Synthesis and characteristics of poly(3-pyrrol-1-ylpropanoic acid) (PPyAA)–Fe3O4 nanocomposite

Facile hydrothermal synthesis of polyhedral Fe3O4 nanocrystals, influencing factors and application in the electrochemical detection of H2O2

“…Many methods have been developed for the preparation of magnetite nanoparticles, including coprecipitation of Fe 2+ and Fe 3+ ions in alkaline solutions [21], ultrasound assisted preparation [22], thermal decomposition of Fe(acac) 3 precursor [23], polyol route [24], hydrothermal process [25,26] and solvothermal technique [27,28].…”

Conductividad iónica en nuevos compositos (PEO)10(CF3COONa)-X % Al2O3

“…El proceso térmicamente activado, observado en gráficos de conductividad versus el inverso de la temperatura (Figura 3) obedece a un aumento de la flexibilidad en las cadenas del polímero, es característica de sistemas poliméricos conductores iónicos (Castillo et al 2001, Karaoglua et al 2011. Con la particularidad de que este composito presenta dos regiones con un comportamiento tipo Arrhenius, entre las cuales existe una región intermedia la cual muestra un comportamiento anómalo entre temperaturas para las que se presentan cambios de fase en el sistema (fusión de PEO y fusión de PEO:CF3COONa; Castillo et al 2001, Johan et al 2011, Ramanjaneyulu et al 2012).…”

Synthesis and characterization of polypropiolate sodium (PPNa)–Fe3O4 nanocomposite

“…So d.c. conductivity of the PPNacapped magnetite nanocomposites as in the case of both salicylic acid-Fe 3 O 4 [31] and poly(2-thiophen-3-yl-malonic acid)-Fe 3 O 4 [32] nanocomposite applications can be classified into three regions over a limited temperature range from RT up to approximately 150 • C. While general transition region of temperatures between 45 • C and 95 • C shows a metallic-like behavior, in this case at around 80 • C, which means electrical conductivity decreases with increasing temperature, d.c. electrical conductivity increases with increasing temperature with the formulation of log d.c. versus 1/T before and after this region. Accordingly, this semiconducting phase in conductivity obeys Mott's variable range hopping mechanism of the conduction because the conduction mechanism of the nanocomposites shows a crossover from the Mott's law, exp(− AT 1/4 ) [33,34], to a simply activated law, exp(− E/k B T). This dependence can be often conveyed in the transition region (between 60 • C and 90 • C) as a slope in logarithmic conductivity versus reciprocal temperature graphs.…”