Granular micro/mesoporous carbon with a ratio of mesopore to total pore volume (V meso/V total) greater than 75% was prepared using coconut shells as a precursor by a one-step thermal treatment, i.e., combined pyrolysis and steam activation process. The process variables, such as final activation temperature, time, and water flow rate were studied. The N2 adsorption isotherms of the samples were of type IV, indicating mesoporous characteristics. The mesoporosity of the resultant porous carbons prepared by this method is greater than the one of those prepared by the conventional two separate pyrolysis and activation processes. Experimental results showed that the yield of porous carbon was proportional to the final pyrolysis temperature and activation time. Additionally, with the increase of activation time and water flow rate, the mesoporosity increased considerably. When the activation time and water flow rate were kept constant, the mesoporosity also increased with a rise in the final pyrolysis temperature. Electrochemical tests indicate that with the increase of V meso/V total of the porous carbons, the equivalent series resistance (ESR) decreases and the capacitance retention is of 93% at a high current density of 5 A g–1. Thereinto, the carbon electrode made from sample CS-800-0.12-60 with the highest V meso/V total have a high capacitance of 228 F g–1 in 6.0 mol L–1 KOH electrolyte at 5 mV s–1 and the energy density of 38.5 Wh kg–1 with an ESR of 1.9 Ω at 0.5 A g–1.

We extended the self-assembly concepts of macromolecules in solutions to create a variety of unique nanosized polymeric core-shell nanoparticles by means which allow scale-up for industrial production. This paper describes the synthesis methods and the mechanisms governing the design of structural features required for a beneficial use as performance-enhancing additives in rubber vulcanizates as well as the performance of such rubber compositions. The nanoparticles were prepared by the polymerization of block copolymers and their self-assembly in solvents into micelles followed by a subsequent stabilization of their structure by core crosslinking. Depending on the type and macrostructure of the block copolymers, the solvent, the concentration, and other process parameters, a variety of core-shell nanoparticles of different shapes (spheres, hollow spheres, ellipsoids, linear and branched strings, etc.) and sizes have been reproducibly synthesized. Most of the nanoparticles were composed of a solid, highly cross-linked core and an elastomeric shell structure. The evolution and structure of the nanoparticles during the different process steps involved were examined and characterized. The unique performance of spherical nanoparticles as performance-enhancing additives and novel reinforcing agents was explored in rubber compounds. It was also shown that the basic spherical or string type nanoparticles can be used as templates for the design of composite structures comprising the basic polymeric nanoparticles and smaller organic, inorganic, or metallic substructures embedded in and attached to the elastomeric shell molecules.

SYNOPSISThe effect of temperature on the ratio of the kinetic rate constants, k 2 / k l , has been investigated using FTIR spectroscopy for the competing reactions of epoxy with secondary amine ( k , ) and primary amine groups ( k , ) in a trimethylene glycol di-p-aminobenzoatel diglycidyl ether of the bisphenol A system. The ratio of the rate constants increases from 0.16 to 0.33 in the temperature range 100-160°C. The corresponding difference in the activation energies for the competing reactions is about 3.7 kcal/ mol. The effect of the ratio on the time-to-vitrify contour of the isothermal time-temperature-transformation (TTT) cure diagram is discussed The effect is more significant at higher curing temperatures.

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