with larger average size were produced. Antibacterial activity of AgNPs against S. aureus and E. coli was determined by the agar disk diffusion method. The higher the AgNPs concentration, the larger the inhibition zone. The minimum inhibitory concentration (MIC) of AgNPs against S. aureus and E. coli was 5 g/disk.

Precipitation of silver nanoparticles at 70°C was carried out by dosing a 1.3 M sodium borohydride aqueous solution over bicontinuous microemulsions formed with a mixture of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and sodium dodecylsulfate (SDS) as surfactants, a 0.5 M silver nitrate aqueous solution, and toluene. Weight ratios of 2.5/1 and 3/1 AOT/SDS were used in the precipitation reactions. Silver nanoparticles were characterized by transmission electronic microscopy, X-ray diffraction, and atomic absorption spectroscopy. A mixture of isolated spheroidal nanoparticles (≈15 wt.%) with an average diameter around 10 nm and wormlike structures (≈85 wt.%) with an average length close to 480 nm and an average diameter ca. 40 nm was obtained, regardless of the AOT/SDS ratio. Higher yields were obtained compared with those reported when reverse microemulsions were employed. Formation of wormlike structures was ascribed to one-dimensional aggregation of crystal and particles within the channels of bicontinuous microemulsions, which performed as templates.

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Synthesis of silver nanoparticles (AgNPs) was carried out in aqueous solutions. Silver nitrate was used as precursor, carboxymethyl cellulose (CMC) as stabilising agent, and sodium borohydride as reducing agent. The reaction was semicontinuous by feeding both the precursor and reducing agent into the stabilising agent aqueous solution in an alternated fashion. Weight ratios of 1:1 AgNO 3 :CMC were used in the reduction reactions. AgNPs were characterised by UV-vis spectroscopy, transmission electronic microscopy (TEM), and X-ray diffraction. The formation of AgNPs was confirmed by the presence of an absorption peak about 400 nm using UV-vis spectrophotometry. Spheroidal nanoparticles with an average diameter between 5 and 90 nm were observed by TEM. High productivity of AgNPs was obtained at lower reaction times and at low temperature compared with others previously reported in the literature.

In this work, the capability to use pine rosin as a biodegradable coupling agent/compatibilizer is studied. To formulate composites, post-consumer polypropylene and discarded agave fibers (as reinforcing agent) are coupled with pine rosin (in pure or maleated form). Besides, poly(lactic acid) (PLA) with poly(butylene adipate-co-terephthalate) (PBAT) are compatibilized with maleated pine rosins to prepare biodegradable blends. For the coupling agent role, the pure or maleated rosin (Amberyl M-15A) are compared with a commercial polyolefin coupling agent (Epolene E-43), while for the blends, two maleated rosins (Amberyls M-15A and MP-30) are used as compatibilizers. Dynamic and static mechanical tests show considerable increments in moduli and strength for both types of polymeric materials surpassing the role of the Epolene E-43 for the composite materials (v.g. 45.2 vs 16.5 increment in storage modulus, or 61.5 vs 40.3 for Young's modulus in specific tests). Scanning electron microscopy photographs clearly show the interfacial interaction effect within composites and polymer blends. Fourier transform infrared spectroscopy allowed the observation of the aforementioned interactions at bond level. Blends biodegradation performed by composting for 3 months exceeded 76% of weight loss. The multirole of modified natural maleated gums as coupling agents/compatibilizers is demonstrated.

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