Rapid continuous microwave-assisted synthesis of silver nanoparticles to achieve very high productivity and full yield: from mechanistic study to optimal fabrication strategy

Systematic studies of silver nanoparticle synthesis in a continuous-flow single-mode microwave reactor using polyol process were performed, revealing that the synthesis is exceptionally effective to give very small metal particles at full reaction yield and very high productivity. Inlet concentration of silver nitrate or silver acetate, applied as metal precursors, varied between 10 and 50 mM, and flow rates ranged from 0.635 to 2.5 dm3/h, to give 3–24 s reaction time. Owing to its much higher reactivity, silver acetate was shown to be far superior substrate for the synthesis of small (10–20 nm) spherical silver nanoparticles within a few seconds. Its restricted solubility in ethylene glycol, applied as the solvent and reducing agent, appeared to be vital for effective separation of the stage of particle growth from its nucleation to enable rapid synthesis of small particles in a highly loaded system. This was not possible to obtain using silver nitrate. All the observations could perfectly be explained by a classical LaMer–Dinegar model of NPs’ formation, but taking into account also nonisothermal character of the continuous-flow process and acetate dissolution in the reaction system. The performed studies indicate an optimal strategy for the high-yield fabrication of metal particles using polyol method

SEM images of fluorescent HFBMA particles

SEM images of fluorescent HFBMA particles. The modiefied fluoresceine was used as fluorescent agent. Detailed description of PM001, PM003 and PM011 presented in "Fluorinated methacrylate nanoparticles with modified fluorescein as a dye agen" by Jarzebski et al. The images were obtained in different magnification. The SEM images confirmed the data obtained from dynamic light scattering (DLS) that prepared polymeric samples were higly polydispersive

SEM images of fluorescent HFBMA particles

SEM images of fluorescent HFBMA particles. The modiefied fluoresceine was used as fluorescent agent. The samples were previously desribed as PM001, PM003 and PM011 and submitted as a supporting materials for the paper called "Fluorinated methacrylate nanoparticles with modified fluorescein as a dye agen" by Jarzebski et al. After reviewers comments we made additional investigations and presented this year in the paper entitled "Fluorescein ether-ester dyes for labeling of fluorinated methacrylate nanoparticles" submitted to Journal of Photochemistry and Photobiology A: Chemistry. We change the samples names for NPs HFBMA 1, NPs HFBMA 2, NPs HFBMA 3. The images were obtained in different magnification. The SEM images confirmed the data obtained from dynamic light scattering (DLS) that prepared polymeric samples were higly polydispersive

Fabrication of Ag and Cu nanoparticles in electromagnetic microwave tield

Artykuł przedstawia wyniki badań nad otrzymywaniem nanocząstek srebra i miedzi w procesie przepływowym wspomaganym oddziaływaniem jednorodnego pola mikrofalowego. Syntezy prowadzono z zastosowaniem glikolu etylenowego jako reduktora, AgN03) AgOAc i Cu(OAc)2jako prekursorów nanocząstek i poliwinylopirolidonu K-30 jako stabilizatora wytwarzanych koloidów. Stwierdzono istotny wpływ temperatury i rodzaju zastosowanego prekursora na rozmiar końcowy nanocząstek wytwarzanych koloidów.The paper presents investigation results dealing with the fabrication of silver and copper nanoparticles in the microwave assisted flow process. The synthesis were carried out with application of ethylene glycol as reducer, AgN03, AgOAc and Cu(OAc)2 as precursors of nanoparticles and polyvi- nylpirrolidone K-30 as stabilizer of colloids. It was found a crucial influ¬ence of process temperature and precursor type on a final size of prepared nanoparticles

Stimuli-Responsive PNIPAM Based Copolymers: Modeling and Light Scattering Investigations

Temperature dependent behavior of poly(N-isopropylacrylamide) (PNIPAM) copolymers was investigated in three buffer-stabilized environments. The tests were performed in thermostabilized goniometer by dynamic and static light scattering. From the dynamic light scattering hydrodynamic radius was obtained. Based on the static light scattering data, calculations of the particle radius from the form factor model were done. Depending of the kind of copolymer, the different material response to temperature was observed. Also the characterization of dry particles was done by scanning electron microscope. These scanning electron microscopy micrograms showed the possibility of particles to aggregation

Effects of Concentration and Type of Lipids on the Droplet Size, Encapsulation, Colour and Viscosity in the Oil-in-Water Emulsions Stabilised by Rapeseed Protein

The objective of this study was to extract the rapeseed protein from by-products and further examine the effect of lab-made rapeseed protein on the droplet size, microstructure, colour, encapsulation and apparent viscosity of emulsions. Rapeseed protein-stabilised emulsions with an increasing gradient of milk fat or rapeseed oil (10, 20, 30, 40 and 50%, v/v) were fabricated using a high shear rate homogenisation. All emulsions showed 100% oil encapsulation for 30 days of storage, irrespective of lipid type and the concentration used. Rapeseed oil emulsions were stable against coalescence, whereas the milk fat emulsion showed a partial micro-coalescence. The apparent viscosity of emulsions raised with increased lipid concentrations. Each of the emulsions showed a shear thinning behaviour, a typical behaviour of non-Newtonian fluids. The average droplet size was raised in milk fat and rapeseed oil emulsions when the concentration of lipids increased. A simple approach to manufacturing stable emulsions offers a feasible hint to convert protein-rich by-products into a valuable carrier of saturated or unsaturated lipids for the design of foods with a targeted lipid profile