Dear Sinaga

You can further analyze the samples to get a concrete insight of your materials as SEM alone may not be able to describe completely the structure/texture or morphology of materials. Also, keep the similar magnification all materials and go to micron level. Moreover, the pores volume and diameter can also be determined via porous texture analyses. Furthermore, repeat your preparation and analyses and see whether you get the similar results or else (for confirmation).

@ Thomas Breuer

While I mostly agree with your post, I strongly disagree with your statement about x50 and sledgehammer. SEM is a very nice tool for low magnifications, be it x50 or x10. And its high depth of focus helps tremendously in surface morphology investigations.

@ Frando Sinaga

Freeze drying, so loved by pharmacists, is a dangerous tool for SEM specimen preparation, can ruin some specimens, can induce a number of artifacts (but I do not know about gels). Looking at your picture 04 I think for pore analysis you can use lower magnifications, like x20, to observe wide area (if needed you can use additionally higher magnifications). On picture 03 I see not pores, but some flakes.

Irfan Shah Thomas Breuer

but i was confused. as i thought,i can analyze like the structure of my gels from sem images, like if acid is there or density of my polymer network. but i think i cant.