Characteristics of particulate matter from ethanol-blended biodiesel on the diesel engine in terms of nanostructure were investigated through electron microscopy. Commercial B20 fuel (20% palm and 80% diesel) was used as the baseline fuel and ethanol was blended at 5% and 10% with B20 fuel. The agglomerated particle size was reduced by increasing the weight ratio of ethanol. The average diameter sizes of the single primary nanoparticles of B20, B20E5, and B20E10 are about 20-40 nm while inter-planar spacing is about 0.404 nm, 0.383 nm, and 0.352 nm, respectively. The total fringe lengths of B20, B20E5, and B20E10 are approximately 521 nm, 470 nm, and 262 nm measured from the areas of 20 nm x 20 nm of primary nanoparticles.
