ABSTRACT
Chitosan-based magnetite nanocomposites were synthesized using a versatile ultrasound assisted in situ method involving one quick step. This synthetic route approach results in the formation of spheroidal nanoparticles (Fe3O4) with average diameter between 10 and 24nm, which were found to be superparamagnetic with saturation magnetization (Ms) ranges from 32-57emug(-1), depending on the concentration. The incorporation of Fe3O4 into chitosan matrix was also confirmed by FTIR and TG techniques. This hybrid nanocomposite has the potential application as electrochemical sensors, since the electrochemical signal was excepitionally stable. In addition, the in situ strategy proposed in this work allowed us to synthesize the nanocomposite system in a short time, around 2min of time-consuming, showing great potential to replace convencional methods. Herein, the procedure will permit a further diversity of applications into nanocomposite materials engineering.
Subject(s)
Chitosan/chemistry , Electrochemistry/instrumentation , Magnetite Nanoparticles/chemistry , Nanocomposites/chemistry , Nanotechnology/methods , Ultrasonic Waves , Chemistry Techniques, Synthetic , Electrodes , Kinetics , Particle SizeABSTRACT
The theory of solvent vapor adsorption of activated carbon is reviewed. Calculated and experimental cartridge service life values are compared using various breathing rates, relative humidities, concentrations and solvent vapors. Cartridge service life (the 10% breakthrough time) can be estimated from the emperical expression: t 10% = 2.4 X 10(6) WC (A + BT)/C 2/3 MQ Carbon weight (wc), relative solvent volatility (a, b and t) concentration (C), molecular weight (M) and breathing rate (Q) all play a vital role in cartridge performance predictions.
Subject(s)
Protective Devices/standards , Respiratory Protective Devices/standards , Adsorption , Carbon , Humidity , Models, Chemical , Solvents , Temperature , Time Factors , VolatilizationABSTRACT
Cartridge service life is not appreciably affected at relative humidities below 50%. However, performance is severely compromised when the humidity exceeds 65%. Experimental values are compared from those calculated from the adsorption isotherm, Mecklenburg and modified Wheeler equations. Calculations indicate that temperature does not play a significant role in service life predictions.
