![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
ABSTRACT
Starch grafted acrylic acid-acrylamide hydrogel was synthesized using an aqueous solution polymerization method. The microstructures of the vacuum-dried hydrogel (VDH) and vacuum-freeze-dried hydrogel (VFDH) were studied by means of scanning electron microscopy and biomicroscopy. The water-absorption rate of the hydrogel was tested. The results showed that the microstructure of the two kinds of dried hydrogels exhibited significant differences. Before absorbing water, VDH had a relatively dense surface whereas the surface of VFDH had a clear macroporous structure. After absorbing water, a three-dimensional network structure was clearly visible in VDH. Many interlaced and free filaments occupied the space between the main skeleton and channels. The holes formed by vacuum-freeze-drying had the effect of squeezing the surrounding network structure, which had an impact on the water-absorption rate and water absorbency of the hydrogel.
Acknowledgments
The authors would like to thank the editors and reviewers for their very useful suggestions.
Funding
This work was supported by the National Undergraduate Training Programs for Innovation and Entrepreneurship (No. 201310220014).