TEM was performed using a Tecnai 20 microscope, operated at 200 kV. Ultrathin sections (70 nm) were obtained at 100 C using a Leica Ultracut S/FCS microtome. The ImageJ software was used to analyze the average particle size. The area of each particle (Ai) was calculated and then converted to an equivalent diameter (di) of a sphere by di ¼ 2 ðAi=pÞ1=2. The number average diameter (dn) of EVA particles is then obtained from dn ¼ PNdi=N.