Enhanced swelling and multiple-responsive properties of gelatin/sodium alginate hydrogels by the addition of carboxymethyl cellulose isolated from pineapple peel

Natural polymers hydrogels were prepared by solution blending of gelatin, sodium alginate and carboxymethyl cellulose isolated from pineapple peel, and cross-linking with CaCl2 and glutaraldehyde solutions. The prepared hydrogels were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and field emission scanning electron microscope. The swelling behaviors and responsiveness to pH, salt and electric field were also investigated. The swelling dynamic mechanism of hydrogels agreed well with the Fickian diffusion and Schott's pseudo second order models. The addition of carboxymethyl cellulose enhanced the swelling ability of the hydrogels in the selected mediums and sensitivities to pH, salt and electric field. The electric response of the hydrogels showed pH-dependent, ionic strength-dependent and electric voltage-dependent. This multiple-responsive characteristic of the prepared hydrogels was conducive to application as potential biomaterials such as microsensors, actuators, artificial muscles and drug delivery systems.