
16 Engineering of Polymers and Chemical Complexity
(NH
4
)
2
SO
4
crystals. Morphology of the prepared scaffolds was characterized by sev-
eral methods including scanning electron microscopy both in swollen (LVSEM) and dry
(HVSEM) state, solvent (water and cyclohexane) regains high and low pressure mercury
porosimetry of lyophilized samples and dynamic desorption of nitrogen. Morphology
and porous structure of the hydrogels were preferentially affected by the character and
amount of the used porogen – NaCl, CyOH/DOH mixture or (NH
4
)
2
SO
4
. After wash-
ing out of the salts and solvents from PHEMA, three types of pores were detected by
microscopic and ...