Figure 7.
The panel a shows closely packed circular pores of different sizes across the foam surface, with a scale bar of 200 micrometres. Panel b shows a denser region with many smaller circular pores and scattered larger pores, also with a scale bar of 200 micrometres. Panel c shows an uneven porous surface with areas of exposed and disrupted pore structure. Panel d shows a more damaged porous surface with two outlined regions marking larger openings and clustered pore disruption, with a scale bar of 200 micrometres.Optical microscopic images of foamed samples prepared by Method 1 (a) and (c) and by Method 2 (b) and (d). Top surfaces shown in (a) and (b), bottom surfaces in (c) and (d)