Conductivity and Thermal Analysis Studies of Solid Polymeric Electrolytes Based on Plasticized Hydroxyethyl Cellulose

Abstract

Transparent film samples of hydroxyethyl cellulose (HEC) based on solid polymeric electrolytes (SPE) were prepared by the plasticization of HEC with glycerol and addition of lithium perchlorate salt. SPEs with different quantities of glycerol and LiClO 4 were studied by electrochemical impedance spectroscopy (EIS), Dynamic Mechanical Thermal Analysis (DMTA), TGA (Thermogravimetric Analysis) and DSC (Differential Scanning Calorimetry). The ionic conductivity measurements revealed that the sample containing [O]/[Li]=8 and 48% of glycerol showed the conductivity value of almost 10 -4 S/cm at room temperature. The TGA analysis of electrolytes with high plastizant and salt concentrations showed 25% weight loss after heating to 130 o C, which can be related to the liberation of absorbed water. Finally, DMTA measurements showed changes attributed to the glass transition (T g ) evidenced by the decrease in the elastic modulus value and peaks in the tanδ curves. These results demonstrated that HEC is a good material to be used as a matrix for new solid polymeric electrolytes.

Plasticized pectin-based gel electrolytes

“…As observed in this figure the best transmittance values were obtained for the sample plasticized with 68 wt.% and the worst transmittance values with the sample plasticized with 70 wt.% of glycerol. The reason for such a big difference can be due to the exudation process, already observed in HEC-based samples and containing high quantity of plasticizer [7,16], and not to the thicknesses of the membranes, which were almost similar, i.e. 4.2 × 10 −2 and 3.9 × 10 −2 cm for the samples with 68 and 70 wt.% of glycerol, respectively.…”

“…7 evidences a 10-15% loss of mass from ambient temperature to 120 • C of pure pectin and pectin-based samples, respectively, which can be attributed to free water loss. At this point it should be stated that both glycerol and lithium perchlorate are hydrophilic substances and their presence promotes an increased water absorption capacity of the film [16]. In the region of 200-260 • C, a pure pectin sample showed a very accentuated mass loss of 40%, which can be attributed to the decomposition, and continues slowly with the increase of temperature up to 800 • C. The remaining residue was 14%.…”

Pectin-based Polymer Electrolytes with Ir(III) Complexes

“…2 evidence a 5-15% loss of mass from ambient temperature to ≈120 • C of pure pectin and pectin-based samples, which can be attributed to free water loss. At this point it should be stated that glycerol and lithium perchlorate are hydrophilic substances and their presence promotes an increase of the water absorption capacity of the film [16]. Moreover, all studied samples present a characteristic two or three-step thermal degradation, typical of pectin [17][18][19].…”

The Influence of Glycerol and Formaldehyde in Gelatin-Based Polymer Electrolytes

“…2 and 3, we can see that the samples have no water. At this point, it should be stated that even glycerol is a hydrophilic substance and its presence does not promote water; when compared with agar-based electrolytes with less amount of glycerol, an increased water absorption capacity of the film is observed for other natural polymer electrolyte-based membranes [30].…”