Controlling of pore size and distribution of PDMAEMA hydrogels prepared by gamma rays

In this study, radiation synthesis and controlling of pore size and distribution of poly(N, N-dimethylaminoethyl methacrylate) (PDMAEMA) hydrogels have been investigated. Monomer mixtures containing various compositions of DMAEMA, water and ethylene glycol dimethacrylate (EGDMA) and poly(ethylene glycol) (PEG) have been prepared and irradiated. The molecular weight between cross-links of P(DMAEMA) hydrogels prepared in the presence of PEG increased with increasing amount of PEG in the initial mixture from 1% to 20%. Hydrogels with highest mesh size were obtained by using 20% PEG10 000. Upon PEG addition, an increase in the equilibrium degree of swelling (Q) was observed with increasing molecular weight of PEG until a molecular weight of 10 000. Maximum swelling was reached for systems containing 1% and 5% PEG10 000. SEM micrographs showed homogeneous pore structure of the hydrogels with open pores at lower pH.