Dielectric, thermal, and swelling properties of calcium ion-crosslinked sodium alginate film

Abstract

In this study, Ca 21 -crosslinked sodium alginate (SA) gel films (SA-Ca/SA2-Ca) have been prepared, and their structural and thermal characterizations were investigated using fourier transform infrared spectroscopy, Xray diffraction, differential scanning calorimetry, and thermogravimetric analysis, respectively. Dielectric characterization was performed at room temperature in the frequency range of 12 Hz-100 kHz. The equilibrium swelling value (ESV) of gel films was determined both in distilled water and in 0.1 M sodium chloride (NaCl) solution at room temperature. Sodium alginate films (SA/ SA2) were also prepared for use as reference. The effect of the crosslinking of sodium alginate on the dielectric and thermal properties of gel films was investigated by comparing the properties of gel films with those of SA/ SA2 films. Although ESV of Ca 21 -crosslinked SA film in distilled water is about 350 g H 2 O /g polymer , it decreased into one third in 0.1 M NaCl solution. The crosslinking of SA did not significantly affect the thermal properties, but it decreased the b-relaxation associated with the polar side groups. Frequency spectra of electric modulus, impedance and Cole-Cole plots confirmed the higher conductance values of SA-Ca films at low frequencies than those of SA film due to the presence of by-product of crosslinking. POLYM. ENG. SCI., 54:1372-1382,

Composition dependent properties of graphene (oxide)‐alginate biopolymer nanocomposites

“…As for sodium alginate, the thermal degradation of calcium alginate (Ca Alg) occurs in two steps, with differential weight loss peaks observed at ∼230 and ∼270°C. The former corresponds to dehydration and the latter to decomposition of the polymer . As the concentration of rGO in the polymer matrix increases, the thermal stability of the composite films somewhat reduces.…”

Preparation, characterization and dielectric properties of sodium alginate/titanium dioxide composite membranes

“…Thus, the usage of SA revealed distinct applications in controlled drug delivery, dehydration of organic solvents, removal of metal ions from aqueous solutions, textile industries, food industries etc., [1]. In addition, the SA based polymeric specimen exhibited high ε′ which in turn responsible for potential applications in actuators, artificial muscles, and charge stored capacitors [3]. The polymers containing high ε′ can also adopt high ε″.…”

“…Polymer composite membranes are the polymer membranes in which small amount of powder particles are dispersed. The physical, chemical, and electrostatic interactions between the polymer and filler result in improvements of electrical, optical, mechanical, thermal properties of polymer membranes [1][2][3][4]. These are needed to meet the demand in emerging technological applications for such advanced materials.…”

Dual responsive polymeric bionanocomposite gel beads for controlled drug release systems

“…As given in the FTIR spectrum of pure SA, the peak at 3441 cm −1 is referred to OH stretching vibration (ν OH ) as well as 2850 and 2920 cm −1 peaks are, respectively, attributed to the stretching vibrations of CH (ν CH ) and OH (ν OH ) bonds. The asymmetric and symmetric stretching vibrations regarding the carboxylate group are recorded at 1415 and 1608 cm −1 , respectively . The peaks at 1024 and 1091 cm −1 are referred to the stretching vibration of CO (ν CO ) bond at the saccharide ring .…”