Session: General Posters:

Hydrogels fabricated via physically cross-linking have various uses in biomedical applications and are well suited for regenerative medicine and controlled drug delivery. Carboxymethyl cellulose (CMC)/Polyvinyl alcohol (PVA) hydrogels with different CMC concentrations from 3 to 5wt% was prepared by freezing-thawing process. Scanning electron microscope(SEM) showed that all of the hydrogels had three-dimensional network structure with porous. Brunauer Emmett Teller(BET) analysis proved that the specific surface areas of CMC/PVA hydrogels with CMC concentration of 3wt%, 3.5wt%, 4wt% and 5wt% were 78.16cm²/g, 84.90cm²/g, 413.48cm²/g and 40.72cm²/g respectively. Compare to Fourier transform infrared spectroscopy(FT-IR) spectrum of CMC, the peak at 3443cm^-1 attributed to -OH stretching vibration in CMC/PVA spectra were shifted to long wave number. PVA had a strong peak at 1402cm^-1 and 1325cm^-1 owed to the vibration absorption of C-O-H. CMC/PVA hydrogels keep the characteristic peak of carboxyl at 1614cm^-1 of CMC, but its strength was greatly reduced in the spectrum of CMC/PVA hydrogels. These results indicated that CMC and PVA had interactions with hydrogen bonds. Differential Scanning calorimeter(DSC) showed that the melting endothermic peaks of all CMC/PVA hydrogels shifted to lower temperatures, compared with PVA. The results of X-ray diffraction(XRD) displayed that all CMC/PVA hydrogels maintained the crystallization curve of PVA，but the characteristic peak intensity of PVA at 19.3^○ was weakened, and the crystallinities of CMC/PVA hydrogels reduced with the increase of CMC concentration.

Mrs Luying Liu

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